JP2001201777A - Shake correcting device and optical equipment including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shake correcting device capable of performing control even when offset is caused concerning the position of an entire shake preventing device while maintaining superiority by controlling the speed of the correction lens. SOLUTION: This shake correcting device for optical equipment equipped with an optical element is provided with a correction optical system capable of decentering the optical axis of the optical element, a speed detection means detecting the speed of shake vibration, a driving means controlling the speed of the correction optical system based on output from the speed detection means and driving the system and a regulating means imparting localizalility to the correction optical system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blur correction device and an optical apparatus including the same.

[0002]

2. Description of the Related Art Conventionally, in a camera, a video camera or the like, an image blur prevention device is installed in order to prevent an image blur due to a hand tremor or a shake due to a wind. In this image blur prevention apparatus, a type for controlling the position of the correction lens and a type for controlling the speed are known (for example, Japanese Patent Application Laid-Open No.
No. 80533 and the like.
issue).

[0003]

In the above-described image blur prevention apparatus, image blur can be correctly corrected only by accurately controlling the position of the correction lens with respect to the blur information.

Therefore, in a shake correcting apparatus of the type which controls the position of a correcting lens (for example, Japanese Patent Laid-Open No. 9-80533), conventionally, shake vibration is first detected by an angular velocity sensor or the like, and then the detected data is integrated by an integrating circuit. Then, the position information is converted into position information, and the position of the correction lens is controlled based on the position information. Further, in order to more accurately perform position control, there has been a device in which a position sensor for detecting the position of the correction lens is provided to perform feedback control.

However, in the above configuration, the cost is increased due to the installation of the integrating circuit and the position sensor, and there is a problem that the position sensor is particularly expensive.

On the other hand, the present inventor paid attention to the following points. In other words, by adopting a shake prevention device of a type that controls the speed of the correction lens, it is possible to control the correction lens without converting detection information from an angular velocity sensor or the like into position information, and the speed sensor is more powerful than the position sensor. Since it is relatively inexpensive, the cost can be kept low.

However, in an image stabilizing apparatus for controlling the speed of the correction lens, the correction lens only controls the driving speed and does not control the absolute position. Cannot be controlled.

[0008] However, in a conventionally proposed speed control type blur prevention device (for example, Japanese Patent Application Laid-Open No. 7-84296), such a problem in realizing the speed control and its solution have not been described. Therefore, it was not possible to actually manufacture a blur prevention device.

SUMMARY OF THE INVENTION An object of the present invention is to provide a shake correction apparatus which can control the position of the entire shake prevention apparatus even when an offset occurs, while maintaining the superiority by controlling the speed of the correction lens. is there.

[0010]

According to a first aspect of the present invention, there is provided a shake correcting apparatus for an optical apparatus having an optical element, wherein the optical axis of the optical element can be decentered. A correcting optical system, a speed detecting means for detecting the speed of the shake vibration, a driving means for controlling the speed of the correcting optical system based on an output of the speed detecting means, and a regulating member for imparting localization to the correcting optical system. It is characterized by having.

According to a second aspect of the present invention, there is provided a shake correcting apparatus for an optical apparatus having an optical element, wherein a correction optical system capable of decentering the optical axis of the optical element, and an angular velocity detecting means for detecting an angular velocity of the shake vibration. Means, a driving means for driving the correction optical system on a plane perpendicular to the optical axis of the correction optical system, a control means for controlling the speed of the driving means based on the speed detected by the angular velocity detecting means, And regulating means for giving

A third structure of the present invention is the shake correcting device according to the first structure, wherein the shake correcting device further performs feedback control in a driving unit.

[0013] A fourth configuration of the present invention is characterized in that the shake correction apparatus further includes a filter section for removing a frequency unnecessary for driving the correction optical system from the output of the speed detection means. This is a shake correction device having a first configuration.

According to a fifth aspect of the present invention, there is provided a shake correcting apparatus according to the fourth aspect, wherein the filter section comprises a combination of a low-pass filter and a high-pass filter or a band-pass filter.

According to a sixth aspect of the present invention, the driving means includes:
A shake correction device according to the first configuration, which is a voice coil motor.

