HK1228515A1 - Lens holder driving device capable of avoiding deleterious effect on hall elements - Google Patents

Description

Lens holder driving device capable of avoiding adverse effect on hall element

The application is a divisional application of an invention patent application with the original application date of 2012, 7 and 13 and the application number of 201210244527. X.

Technical Field

The present invention relates to a lens holder driving device, and more particularly, to a lens holder driving device that corrects camera shake (vibration) generated when a still image is captured by a small-sized video camera for a portable terminal so that a still image without blurring can be captured.

Background

Various lens holder driving devices have been proposed which can prevent image blur on an image forming surface even if there is camera shake (vibration) when a still image is captured, and can perform clear image capturing.

As camera shake correction methods, "optical methods" such as a sensor displacement method and a lens displacement method, and "software correction methods" for correcting camera shake by image processing using software are known. A camera shake correction method introduced into a mobile terminal mainly employs a software correction method.

A software modification method is disclosed in, for example, japanese patent application laid-open No. 11-64905 (hereinafter also referred to as patent document 1). In the camera-shake correction method disclosed in patent document 1, an interference component is removed from the detection result of the detection means, and specific information necessary for correcting image blur due to camera-shake of the imaging apparatus is calculated from the detection signal from which the interference component has been removed, whereby the captured image is still in a state where the imaging apparatus is still without camera-shake.

However, the camera shake correction method of the "software correction method" disclosed in patent document 1 has a problem of deterioration in image quality as compared with the "optical method" described later. In addition, the camera shake correction method of the software correction method has a drawback that the imaging time also includes software processing, and therefore, the time is long.

Therefore, with the recent increase in the number of pixels, there has been an increasing demand for "optical systems" as camera shake correction systems. As camera shake correction methods of the "optical type", a "sensor displacement method", a "lens displacement method", and an "optical unit tilt method" are known.

The sensor displacement system is disclosed in, for example, japanese patent application laid-open No. 2004-274242 (hereinafter also referred to as patent document 2). The digital camera disclosed in patent document 2 has a configuration in which an image pickup device (CCD) is movable about a standard position (center) by a driver. The driver performs camera shake correction for moving the CCD based on camera shake detected by the vibration sensor. The CCD is disposed in the CCD moving section. The CCD can be moved in an XY plane orthogonal to the Z axis by the CCD moving unit. The CCD moving part mainly includes: a base plate fixedly arranged on the shell; a first slider that moves in the X-axis direction with respect to the base plate; and a second slider that moves in the Y-axis direction with respect to the first slider.

However, the "sensor displacement system" disclosed in patent document 2 causes the CCD moving part (movable mechanism) to become large. Therefore, it is very difficult to apply the camera shake correction device of the sensor displacement system to a small-sized video camera for a mobile phone in terms of size (outer shape, height).

Next, a lens shift method will be described.

For example, japanese patent laid-open No. 2009-. The vibration correction unit includes: a base plate as a fixing member; a movable lens barrel holding the correction lens to be movable; three balls sandwiched by the base plate and the movable lens barrel; a plurality of elastic bodies elastically supporting the movable lens barrel with respect to the base plate; two coils fixed on the base plate; and two magnets fixed to the movable barrel.

Further, japanese patent laid-open No. 2006-65352 (hereinafter also referred to as patent document 4) discloses an "image blur correction device" that corrects an image blur by performing movement control of a specific one lens group (hereinafter referred to as a "correction lens") in a photographing optical system (imaging optical system) composed of a plurality of lens groups in two directions orthogonal to each other in a vertical plane with respect to an optical axis. In the image blur correction device disclosed in patent document 4, the correction lens is supported movably in the vertical direction (pitch direction) and the horizontal direction (yaw direction) with respect to the fixed frame via the pitch (ピッチング) moving frame and the yaw moving frame.

Japanese patent laid-open No. 2008-26634 (hereinafter also referred to as patent document 5) discloses a "camera shake correction unit" including a correction optical member that corrects a blur of an image formed by an imaging optical system by moving in a direction intersecting an optical axis of the imaging optical system. In the correction optical component disclosed in patent document 5, a lens holding frame that holds a correction lens is supported by a storage cylinder so as to be movable in a pitch direction and a yaw direction via a pitch slider and a yaw slider.

Japanese patent application laid-open No. 2006-215095 (hereinafter also referred to as patent document 6) discloses an "image blur correction device" that can move a correction lens with a small driving force and can perform image blur correction quickly and with high accuracy. The image blur correction device disclosed in patent document 6 includes: a holding frame for holding the correction lens; a first slider for supporting the holding frame to be slidable in a first direction (pitch direction); a second slider for supporting the holding frame to be slidable in a second direction (a deflecting direction); a first coil motor driving the first slider in a first direction; and a second coil motor driving the second slider in a second direction.

Japanese patent application laid-open No. 2008-15159 (hereinafter also referred to as patent document 7) discloses a lens barrel provided with a blur correction optical system movably disposed in a direction orthogonal to an optical axis. In the blur optical system disclosed in patent document 7, a movable VR unit disposed in a VR body unit holds a correction lens (third lens group) and is movably disposed in an XY plane orthogonal to an optical axis.

Jp 2007-212876 a (hereinafter also referred to as patent document 8, corresponding to US 7619838) discloses an "image blur correction device" capable of correcting an image blur by controlling a correction lens held on a moving frame so as to be movable in first and second directions orthogonal to each other with respect to an optical axis of a lens system, and causing the optical axis of the correction lens to coincide with the optical axis of the lens system by a drive mechanism.

Japanese patent application laid-open No. 2007-17957 (hereinafter also referred to as patent document 9) discloses an "image blur correction device" that corrects an image blur by driving a correction lens for correcting a blur of an image formed by a lens system by an operation of a lens driving unit in a first direction and a second direction that are orthogonal to an optical axis of the lens system and are orthogonal to each other. In the image blur correction device disclosed in patent document 9, the lens driving unit is disposed on one side in a direction orthogonal to the optical axis of the correction lens.

Jp 2007-17874 a (hereinafter, also referred to as patent document 10, corresponding to US 7650065) discloses an "image blur correction device" capable of correcting an image blur by controlling a correction lens held on a moving frame so as to be movable in a direction orthogonal to an optical axis of a lens system and in a first direction and a second direction orthogonal to each other, and making the optical axis of the correction lens coincide with the optical axis of the lens system. The image blur correction device disclosed in patent document 10 includes a drive mechanism having a coil and a magnet that are relatively movable. One of the coil and the magnet is fixed to the moving frame, and the other is fixed to a support frame that supports the moving frame so as to be movable. Further, the image blur correction device disclosed in patent document 10 includes: a first hall element for detecting position information of the correction lens related to the first direction by detecting a magnetic force of the magnet; and a second hall element that detects position information of the correction lens related to the second direction by detecting a magnetic force of the magnet.

The image blur correction devices (camera shake correction devices) of the "lens shift system" disclosed in patent documents 3 to 10 each have a structure in which a correction lens is moved and adjusted in a plane perpendicular to an optical axis. However, the image blur correction device (camera shake correction device) having such a configuration has a problem that the configuration is complicated and is disadvantageous for miniaturization. That is, it is difficult to apply the lens shift type camera shake correction apparatus to a small-sized video camera for a mobile phone in terms of size (outer shape, height) as in the sensor shift type camera shake correction apparatus described above.

In order to solve the above problems, the following devices are proposed: a camera shake correction device (image blur correction device) corrects a camera shake (image blur) by swinging a lens module (camera module) itself that holds a lens and an imaging element (image sensor). This mode is referred to herein as an "optical unit tilting mode".

The "optical unit tilting system" will be described below.

For example, japanese patent application laid-open No. 2007-41455 (hereinafter also referred to as patent document 11) discloses an "image blur correction device for an optical device" including: a lens module holding the lens and the image pickup element; a frame structure rotatably supporting the lens module by a rotation shaft; a drive mechanism (actuator) for applying a drive force to a driven portion (rotor) of the rotary shaft to rotate the lens module relative to the frame structure; and a biasing mechanism (plate spring) for biasing the driving mechanism (actuator) against the driven portion (rotor) of the rotating shaft. The frame structure is composed of an inner frame and an outer frame. The driving mechanism (actuator) is disposed so as to abut against a driven portion (rotor) of the rotating shaft from a direction perpendicular to the optical axis. The drive mechanism (actuator) is composed of a piezoelectric element and an action portion on the side of the rotation axis. The action portion drives the rotating shaft by using the longitudinal vibration and the bending vibration of the piezoelectric element.

However, in the image blur correction device of the "optical unit tilt system" disclosed in patent document 11, it is necessary to cover the lens module with a frame structure composed of an inner frame and an outer frame. As a result, the image blur correction device becomes large.

Jp 2007-a 93953 (hereinafter also referred to as patent document 12) discloses a "camera shake correction device for a video camera" in which a camera module in which a photographing lens and an image sensor are integrated is housed in a housing, the camera module is attached to a shaft of the housing so as to be swingable about a first shaft and a second shaft which are orthogonal to a photographing optical axis and intersect at right angles to each other, and the posture of the entire camera module is controlled in the housing based on vibration of the housing detected by a camera shake sensor, thereby correcting camera shake during photographing of a still image. The camera shake correction device for a video camera disclosed in patent document 12 includes: a middle frame which supports the inner frame fixed with the camera module in a manner of freely swinging from the outer side of the inner frame by taking the first shaft as a center; an outer frame fixed to the case and supporting the middle frame in a freely swinging manner from the outer side of the middle frame with a second shaft as a center; a first drive mechanism which is assembled to the inner frame and swings the inner frame about a first axis in accordance with a camera shake signal from a camera shake sensor (a first sensor module which detects camera shake in a pitch direction); and a second drive mechanism which is assembled on the outer frame and swings the middle frame around a second axis according to a camera shake signal from a camera shake sensor (a second sensor module which detects camera shake in a yaw direction). The first drive mechanism includes: a first stepping motor; a first reduction gear set that reduces rotation of the first stepping motor; and a first cam that swings the inner frame via a first cam follower provided on the inner frame so as to rotate integrally with the final-stage gear. The second drive mechanism includes: a second stepping motor; a second reduction gear set that reduces rotation of the second stepping motor; and a second cam that swings the middle frame via a second cam follower provided on the middle frame so as to rotate integrally with the final stage gear.

However, the camera shake correction device of the "optical unit tilting system" disclosed in patent document 12 also needs to cover the camera module with an inner frame, a middle frame, and an outer frame. As a result, the camera shake correction apparatus becomes large. Further, the "optical unit tilting system" has a problem that friction between hole axes occurs due to the existence of a rotation axis, and hysteresis occurs.

