JP2008076485A - Lens barrel and imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens barrel that is small and rigid and can easily be incorporated and to provide a small imaging apparatus. <P>SOLUTION: The box-shaped lens barrel includes: an imaging optical system having two lens groups held in lens frames; and two drive shafts for supporting the respective lens frames so that they are movable relative to each other in the direction of an optical axis. In the lens barrel, openings are made in opposite walls of the lens barrel, which are orthogonal to a plane including the two drive shafts so as to be displaced from each other in the direction of the optical axis. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lens barrel and an imaging device.

  Conventionally, the lens is driven in the optical axis direction by utilizing the engagement between the pin fixed to the lens frame (moving frame) of the lens and the cam slot formed in the plurality of cylindrical members fitted in a telescopic manner. It was.

  However, in such a cam mechanism, there is a limit in processing and assembling even when trying to downsize parts such as a cylindrical member in which a cam slot is formed and a pin engaged therewith. There was a problem that the miniaturization of the mechanism could not keep up with the miniaturization of the optical system.

  In addition, the cam mechanism is provided with a tilt regulating mechanism that prevents each lens moving forward and backward in the optical axis direction from tilting with respect to the optical axis. However, the moving frame that holds the lens rotates around the optical axis. In order to move forward and backward while trying to reduce the size of a plurality of moving frames while avoiding their mutual interference, the span of the tilt regulating mechanism cannot be made long, and as a result, it is difficult to prevent the lens from tilting. It was.

Further, in the conventional cam mechanism, since each lens is housed inside the cylindrical member, it is difficult to align the optical system after assembly.
Therefore, a rod-shaped drive shaft provided with a spiral screw on the outer peripheral surface is arranged in parallel to the optical axis of the lens, and a screw that engages with the screw of the drive shaft is provided on the lens frame to rotate the drive shaft. Thus, the lens is moved in the optical axis direction. In this case, it is necessary to prevent tilting and displacement of the optical axis. For this purpose, a guide shaft parallel to the optical axis of the lens is provided, and a through hole through which the guide shaft passes is provided in the lens frame. It is common to support the movably. In this configuration, there is no restriction on the shape of the lens barrel, and a drive unit for rotating the drive shaft can be arranged in the lens barrel together with the drive shaft and the guide shaft, so that the overall size can be easily suppressed. Become.

  In recent years, in addition to adopting such a configuration, by adopting a bending optical system that bends the optical axis of the imaging optical system with a mirror or prism, the camera can also be thinned (downsized in the front-rear direction). (For example, see Patent Document 1).

In addition, a method of driving the movable lens in the optical axis direction using a linear drive mechanism using an electromechanical element such as a piezoelectric element is also performed. For example, in Patent Document 2, a flat plate-like moving body connected to two lens groups is arranged with its position shifted from each other in a direction orthogonal to the optical axis direction, and each is driven by using a linear drive mechanism. A lens driving mechanism that facilitates access to each lens is disclosed.
JP 2005-352236 A JP-A-11-95082

  However, in the configuration of Patent Document 1, since there is a large opening for assembling a lens in the lens barrel, it is necessary to increase the thickness of the lens barrel in order to maintain rigidity. Therefore, it has become an obstacle to reducing the size and weight.

  Since the lens driving mechanism disclosed in Patent Document 2 is configured to assemble a lens on a fixed substrate, assembly is easy. However, since the rigidity cannot be sufficiently increased only by the substrate, it cannot be applied to a high-magnification zoom lens or a bending optical system that requires high accuracy.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a lens barrel and a small imaging device that are small and have high rigidity and are easy to incorporate.

1.
An imaging optical system including two lens groups held by a ball frame;
Two drive shafts that support the respective ball frames so as to be relatively movable in the optical axis direction;
In a box-shaped lens barrel with
A lens barrel characterized in that openings are provided on the opposing wall surfaces of the lens barrel perpendicular to a plane including two drive shafts, with the positions being shifted in the optical axis direction.

2.
2. The two drive shafts are disposed on the same wall surface side of the lens barrel and are shifted from each other in the optical axis direction of the two lens groups and in a direction perpendicular to the optical axis. Lens barrel.

3.
The lens barrel according to 1 or 2, wherein the two drive shafts are driven in a direction of an optical axis by a linear actuator.

4).
A pressing plate connected to the lens frame and in contact with the two drive shafts inserted into the contact portion of the lens frame;
A spring member that urges the pressing plate in a direction in which the pressing plate is pressed against the two drive shafts,
4. The lens barrel according to claim 3, wherein the spring member is detachably arranged from each opening side.