A seventh aspect of the present invention is the shake correcting apparatus according to the first structure, wherein the shake correcting apparatus further includes a detecting means for detecting a driving speed of the driving means.

According to an eighth aspect of the present invention, the regulating member is
A shake correcting apparatus according to a second configuration, comprising a pair of urging members for urging the correction optical system in directions perpendicular to the optical axis and in directions opposite to each other.

According to a ninth configuration of the present invention, the restricting member is
A shake correction apparatus according to a second configuration, wherein the correction optical system is returned to a predetermined position when there is no output from the driving unit.

According to a tenth aspect of the present invention, there is provided an optical apparatus including the shake correcting apparatus according to any one of the first to ninth aspects.

[0020]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIGS. 1 and 2 schematically show the entire first and second embodiments, respectively. First, an overall description will be given with reference to these drawings.

FIG. 1 is a schematic overall view of a single-lens reflex camera. The left side of the figure is the front of the camera, and from the left, the objective lens 1, the diaphragm 2, the first correction optical unit 3, the second correction optical unit 4,
The movable mirror 5 and the shutter 6 are arranged in this order, and the shutter 6
Is loaded behind the film. The objective lens 1
To the second correction optical unit 4 are referred to as a photographing lens unit 11.

On the movable lens 5, a focusing plate 16 and a penta roof prism 8 are arranged, and on the right side of the penta roof prism 8, an eyepiece 9 and a photometry unit 10 are installed. The movable mirror 5 is installed at an angle of 45 degrees with respect to the bottom of the penta roof prism 8. A focus detection unit 12 is provided below the movable mirror 5. An objective lens driving unit 13 that drives the objective lens 1 above and below the objective lens 1
Is installed. An angular velocity sensor 14 for detecting camera shake at an angular velocity is provided above the first correction optical unit 3 and in the measurement of the second correction optical unit 4. A microcomputer 15 is provided below the position where the shutter 6 and the film 7 are loaded, and the objective lens drive unit 13, the first correction optical unit 3, the second correction optical unit 4, the movable mirror 5, the focus detection unit 12, The respective movements of the photometry unit 10, the aperture 2, and the shutter 6 are controlled.

In the single-lens reflex camera having the above structure, the light beam reflected by the object passes through the photographing lens unit 11, is reflected by the movable mirror 5, forms an image on the focusing screen 16, and then enters the penta roof prism 8. The light incident on the penta roof prism 8 is changed in traveling direction toward the eyepiece 9 by the penta roof prism 8, and the photographer checks the image of the subject through the eyepiece 9. When the photographer confirms the image and depresses a release button (not shown) halfway, the photometric unit 1 that receives light from the penta roof prism 8
0 starts photometry and outputs photometry data to the microcomputer 15. The microcomputer 15 performs an exposure calculation based on the photometric data and information obtained from the objective lens 1 (for example, an open aperture value and a maximum aperture value) to determine an aperture value and a shutter speed.

When the release button is half-pressed, the focus detecting unit 12 measures the shift of the image forming position by the photographing lens unit 11 and outputs it to the microcomputer 15 as in the photometric unit 10. The microcomputer 15 determines the photographing lens unit 11 based on the measurement data and the information obtained from the objective lens 1.
The drive amount of the objective lens 1 is determined so that the focus of the object lens is adjusted to the object. Then, the objective lens driving unit 13 is connected to the microcomputer 15
Then, the objective lens 1 is driven by the above-described drive amount in response to the output.

Then, when the photographer further presses the release button, the angular velocity sensor 14 starts detecting shake vibration. Based on the detected data, the microcomputer 15 drives the first correction optical unit 3 to start the image blur correction in the yaw direction, and drives the second correction optical unit 4 to start the image blur correction in the pitch direction. Next, the diaphragm 2 is connected to the microcomputer 1
The light amount is narrowed down to the aperture value determined at 5. Then, the movable mirror 5 rotates upward about the edge located at the top, and the light transmitted through the photographing lens unit 11 is transmitted to the shutter 6.
Will be reachable. After the rotation of the movable mirror 5, the shutter 6 is opened and closed at the shutter speed determined by the microcomputer 13, and a latent image of the subject is formed on the film 7 surface.