Further, japanese patent application laid-open No. 2009-288770 (hereinafter also referred to as patent document 13, corresponding to US 2011/097062) discloses an imaging optical device in which the configuration of an imaging unit driving mechanism for shake correction with respect to an imaging unit is improved so that shake can be reliably corrected. In the optical imaging device disclosed in patent document 13, an imaging unit (movable module) and a shake correction mechanism for correcting shake by displacing the imaging unit are formed inside a fixed cover. The photographing unit is a member for moving the lens in the optical axis direction. The imaging unit includes: a movable body holding the lens and the fixed diaphragm inside; a lens driving mechanism for moving the movable body in the optical axis direction; and a support body on which the drive mechanism and the moving body are mounted. The lens driving mechanism includes a lens driving coil, a lens driving magnet, and a yoke. The photographing unit is supported on the fixed body by four suspension wires. Two first and second image pickup unit drive mechanisms for shake correction are provided in a pair at two locations on both sides of the optical axis. In these imaging unit driving mechanisms, an imaging unit driving magnet is held on the movable body side, and an imaging unit driving coil is held on the fixed body side.

However, in the "optical unit tilting system" photographing optical device disclosed in patent document 13, a photographing unit driving magnet is required in addition to the lens driving magnet. As a result, the imaging optical device has a problem of becoming large.

Further, japanese patent application laid-open No. 2011-107470 (hereinafter also referred to as patent document 14) discloses a lens driving device capable of driving a lens in an optical axis direction and correcting shake. The lens driving device disclosed in patent document 14 includes: a first holding body that holds the lens and is movable in an optical axis direction (Z direction); a second holding body for holding the first holding body to be movable in the Z direction; a fixed body for holding the second holding body to be movable in a direction substantially orthogonal to the Z direction; a first drive mechanism for driving the first holder in the Z direction; a second drive mechanism for driving the second holding body in the X direction; and a third drive mechanism for driving the second holding body in the Y direction. The first holder is supported on the second holder movably in the Z direction by a first support member made of an elastic material. The second holding body is supported on the fixed body so as to be movable in a direction substantially orthogonal to the Z direction by a second support member made of an elastic material. The first drive mechanism includes a first drive coil and a first drive magnet, the second drive mechanism includes a second drive coil and a second drive magnet, and the third drive mechanism includes a third drive coil and a third drive magnet.

In the lens driving device disclosed in patent document 14, three types of driving mechanisms, i.e., first to third driving mechanisms, are required as the driving mechanisms, and each of the first to third driving mechanisms is composed of a coil and a magnet, which causes a problem of an increase in the number of components.

Jp 2011-113009 (hereinafter also referred to as patent document 15) discloses a lens driving device having a basic configuration in which a plurality of wires are used as a second support member and a buckling prevention member is provided for preventing buckling of the wires, as in the lens driving device disclosed in patent document 14. The wire is linearly formed, and the second holding body is supported by the wire so as to be movable in a direction substantially orthogonal to the Z direction. The buckling preventive member is formed of an elastic member and elastically deforms in the Z direction with a force smaller than the buckling load of the wire. More specifically, the buckling preventive member is constituted by a wire fixing portion formed on the leaf spring of the first support member. When a downward force is applied to a movable portion such as a second holder, the wire fixing portion is elastically deformed downward.

The lens driving device disclosed in patent document 15 also has a problem that the number of components increases, as in the lens driving device disclosed in patent document 14. In addition, the lens driving device disclosed in patent document 15 merely prevents the wire from buckling by applying a force in a direction of compression to the wire. In other words, in the lens driving device disclosed in patent document 15, there is no consideration given to a case where a force in a drawing direction is applied to the wire and the wire may be broken.

In view of the above, the present inventors have proposed a camera shake correction device that can be reduced in size and height by using a permanent magnet for an auto-focusing (AF) lens driving device as a permanent magnet for a camera shake correction device (see japanese patent application laid-open No. 2011-.

The camera shake correction device disclosed in patent document 16 is referred to as a "barrel displacement type" camera shake correction device, since it corrects camera shake by moving a lens barrel itself housed in an AF lens driving device. The camera shake correction device of the "barrel displacement system" is classified into a "moving magnet system" in which a permanent magnet moves (moves), and a "moving coil system" in which a coil moves (moves).

Patent document 16 discloses, in a second embodiment thereof, the following structure: a camera-shake correction device of the "moving magnet system" includes a permanent magnet including four first permanent magnet pieces and four second permanent magnet pieces arranged vertically apart from each other in the optical axis direction, and a camera-shake correction coil is arranged between the upper four first permanent magnet pieces and the lower four second permanent magnet pieces. That is, the second embodiment is a camera shake correction device of the "moving magnet system" including permanent magnets composed of eight permanent magnet pieces in total.

In the camera shake correction device disclosed in patent document 16, a base is disposed at a bottom surface portion of the lens driving device for auto focusing with a gap therebetween, and one ends of a plurality of suspension wires are fixed to an outer peripheral portion of the base. The other ends of the plurality of suspension wires are firmly fixed to the lens driving device for automatic focusing.

In the camera shake correction device disclosed in patent document 16, since the permanent magnet is formed of eight permanent magnet pieces, there is a problem that the number of components increases. Further, since the camera shake correction coil is disposed between the upper four first permanent magnet pieces and the lower four second permanent magnet pieces, there is a problem that assembly takes time and labor.

Further, japanese patent application laid-open publication No. 2011-85666 (hereinafter, also referred to as patent document 17) discloses a lens driving device that also uses a magnet for AF control and a magnet for blur control. The lens driving device disclosed in patent document 17 includes: a lens holder including a first coil (coil for AF) arranged on the outer periphery of the lens; a magnet holding member having a first face opposed to the first coil and fixing the magnet; a spring which connects the lens holder and the magnet holding member and supports the lens holder to be movable in the optical axis direction with respect to the magnet; and a base member to which a second coil (coil for anti-shake) is fixed so as to face a second surface perpendicular to the first surface of the magnet. A lens holding unit having a lens holder, a magnet holding member, and a spring is held on a base member so as to be relatively movable in a direction perpendicular to an optical axis.

In the lens driving device disclosed in patent document 17, as a sixth embodiment, a configuration is disclosed in which a position detection sensor is disposed in a gap between one of the anti-shake coils wound around the lens. As the position detection sensor, a hall element is used. In addition, the lens holding unit is held by suspension wires provided at four corners of the fixing portion. That is, one end of the suspension wire is fixed to the four corners of the fixing portion, and the other end of the suspension wire is firmly fixed to the lens holding unit.

In the lens driving device disclosed in patent document 17, the position detection sensor is disposed in the gap between the anti-shake coils (second coils). As described above, the hall element is used as the position detection sensor. When the hall element is disposed in the gap (i.e., the ring portion) of the anti-shake coil (second coil), there is a problem that the hall element is adversely affected by a magnetic field generated by a current flowing through the anti-shake coil (second coil). That is, as will be described in detail with reference to fig. 5 to 10, the operation of the magnet (permanent magnet) and the phase of the current flowing through the second coil (anti-shake coil) are shifted by 180 degrees and become opposite phases at the time of primary resonance of the lens driving device (actuator). As a result, there is a problem that resonance occurs in the output of the hall element.

Disclosure of Invention

Accordingly, an object of the present invention is to provide a lens holder driving device capable of avoiding a hall element as a position detection sensor from being adversely affected by a magnetic field generated by a current flowing through a coil.

Other objects of the invention will become apparent as the description proceeds.

In order to describe the gist of an exemplary embodiment of the present invention, a lens driving device includes: a component which is provided with a lens frame and a permanent magnet arranged around the lens frame; and a camera-shake correction unit that corrects camera shake by moving the unit in a first direction and a second direction that are orthogonal to the optical axis of the lens holder and to each other, wherein the permanent magnet is formed of a plurality of permanent magnet pieces that are arranged around the lens holder so as to face each other in the first direction and the second direction, and the camera-shake correction unit includes: a fixing portion disposed apart from the module in the optical axis direction; a support member that supports the component with respect to the fixing portion so that the component can swing in the first direction and the second direction; a camera shake correction coil including a plurality of camera shake correction coil portions arranged on the fixing portion so as to face the permanent magnet pieces, respectively, wherein each of specific camera shake correction coil portions arranged in the first direction and the second direction among the plurality of camera shake correction coil portions is divided into a plurality of coil portions so as to be separated in a longitudinal direction of the permanent magnet pieces facing each other; and a plurality of hall elements arranged at the fixed portion at positions separated from the plurality of coil portions of the specific coil portion for camera shake correction having the plurality of coil portions divided.

According to an exemplary embodiment of the present invention, a lens holder driving device includes: an automatic focusing lens holder driving unit for moving a lens holder holding a lens barrel along an optical axis; and a camera shake correction unit that corrects camera shake by moving the autofocus lens holder drive unit in a first direction and a second direction that are orthogonal to the optical axis and to each other. According to an exemplary embodiment of the present invention, an autofocus lens holder driving unit includes: a focusing coil fixed on the lens holder; a permanent magnet including a plurality of permanent magnet pieces, each of the plurality of permanent magnet pieces having a first surface facing the focus coil, being disposed radially outward of the focus coil with respect to an optical axis, and facing each other in a first direction and a second direction; a magnet holder which is disposed on an outer periphery of the lens holder, holds the permanent magnet, and has a first end and a second end that are opposed to each other in the optical axis direction; and first and second plate springs attached to first and second ends of the magnet holder, respectively, for supporting the lens holder so as to be displaceable in the optical axis direction in a state where the lens holder is positioned in the radial direction. The camera shake correction unit includes: a fixing portion disposed at a position close to the second plate spring and separated from the autofocus lens holder driving portion in the optical axis direction; a support member that supports the autofocus lens holder driving unit so as to be swingable in a first direction and a second direction with respect to the fixing unit; a camera shake correction coil including a plurality of camera shake correction coil portions arranged on the fixing portion so as to face second surfaces perpendicular to the first surfaces of the plurality of permanent magnet pieces, respectively, and having specific camera shake correction coil portions arranged in the first direction and the second direction, each of the specific camera shake correction coil portions being divided into a plurality of coil portions so as to be separated in the longitudinal direction of the opposing permanent magnet piece; and a plurality of Hall elements arranged on the fixing part at the separated positions of the coil parts of each coil part for correcting the camera shake.

Drawings

Fig. 1 is an external perspective view of a lens holder driving device according to a first embodiment of the present invention.

Fig. 2 is a partial longitudinal sectional view of the lens holder driving device shown in fig. 1.

Fig. 3 is an exploded perspective view showing the lens holder driving device shown in fig. 1.

Fig. 4 is a perspective view showing a coil substrate and a camera shake correction coil formed on the coil substrate, which are used in the lens holder driving device shown in fig. 1.

Fig. 5 is a perspective view showing a relationship between the relevant magnetic circuit and the hall element.