5.
The imaging optical system includes a reflective element that reflects light closer to the subject side than the two lens groups,
The optical axis of the imaging optical system is bent by a reflecting element, and the plane formed by the incident optical axis of the imaging optical system and the optical axes of the two lens groups is substantially parallel to the plane including the two drive axes. 5. The lens barrel according to any one of 1 to 4, wherein:

6).
6. The lens barrel according to any one of claims 1 to 5, wherein ranges in which the two lens groups held by the lens frame move in the optical axis direction at the time of imaging overlap each other.

7).
An image pickup apparatus comprising the lens barrel according to any one of 1 to 6.

  According to the present invention, the driving means is arranged on the same surface side of the lens barrel, the optical axis direction and the direction orthogonal to the optical axis direction are shifted from each other, and the driving means of the lens barrel is arranged. Since the openings are provided on the two surfaces orthogonal to the surface in accordance with the position in the optical axis direction of the driving means closer to the surface, the lens barrel having a small size and high rigidity and easy to incorporate, and a small imaging device Can provide.

  Hereinafter, the present invention will be described in detail with reference to embodiments, but the present invention is not limited thereto.

  FIG. 1 is an external view showing an example of a camera 100 provided with a lens barrel 1 according to the present invention. FIG. 1 is a perspective view of the front surface of the camera 100.

  In FIG. 1, 1 indicated by a dotted line is the lens barrel described in the embodiment of the present invention, and represents a state in which the lens barrel 1 is incorporated in the camera body 102. 161 is a release button, and 162 is a power switch. The camera 100 is activated in conjunction with the power switch 162. When the release button 161 is pushed in one step, a shooting preparation operation of the camera 100, that is, a focusing operation and a photometric operation are performed.

  FIG. 2 is an external perspective view for explaining the opening of the lens barrel 1 having the variable magnification optical system according to the embodiment of the present invention, and FIG. 3 is a cross-sectional view showing the lens barrel 1 in a wide state. is there.

  2A is an external perspective view of the lens barrel 1, and FIG. 2B is an external perspective view of the lens barrel 1 as viewed from the surface opposite to FIG. 2A. In the following description, directions and directions will be indicated by appropriately using the XYZ three-dimensional orthogonal coordinate system shown in FIGS.

  The internal configuration of the lens barrel 1 shown in FIG. 2 will be described with reference to FIG. FIG. 3B is a front view of the lens barrel 1 of FIG. 1 viewed from the Z direction. 3A is a cross-sectional view as seen from a cross-section CC in FIG. 3B, FIG. 3C is a cross-sectional view as seen from a cross-section DD in FIG. 3B, and FIG. ) Is a cross-sectional view seen from the cross-section AA of FIG. 3B, and FIG. 3E is a cross-sectional view seen from the cross-section BB of FIG.

  In FIG. 3, 10 is a first movable lens group, 20 is a second movable lens group, 70 is a first fixed lens, 71 is a prism, and 72 is a second fixed lens, which are fixed to the two movable lens groups. An imaging optical system is formed by the optical parts. The light beam incident from the first fixed lens 70 is bent in the Y-axis negative direction by the prism 71, and is imaged on the imaging element 8 by the first movable lens group 10, the second movable lens group 20, and the second fixed lens 72. To form an image. An infrared filter (not shown) or an optical filter in which an infrared cut filter and an optical low-pass filter are stacked is disposed in front of the imaging surface of the imaging element 8. An image sensor substrate 9 on which an image sensor 8 and a circuit for driving the image sensor 8 are mounted is fixed to the fixed frame 4.

  In the present embodiment, the optical axis L1 from the first fixed lens 70 until it is bent by the prism 71 is the Z-axis direction, and the optical axis L2 from the time it is bent by the prism 71 to the image formation on the image sensor 8 is Y Axial direction. The prism 71 is a reflective element of the present invention. Hereinafter, regarding the moving direction of the first movable lens group 10 and the second movable lens group 20, the Y-axis positive direction is referred to as the objective side, and the Y-axis negative direction is referred to as the image plane side.

  In the embodiment of the present invention, a description will be given of a photographing optical system using a bending optical system suitable for miniaturization as an optical device, but the present invention is not limited to a photographing optical system using a bending optical system. . An example in which a prism is used as a reflective element will be described, but the invention is not limited to a prism, and a vapor deposition mirror or the like may be used.

  As shown in FIG. 3A, the rod 40 and the rod 41 are arranged with their positions shifted in the direction of the optical axis L2, that is, the Z-axis direction that is a direction orthogonal to the Y-axis direction and the optical axis L2. The rod 40 and the rod 41 are attached to the surface 4d side of the fixed frame shown in FIG. The rod 40 and the rod 41 are drive shafts of the present invention.

  2A, the first opening 2 is formed on the surface 4b of the fixed frame close to the rod 40, and the surface 4c of the fixed frame close to the rod 41 as shown in FIG. Two openings 3 are provided respectively. The surface 4b of the fixed frame and the surface 4c of the fixed frame are surfaces orthogonal to the surface 4d of the fixed frame. The first opening 2 and the second opening 3 are provided on the surface 4b of the fixed frame and the surface 4c of the fixed frame with their positions shifted in the optical axis L2 direction. The first opening 2 and the second opening 3 are sized so that the first lens frame 11 and the second lens frame 21 can be attached to and detached from the driving means 5 and the driving means 6. By assembling, the assembling work of the lens barrel can be easily performed. In addition, it is possible to easily replace parts when a failure occurs.

  As described above, since the opening of a size that allows one ball frame to be attached / detached is provided at a position obliquely intersecting the surface 4b of the fixed frame and the surface 4c of the fixed frame, the opening of each surface can be reduced. The rigidity of the fixed frame 4 can be increased.

  Each opening is covered with a cover (not shown) attached to the fixed frame, so that no light enters.

  Next, assembly of the lens barrel 1 of the present invention will be described with reference to FIGS. FIG. 4 is a plan view when the first lens frame 11 is attached to the rod 40. FIG. 5 is an explanatory diagram for explaining a procedure for attaching the first lens frame 11 to the rod 40. FIG. 5 is a cross-sectional view taken along line EE shown in FIG. 4, and the cross-sectional view of FIG. 5G shows the state of FIG.

  The attachment of the first lens frame 11 to the rod 40 will be described in order with reference to FIG.

  5A shows a state in which a rod 40 and a piezoelectric element 42 not shown in FIG. 5A are attached to the fixed frame 4.

  Next, the first ball frame 11 is inserted from the first opening 2 as shown in FIG. 5B, and the contact portion 11a is engaged with the rod 40 as shown in FIG. One end of the pressing plate 23 is inserted into a hole provided in the first ball frame 11 as shown in FIG. 5D, and the other end is pressed by a biasing spring 48 as shown in FIG. The biasing spring 48 is a spring member of the present invention, and is easily assembled because it is provided on the first opening 2 side.

  FIG. 5F shows a state in which the biasing spring holding plate 61 is fitted into the first ball frame 11 and one end of the biasing spring 48 is fixed. In this state, the contact portion 11a of the first lens frame 11 is frictionally engaged with the rod 40 by the pressing plate 23 biased by the spring.

  FIG. 5G shows a state in which the guide 60 is inserted from an opening provided in the Y axis negative direction of the fixed frame 4. Since the guide 60 is a component common to the second lens frame 21, the guide 60 is assembled after the second lens frame 21 is attached to the rod 41. The second lens frame 21 is attached to the rod 41 in the same procedure as the first lens frame 11 through the second opening 3.

  As described above, the first ball frame 11 and the second ball frame 21 can be easily assembled. Since the opening necessary for assembly is provided on the surface 4b (front surface) and the surface 4c (back surface) of the fixed frame 4, the rigidity of the fixed frame 4 is higher than that in the case where the opening is provided on the same surface. can do.

  The structure of this embodiment is particularly effective in a photographing optical system using a bending optical system. In the present embodiment, the openings 4 are provided on the surfaces 4b and 4c of the fixed frame orthogonal to the optical axis L1, and the partial protrusions of the movable lens frame such as the drive unit are arranged on the respective opening sides. The inner surfaces of 4b and 4c can be provided inside these protrusions. In this way, the size of the lens barrel 1 in the direction perpendicular to the optical axis L1 (Z-axis direction) can be reduced while ensuring the thickness of the surfaces 4b and 4c so as not to impair the rigidity. This is particularly effective when the lens barrel 1 is mounted on a camera using a bending optical system that is required to be thin in the thickness direction (Z-axis direction).

  In the drive mechanism of the present invention described above, a piezoelectric element is used as a drive source. However, the present invention is not limited to this, and a linear motor or the like may be used.

  FIG. 6 shows zoom curves of the first movable lens group 10 and the second movable lens group 20 during zooming. The vertical direction of the drawing represents the focal length of the imaging optical system, with the upper side of the drawing being the wide side and the lower side of the drawing being the tele side. Further, the horizontal direction of the drawing represents the position on the optical axis of each optical system at each focal length. In the figure, O1 is the position of the first fixed lens 70, O2 is the position of the first movable lens group 10, O3 is the position of the second movable lens group 20, and O4 is the position of the second fixed lens 72. Each is shown.

  In the range in which the first movable lens group 10 and the second movable lens group 20 move in the direction of the optical axis L2, the portions indicated by Q in FIG. 6 overlap. By doing so, the moving distance in the direction of the optical axis L2 can be reduced, so that the length of the lens barrel 1 in the direction of the optical axis L2 (Y-axis direction) can be shortened. By doing so, it is possible to increase the magnification and reduce the manufacturing difficulty without increasing the length of the lens barrel 1 in the optical axis L2 direction, and it is possible to provide a small and inexpensive lens unit.

  In addition, the structure of this embodiment is particularly effective in an optical system in which the movable ranges of the movable groups overlap. When the movable range of the movable group overlaps, if the opening is provided only on one side, the opening for incorporating the two lens groups is connected, and the rigidity of the frame is extremely reduced. In addition, since the movable ranges of the movable groups overlap, it is difficult to provide reinforcing ribs or the like inside the fixed frame. By providing the openings obliquely as shown in the present embodiment, it is possible to provide a high-performance and small-sized lens unit capable of ensuring the rigidity of the frame and reducing the size.

  Next, the rod 40 that drives the first movable lens group 10 and the rod 41 that drives the second movable lens group 10 will be described. The rod 40 is driven by a piezoelectric element 42. Since the rod 41 is also driven by the piezoelectric element 43, the explanation of the operation principle will be made by taking the rod 40 as an example.

  Next, driving of the first lens frame 11 and the second lens frame 21 will be described.

  As shown in the cross-sectional view of FIG. 3A, one end of the piezoelectric elements 42 and 43 in the positive direction of the Y axis is bonded and fixed to the inner surface of the fixed frame 4. A through hole is formed in the fixed frame 4 as shown in FIG. 3A, and a rod 40 is slidably inserted into the through hole. One end of the rod 40 is bonded and fixed to the other end of the piezoelectric element 42. The piezoelectric element 42 is a kind of electromechanical conversion means formed by laminating a large number of piezoelectric plates. The rod 40 and rod 41 and the piezoelectric elements 42 and 43 are linear actuators of the present invention, and the rod 40 and rod 41 also serve as a drive shaft.

  The first movable lens group 10 is held by a first lens frame 11, and the first lens frame 11 is supported by a guide 60 and a rod 40. The second movable lens group 20 is held by a second lens frame 21, and the second lens frame 21 is supported by a guide 60 and a rod 41.

  The contact portion 11a of the first lens frame 11 is frictionally engaged with the rod 40 by a spring-biased pressing plate 23. That is, as shown in FIG. 3D, one end of the pressing plate 23 in the negative X-axis direction is locked to the contact portion 11a, and the other end is biased in the negative Z-axis direction by the biasing spring 48. . The pressing portion 23 thus spring-biased and the abutting portion 11a of the first ball frame 11 facing the rod 40 elastically sandwiches the rod 40. The biasing spring 48 is, for example, a coil spring, and one end of the biasing spring 48 is held on the first ball frame 11 by a biasing spring holding plate 61.

  When a fluctuating voltage represented by a sawtooth waveform as shown by a solid line in FIG. 7 is continuously applied to the piezoelectric element 42, the piezoelectric element 42 expands and contracts, and the rod 40 moves in the length direction accordingly. Vibrate. FIG. 8 is a graph showing the moving speed of the rod 40 at this time. In FIG. 8, the speed when the rod 40 moves in the negative Y-axis direction is positive.

  The piezoelectric element 42 expands relatively slowly with respect to the gently rising slope 51 of the voltage waveform shown by the solid line in FIG. 7, and the rod 40 moves slowly in the negative Y-axis direction. In addition, the piezoelectric element 42 rapidly contracts with respect to the sudden falling inclined portion 52 and returns to the initial length, and the rod 40 suddenly moves in the positive Y-axis direction. When a voltage is continuously applied so that the same waveform repeats, the rod 40 moves slowly in the Y-axis negative direction (velocity v1 in FIG. 8) and suddenly moves in the Y-axis positive direction (in FIG. 8). Velocity -v2) is repeated to vibrate.

Here, when the rod 40 moves slowly, the first lens frame 11 moves together with the rod 40, and when the rod 40 moves suddenly, the first lens frame 11 stops on the spot due to inertia (or The biasing spring 48 for biasing the pressing plate 23 (the frictional coupling force of the pressing plate 23 and the first ball frame 11 with respect to the rod 40) is adjusted so as to move by a smaller amount than the rod 40). . Therefore, the first lens frame 11 moves in the Y-axis negative direction relative to the fixed frame 4 while the rod 40 vibrates (the speed of the first lens frame 11 at this time is indicated by a broken line in FIG. 8). ). When the first lens frame 11 is moved in the B direction, a fluctuating voltage having a gradual falling slope 53 and a sudden rise slope 54 as shown by a broken line in FIG. 7 is continuously applied. do it.

  Since the amplitude of the rod 40 is very small, the amount of movement of the first lens frame 11 corresponding to the voltage of one pulse is very small. Therefore, the position of the lens group can be precisely controlled. The fixed frame 4 has a first pulse generator 215 (not shown in FIG. 3) for detecting the amount of movement of the first lens frame 11 and a first pulse generator 215 for detecting the amount of movement of the second lens frame 21. Two pulse generators 216 (not shown in FIG. 3) are provided to detect the amount and direction of movement.

  A configuration example of the first pulse generator 215 will be described.

  For example, an elongated magnet scale (not shown) extending in parallel with the rod 40 is provided on the upper surface of the first ball frame 11. This magnet scale is magnetized in a pattern in which S poles and N poles are alternately switched at a pitch of several tens of μm in the longitudinal direction. On the other hand, an MR sensor (not shown) is fixed to the inner surface of the fixed frame 4, and this MR sensor is pressed against the magnet scale by the elastic force of the leaf spring. Therefore, when the first lens frame 11 moves, the MR sensor slides on the magnet scale, and the MR sensor generates a two-phase signal. Therefore, the amount and direction of movement of the first lens frame 11 can be detected using this. The second pulse generator 216 can also detect the moving amount and moving direction of the second lens frame 21 with the same configuration.

  The fixed frame 4 is provided with a first photo interrupter 213 for detecting the initial position of the first lens frame 11 and a second photo interrupter 214 for detecting the initial position of the second lens frame 21. It has been. For example, when the first lens frame 11 reaches the initial position, a part of the first lens frame 11 blocks the light flux of the first photo interrupter 213 and generates a signal. The sensor is not limited to a photo interrupter, and a magnetic sensor, a mechanical switch, or the like can be used as long as the initial position can be detected.

  The rod 41 is provided on the back surface side (Z-axis negative direction) of the fixed frame 4 in FIG. 3, but the drive mechanism for the second movable lens group 21 is exactly the same as the drive mechanism for the first movable lens group 10. belongs to.

  FIG. 9 is a circuit block diagram of the camera 100 that functions as an imaging apparatus according to the present invention. In the figure, the same parts as those in FIGS.

  The camera control unit 107, which is a control means in the present embodiment, includes a CPU (Central Processing Unit) (not shown), a work memory, and the like, and reads a program stored in a storage unit (not shown) to a work memory (not shown). According to the program, each part of the camera 100 including the lens barrel 1 and the lens group of the lens barrel is centrally controlled.

  The camera control unit 107 receives inputs from a release button 161, a power switch 162, a zoom button 164, an operation button 165, and the like provided on the operation unit 160 to control the entire camera 100, and a power unit (not shown) Is used to supply power to each part of the camera.

  The camera control unit 107 manages a sequence related to shooting. The camera control unit 107 controls the imaging operation of the imaging element 8 via the CCD driving unit 106. In the present embodiment, the image sensor may be a solid-state image sensor such as a CMOS sensor or a CID sensor instead of the CCD. The image of the analog signal acquired by the image sensor 8 is converted to a digital signal after noise removal processing by the A / D conversion unit 121, and the digital signal of the image is sequentially output to the image processing unit 122.

  The image processing unit 122 has image processing functions such as gamma correction, contour correction, and image compression. These image processes are also performed by commands from the camera control unit 107. The camera control unit 107 performs image processing on the image output of the image sensor 8, temporarily records it in the image memory 123, and displays it on the image display unit 125. When the release button 161 is turned ON, the image output of the image sensor 8 is subjected to image processing, and then temporarily recorded in the image memory 123 and finally recorded in the memory card 25.