FIG. 2 is a schematic structural view of the binoculars.
The binoculars have left and right optical systems, and the left optical system is composed of an objective lens 17a, an eyepiece 18a, a prism unit 19a, a first correction optical unit 20a, and a second correction optical unit 21a. Objective lens 17b, eyepiece 1
8b, a prism section 19b, a first correction optical section 20b, and a second correction optical section 21b.

In both the left and right optical systems, the objective lens, the first correction optical unit, the second correction optical unit, the prism unit, and the eyepiece are linearly arranged in this order, and the light beam incident on the objective lens is the first correction optical unit. After passing through the second correction optical section and the prism section, they are arranged so as to reach the eyepiece.

An angular velocity sensor 22 is provided between the left and right optical systems. The angular velocity sensor 22 detects shake vibration of the binoculars based on the angular velocity.

In the binoculars having the above-described configuration, the luminous flux passing through the objective lenses 17a and 17b is based on the data of the shake detected by the angular velocity sensor 22, and the first correction optical units 20a and 20b and the second correction optical unit. 21a
The blur is corrected in the prism portion 21b and the prism portion 19a
9b. The prism portions 19a and 19b are formed of two right-angle prisms, and the observer can use the eyepieces 18a and 19b.
The incident light flux is inverted in the vertical and horizontal directions so that an erect image of the object to be observed can be seen through 18b. Then, the inverted light flux reaches the eyepieces 18a and 18b.

The first correction optical units 20a and 20b and the second correction optical units 21a and 21b used for the above-mentioned binoculars are the first correction optical unit 3 and the second correction optical unit 4 used for the single-lens reflex camera. It has the same configuration and function. In addition, the arrangement directions of the first correction optical unit and the second correction optical unit used in the single-lens reflex camera and the binoculars are different from each other only by 90 degrees, and the configurations and functions are common.

Next, the configuration and function of the correction optical unit used in the single-lens reflex camera and the binoculars will be described. A description will be given by taking the one correction optical unit 3 as an example.

FIG. 3 is a block diagram showing the configuration of the first correction optical unit 3.

The low-pass filter 23 is used to output high-frequency noise components other than the angular velocity signal (for example, the dark noise output of the angular velocity sensor 14 and the inside of the angular velocity sensor 14). Signal leakage component), and the generation of aliasing noise when the angular velocity signal is converted from analog to digital. The high-pass filter unit 24 is the angular velocity sensor unit 1
4 to remove DC drift and offset from the output signal from Note that a band-pass filter may be provided instead of the high-pass filter unit 24 and the low-pass filter unit 23.

The analog-to-digital converter 25 converts the angular velocity signal from an analog signal to a digital signal.

The level setting section 26 includes the angular velocity sensor 14
And the difference in sensitivity of the drive unit 29 described later is adjusted to match the signal level. When the release button is pressed all the way, the adjusted correction speed control signal is output from the level setting unit 26.

The driving section 29 receives the corrected speed control signal output from the level setting section 26 and applies a voltage (hereinafter, referred to as an input signal voltage) to a voice coil motor section 30 (indicated as a VCM section in FIG. 2). Is applied. The voice coil motor unit 30 drives the correction lens 31 according to the magnitude of the voltage, and the driven correction lens 31
The optical axis 1 is decentered to cancel the image blur on the film surface caused by the camera vibration.

Then, as will be described later, the speed detecting section 34 detects the driving speed of the correction lens 31 by the speed detecting coil 39, and performs the PID section 28 which performs proportional compensation, integral compensation and differential compensation.
And outputs a signal of the drive speed (hereinafter, referred to as a corrected speed signal) to a subtraction unit 27 provided before the control unit. In the subtraction unit 27,
Feedback control is performed by subtracting the corrected speed signal from the corrected speed control signal output from the level setting unit 26. Further, the PID of the output signal from the subtractor 27 is
Each operation of proportional compensation, integral compensation, and differential compensation is performed by the unit 28, and the delay transmission characteristic from the drive unit 29 to the correction lens 31 is compensated by differential compensation. PID part 2 above
8, the control performance of the drive unit 29 with respect to the correction speed control signal is improved.

Next, the configuration and operation of the voice coil motor unit 30 will be described in detail with reference to FIG. The voice coil motor unit 30 includes a lens holding frame 33, a pair of tension springs 34, an armature coil 35, a bobbin 36, a field magnet 37, and a yoke 38.