Fig. 6 is a longitudinal sectional view showing a relationship between the relevant magnetic circuit and the hall element.

Fig. 7 is a vertical cross-sectional view showing the relationship between the relevant magnetic circuit and the hall element when the AF unit is displaced in the front-rear direction X.

Fig. 8 is a diagram showing the frequency characteristics of the front hall element in the relevant magnetic circuit.

FIGS. 9A, 9B, and 9C show the magnetic flux density a of the magnetic field B generated by the front permanent magnet pieces in the region I, the region II, and the region III of FIG. 8, respectively, and the first IS current I flowing through the front camera shake correction coil_IS1Generated magnetic field B_I1And a graph of the magnitude of the total magnetic flux density (a + b) detected by the front side hall element versus the phase.

Fig. 10 is a table showing the relationship between fig. 9A to 9C.

Fig. 11 is a perspective view showing a relationship between a magnetic circuit and a hall element used in the lens holder driving device shown in fig. 1.

Fig. 12 is a longitudinal sectional view showing a relationship between the magnetic circuit and the hall element shown in fig. 11.

Fig. 13 is a vertical cross-sectional view showing a relationship between the magnetic circuit shown in fig. 11 and the hall element when the AF unit is displaced in the front-rear direction X.

Fig. 14 is a cross-sectional view taken along line XIV-XIV of fig. 13.

Fig. 15 is a diagram showing the frequency characteristics of the front hall element in the magnetic circuit shown in fig. 11.

Fig. 16A, 16B, and 16C show the magnetic flux density a of the magnetic field B generated by the front permanent magnet piece and the first IS current I flowing through the front camera shake correction coil part in the region I, the region II, and the region III of fig. 15, respectively_IS1Generated magnetic field B_I1And a graph of the magnitude of the total magnetic flux density (a + b) detected by the front side hall element versus the phase.

Fig. 17 is a table showing the relationship between fig. 16A to 16C.

Fig. 18 is a cross-sectional view showing the arrangement relationship between one permanent magnet piece of the permanent magnet, the focusing coil and the camera shake correction coil portion arranged around the permanent magnet piece in the magnetic circuit shown in fig. 11.

Fig. 19 is an enlarged partial perspective view showing a portion where the second end of the suspension wire used in the lens holder driving device shown in fig. 1 is fixed to the upper leaf spring.

Fig. 20 is a partial sectional view of the portion shown in fig. 19 where the fixation is performed.

Fig. 21 is a perspective view of a structure in which a coil substrate and a Flexible Printed Circuit (FPC) are combined, which is used in the lens holder driving device shown in fig. 1, as viewed from the back side.

Fig. 22 is a plan view showing a state where a shield cover is omitted in the lens holder driving device shown in fig. 1.

Fig. 23 is a partially enlarged perspective view showing a bundled portion of the wire end portions constituting the focusing coil in fig. 22 in an enlarged manner.

Fig. 24 is a longitudinal sectional view of a lens holder driving device according to a second embodiment of the present invention.

Fig. 25 is an exploded perspective view showing the lens holder driving device shown in fig. 24.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

A lens holder driving device 10 according to a first embodiment of the present invention will be described with reference to fig. 1 to 3. Fig. 1 is an external perspective view of a lens holder driving device 10. Fig. 2 is a partial longitudinal sectional view of the lens holder driving device 10. Fig. 3 is an exploded perspective view showing the lens holder driving device 10.

Here, as shown in fig. 1 to 3, a rectangular coordinate system (X, Y, Z) is used. In the state shown in fig. 1 to 3, in the rectangular coordinate system (X, Y, Z), the X-axis direction is the front-rear direction (depth direction), the Y-axis direction is the left-right direction (width direction), and the Z-axis direction is the up-down direction (height direction). In the example shown in fig. 1 to 3, the vertical direction Z is the optical axis O direction of the lens. In the second embodiment, the X-axis direction (front-back direction) is also referred to as a first direction, and the Y-axis direction (left-right direction) is also referred to as a second direction.

However, in an actual use situation, the optical axis O direction, i.e., the Z-axis direction is the front-rear direction. In other words, the upward direction of the Z axis is the forward direction, and the downward direction of the Z axis is the rearward direction.

The illustrated lens holder driving device 10 is provided in a mobile terminal such as a mobile phone, a smart phone, a notebook computer, a tablet computer, a portable game machine, a Web camera, and a vehicle-mounted camera, which are equipped with an auto-focusing camera. The lens holder driving device 10 is a device capable of capturing an image without blurring, including an autofocus lens holder driving unit 20 described later and a camera shake correction unit (described later) that corrects camera shake (vibration) generated by the autofocus lens holder driving unit 20 when a still image is captured by a compact video camera for a mobile terminal. The camera-shake correction unit of the lens holder drive device 10 corrects camera shake by moving the autofocus lens holder drive unit 20 in a first direction (front-back direction) X and a second direction (left-right direction) orthogonal to the optical axis O and to each other.

The autofocus lens holder driving unit 20 moves a lens holder 24 (described later) to which a lens barrel (not shown) can be attached along the optical axis O. The fixing portion 13 is disposed apart from the bottom of the autofocus lens holder driving portion 20. Although not shown, an imaging element disposed on an imaging substrate is mounted on a lower portion (rear portion) of the fixing portion 13. The image pickup element picks up an image of a subject imaged by the lens barrel and converts the image into an electric signal. The image pickup element is constituted by, for example, a ccd (charge coupled device) type image sensor, a cmos (complementary metal oxide semiconductor) type image sensor, or the like. Therefore, the camera module is configured by a combination of the autofocus lens holder driving unit 20, the imaging substrate, and the imaging element.

The fixing portion 13 is composed of a base 14, a coil substrate 40, and a flexible printed circuit board (FPC) 44.

The base 14 has a ring shape having a quadrangular outer shape and a circular opening 14a in the inside.

The camera shake correction unit of the lens holder drive device 10 includes: four suspension wires 16 for fixing the first end 161 to the four corners of the fixing portion 13; and a camera shake correction coil 18 disposed to face a permanent magnet 28 of an autofocus lens holder driving unit 20 described later.

The four suspension wires 16 extend along the optical axis O, and support the entire autofocus lens holder driving unit 20 so as to be swingable in the first direction (front-rear direction) X and the second direction (left-right direction) Y. The second end portions 162 of the four suspension wires 16 are fixed to the upper end portion of the autofocus lens holder driving unit 20 as described later.

In this way, the four suspension wires 16 function as a support member that supports the autofocus lens holder driving unit 20 so as to be swingable in the first direction X and the second direction Y with respect to the fixed unit 13.

The camera shake correction unit of the lens holder drive device 10 includes a rectangular ring-shaped coil substrate 40 disposed opposite to and apart from the permanent magnet 28, as will be described later. The coil substrate 40 is mounted on the base 14 with a flexible printed circuit board (FPC)44, which will be described later, interposed therebetween. The camera shake correction coil 18 is formed on the coil substrate 40.

As described above, the fixing portion 13 is constituted by a combination of the base 14, the coil substrate 40, and the Flexible Printed Circuit (FPC) 44.

Next, the autofocus lens holder driving unit 20 will be described with reference to fig. 3. The autofocus lens holder driving unit 20 is also referred to as an AF unit.

The lens holder driving unit 20 for automatic focusing includes: a lens holder 24 having a cylindrical portion 240 for holding a lens barrel; an annular focusing coil 26 fixed to the lens holder 24 so as to be positioned around the cylindrical portion 240; a magnet holder 30 holding a permanent magnet 28 disposed outside the focusing coil 26 so as to face the focusing coil 26; and first and second plate springs 32, 34 attached to first and second ends 30a, 30b of the magnet frame 30 in the optical axis O direction, respectively.

The first and second leaf springs 32, 34 support the lens holder 24 in a state where the lens holder 24 is positioned in the radial direction so as to be displaceable in the optical axis O direction. In the illustrated example, the first leaf spring 32 is referred to as an upper leaf spring, and the second leaf spring 34 is referred to as a lower leaf spring.

As described above, in an actual usage situation, the upper direction in the Z-axis direction (optical axis O direction) is the front direction, and the lower direction in the Z-axis direction (optical axis O direction) is the rear direction. Therefore, the upper leaf spring 32 is also referred to as a front spring, and the lower leaf spring 34 is also referred to as a rear spring.

The magnet holder 30 has a substantially octagonal cylindrical shape. That is, the magnet holder 30 includes: an outer cylindrical portion 302 having an octagonal cylindrical shape; an octagonal upper annular end portion 304 provided at an upper end (front end, first end) 30a of the outer cylindrical portion 302; and an octagonal lower annular end portion 306 provided at the lower end (rear end, second end) 30b of the outer tube portion 302. The upper annular end portion 304 has eight upper protrusions 304a protruding upward at four corners. The lower annular end portion 306 has four lower protrusions 306a protruding downward at four corners.

The focusing coil 26 has an octagonal tube shape conforming to the shape of the octagonal tube-shaped magnet holder 30. The permanent magnet 28 is composed of four rectangular permanent magnet pieces 282 arranged on the octagonal cylindrical outer tube portion 302 of the magnet frame 30 so as to be separated from each other in the first direction (front-rear direction) X and the second direction (left-right direction) Y. The four permanent magnet pieces 282 are disposed at intervals from the focusing coil 26. In the illustrated embodiment, each permanent magnet piece 282 is magnetized such that the inner peripheral end side is an N pole and the outer peripheral end side is an S pole.

The upper plate spring (front spring) 32 is disposed on the upper side (front side) of the lens holder 24 in the optical axis O direction, and the lower plate spring (rear spring) 34 is disposed on the lower side (rear side) of the lens holder 24 in the optical axis O direction.

The upper leaf spring (front spring) 32 includes: an upper inner peripheral end 322 attached to an upper end of the lens holder 24 as described later; and an upper outer peripheral end 324 attached to the upper annular end 304 of the magnet holder 30 as described later. A plurality of upper arm portions 326 are provided between the upper inner peripheral end portion 322 and the upper outer peripheral end portion 324. That is, the plurality of arm portions 326 connect the upper inner peripheral end 322 and the upper outer peripheral end 324.

The cylindrical portion 240 of the lens holder 24 has four upper protrusions 240a protruding upward at four corners of the upper end thereof. The upper inner peripheral end 322 has four upper side holes 322a into which the four upper protrusions 240a are press-fitted (fitted). That is, the four upper protrusions 240a of the cylindrical portion 240 of the lens holder 24 are press-fitted (fitted) into the four upper holes 322a of the upper inner circumferential end 322 of the upper leaf spring 32.

On the other hand, the upper outer circumferential end 324 has eight upper holes 324a into which the eight upper protrusions 304a of the magnet holder 30 are respectively fitted. That is, the eight upper protrusions 304a of the magnet holder 30 are fitted into the eight upper holes 324a of the upper outer circumferential end portion 324, respectively.

The upper leaf spring (front spring) 32 further has four arc-shaped protruding portions 328 protruding outward in the radial direction at four corners of the upper outer circumferential end 324. The four arc-shaped extensions 328 have four wire fixing holes 328a into which the second ends 162 of the four suspension wires 16 are inserted (fitted), respectively. The detailed structure of each arcuate projecting portion 328 will be described in more detail later with reference to fig. 19.

The lower leaf spring (rear spring) 34 includes: a lower inner peripheral end 342 attached to a lower end of the lens holder 24 as described later; and a lower outer peripheral end 344 attached to the lower annular end 306 of the magnet holder 30 as described later. A plurality of lower arm portions 346 are provided between the lower inner end 342 and the lower outer end 344. That is, the plurality of lower arm portions 346 connect the lower inner end 342 and the lower outer end 344.

A spacer 36 having substantially the same outer shape is disposed below the lower leaf spring 34. Specifically, the spacer 36 includes: an outer ring portion 364 having substantially the same shape as the lower outer peripheral side end portion 344 of the lower plate spring 34; and an inner ring portion 362 having a shape covering the lower inner peripheral end portion 342 and the lower arm portion 346 of the lower leaf spring 34.

The cylindrical portion 240 of the lens holder 24 has four lower protrusions (not shown) protruding downward at four corners of the lower end thereof. The lower inner peripheral end 342 has four lower holes 342a into which the four lower protrusions are respectively press-fitted (fitted). That is, the four lower protrusions of the cylindrical portion 240 of the lens holder 24 are press-fitted (fitted) into the four lower holes 342a of the lower inner peripheral end 342 of the lower plate spring 34.

On the other hand, the lower outer peripheral end 344 of the lower plate spring 34 has four lower holes 344a into which the four lower protrusions 306a of the magnet holder 30 are fitted. The outer ring portion 364 of the spacer 36 further has four lower holes 364a into which the four lower protrusions 306a of the magnet holder 30 are respectively pressed at positions corresponding to the four lower holes 344 a. That is, the four lower protrusions 306a of the magnet holder 30 are press-fitted into the four lower holes 364a of the outer ring portion 364 of the spacer 36 via the four lower holes 344a of the lower outer peripheral end 344 of the lower plate spring 34.

The elastic member composed of the upper plate spring 32 and the lower plate spring 34 functions as a guide mechanism for guiding the lens holder 24 to be movable only in the optical axis O direction. Each of the upper leaf spring 32 and the lower leaf spring 34 is made of beryllium bronze, phosphor bronze, or the like.

Female screws (not shown) are cut into the inner peripheral wall of the cylindrical portion 240 of the lens holder 24. On the other hand, although not shown, a male screw screwed to the female screw is cut on the outer peripheral wall of the lens barrel. Therefore, when the lens barrel is mounted on the lens holder 24, the lens barrel is housed in the lens holder 24 by screwing the lens barrel in the direction of the optical axis O while rotating about the optical axis O with respect to the cylindrical portion 240 of the lens holder 24, and the lens barrel is bonded to the lens holder 24 with an adhesive or the like.

As described later, the lens holder 24 (lens barrel) can be adjusted in position in the optical axis O direction by flowing an Autofocus (AF) current to the focus coil 26 and by the interaction of the magnetic field of the permanent magnet 28 and the magnetic field formed by the AF current flowing in the focus coil 26.

As described above, the autofocus lens holder driving unit (AF unit) 20 includes the lens holder 24, the focusing coil 26, the permanent magnet 28, the magnet holder 30, the upper plate spring 32, the lower plate spring 34, and the spacer 36.

Next, the camera shake correction unit of the lens holder driving device 10 will be described in more detail with reference to fig. 3.

As described above, the camera shake correction section of the lens holder driving device 10 includes: four suspension wires 16 for fixing the first end 161 to the four corners of the fixing portion 13; and a camera shake correction coil 18 disposed so as to face the permanent magnet 28 of the autofocus lens holder driving unit 20.

The four suspension wires 16 extend along the optical axis O, and support the entire autofocus lens holder drive unit (AF unit) 20 so as to be swingable in the first direction (front-rear direction) X and the second direction (left-right direction) Y. Second end portions 162 of the four suspension wires 16 are fixed to an upper end portion of the autofocus lens holder driving unit 20.

As described above, the four arc-shaped protruding portions 328 of the upper leaf spring 32 have the four wire fixing holes 328a into which the second end portions 162 of the four suspension wires 16 are inserted (fitted), respectively (see fig. 3). The second end portions 162 of the four suspension wires 16 are inserted (fitted) into the four wire fixing holes 328a and fixed thereto by an adhesive, solder, or the like.

In the illustrated example, the extension 328 on each arc has an L shape, but it is needless to say that the present invention is not limited thereto.

Two of the four suspension wires 16 are also used to power the focusing coil 26.

As described above, the permanent magnet 28 is composed of the four permanent magnet pieces 282 arranged to face each other in the first direction (front-rear direction) X and the second direction (left-right direction) Y.

The camera shake correction unit of the lens holder drive device 10 includes one annular coil substrate 40 which is inserted between the four permanent magnet pieces 282 and the base 14 and is disposed separately therefrom. The coil substrate 40 has through holes 40a at its four corners for inserting the four suspension wires 16 and fixing the first end 161. The camera shake correction coil 18 is formed on the one coil substrate 40.

Here, among the four permanent magnet pieces 282, the permanent magnet pieces disposed on the front side, the rear side, the left side, and the right side with respect to the optical axis O are referred to as a front permanent magnet piece 282f, a rear permanent magnet piece 282b, a left permanent magnet piece 282l, and a right permanent magnet piece 282r, respectively.

Referring also to fig. 4, four camera shake correction coil portions 18f, 18b, 18l, and 18r are formed as the camera shake correction coil 18 on the coil substrate 40.

The two camera shake correction coil sections 18f and 18b arranged to face each other in the first direction (front-rear direction) X are used to move (swing) the autofocus lens holder driving section (AF unit) 20 in the first direction (front-rear direction) X. These two camera shake correction coil sections 18f and 18b are collectively referred to as a first direction driver. Here, the coil part 18f for camera shake correction located on the front side with respect to the optical axis O is referred to as a "coil part for front camera shake correction", and the coil part 18b for camera shake correction located on the rear side with respect to the optical axis O is referred to as a "coil part for rear camera shake correction".

On the other hand, the two camera shake correction coil sections 18l and 18r arranged to face each other in the second direction (left-right direction) Y are used to move (swing) the autofocus lens holder driving section (AF unit) 20 in the second direction (left-right direction) Y. These two coil portions 18l and 18r for camera shake correction are referred to as second direction drivers. Here, the coil portion 18l for camera shake correction located on the left side with respect to the optical axis O is referred to as a "left-side coil portion for camera shake correction", and the coil portion 18r for camera shake correction located on the right side with respect to the optical axis O is referred to as a "right-side coil portion for camera shake correction".

As shown in fig. 4, in the illustrated camera shake correction coil 18, each of the front camera shake correction coil portion 18f and the left camera shake correction coil portion 18l is divided into two coil portions so as to be separated at the center in the longitudinal direction of the front permanent magnet piece 282f and the left permanent magnet piece 282l facing each other. That is, the front camera shake correction coil portion 18f is constituted by the left coil portion 18fl and the right coil portion 18 fr. Similarly, the left-side camera shake correction coil portion 18l is constituted by a front coil portion 18lf and a rear coil portion 18 lb.

In other words, each of the front-side camera shake correction coil portion 18f and the left-side camera shake correction coil portion 18l is formed of two ring portions, whereas each of the rear-side camera shake correction coil portion 18b and the right-side camera shake correction coil portion 18r is formed of one ring portion.

In this way, each of the two specific camera shake correction coil portions 18f and 18l arranged in the first direction X and the second direction among the four camera shake correction coil portions 18f, 18b, 18l and 18r is divided into two coil portions 18fl, 18fr, 18lf and 18lb so as to be separated at the center in the longitudinal direction of the opposing permanent magnet pieces 282f and 282 l.

The four coil portions 18f, 18b, 18l, and 18r for camera shake correction configured as described above are used to drive the entire autofocus lens holder driving unit (AF unit) 20 in the X-axis direction (first direction) and the Y-axis direction (second direction) in cooperation with the permanent magnet 28. The combination of the coil portions 18f, 18b, 18l, and 18r for camera shake correction and the permanent magnet 28 functions as a Voice Coil Motor (VCM).

In this way, the camera-shake correction unit of the illustrated lens holder driving device 10 corrects camera shake by moving the lens barrel itself housed in the autofocus lens holder driving unit (AF unit) 20 in the first direction (front-back direction) X and the second direction (left-right direction) Y. Therefore, the camera shake correction unit of the lens holder driving device 10 is referred to as a "barrel displacement type" camera shake correction unit.

Returning to fig. 3, the lens holder driving device 10 further includes a shield cover 42 covering the autofocus lens holder driving unit (AF unit) 20. The shield cover 42 has a rectangular tube 422 covering the outer peripheral side surface of the autofocus lens holder driving unit (AF unit) 20, and an annular upper end 424 covering the upper surface of the autofocus lens holder driving unit (AF unit) 20. The upper end 424 has a circular opening 424a concentric with the optical axis O.

The camera-shake correction unit of the illustrated lens holder driving device 10 further includes a position detection mechanism 50 for detecting the position of the autofocus lens holder driving unit (AF unit) 20 with respect to the base 14 (fixing unit 13). The illustrated position detection mechanism 50 is constituted by a magnetic position detection mechanism constituted by two hall elements 50f, 50l attached to the base 14 (see fig. 11). As will be described later, the two hall elements 50f and 50l are disposed so as to face two of the four permanent magnet pieces 282 separately. As shown in fig. 2, the hall elements 50f and 50l are arranged so as to extend in the direction from the N pole to the S pole of the permanent magnet piece 282.

In the illustrated example, the one hall element 50f is disposed on the front side in the first direction (front-rear direction) X with respect to the optical axis O, and is therefore referred to as a front hall element. The other hall element 50l is disposed on the left side of the second direction (left-right direction) Y with respect to the optical axis O, and is therefore referred to as a left hall element.

The front hall element 50f is disposed on the base 14 at a position separated from the two coil portions 18fl and 18fr of the front camera shake correction coil portion 18f having the two divided coil portions 18fl and 18 fr. Similarly, the left hall element 50l is disposed on the base 14 at a position separated from the two coil portions 18lf and 18lb of the left camera shake correction coil portion 18l having the two coil portions 18lf and 18lb divided.

In this way, the two hall elements 50f and 50l are arranged on the base 14 at the separated portions of the two coil portions 18fl, 18fr, 18lf, and 18lb of the two specific camera shake correction coil portions 18f and 18l having the two divided coil portions 18fl, 18fr, 18lf, and 18 lb.

The front hall element 50f detects the magnetic force of the front permanent magnet piece 282f facing thereto, thereby detecting the first position accompanying the movement (oscillation) in the first direction (front-rear direction) X. The left hall element 50l detects the magnetic force of the left permanent magnet piece 282l facing thereto, thereby detecting the second position accompanying the movement (swing) in the second direction (left-right direction) Y.

With reference to fig. 5 to 7, in order to facilitate understanding of the lens holder driving device 10 according to the first embodiment of the present invention, a description will be given of a relationship between a relevant magnetic circuit used in the relevant lens holder driving device and a hall element. The illustrated relationship between the relevant magnetic circuit and the hall element has the same structure (relationship) as the structure disclosed in patent document 17. Fig. 5 is a perspective view showing a relationship between the relevant magnetic circuit and the hall element, fig. 6 is a vertical sectional view showing a relationship between the relevant magnetic circuit and the hall element, and fig. 7 is a vertical sectional view showing a relationship between the relevant magnetic circuit and the hall element in a case where the AF unit 20 is displaced in the front-rear direction X.

The difference between the magnetic circuit and the magnetic circuit used in the lens holder driving device 10 of the present embodiment is that, in the magnetic circuit, the four camera shake correction coil portions 18f ', 18b ', 18l ' and 18r ' constituting the camera shake correction coil 18 ' are not divided into two annular coils. That is, in the relevant magnetic circuit, each of the four camera shake correction coil portions 18f ', 18 b', 18l ', and 18 r' is constituted by only one annular portion.

As described above, the four permanent magnet pieces 282f, 282b, 282l, and 282r are magnetized so that the inner side is the N pole and the outer side is the S pole. The arrow B shown in fig. 5 indicates the direction of the magnetic flux generated by these permanent magnet pieces.

Next, with reference to fig. 5, an operation when the lens holder 24 (lens barrel) is adjusted in position in the optical axis O direction using the relevant magnetic circuit will be described.

For example, an AF current flows in the focusing coil 26 in the counterclockwise direction. In this case, an upward electromagnetic force acts on the focusing coil 26 according to fleming's left-hand law. As a result, the lens holder 24 (lens barrel) can be moved upward in the optical axis O direction.

Conversely, by flowing the AF current clockwise through the focusing coil 26, the lens holder 24 (lens barrel) can be moved downward in the optical axis O direction.

Next, with reference to fig. 5 to 7, an operation when the entire autofocus lens holder driving unit (AF unit) 20 is moved in the first direction (front-back direction) X or the second direction (left-right direction) Y using the relevant magnetic circuit will be described.

First, the entire autofocus lens holder drive unit (AF unit) 20 is driven to the second positionThe operation when moving to the rear side in one direction (front-rear direction) X will be described. In this case, as shown in fig. 5, the front camera shake correction coil portion 18 f' flows in the counterclockwise direction as indicated by the arrow I_IS1As shown, the first camera shake correction (IS) current flows in the rear camera shake correction coil portion 18 b' in the clockwise direction as indicated by the arrow I_IS2A second camera jitter correction (IS) current as shown.

In this case, according to fleming's left-hand law, the front electromagnetic force acts on the front camera shake correction coil portion 18f ', and the front electromagnetic force also acts on the rear camera shake correction coil portion 18b '. However, since the coil parts 18F 'and 18 b' for camera shake correction are fixed to the base 14 (fixing part 13), the arrow F in fig. 6 acts on the entire autofocus lens holder driving part (AF unit) 20 as a reaction to the above-mentioned coil parts_IS1And F_IS2Shown, back-directed electromagnetic force. As a result, the entire autofocus lens holder driving unit (AF unit) 20 can be moved in the backward direction.

Conversely, the entire autofocus lens holder driving unit (AF unit) 20 can be moved forward by passing the first IS current in the clockwise direction through the front camera shake correction coil portion 18f 'and the second IS current in the counterclockwise direction through the rear camera shake correction coil portion 18 b'.

On the other hand, the autofocus lens holder driving unit (AF unit) 20 can be moved to the right as a whole by passing the third IS current in the counterclockwise direction through the left camera shake correction coil portion 18l 'and passing the fourth IS current in the clockwise direction through the right camera shake correction coil portion 18 r'.

Further, the autofocus lens holder driving unit (AF unit) 20 can be moved in the left direction as a whole by passing the third IS current in the clockwise direction through the left camera shake correction coil portion 18l 'and passing the fourth IS current in the counterclockwise direction through the right camera shake correction coil portion 18 r'.

In this way, camera shake of the video camera can be corrected.

Next, the problem of the lens holder driving device using the magnetic circuit will be described in detail with reference to fig. 8 to 10 in addition to fig. 5 to 7.

As described above, in order to move the entire autofocus lens holder driving unit (AF unit) 20 in the backward direction, as shown in fig. 5, the current flows in the counterclockwise direction as indicated by the arrow I through the front camera shake correction coil portion 18f_IS1The first IS current shown flows in the rear camera shake correction coil portion 18 b' in the clockwise direction as indicated by the arrow I_IS2The case of the second IS current shown IS explained as an example.

In this case, as shown in fig. 7, the first IS current I flowing through the front camera shake correction coil portion 18 f' passes_IS1Generated magnetic field B_I1And the magnetic field B generated by the front permanent magnet piece 282f after the movement is in the same phase. The magnetic flux density of the magnetic field B is represented by a, and the magnetic field B is represented by B_I1The magnetic flux density of (1). Therefore, the front hall element 50f detects the magnetic flux density a of the magnetic field B and the magnetic field B_I1The total magnetic flux density (a + b) of the magnetic flux density b.

Here, in order to detect the position of the autofocus lens holder driving unit (AF unit) 20 by the front hall element 50f, it is necessary to note that the magnetic flux density a of the magnetic field B and the total magnetic flux density (a + B) have the same phase.

Fig. 8 is a diagram showing the frequency characteristics of the front hall element 50f in the relevant magnetic circuit. In fig. 8, the horizontal axis represents Frequency (Frequency) (Hz), the left vertical axis represents Gain (Gain) (dB), and the right vertical axis represents Phase (deg). In fig. 8, the solid line indicates the gain characteristic, and the alternate long and short dash line indicates the phase characteristic.

As can be seen from fig. 8, the frequency characteristics of the front hall element 50f are divided into regions I, II, and III. The region I is a frequency band below the primary resonance of the driver and is a region with a low frequency. The region II is a frequency band of the driver at least at the primary resonance, and is a region with an intermediate frequency. The region III is a frequency band of the driver at least one resonance, and is a region of high frequency.

Fig. 9A, 9B, and 9C show the magnetic flux density a of the magnetic field B generated by the front permanent magnet piece 282f and the first IS current I flowing through the front camera shake correction coil 18 f' in the region I, the region II, and the region III of fig. 8, respectively_IS1Generated magnetic field B_I1And a graph of the magnitude and phase relationship of the total magnetic flux density (a + b) detected by the front hall element 50 f. Fig. 10 is a table showing the relationship between fig. 9A to 9C.

The following relationship is known from fig. 9A to 9C and fig. 10.

In the region I, i.e., a frequency band not greater than the primary resonance, the magnetic flux density a of the magnetic field B has a magnitude-a-which is larger than that of the magnetic field B_I1The magnitude of the magnetic flux density b is large (| a |)>B |), the magnetic flux density a of the magnetic field B, and the magnetic field B_I1The magnetic flux density (b) and the total magnetic flux density (a + b) have the same phase. Therefore, in the area I, the position of the autofocus lens holder driving unit (AF unit) 20 can be detected by the front hall element 50 f.

On the other hand, when the actuator has a primary resonance or more, the operation of the front permanent magnet piece 282f IS caused by the first IS current I flowing through the front camera shake correction coil 18f_IS1Is shifted by 180 DEG, the magnetic flux density a of the magnetic field B and the magnetic field B₁₁The magnetic flux density b becomes opposite in phase.

In the region II, i.e., the frequency band above the primary resonance, the magnetic flux density a due to the magnetic field B has a magnitude-a-which is higher than that of the magnetic field B_I1The magnitude of the magnetic flux density b is large (| a |)>B |) so that the magnetic flux density a of the magnetic field B and the total magnetic flux density (a + B) become the same phase. Therefore, in the area II, the position of the autofocus lens holder driving unit (AF unit) 20 can be detected by the front hall element 50 f.

However, in region III, i.e. primary resonanceIn the above frequency band, the magnitude a of the magnetic flux density a of the magnetic field B is larger than the magnetic field B_I1The magnitude of the magnetic flux density b is small (a)<| b |). Therefore, the magnetic flux density a of the magnetic field B and the total magnetic flux density (a + B) are in opposite phases. As a result, in the region III, the position of the autofocus lens holder driving unit (AF unit) 20 cannot be detected by the front hall element 50 f. That is, the output of the hall element has a resonance point.

Therefore, it is found that if the hall element is disposed between (in) one annular portion of the coil, the position of the autofocus lens holder driving unit (AF unit) 20 cannot be detected in the region III of the primary resonance or more. In other words, the hall elements 50f and 50l are adversely affected by magnetic fields generated by currents flowing through the camera shake correction coils 18f 'and 18 l', respectively.

Next, the relationship between the magnetic circuit and the hall element of the present embodiment used in the lens holder driving device 10 of the first embodiment of the present invention will be described with reference to fig. 11 to 14. Fig. 11 is a perspective view showing the relationship between the magnetic circuit and the hall element of the present embodiment, fig. 12 is a vertical sectional view showing the relationship between the magnetic circuit and the hall element of the present embodiment, fig. 13 is a vertical sectional view showing the relationship between the magnetic circuit and the hall element of the present embodiment when the AF unit 20 is displaced in the front-rear direction X, and fig. 14 is a sectional view of line XIV-XIV of fig. 13.

As described above, each of the four permanent magnet pieces 282f, 282b, 282l, and 282r is magnetized so that the inner side is an N pole and the outer side is an S pole. The arrow B shown in fig. 11 indicates the direction of the magnetic flux generated by these permanent magnet pieces.

Next, an operation when the lens holder 24 (lens barrel) is adjusted in the optical axis O direction using the magnetic circuit of the present embodiment will be described with reference to fig. 11.

For example, the AF current flows in the counterclockwise direction in the focusing coil 26. In this case, an upward electromagnetic force acts on the focusing coil 26 according to fleming's left-hand law. As a result, the lens holder 24 (lens barrel) can be moved upward in the optical axis O direction.

Conversely, by flowing the AF current clockwise to the focusing coil 26, the lens holder 24 (lens barrel) can be moved downward in the optical axis O direction.

Next, with reference to fig. 11 to 14, an operation when the entire autofocus lens holder driving unit (AF unit) 20 is moved in the first direction (front-back direction) X or the second direction (left-right direction) Y using the magnetic circuit of the present embodiment will be described.

First, an operation when the entire autofocus lens holder driving unit (AF unit) 20 is moved to the rear side in the first direction (front-rear direction) X will be described. In this case, as shown in fig. 11, the counterclockwise direction flows as indicated by an arrow I in each of the two coil portions 18fl and 18fr of the front camera shake correction coil portion 18f_IS1The first camera shake correction (IS) current shown flows in the rear camera shake correction coil portion 18b in the clockwise direction as indicated by the arrow I_IS2The second camera jitter correction (IS) current IS shown.

In this case, according to fleming's left-hand law, the forward electromagnetic force acts on the front camera shake correction coil portion 18f, and the forward electromagnetic force acts on the rear camera shake correction coil portion 18 b. However, since these coil parts 18F and 18b for camera shake correction are fixed to the base 14, the entire autofocus lens holder driving unit (AF unit) 20 functions as indicated by arrow F in fig. 12 in reaction thereto_IS1And F_IS2The back direction electromagnetic force is shown. As a result, the entire autofocus lens holder driving unit (AF unit) 20 can be moved in the backward direction.

Conversely, by flowing the first IS current in the clockwise direction in each of the two coil portions 18fl, 18fr of the front camera shake correction coil portion 18f and the second IS current in the counterclockwise direction in the rear camera shake correction coil portion 18b, the entire autofocus lens holder driving unit (AF unit) 20 can be moved in the forward direction.

On the other hand, by flowing the third IS current in the counterclockwise direction in each of the two coil portions 18lf, 18lb of the left-side camera shake correction coil portion 18l and flowing the fourth IS current in the clockwise direction in the right-side camera shake correction coil portion 18r, the entire autofocus lens holder driving unit (AF unit) 20 can be moved in the right direction.

Further, by flowing the third IS current in the clockwise direction in each of the two coil portions 18lf, 18lb of the left-side camera shake correction coil portion 18l and flowing the fourth IS current in the counterclockwise direction in the right-side camera shake correction coil portion 18r, the entire autofocus lens holder driving unit (AF unit) 20 can be moved in the left direction.

In this way, camera shake of the video camera can be corrected.

Next, the advantages of the lens holder driving device 10 using the magnetic circuit of the present embodiment will be described in detail with reference to fig. 15 to 17 in addition to fig. 11 to 14.

As described above, in order to move the entire autofocus-lens holder driving unit (AF unit) 20 in the backward direction, as shown in fig. 11, the two coil portions 18fl, 18fr of the front-side camera-shake correction coil portion 18f are caused to flow in the counterclockwise direction as indicated by the arrow I_IS1The first IS current shown flows in the clockwise direction as indicated by arrow I in the rear camera shake correction coil portion 18b_IS2The second IS current shown IS described as an example.

In this case, as shown in fig. 13 and 14, the first IS current I flowing through the front camera shake correction coil portion 18f_IS1Generated magnetic field B_I1And the magnetic field B generated by the front permanent magnet piece 282f after the movement are in opposite phases. The magnetic flux density of the magnetic field B is represented by a, and the magnetic field B is represented by B_I1The magnetic flux density of (1). Therefore, the front hall element 50f can detect the magnetic flux density a of the magnetic field B and the magnetic field B_I1The total magnetic flux density (a + b) of the magnetic flux density b.

As described above, in order to detect the position of the autofocus lens holder driving unit (AF unit) 20 by the front hall element 50f, it is necessary to note that the magnetic flux density a of the magnetic field B and the total magnetic flux density (a + B) have the same phase.

Fig. 15 is a diagram showing the frequency characteristics of the front hall element 50f in the magnetic circuit of the present embodiment. In fig. 15, the horizontal axis represents Frequency (Frequency) (Hz), the left vertical axis represents Gain (Gain) (dB), and the right vertical axis represents Phase (deg). In fig. 15, the solid line indicates the gain characteristic, and the alternate long and short dash line indicates the phase characteristic

As is clear from fig. 15, the frequency characteristics of the front hall element 50f are divided into a region I, a region II, and a region III in order from the lower frequency side. The region I is a frequency band below the primary resonance of the driver and is a region with a low frequency. The region II is a frequency band of the driver at least at the primary resonance, and is a region with an intermediate frequency. The region III is a frequency band of the driver at least one resonance, and is a region of high frequency.

Fig. 16A, 16B, and 16C show the magnetic flux density a of the magnetic field B generated by the front permanent magnet piece 282f in the region I, the region II, and the region III of fig. 15, and the first IS current I flowing through the front camera shake correction coil section 18f, respectively_IS1Generated magnetic field B_I1And a graph of the magnitude and phase relationship of the total magnetic flux density (a + b) detected by the front hall element 50 f. Fig. 17 is a table showing the relationship between fig. 16A to 16C.

The following relationship is known from fig. 16A to 16C and fig. 17.

In the region I, i.e., in the frequency band below the primary resonance, the magnitude a-of the magnetic flux density a of the magnetic field B is larger than the magnetic field B_I1The magnitude of the magnetic flux density b is large (| a |)>B |), the magnetic flux density a of the magnetic field B and the magnetic field B_I1Becomes opposite phase, and the magnetic flux density a of the magnetic field B and the total magnetic flux density (a + B) become the same phase. Therefore, in the region I, the front hall element 50f can detect autofocusThe position of the lens holder driving section (AF unit) 20.

On the other hand, at the time of the primary resonance of the actuator or more, the operation of the front permanent magnet piece 282f and the first IS current I flowing in the front camera shake correction coil portion 18f_IS1The magnetic flux density a of the magnetic field B and the magnetic field B are in the same phase₁₁The magnetic flux densities b of (a) and (b) are in the same phase.

In the region II, i.e., the frequency band above the primary resonance, the magnetic flux density a due to the magnetic field B has a magnitude-a-compared with the magnetic field B_I1The magnitude of the magnetic flux density b is large (| a |)>B |) so that the magnetic flux density a of the magnetic field B and the total magnetic flux density (a + B) become the same phase. Therefore, in the area II, the position of the autofocus lens holder driving unit (AF unit) 20 can be detected by the front hall element 50 f.

On the other hand, in the region III, i.e., in the frequency band of primary resonance or higher, the magnitude a-of the magnetic flux density a of the magnetic field B is larger than the magnetic field B_I1The magnitude of the magnetic flux density b is small (a)<| b |). However, since the magnetic flux density a of the magnetic field B and the magnetic flux density B of the magnetic field B11 have the same phase, the magnetic flux density a of the magnetic field B and the total magnetic flux density (a + B) also have the same phase. As a result, in the region III, the position of the autofocus lens holder driving unit (AF unit) 20 can be detected by the front hall element 50 f. That is, no resonance occurs in the output of the hall element.

Therefore, by disposing the hall element between the two annular portions of the coil, the position of the autofocus lens holder driving unit (AF unit) 20 can be detected in the entire frequency range. In other words, the hall elements 50f and 50l can be prevented from being adversely affected by the magnetic field generated by the current flowing through the coil portions 18f and 18l for camera shake correction, respectively.

Fig. 18 is a cross-sectional view showing the arrangement relationship between one permanent magnet piece 282 of the permanent magnet 28, the focusing coil 26 arranged around the permanent magnet piece, and the camera shake correction coil unit 18 in the magnetic circuit shown in fig. 11.

The height of the focusing coil 26 becomes lower than the height of the permanent magnet piece 282. This makes it possible to increase the stroke for adjusting the position of the lens holder 24 (lens barrel) in the optical axis O direction.

The permanent magnet piece 282 and the camera shake correction coil unit 18 are arranged such that the edge of the permanent magnet piece 282 in the radial direction enters the coil cross-sectional width of the camera shake correction coil unit 18 in the radial direction. This can improve the sensitivity of the driving force for moving the entire autofocus lens holder driving unit (AF unit) 20 in the direction orthogonal to the optical axis O.

In the lens holder driving device 10 having such a configuration, a force in a direction in which the four suspension wires 16 are pulled is applied by a drop impact or the like, and there is a possibility that the four suspension wires 16 are broken. Therefore, the lens holder driving device 10 of the present embodiment includes a breakage preventing member for preventing breakage of the four suspension wires 16 as described later.

The breakage preventing member of the present embodiment will be described in detail with reference to fig. 19 and 20. Fig. 19 is a partial perspective view showing an enlarged portion of the second end 161 of the suspension wire 16 fixed to the upper leaf spring 32, and fig. 20 is a partial sectional view of the fixed portion.

As described above, the upper leaf spring 32 has four arc-shaped protruding portions 328 protruding outward in the radial direction at four corners of the upper outer circumferential end portion 324 (only one arc-shaped protruding portion 328 is illustrated in fig. 19). The four arc-shaped extensions 328 have four wire fixing holes 328a (see fig. 3) at the distal ends thereof, into which the second ends 162 of the four suspension wires 16 are inserted (fitted). The second end portions 162 of the four suspension wires 16 are inserted into the four wire fixing holes 328a and fixed to the four arc-shaped extensions 328 by solder 60 or an adhesive (not shown).

Therefore, the four arc-shaped protruding portions 328 function as wire fixing portions for fixing the second end portions 162 of the four suspension wires 16.

In the lens holder driving device 10 configured as described above, even if a force in a direction away from the base 14 (fixing portion 13) is applied to the autofocus lens holder driving portion (AF unit) 20 by a drop impact or the like, the four arc-shaped protruding portions 328 of the upper plate spring 32 are elastically deformed and the autofocus lens holder driving portion (AF unit) 20 is raised in a state where the second end portions 162 of the four suspension wires 16 are fixed to the four arc-shaped protruding portions 328 in the upper plate spring 32.

As a result, the four suspension wires 16 can be prevented from being broken. Therefore, the four arc-shaped protruding portions 328 function as a breakage preventing member that prevents the four suspension wires 16 from being broken.

On the other hand, as shown in fig. 19, the magnet holder 30 has four upper stoppers 308 protruding upward at four corners of the upper annular end portion 304 (only one upper stopper 308 is illustrated in fig. 19). Each upper limiter 308 protrudes from an opening 32a formed between the upper outer peripheral end 324 of the upper leaf spring 32 and each arcuate projecting portion 328.

In other words, the four upper stoppers 308 protrude from the magnet holder 30 toward the inner wall surface of the shield cover 42.