  Next, control of the lens barrel 1 will be described.

  The first drive voltage generator 211 and the second drive voltage generator 212 generate a variable voltage represented by the sawtooth waveform described with reference to FIG. 7 in response to a control signal from the camera controller 107. When the power switch 162 is turned ON, the camera control unit 107 sends a control signal for driving the first lens frame 11 and the second lens frame 21 in the negative Y-axis direction to return to the initial position with the first drive voltage generating unit 211. This is applied to the second drive voltage generator 212.

  The piezoelectric element 42 to which the variable voltage is applied from the first drive voltage generator 211 drives the rod 40 and moves the first lens frame 11 in the negative Y-axis direction. When the camera control unit 107 receives the detection signal of the first photo interrupter 213, the camera control unit 107 stops the signal generation of the first drive voltage generation unit 211. The same applies to the second drive voltage generator 212.

  Next, the camera control unit 107 moves the first lens frame 11 and the second lens frame 21 to target positions while counting pulses from the first pulse generation unit 215.

  At the time of shooting, the camera control unit 107 controls the piezoelectric element 42 via the first drive voltage generation unit 211 based on the focus information and exposure information obtained from the image output of the image sensor 8, and the shutter of the image sensor 8. Control the speed.

  Further, the camera control unit 107 displays a live view of the image captured by the image sensor 8 on the image display unit 127 according to the setting of the display button 127, and displays the image recorded in the image memory 123 as an after view. The image displayed on the unit 127 and recorded on the memory card 25 is displayed on the image display unit 127 as a reproduced image.

  As described above, according to the present invention, it is possible to provide a lens barrel and a small imaging device that are small and have high rigidity and are easy to incorporate.

It is an external view which shows an example of the camera 100 provided with the lens barrel 1 which concerns on this invention. It is an external appearance perspective view explaining the opening part of the lens barrel 1 which concerns on this invention. It is sectional drawing which shows the state at the time of wide of the lens barrel 1 which concerns on this invention. FIG. 6 is a plan view when the first lens frame 11 is attached to the rod 40. It is explanatory drawing explaining the attachment procedure to the rod 40 of the 1st ball frame 11. FIG. 4 is a diagram of zoom curves of a first movable lens group 10 and a second movable lens group 20. FIG. It is a graph of the voltage waveform which drives a piezoelectric element. It is a graph of the moving speed of a rod. 1 is a circuit block diagram of a camera 100 that functions as an imaging apparatus according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lens barrel 2 1st opening part 3 2nd opening part 4 Fixed frame 8 Imaging element 9 Imaging element board | substrate 10 1st movable lens group 11 1st lens frame 20 2nd movable lens group 21 2nd lens frame 11a, 21a Contact portion 23, 33 Press plate 40, 41 Rod 42, 43 Piezo element 48, 49 Biasing spring 60 Guide 61, 62 Biasing spring holding plate 70 First fixed lens 71 Prism 72 Second fixed lens L1, L2 optical path

Claims (7)

An imaging optical system including two lens groups held by a ball frame;
Two drive shafts that support the respective ball frames so as to be relatively movable in the optical axis direction;
In a box-shaped lens barrel with
A lens barrel characterized in that openings are provided on the opposing wall surfaces of the lens barrel perpendicular to a plane including two drive shafts, with the positions being shifted in the optical axis direction. 2. The two drive shafts are disposed on the same wall surface side of the lens barrel and are shifted from each other in the optical axis direction of the two lens groups and in a direction perpendicular to the optical axis. The lens barrel described in 1. The lens barrel according to claim 1, wherein the two drive shafts are driven in the optical axis direction by a linear actuator. A pressing plate connected to the lens frame and in contact with the two drive shafts inserted into the contact portion of the lens frame;
A spring member that urges the pressing plate in a direction in which the pressing plate is pressed against the two drive shafts,
The lens barrel according to claim 3, wherein the spring member is detachably disposed from each opening side. The imaging optical system includes a reflective element that reflects light closer to the subject side than the two lens groups,
The optical axis of the imaging optical system is bent by a reflecting element, and the plane formed by the incident optical axis of the imaging optical system and the optical axes of the two lens groups is substantially parallel to the plane including the two drive axes. The lens barrel according to any one of claims 1 to 4, wherein: 6. The lens barrel according to claim 1, wherein ranges in which the two lens groups held by the lens frame move in the optical axis direction at the time of imaging overlap each other. An imaging apparatus comprising the lens barrel according to claim 1.

Images