The lens holding frame 33 has a donut shape having a hollow center. The hollow portion has a shape and a size which hold the peripheral portion of the correction lens 31 and just fit the correction lens 31. The extension spring 34 is connected to the lens holding frame 33.
The end is fixed to the side surface of the lens barrel and the wall surface of the lens barrel. The tension spring 34 is provided at a position where the optical axis of the correction lens 31 and the optical axis of the objective lens 1 coincide with each other so that the correction lens 31 is stabilized. The bobbin 36 is a hollow cylinder inside, and is attached to the lower part of the lens holding frame 33.
The yoke 38 has a protrusion at the center, and arms on the both sides are provided at the same height as the protrusion, so that the yoke 38 is shaped like a “mountain”. The central projection is inserted into the hollow portion of the bobbin 36, and field magnets 37 are respectively installed at the tips of both arms. The field magnet 37 is installed with the N pole facing the bobbin 36 and keeping a distance from the bobbin 36. Armature coil 35
Is the bobbin 3 between the projection of the field magnet 37 and the yoke 38.
6 and both ends thereof are connected to the drive unit 29. In addition, in the bobbin 36, the armature coil 3
The speed detecting unit 3 is provided below the portion where the wire 5 is wound.
2 is wound around a speed detection coil 39. The armature coil 35 and the speed detection coil 39 are not in contact.

The operation of the voice coil motor unit 30 having the above configuration will be described below. First, the field magnet 37
Are oriented in the direction of the protrusion of the yoke 38, magnetic flux is applied to the armature coil 35 and the speed detection coil 39 from the field magnet 37 toward the direction of the protrusion of the yoke 38. Therefore, the drive unit 29 sends the armature coil 3
5, a bobbin 36 and a lens holding frame 33 joined to the bobbin 36 are applied according to Fleming's left-hand rule.
And the correction lens 31 are moved up and down, whereby the optical axis position of the correction lens 31 is shifted, the optical axis of the photographing lens unit 11 is decentered, and the image blur on the film surface is corrected. According to Fleming's right-hand rule, a current corresponding to the driving amount of the bobbin 36 is applied to the speed detecting coil 39, and the speed detecting unit 32 detects the driving speed of the correction lens 31.

Since the tension spring 34 is attached to the side surface of the lens holding frame 33, the lens holding frame 33 and the correction lens 31 return to their original positions after being driven (the lens holding frame 33 and the correction lens 31). Localization of the lens 31). Therefore, the drive start position of the correction lens 31 is kept constant, and the drive amount of the correction lens 31 may be speed-controlled always based on the position, so that sufficient correction control performance can be obtained.

In the above case, the output displacement of the correction lens 31 is x
And the input signal voltage as V, the voice coil motor unit 3
Transfer function G1 from 0 to correction lens 31 (= x / V)
Is represented by the following equation.

[0043]

(Equation 1)

(V; input signal voltage applied to armature coil 35; output displacement of correction lens 31; Laplace operator m; load mass of voice coil motor unit L; inductance of armature coil 35; Electric resistance μ of armature coil 35; Viscous friction coefficient of load of voice coil motor section B; Magnetic flux density in armature coil 35 by field magnet 37 l; Length of armature coil 35 k; Spring of extension spring 34 Constant) As can be seen from the above equation, G1 does not have a factor of 1 / S and shows localization. G1 gain by the above equation | G1 |
And the frequency characteristics of the phase angle are as shown in FIG. 5 (f indicates the input signal frequency).

A tension spring 34 is attached to the correction lens 31.
Is not provided, the transfer function G2 (x / V) is as follows, and has a factor of 1 / S, and shows unlocalization. FIG. 6 shows the frequency characteristics of the gain | G2 | of G2 and the phase angle at that time.

[0046]

(Equation 2)

According to the equation of G1, the transfer characteristic of the correction lens 31 in the DC operation (S = 0) is as follows.