As shown in fig. 2, the four upper limiters 308 limit the upward movement of the autofocus lens holder driving unit (AF unit) 20. In other words, when the autofocus lens holder driving unit (AF unit) 20 moves in the upward direction, the four arc-shaped protruding portions 328 deform elastically, but before the four arc-shaped protruding portions 328 are bent and a force to break the four suspension wires 16 is applied, the four upper stoppers 308 of the magnet holder 30 come into contact with the inner wall surface of the upper end portion 424 of the shield cover 42.

That is, the four upper side restrainers 308 function as fracture prevention auxiliary members that assist in preventing the four suspension wires 16 from being fractured.

Further, as shown in fig. 2, there is substantially no gap (clearance) between the fixing portion 13 (coil substrate 40) and the autofocus lens holder driving portion (AF unit) 20. Therefore, even if a force in the direction of approaching the fixing portion 13 (coil substrate 40) is applied to the autofocus lens holder driving unit (AF unit) 20 by a drop impact or the like, the autofocus lens holder driving unit (AF unit) 20 immediately comes into contact with the upper surface of the fixing portion 13 (coil substrate 40), and the four suspension wires 16 are not bent in length.

A flexible printed circuit board (FPC)44 disposed between the base 14 and the coil substrate 40 and a mounting method thereof will be described with reference to fig. 21 in addition to fig. 2 to 4. Fig. 21 is a perspective view of a structure in which a coil substrate 40 and a Flexible Printed Circuit (FPC)44 are combined, as viewed from the back side.

As shown in fig. 3, the base 14 has four positioning projections 142 projecting upward on the diagonal lines on the outer side in the radial direction in the vicinity of the circular opening 14 a. On the other hand, as shown in fig. 4, the coil substrate 40 has four positioning hole portions 40b into which the four positioning projections 142 are respectively fitted. As shown in fig. 21, the Flexible Printed Circuit (FPC)44 also has four positioning hole portions 44a at positions corresponding to the four positioning hole portions 40 b. Therefore, the four positioning protrusions 142 of the base 14 are fitted into the four positioning hole portions 40b of the coil substrate 40 through the four positioning hole portions 44a of the Flexible Printed Circuit (FPC)44, respectively.

As shown in fig. 21, two hall elements 50f and 50l are mounted on the back surface of a Flexible Printed Circuit (FPC) 44. On the other hand, as shown in fig. 2, a hole 14b into which the two hall elements 50f, 50l are fitted is formed in the base 14.

As shown in fig. 4, six pads 18a are formed on the coil substrate 40 along a circular opening 40c located at the center thereof, and the six pads 18a are used to supply current to the four camera shake correction coil portions 18f, 18b, 18l, and 18 r. On the other hand, as shown in fig. 21, six notch portions 44b are formed in the flexible printed circuit board (FPC)44 at positions corresponding to the six pads 18a, respectively. Therefore, by placing solder paste in the six notch portions 44b and performing reflow soldering, internal wiring (not shown) of the flexible printed circuit board (FPC)44 can be electrically connected to the six lands 18a of the coil substrate 40.

As described above, the first end portions 161 of the four suspension wires 16 are inserted through the four through holes 40a of the coil substrate 40 and fixed to the coil substrate 40.

As shown in fig. 4, four lands are formed on the coil substrate 40 around the four through holes 40a, respectively. Two of the four pads (in the example of fig. 4, the right-rear and left-front) formed around the four through holes 40a are electrically connected to internal wiring (not shown) of a Flexible Printed Circuit (FPC)44 by solder. Therefore, the first end portions 161 of two suspension wires 16 of the four suspension wires 16 are fixed to the coil substrate 40 by the two pads by the solder, and are electrically connected to the flexible printed circuit board (FPC) 44. On the other hand, the first end portions 161 of the remaining two suspension wires 16 are fixed to the coil substrate 40 by the remaining two lands by solder or an adhesive, but are electrically insulated from the internal wiring (not shown) of the Flexible Printed Circuit (FPC) 44.

As shown in fig. 21, a controller 46 is mounted on the back surface of a flexible printed circuit board (FPC) 44. The control unit 46 controls the AF current flowing through the focusing coil 16, or controls the first to fourth IS currents flowing through the four camera shake correction coil portions 18f, 18b, 18l, and 18r based on the position detection signals detected by the two hall elements 50f and 50l so as to cancel out the shake detected by the two-direction rotation sensors (not shown).

A method of supplying power to the focusing coil 26 will be described with reference to fig. 22 and 23. Fig. 22 is a plan view of the lens holder driving device 10 with the shield cover 42 omitted. Fig. 23 is an enlarged partial perspective view showing a bundled portion of the wire end portion constituting the focusing coil 26 in fig. 22.

As shown in fig. 22, the lens holder 24 has first and second protrusions 241 and 242 protruding in a direction (radially outward) away from each other in the left-right direction Y at the upper end thereof. In the illustrated example, the first protrusion 241 protrudes to the right side and is therefore referred to as a right-side protrusion, and the second protrusion 242 protrudes to the left side and is therefore referred to as a left-side protrusion.

On the other hand, the wire constituting the focusing coil 26 has first and second end portions 261 and 262. As shown in fig. 23, the first distal end portion 261 of the wire of the focusing coil 26 is bundled on the first protrusion portion (right protrusion portion) 241 of the lens holder 24. Similarly, the second distal end portion 262 of the wire of the focusing coil 26 is bundled on the second protrusion portion (left protrusion portion) 242 of the lens holder 24. Therefore, the first and second end portions 261 and 262 are also referred to as first and second strapping portions, respectively.

On the other hand, as shown in fig. 22, the first plate spring (upper plate spring) 32 is composed of first and second plate spring pieces 32-1 and 32-2 electrically insulated from each other. The first and second plate reeds 32-1 and 32-2 are formed in a rotationally symmetrical shape with respect to the optical axis O of the lens. The first plate spring pieces 32-1 are disposed substantially on the rear side and the right side at the first end (upper end) of the magnet frame 30, and the second plate spring pieces 32-2 are disposed substantially on the front side and the left side at the first end (upper end) of the magnet frame 30.

The upper inner peripheral end 322 positioned on the right side of the first plate spring 32-1 has a first U-shaped terminal portion 322-1 projecting rightward (radially outward) at a position corresponding to the first projecting portion (right projecting portion) 241 of the lens holder 24. Similarly, the upper inner peripheral end 322 positioned on the left side of the second plate spring 32-2 has a second U-shaped terminal portion 322-2 projecting leftward (radially outward) at a position corresponding to the second projecting portion (left projecting portion) 242 of the lens holder 24. The first U-shaped terminal portion 322-1 is also referred to as a right-side U-shaped terminal portion, and the second U-shaped terminal portion 322-2 is also referred to as a left-side U-shaped terminal portion.

The first U-shaped terminal portion (right-side U-shaped terminal portion) 322-1 is electrically connected to a first end portion (first bundling portion) 261 of the focusing coil 26 at a first protrusion portion (right-side protrusion portion) 241 of the lens holder 24 by solder (not shown). Similarly, the second U-shaped terminal portion (left U-shaped terminal portion) 322-2 is electrically connected to the second end portion (second bundling portion) 262 of the focusing coil 26 at the second protrusion portion (left protruding portion) 242 of the lens holder 24 by solder (not shown).

As described above, the second end portions 162 of two suspension wires 16 (right-rear and left-front in the example of fig. 22) of the four suspension wires 16 are fixed to the arc-shaped extensions 328 by the solder 60 through the wire fixing holes 328 a. The second end portions 162 of the remaining two suspension wires 16 (left inner and right front in the example of fig. 22) are fixed to the arc-shaped extensions 328 by the adhesive 62 through the wire fixing holes 328 a. Solder may be used instead of the adhesive 62.

As described above, the first end portions 161 of two suspension wires 16 (the right-side and the left-side in the example of fig. 22) of the four suspension wires 16 are fixed to the lands of the coil substrate 40 by solder through the through holes 40a, and are electrically connected to the flexible printed circuit board (FPC) 44. The first end portions 161 of the remaining two suspension wires 16 (left and right front in the example of fig. 22) are fixed to the lands of the coil substrate 40 by solder or an adhesive through the through holes 40a, but are electrically insulated from the Flexible Printed Circuit (FPC) 44.

Therefore, the flexible printed circuit board (FPC)44 is electrically connected to the first end portion (first bound portion) 261 of the focus coil 26 via the one suspension wire 16 on the right-back side, the first plate spring piece 32-1 of the first plate spring (upper plate spring) 32, and the first U-shaped terminal portion (right U-shaped terminal portion) 322-1. Similarly, the flexible printed circuit board (FPC)44 is electrically connected to the second end portion (second bundling portion) 262 of the focus coil 26 via the one suspension wire 16 on the front left, the second plate spring piece 32-2 of the first plate spring (upper plate spring) 32, and the second U-shaped terminal portion (left U-shaped terminal portion) 322-2.

In this way, power is supplied from the flexible printed circuit board (FPC)44 to the focus coil 26 through the two suspension wires 16 and the first plate spring 32.

Next, a method of assembling the lens holder driving device 10 will be described.

First, the lens holder 24, the focusing coil 26, the permanent magnet 28, the magnet holder 30, the upper plate spring 32, the lower plate spring 34, and the spacer 36 are combined to manufacture the autofocus lens holder driving unit (AF unit) 20.

On the other hand, an assembly of the coil substrate 40 and a flexible printed circuit board (FPC)44 is produced by the above-described reflow soldering as shown in fig. 21. This assembly is mounted on the base 14 provided on the first end 161 side of the four suspension wires 16.

The autofocus lens holder drive unit (AF unit) 20 is mounted on the base 14 via the assembly, and the second ends 162 of the four suspension wires 16 are fixed to the arc-shaped extensions 328 by the wire fixing holes 328a and the solder 60 or the adhesive 62.

The first and second U-shaped terminal portions 322-1 and 322-2 of the first plate spring (upper plate spring) 32 are connected to the first and second end portions 261 and 262 of the focus coil 26, respectively, by soldering.

Finally, the shield cover 42 is closed so as to cover the autofocus lens holder drive unit (AF unit) 20, and the lower end of the shield cover 42 is fixed to the base 14.

Thus, the lens holder driving device 10 can be easily assembled.

Further, the lens holder driving device 10 thus assembled has dimensions of 11mm × 11mm × 4.2 mm.

The lens holder driving device 10 according to the first embodiment of the present invention described above has the following effects.

First, since the two hall elements 50f and 50 are disposed on the base 14 at the positions of the two specific camera shake correction coil portions 18f and 18l, which are separated from each other by the two coil portions 18fl, 18fr, 18lf, and 18lb, the two hall elements 50f and 50l can avoid adverse effects due to a magnetic field generated by a current flowing through the two specific camera shake correction coil portions 18f and 18 l.

Secondly, since the breakage preventing member 328 is provided, breakage of the four suspension wires 16 can be prevented, and shock resistance of the lens holder driving device 10 can be improved.

Thirdly, since the cut-out portions 44b are formed in the flexible printed circuit board (FPC)44 at positions corresponding to the plurality of pads 18a formed on the coil substrate 40, the internal wiring of the flexible printed circuit board (FPC)44 can be electrically connected to the plurality of pads 18a of the coil substrate 40 by reflow soldering.

Fourth, since the height of the focusing coil 26 is reduced with respect to the height of the permanent magnet piece 282, the stroke in adjusting the position of the lens holder 24 (lens barrel) in the optical axis O direction can be increased.

Fifth, since the permanent magnet piece 282 and the camera shake correction coil unit 18 are arranged so that the edge of the permanent magnet piece 282 in the radial direction enters the coil cross-sectional width of the camera shake correction coil unit 18 in the radial direction, the sensitivity of the driving force for moving the entire autofocus lens holder driving unit (AF unit) 20 in the direction orthogonal to the optical axis O can be improved.

A lens holder driving device 10A according to a second embodiment of the present invention will be described with reference to fig. 24 and 25. Fig. 24 is a longitudinal sectional view of the lens holder driving device 10A. Fig. 25 is an exploded perspective view showing the lens holder driving device 10A.

As shown in fig. 24 and 25, a rectangular coordinate system (X, Y, Z) is used. In the state shown in fig. 24 and 25, in the rectangular coordinate system (X, Y, Z), the X-axis direction is the front-rear direction (depth direction), the Y-axis direction is the left-right direction (width direction), and the Z-axis direction is the up-down direction (height direction). In the examples shown in fig. 24 and 25, the vertical direction Z is the optical axis O direction of the lens. In the second embodiment, the X-axis direction (front-rear direction) is also referred to as a first direction, and the Y-axis direction (left-right direction) is also referred to as a second direction.

However, in the use state, the optical axis O direction, i.e., the Z-axis direction is the front-rear direction. In other words, the upward direction of the Z axis is the forward direction, and the downward direction of the Z axis is the rearward direction.

The illustrated lens holder driving device 10A includes an auto-focusing lens holder driving unit 20A and a camera shake correction unit that corrects camera shake (vibration) generated in the auto-focusing lens holder driving unit 20A when a still image is captured by a compact video camera for a mobile terminal, and can capture an image without blurring.

The illustrated lens holder driving device 10A is substantially opposite in structure to the lens holder driving device 10 of the first embodiment described above. Therefore, the "upper side" may be replaced with the "lower side" and the "lower side" may be replaced with the "upper side". For the sake of simplicity of explanation, the same reference numerals are assigned to portions having the same functions as those of the lens holder driving device 10 according to the first embodiment, and only different points will be described below.

The lens barrel 12 has a bell shape. Instead of the shield case 42, a quadrangular cylindrical protection wall 422A and a second base (cover) 424A are used. In the autofocus lens holder driving unit (AF unit) 20A, the spacer 36A is attached to the lower leaf spring 32 as the first leaf spring.

The other structure is the same as the lens holder driving device 10 of the first embodiment.

Therefore, the lens holder driving device 10A according to the second embodiment of the present invention has the same effects as those of the lens holder driving device 10 according to the first embodiment described above.

The present invention has been described above with reference to the embodiments, but the present invention is not limited to the above embodiments. It is apparent to those skilled in the art that various modifications can be made in the structure and details of the present invention within the scope of the present invention.

For example, in the above-described embodiment, as the supporting member for supporting the autofocus lens holder driving unit so as to be swingable with respect to the fixed unit, a plurality of suspension wires having first end portions fixed to the outer peripheral portion of the fixed unit are used, but the supporting member is not limited thereto.

Some or all of the above embodiments are described as in the attached notes below, but the embodiments are not limited to the description below.

(supplementary note 1) a lens holder driving device 10, 10A, comprising:

autofocus lens holder driving units 20 and 20A for moving a lens holder 24 holding the lens barrel 12 along the optical axis O;

a camera-shake correction unit for correcting camera shake by moving the automatic-focusing lens-holder driving units 20 and 20A in a first direction X and a second direction Y orthogonal to the optical axis O and to each other, the lens-holder driving units 10 and 10A being characterized in that,

the autofocus lens holder driving units 20 and 20A include:

a focusing coil 26 fixed to the lens holder 24;

a permanent magnet 28 including a plurality of permanent magnet pieces 282f, 282b, 282l, and 282r, the plurality of permanent magnet pieces 282f, 282b, 282l, and 282r each having a first surface facing the focus coil 26, being arranged radially outward of the focus coil 26 with respect to the optical axis O, and facing each other in the first direction X and the second direction Y;

a magnet holder 30, which is disposed on the outer periphery of the lens holder 24, holds the permanent magnet 28, and has first and second ends 30a, 30b facing each other in the optical axis O direction; and

first and second plate springs 32 and 34, the first and second plate springs 32 and 34 being attached to the first and second ends 30a and 30b of the magnet holder 30, respectively, and supporting the lens holder 24 so as to be displaceable in the optical axis direction in a state where the lens holder 24 is positioned in the radial direction,

the camera shake correction unit includes:

a fixing portion 13, which is disposed at a position close to the second plate spring 34 and is separated from the autofocus lens holder driving portions 20 and 20A in the optical axis O direction, 13;

a support member 16 for supporting the autofocus lens holder drive unit 20 or 20A to the fixed unit 13 so as to be swingable in the first direction X and the second direction Y, the support member 16 being provided with a support member for supporting the autofocus lens holder drive unit 20 or 20A;

a camera shake correction coil 18, the camera shake correction coil 18 being constituted by a plurality of camera shake correction coil portions 18f, 18b, 18l, 18r arranged on the fixing portion 13 so as to face second surfaces perpendicular to the first surfaces of the plurality of permanent magnet pieces 282f, 282b, 282l, 282r, respectively, the camera shake correction coil 18 having specific camera shake correction coil portions 18f, 18l arranged in the first direction X and the second direction Y among the plurality of camera shake correction coil portions, each of the specific camera shake correction coil portions 18f, 18l being divided into a plurality of coil portions 18fl, 18fr, 18lf, 18lb so as to be separated in the longitudinal direction of the opposing permanent magnet pieces 282f, 282 l; and

and a plurality of hall elements 50f and 50l, the plurality of hall elements 50f and 50l being disposed at positions separated from the plurality of coil portions 18fl, 18fr, 18lf, and 18lb of the specific coil portions 18f and 18l for camera shake correction, respectively, on the fixing portion 13.

(additional note 2) in the lens holder driving device described in (additional note 1),

the permanent magnet 28 is composed of four permanent magnet pieces 282f, 282b, 282l, 282r,

the camera shake correction coil 18 is constituted by four camera shake correction coil sections 18f, 18b, 18l, and 18r including two specific camera shake correction coil sections 18f and 18l arranged in the first direction X and the second direction Y, each of the two specific camera shake correction coil sections 18f and 18l is divided into two coil sections 18fl, 18fr, 18lf, and 18lb so as to be separated at the center in the longitudinal direction of the opposing permanent magnet pieces 282f and 282l,

the plurality of hall elements are constituted by two hall elements 50f, 50l, and the two hall elements 50f, 50l are disposed on the fixing portion 13 at positions separated from the two coil portions 18fl, 18fr, 18lf, 18lb of the two specific coil portions 18f, 18l for camera shake correction.

(additional note 3) in the lens holder driving device described in (additional note 1),

the support member is composed of a plurality of suspension wires 16 having first end portions 161 fixed to the outer peripheral portion of the fixing portion 13, and the plurality of suspension wires 16 extend along the optical axis O and support the autofocus lens holder driving portion 20, 20A so as to be swingable in the first direction X and the second direction Y.

(additional character 4) in the lens holder driving device described in (additional character 3),

the second end portions 162 of the plurality of suspension wires 16 are fixed to the first plate spring 32.

(additional character 5) in the lens holder driving device described in (additional character 4),

the lens holder 24 includes: a cylindrical portion 240 for holding the lens barrel 12; and protrusions 241, 242 protruding from the outer wall of the cylindrical portion 240,

the projection is bundled with the end portions 261 and 262 of the wire material constituting the focusing coil 26,

the first plate spring 32 has terminal portions 322-1 and 322-2 arranged to protrude in the vicinity of the protruding portion binding the terminal portions of the wires,

the terminal portions 322-1 and 322-2 are electrically connected to the terminal portions 261 and 262 of the wire rods bundled on the protruding portions 241 and 242, and power is supplied from the suspension wire 16 to the focus coil 26 via the first plate spring 32.

Note that the above reference signs are merely examples given for easy understanding, and it is needless to say that the present invention is not limited thereto.

The present application claims priority based on japanese patent application No. 2011-157035, which is filed on 7/15/2011, the disclosure of which is incorporated herein in its entirety.

Claims (4)

1. A lens driving device has:

a component which is provided with a lens frame and a permanent magnet arranged around the lens frame; and

a camera shake correction section that corrects camera shake by moving the unit in a first direction and a second direction orthogonal to the optical axis of the lens holder and to each other,

the permanent magnet is composed of a plurality of permanent magnet pieces,

the plurality of permanent magnet pieces are arranged around the lens holder so as to face each other in the first direction and the second direction,

the camera shake correction unit includes:

a fixing portion disposed apart from the module in the optical axis direction;

a support member that supports the component with respect to the fixing portion so that the component can swing in the first direction and the second direction;

a camera shake correction coil including a plurality of camera shake correction coil portions arranged on the fixing portion so as to face the permanent magnet pieces, respectively, wherein each of specific camera shake correction coil portions arranged in the first direction and the second direction among the plurality of camera shake correction coil portions is divided into a plurality of coil portions so as to be separated in a longitudinal direction of the permanent magnet pieces facing each other; and

and a plurality of hall elements arranged at the fixed portion at positions separated from the plurality of coil portions of the specific coil portion for camera shake correction having the plurality of divided coil portions.

2. The lens driving device according to claim 1,

the permanent magnet is composed of four permanent magnet pieces,

the camera shake correction coil is configured by four camera shake correction coil portions, each of two specific camera shake correction coil portions arranged in the first direction and the second direction among the four camera shake correction coil portions being divided into two coil portions so as to be separated at a center in a longitudinal direction of each of the permanent magnet pieces facing each other;

the plurality of hall elements are formed of two hall elements arranged at the fixing portion at positions separated from each other in the two coil portions of the two coil portions for camera shake correction having the two coil portions divided.

3. The lens driving device according to claim 1 or 2,

the support member is configured by a plurality of suspension wires, one end of each of which is fixed to an outer peripheral portion of the fixing portion, and the plurality of suspension wires extend along the optical axis and support the module so as to be swingable in the first direction and the second direction.

4. The lens driving device according to claim 3,

the other ends of the plurality of suspension wires are fixed to the assembly.