JP2004045566A - Lens device and imaging device provided with the same - Google Patents

Abstract

A conventional lens barrel in which a light-shielding line is formed on the inner surface of a lens barrel body has a complicated mold structure.
An apparatus body 1a, 1b, 5; a plurality of lens units L1 to L4 housed in the apparatus body; and an image plane side of an innermost periphery of the apparatus body that is closer to an object side first lens unit L1. A light beam blocking unit 1e that is provided so as to protrude toward the optical axis side, and that blocks a light beam that enters through the first lens unit and is reflected on the inner peripheral surface of the apparatus main body from traveling to the image plane side. The light-blocking portion is formed at the end of the member 1b constituting the lens barrel main body in the optical axis direction. Further, a surface 1g of the light-blocking portion on which the light reflected by the inner peripheral surface shines, A shape such as a slope projecting toward the first lens unit side from the side is provided.
[Selection] Figure 2

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a lens device used for an imaging device such as a video camera and a digital still camera.
[0002]
[Prior art]
2. Description of the Related Art As a zoom lens for a video camera, for example, there is a zoom lens composed of four lens groups of a fixed convex, a movable concave, a fixed convex, and a movable convex in order from the subject side.
[0003]
FIGS. 6A and 6B show a lens barrel structure of a general zoom lens having a four-group lens configuration. (B) shows a cross section taken along line AA in (A).
[0004]
The four lens groups 201a to 201d constituting the zoom lens are a fixed front lens 201a, a variator lens group 201b that performs a variable power operation by moving along the optical axis, a fixed afocal lens 201c, And a focusing lens group 201d that moves along the optical axis to maintain a focal plane during focusing and focus.
[0005]
The guide bars 203, 204a, and 204b are arranged parallel to the optical axis 205, and guide and stop the moving lens group. The DC motor 206 is a driving source for moving the variator lens group 201b.
[0006]
The front lens 201a is held by a front lens barrel 202, and the variator lens group 201b is held by a V-moving ring 211. The afocal lens 201c is held by the intermediate frame 215, and the focusing lens group 201d is held by the RR moving ring 214.
[0007]
The front lens barrel 202 is positioned and fixed to the rear lens barrel 216. The guide bars 203 are positioned and supported by the two lens barrels 202 and 216, and the guide screw shaft 208 is rotatably supported. The guide screw shaft 208 is driven to rotate by the rotation of the output shaft 206 a of the DC motor 206 being transmitted through a gear train 207.
[0008]
The V-moving ring 211 that holds the variator lens group 201b has a pressing spring 209 and a ball 210 that engages with a screw groove 208a formed in the guide screw shaft 208 by the force of the pressing spring 209. When the guide screw shaft 208 is rotationally driven by the 206, the guide screw shaft 208 moves forward and backward in the optical axis direction while being guided and regulated by the guide bar 203.
[0009]
Guide bars 204a and 204b are fitted and supported by the rear barrel 216 and the intermediate frame 215 positioned at the rear barrel 216. The RR moving ring 214 can move forward and backward in the optical axis direction while being guided and rotated by the guide bars 204a and 204b.
[0010]
The RR moving ring 214 that holds the focusing lens group 201d is formed with a sleeve portion that is slidably fitted to the guide bars 204a and 204b, and the rack 213 is integrated with the RR moving ring 214 in the optical axis direction. It is assembled so that it becomes.
[0011]
The stepping motor 212 rotationally drives a lead screw 212a formed integrally with the output shaft. A rack 213 assembled to the RR moving ring 214 is engaged with the lead screw 212a. When the lead screw 212a rotates, the RR moving ring 214 moves in the optical axis direction while being guided by the guide bars 204a and 204b. I do.
[0012]
Note that a stepping motor may be used as a drive source for the variator lens group, similarly to the drive source for the focusing lens group.
[0013]
The front lens barrel 202, the intermediate frame 215, and the rear lens barrel 216 form a lens barrel body that substantially accommodates a lens or the like.
[0014]
When the lens group holding frame is moved using such a stepping motor, the stepping motor is moved after detecting that the holding frame is located at one reference position in the optical axis direction using a photo interrupter or the like. The absolute position of the holding frame is detected by continuously counting the number of applied drive pulses.
[0015]
In recent years, as video cameras have been increasingly required to be miniaturized, miniaturization of lens barrels has been required.
[0016]
However, if the inner wall of the lens barrel is simply brought closer to the optical axis, light from the subject hits the inner surface of the lens barrel body, and the light reflected there passes through the lens group and forms an image on the imaging surface. This causes so-called harmful light that causes ghost and flare.
[0017]
Increasing the diameter (inner diameter) of the lens barrel body makes it difficult for light reflected on the inner surface of the lens barrel body to enter the lens, but it is not possible to reduce the size of the lens barrel.
[0018]
FIG. 7 shows a configuration proposed in Japanese Patent Application Laid-Open No. 7-27960 as a measure for preventing ghost and flare due to reflection on the inner surface of the lens barrel body while reducing the size of the lens barrel. .
[0019]
That is, a plurality of light-shielding lines 230 are formed on the inner surface of the lens barrel main body 231 to suppress the reflection of light 232 from the subject toward the imaging surface at the light-shielding line 230, thereby reducing the intensity of reflected light entering the imaging surface. Ghost and flare due to reflection are avoided.
[0020]
[Problems to be solved by the invention]
However, when such a light-shielding line is integrally formed on the inner wall of a plastic-molded lens barrel, the mold for the lens barrel must have an inner diameter slide structure, which complicates the structure of the mold and increases costs. Connect.
[0021]
Further, in practice, the filling rate of the plastic in the mold portion for molding the tip of the light-shielding line is likely to be deteriorated, and the tip of the molded light-shielding line is often rounded. In this case, ghosts and flares cannot be reliably avoided such that a light beam hitting the end of the rounded light-shielding line enters the imaging surface.
[0022]
[Means for Solving the Problems]
In order to solve the above problems, a lens device according to the present invention includes a device main body, a plurality of lens units housed in the device main body, and a first lens unit closest to an object in an inner periphery of the device main body. A light-blocking unit that is provided on the image surface side so as to protrude toward the optical axis, and blocks light rays that enter through the first lens unit and are reflected by the inner peripheral surface of the apparatus main body from traveling toward the image surface; A light blocking portion is formed at an optical axis direction end of a member constituting the lens barrel main body, and a light beam side of the light blocking portion that is reflected by the inner peripheral surface hits the inner peripheral surface. It has a shape such as a slope projecting toward the first lens unit side from the surface side.
[0023]
By forming the light blocking portion at the optical axis end of the member constituting the lens barrel main body in this manner, it is possible to simplify the mold structure when the member is molded with plastic. In addition, the surface of the light-blocking portion, on which the light beam reflected by the inner peripheral surface of the apparatus main body is applied, has a shape in which the optical axis side projects toward the first lens unit side from the inner peripheral surface side of the apparatus main body, that is, By making the light reflected on the peripheral surface not reflected on the optical axis side, it is possible to more reliably prevent the occurrence of ghosts and flares due to the internal reflected light compared to the case where a light shielding line is provided as in the past. Become.
[0024]
Furthermore, by making the surface of the light blocking portion, on which the light beam reflected by the inner peripheral surface of the apparatus main body falls, a granular surface such as a matte surface, the reflection action of the light blocking portion is weakened, and the reflected light at the light blocking portion is reduced. Ghosts and flares can be prevented from occurring.
[0025]
BEST MODE FOR CARRYING OUT THE INVENTION
1 and 2 show the configuration of a lens barrel according to an embodiment of the present invention. The lens barrel of the present embodiment is a lens barrel having a variable power optical system of a four-group configuration of convex, concave, convex, and convex purely from the object (subject) side. FIG. 1 is an exploded perspective view of the entire lens barrel, and FIG. 2 is a main sectional view thereof.
[0026]
In these figures, L1 is a first lens group, L2 is a second lens group that performs a zooming operation by moving in the optical axis direction, and L3 is a second lens group that moves in a plane orthogonal to the optical axis to perform an image blur correction operation. The third lens unit L4 is a fourth lens unit that performs a focusing operation by moving in the optical axis direction.
[0027]
1a is a front lens barrel that holds the first lens unit L1, 1b is a fixed lens barrel that is an intermediate member between the shift unit 3 and the front lens barrel 1a for fixing the first lens unit L1 at a predetermined position. It is.
[0028]
Reference numeral 2 denotes a second moving frame that holds the second lens unit L2, and reference numeral 3 denotes a shift unit that can move the third lens unit L3 in a plane orthogonal to the optical axis.
[0029]
Reference numeral 4 denotes a fourth moving frame for holding the fourth lens unit L4, and reference numeral 5 denotes a rear barrel to which an image pickup device such as a CCD is attached.
[0030]
The two guide bars 6 and 7 are positioned and fixed by the fixed lens barrel 1b and the rear lens barrel 5. The sleeve portion 2d provided on the second moving frame 2 is movably engaged with the guide bar 6 to be guided in the optical axis direction, and the U-groove portion 2e provided on the second moving frame 2 moves on the guide bar 7. The second movable frame 2 is prevented from rotating around the guide bar 6 as much as possible.
[0031]
The sleeve portion 4d provided on the fourth moving frame 4 is movably engaged with the guide bar 7 to be guided in the optical axis direction, and the U groove 4e provided on the fourth moving frame 4 is To movably engage with each other to prevent rotation of the fourth moving frame 4 around the guide bar 7.
[0032]
The shift unit 3 is positioned with respect to the fixed barrel 1b, and is sandwiched between the rear barrel 5 and the fixed barrel 1b.
[0033]
Reference numeral 9 denotes a light amount adjusting unit for changing the amount of light incident on the optical system, and is opened by moving the two aperture blades 9a shown in FIG. 2 perpendicularly to the optical axis by the driving force of an aperture motor 9b composed of a stepping motor. This is a so-called guillotine-type diaphragm that changes the caliber. In the light amount adjusting unit 9, a two-density type ND filter (not shown) can advance and retreat with respect to the optical path independently of the aperture blade 9a. The light amount adjusting unit 9 is fixed to the shift unit 3 from the front by screws (not shown).
[0034]
The rear barrel 5 is positioned in the fixed barrel 1b, and at the same time, is sandwiched and fixed from behind by three screws (not shown) while sandwiching the shift unit 3 as described above. The front lens barrel 1a, the fixed lens barrel 1b, and the rear lens barrel 5 constitute a lens barrel body (apparatus body).
[0035]
4a, 4b, 4c are focus drive units for moving the fourth lens unit L4 in the optical axis direction to perform a focusing operation, 4a is a coil, 4b is a drive magnet, 4c is a yoke for closing magnetic flux It is.
[0036]
When a current flows through the coil 4a, Lorentz force is generated due to repulsion of the lines of magnetic force generated in the magnet 4b and the coil 4a, and the fourth lens unit L4 is driven back and forth in the optical axis direction together with the fourth moving frame 4. The fourth moving frame 4 holds a sensor magnet (not shown) that is multipolarly magnetized in the optical axis direction.
[0037]
Then, an MR sensor 12 for reading a change in the line of magnetic force due to the movement of the sensor magnet is screwed and fixed to the rear barrel 5, whereby the position of the fourth moving frame 4 (the fourth lens group L4) is detected.
[0038]
Reference numeral 10 denotes a zoom motor including a stepping motor that moves the second lens unit L2 in the optical axis direction to perform a zooming operation. The front end of the output shaft of the zoom motor 10 is rotatably held by a bearing formed on the front side of a horizontally long U-shaped holding plate 10a, and the vicinity of the root of the output shaft is formed on the rear side of the holding plate 10a. It is rotatably held by the bearing part. The output shaft of the zoom motor 10 is a lead screw, which meshes with a rack 2 a attached to the second moving frame 2.
[0039]
For this reason, when the zoom motor 10 rotates, the second moving frame 2 is driven in the optical axis direction by the engagement between the lead screw and the rack 2a. The torsion coil spring 2b biases the second moving frame 2 and the guide bars 6 and 7, the second moving frame 2, the rack 2a, and the rack 2a and the lead screw, respectively, to prevent rattling therebetween. are doing.
[0040]
Numeral 11 denotes a zoom reset switch composed of a photo interrupter, which optically detects the movement of the light shielding portion 2c formed on the second moving frame 2, outputs an electric signal, and sends the electric signal to the CPU 132 as a control circuit to be described later. It is determined whether or not the frame 2 (the second lens group L2) is located at the reference position. The zoom reset switch 11 is fixed to the front lens barrel 1 with screws via a substrate.
[0041]
FIG. 5 shows an electrical configuration of a video camera (imaging device) equipped with the lens barrel of the present embodiment. In this figure, the components of the lens barrel described in FIGS. 1 and 2 are denoted by the same reference numerals as those figures, and description thereof will be omitted.
[0042]
Reference numeral 121 denotes a solid-state imaging device such as a CCD or CMOS sensor, and reference numeral 132 denotes a CPU that controls the camera. A camera signal processing circuit 128 performs predetermined amplification, gamma correction, and the like on the output of the solid-state imaging device 121. The contrast signal of the video signal that has undergone these predetermined processes passes through the AE gate 129 and the AF gate 130. That is, an optimum signal extraction range for exposure determination and focusing is set by this gate in the entire screen. The size of the gate may be variable or a plurality of gates may be provided.
[0043]
Reference numeral 131 denotes an AF signal processing circuit that processes an AF signal for AF (autofocus), and generates one or a plurality of outputs related to a high-frequency component of a video signal. 133 is a zoom switch operated by the photographer, and 134 is a zoom tracking memory. The zoom tracking memory 134 stores information on the focusing lens position to be set according to the subject distance and the position of the variator lens (second lens unit L2) at the time of zooming. Note that a memory in the CPU 132 may be used as the zoom tracking memory.
[0044]
For example, when the photographer operates the zoom switch 133, the CPU 132 maintains a predetermined positional relationship between the variator lens and the focusing lens (the fourth lens unit L4) calculated based on the information in the zoom tracking memory 134. In this way, the current position of the variator lens in the optical axis direction and the calculated position of the variator lens should be set, and the current position of the focus lens in the optical axis direction and the calculated position of the focus lens should be set to match each other. Next, the drive of the zoom motor 10 and the focus drive unit (coil 4a) is controlled.
[0045]
In the autofocus operation, the CPU 132 drives and controls the focus drive unit so that the output of the AF signal processing circuit 231 indicates a peak.
[0046]
Further, in order to obtain an appropriate exposure, the CPU 132 controls the drive of the aperture motor 9b based on the average value of the output of the Y signal that has passed through the AE gate 129 to control the aperture diameter.
[0047]
Here, although not shown in FIG. 5, an example of the configuration and operation of the shift unit 3 that enables the third lens unit L3 to move in a plane orthogonal to the optical axis will be described with reference to FIG.
[0048]
The third lens unit L3 is driven by independent drive units in the PITCH direction (vertical direction) and the YAW direction (horizontal direction) in order to correct image blur due to changes in the angle in the vertical direction and the horizontal direction of the camera. The position in the PITCH direction and the position in the YAW direction of the third lens unit L3 are respectively detected by the position detector, and the detected positions are calculated based on the output of a shake sensor that detects the shake in the PITCH direction and the YAW direction of the camera described later. The drive unit is controlled by the CPU 132 so as to match the drive position.
[0049]
Since the drive units and the position detectors in the PITCH direction and the YAW direction have the same structure and are arranged at an angle of 90 degrees around the optical axis, they have the same configuration. Only the PITCH direction driving unit and the position detector shown in FIG.
[0050]
In FIG. 2, reference numeral 3b denotes a shift base serving as a base of the shift unit 3, which is integrated with the lens barrel. Reference numeral 3d denotes a compression coil spring, which is formed of a phosphor bronze wire or the like so as not to be attracted to detection and drive magnets, which will be described later, disposed in the vicinity thereof.
[0051]
3a is a shift barrel that holds the third lens unit L3. The front end of the compression coil spring 3d fits into the V-shaped groove (not shown) provided in the shift barrel 3a, and is attached to the shift barrel 3a so as to be substantially coaxial with the optical axis of the third lens unit L3. I have.
[0052]
Reference numeral 31 denotes a ball sandwiched between the shift base 3b and the shift lens barrel 3a. Although only one ball is shown in the figure, three balls are arranged in a circumferential direction in a plane orthogonal to the optical axis. These balls 3l are formed of SUS304 (austenitic stainless steel) or the like so as not to be attracted by a driving magnet arranged in the vicinity thereof.
[0053]
Since the nominal diameters of the three balls 3l are the same, it is possible to hold and guide the shift while keeping the shift barrel 3 (the third lens unit L3) at a right angle to the optical axis.
[0054]
Reference numeral 3c denotes a sensor base serving as a rear-side fixing member, which is positioned by two positioning pins and is coupled to the shift base 3b by screws. The rear end of the compression coil spring 3d is fixed to the sensor base 3c so as to be substantially coaxial with the optical axis of the lens barrel. The compression coil spring 3d is compressed between the shift barrel 3a and the sensor base 3c, and urges the shift barrel 3a toward the ball 31 and the shift base 3b. Further, by applying lubricating oil having a certain degree of viscosity between the contact surfaces of the three balls 31 and the shift barrel 3a and the shift base 3b, the inertia force exceeding the urging force of the compression coil spring 3d is increased. Even when the ball 3l is put into the non-nipping state by acting on the ball 3a, it is possible to prevent the ball 3l from easily shifting.
[0055]
Next, the driving of the shift barrel 3a will be described. Reference numeral 3j denotes a driving magnet polarized in two poles in a radial direction with respect to the optical axis. Reference numeral 3k denotes a yoke for closing a magnetic flux on the front side of the driving magnet 3j in the optical axis direction. Reference numeral 3i denotes a shift barrel 3a fixed by bonding. The coil 3h is a yoke for closing the magnetic flux behind the driving magnet 3j in the optical axis direction. The yoke 3h is fixed to the shift base 3b by the magnetic force of the magnet 3j, and a space is formed between the driving magnet 3j and the yoke 3h for the coil 3i to move together with the shift barrel 3a. As well as a magnetic circuit. Therefore, when a current flows through the coil 3i, Lorentz force is generated in a direction substantially perpendicular to the boundary between the magnetizing of the driving magnet 3j and the magnetized boundary between the magnet 3j and the coil 3i. Then, the shift lens barrel 3a is moved. This drive unit is a so-called moving coil type drive unit.
[0056]
Since such drive units are provided as drive units in the PITCH and YAW directions, respectively, the shift barrel 3a can be driven in the PITCH and YAW directions, and the drive positions in the PITCH and YAW directions are independent. Control, the shift barrel 3a can be shifted to the entire region in the plane orthogonal to the optical axis.
[0057]
At this time, the shift barrel 3a is urged by the compression coil spring 3d while pinching the three balls 31 with respect to the shift base 3b. Therefore, the frictional force acting as a load when the shift barrel 3a is driven is small. Only the rolling friction of the ball 3l results. Since the frictional force there is extremely small, the shift barrel 3a can be driven by a very small amount.
[0058]
Next, detection of the position of the shift barrel 3a will be described. Reference numeral 3f denotes a detection magnet magnetized in two poles in a radial direction with respect to the optical axis, 3g denotes a yoke for closing the magnetic flux on the front side in the optical axis direction of the detection magnet 3f, and both are fixed to the shift barrel 3a. Have been.
[0059]
Reference numeral 3e denotes a Hall element for converting a magnetic flux density into an electric signal, which is positioned and fixed to the sensor base 3c. The above configuration constitutes a position detector.
[0060]
When the shift barrel 3a is driven in the PITCH direction and the YAW direction, the magnetic flux density detected by the Hall element 3e changes. Then, the CPU 132 can detect the position of the shift barrel 3a (the third lens unit L3) based on the electric signal from the Hall element 3e that changes in response to the change in the magnetic flux density.
[0061]
Next, the harmful light cutting structure provided in the fixed lens barrel 1b will be described with reference to FIGS.
[0062]
FIG. 3 is an exploded perspective view of the front lens barrel 1a and the fixed lens barrel 1b, and FIG. 4 is a sectional view of a lens barrel including them.
[0063]
The front lens barrel 1a holds the first lens unit L1 as described above. When attaching the front lens barrel 1a to the fixed lens barrel 1b, the screws 1c are fixed to screw lower holes 1d provided at three places in the circumferential direction of the fixed lens barrel 1b. Therefore, the inclination of the first lens unit L1 with respect to the image plane is determined at these three positions. Therefore, if the image plane that forms an image on the imaging surface of the image sensor 121 is tilted for some reason, a washer is laid in the three screw holes 1d, and then the screws are fixed to correct the tilt of the image plane. And good images can be obtained.
[0064]
Reference numeral 1e denotes a light beam blocking portion for cutting harmful light, which is formed above the front end of the fixed lens barrel 1b. Here, in FIG. 4, if there is no light beam blocking unit 1 e, light reflected by the inner peripheral surface of the lens barrel (the front lens barrel 1 a in FIG. 4) among the light rays 1 f incident from the subject side is on the image plane side. In the opposite direction, an image is formed on the image sensor 121, and ghost and flare occur.
[0065]
In the present embodiment, the light reflected from the inner peripheral surface of the front lens barrel 1a among the light rays 1f incident from the subject side is prevented from traveling to the image plane side by being received by the front face 1g of the light beam blocking unit 1e. are doing.
[0066]
Here, in the front surface 1g of the light beam blocking portion 1e, the portion on the optical axis side projects toward the first lens unit L1 side from the portion on the inner peripheral surface side of the fixed lens barrel 1b, ie, the inner periphery of the front lens barrel 1a. (Inclination angle 1h) (in other words, facing outward and forward in the lens barrel radial direction) so as to intersect with the surface at an angle smaller than 90 °. I have. Therefore, the light reflected on the inner peripheral surface of the front lens barrel 1a is not reflected toward the optical axis by the light beam blocking unit 1e.
[0067]
In addition, the front surface 1g of the light beam blocking portion 1e has a matte surface (granular surface). This is because the light hitting the front surface 1g of the light beam blocking portion 1e is reflected again by the inner peripheral surface of the front lens barrel 1a and the image surface side surface 1i of the first lens unit L1, and proceeds to the image pickup surface side. Is reached, the intensity is weakened by the scattering effect of the pear ground to prevent ghosts and flares from being imaged.
[0068]
In addition, such a satin finish may be performed only on the front surface 1g of the light beam blocking unit 1e, but may be performed on the entire light beam blocking unit 1e.
[0069]
As described above, the harmful light can be cut without providing a light-shielding line as shown in FIG. 7 by forming the light beam blocking portion 1e at the end in the optical axis direction of the fixed lens barrel 1b. When the light-shielding line as shown in FIG. 7 is provided, the structure of the mold is an inner slide structure, which complicates the structure of the mold and increases the cost of the mold. Can be solved.
[0070]
Further, in the present embodiment, the light blocking portion 1e is formed linearly only on the upper portion of the fixed lens barrel 1b, but may be provided on the entire circumferential direction of the fixed lens barrel 1b. In addition, the arc may be formed in a wider range including the upper part of the fixed lens barrel 1b, instead of the entire circumferential direction.
[0071]
Further, in the present embodiment, the case where the light blocking portion 1e is formed in the fixed lens barrel 1b has been described, but it may be provided on a part of the rear end of the front lens barrel 1a or on the entire circumference. Also in this case, the structure of the mold for plastic molding can be simplified, similarly to the case where it is provided on the fixed lens barrel 1b.
[0072]
The embodiment described above can be variously modified and improved within the scope described in the claims.
[0073]
Further, in the above embodiment, the lens barrel for a video camera has been described. However, the present invention can be applied to a lens barrel (lens device) for another imaging device such as a digital still camera.
[0074]
【The invention's effect】
As described above, according to the present invention, since the light blocking portion is formed at the optical axis direction end of the member constituting the lens barrel main body, the mold structure for plastically molding the member can be simplified. can do. In addition, since the surface of the light-blocking portion, on which the light beam reflected on the inner peripheral surface of the apparatus main body hits, has a shape that does not reflect the light beam on the optical axis side, it is more reliable than a conventional case where a light-shielding line is provided. In addition, it is possible to prevent ghosts and flares from occurring due to the internally reflected light.
[0075]
In addition, by making the surface of the light blocking unit, on which the light beam reflected by the inner peripheral surface of the device body falls, a granular surface, the intensity of the reflected light at the light blocking unit is reduced, and the reflected light at the light blocking unit is ghosted. And flare can be prevented.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a lens barrel according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of the lens barrel.
FIG. 3 is an exploded perspective view of a front lens barrel and a fixed lens barrel of the lens barrel.
FIG. 4 is a cross-sectional view of the lens barrel, illustrating an operation of a light shielding unit.
FIG. 5 is a configuration diagram of an electric circuit of a video camera including the lens barrel.
FIG. 6 is a sectional view of a conventional lens barrel for a video camera.
FIG. 7 is a cross-sectional view showing a light-shielding line structure of a conventional lens barrel.
[Explanation of symbols]
1a Front lens barrel 1b Fixed lens barrel 1e Light blocking unit 2 Second moving frame 3 Shift unit 4 Fourth moving frame 5 Rear lens barrel 6, 7 Guide bar 9 Light amount adjusting unit 10 Zoom motor 11 Zoom reset switch 12 MR sensor

Claims (4)

The device body,
A plurality of lens units housed in the device body;
The inner peripheral surface of the apparatus main body is provided so as to protrude toward the optical axis side on the image surface side of the innermost periphery of the apparatus main body than the first lens unit closest to the object side, enters through the first lens unit, and enters the first lens unit. Having a light-blocking unit that blocks light rays reflected at the image surface side,
The light beam blocking portion is formed at an optical axis direction end of a member constituting the apparatus main body, and a surface of the light beam blocking portion that is hit by a light beam reflected by the inner peripheral surface has a portion on the optical axis side. A lens device having a shape protruding toward the first lens unit side from a portion on the inner peripheral surface side. The lens device according to claim 1, wherein the light beam blocking portion is formed substantially entirely in a circumferential direction of the device main body. The lens device according to claim 1, wherein a surface on which the light beam reflected by the inner peripheral surface is a granular surface. An imaging apparatus for capturing a subject image through the lens device according to claim 1.

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