[0048]

(Equation 3)

## EQU5 ## When the voice coil motor unit 30 having such transfer characteristics is used in the loop of the feedback control by the subtraction unit 27, the DC component of the output of the subtraction unit 27 is zero, and the DC component of the input signal voltage V is also zero. , The output displacement x of the correction lens 31 is also x = G1
・ V = 0. Therefore, the correction lens 31 in the DC operation
Is always zero, indicating that the correction lens 31 is held at a fixed position when no voltage is applied to the voice coil motor unit 30.

When the loop gain of the feedback control is infinite or the output of the subtraction unit 27 has an offset, a DC voltage is applied to the voice coil motor unit 30, but the PID unit 28 and the drive unit 29 The loop gain can be sufficiently reduced by giving the high-pass filter characteristic to the. As a result, the output displacement x of the correction lens 31 can be made substantially equal to that when the output displacement x is zero, and the correction lens 31 can be held at a fixed position.

In order to hold the correction lens at a fixed position, an electromagnet may be used instead of the tension spring, and the correction lens may be held using a repulsive force or an attractive force of the electromagnet.

[0052]

According to the present invention, there is provided a shake correcting apparatus which can control the speed of the correcting lens so that the manufacturing cost can be reduced and the offset of the entire position of the shake preventing apparatus can be controlled. Can be provided.

[0053]

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a single-lens reflex camera.

FIG. 2 is a schematic configuration diagram of binoculars.

FIG. 3 is a schematic block diagram of a first correction optical unit 3;

FIG. 4 is a front view of the voice coil motor unit 30.

FIG. 5 is a graph showing frequency characteristics of gain | G1 | of a transfer function G1 and a phase angle.

FIG. 6 is a graph showing frequency characteristics of gain | G2 | of a transfer function G2 and a phase angle.

[Explanation of symbols]

1; objective lens; 2; stop; 3; first correction optical unit; 4;
Second correction optical unit, 5; movable mirror, 6; shutter,
7; film setting unit; 8; penta roof prism; 9; eyepiece; 10; photometric unit; 11; photographing lens unit;
Focal length measuring unit, 13; photographing lens driving unit, 14; angular velocity sensor, 15; microcomputer, 17a / 17b; objective lens, 18a / 18b; eyepiece, 19a / 19b;
Prism section, 20a / 20b; first correction optical section, 21a
21b: second correction optical unit, 22: angular velocity sensor, 3
0: voice coil motor section, 31: correction lens, 3
3; lens holding frame, 34; tension spring, 35; armature coil, 36; bobbin, 37; field magnet, 38;
39; speed detection coil

Claims (10)

[Claims] 1. A blur correction device for an optical device including an optical element, comprising: a correction optical system capable of decentering an optical axis of the optical element; speed detecting means for detecting a speed of shake vibration; A blur correction device comprising: a driving unit that controls the speed of a correction optical system based on an output to drive the correction optical system; and a regulating unit that imparts localization to the correction optical system. 2. A blur correction device for an optical device including an optical element, comprising: a correction optical system capable of decentering an optical axis of the optical element; an angular velocity detection unit configured to detect an angular velocity of a shake vibration; Driving means for driving the correction optical system on the plane perpendicular to the optical axis; control means for controlling the speed of the driving means based on the speed detected by the angular velocity detecting means; and regulating means for imparting localization to the correction optical system. A blur correction device comprising: 3. The shake correction apparatus according to claim 1, wherein the shake correction apparatus further performs feedback control in a driving unit. 4. The camera shake correction apparatus according to claim 1, wherein the camera shake correction apparatus further includes a filter section for removing a frequency unnecessary for driving a correction optical system from an output of the speed detection means. apparatus. 5. The blur correction device according to claim 4, wherein the filter unit comprises a combination of a low-pass filter and a high-pass filter, or a band-pass filter. 6. The apparatus according to claim 1, wherein the driving unit is a voice coil motor. 7. The camera shake correction apparatus according to claim 1, wherein the camera shake correction apparatus further includes detection means for detecting a drive speed of the drive means. 8. The regulating member according to claim 1, wherein the regulating member is a pair of urging members for urging the correction optical system in directions perpendicular to the optical axis and in directions opposite to each other. 2. The blur correction device according to 2. 9. The blur correction device according to claim 2, wherein the regulating member returns the correction optical system to a predetermined position when there is no output from the driving unit. 10. An optical apparatus comprising the shake correction device according to claim 1. Description: