JP2018180345A - Lens barrel, optical apparatus and imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the deformation of a rotation member provided in a diaphragm and moving a light shielding member.SOLUTION: A lens barrel includes at least one movable lens 103 which can be moved in an optical axis direction. The lens barrel includes a light shielding member 109 which can be moved to adjust a light quantity, a moving member 29 which is moved in the optical axis direction, when the movable lens is moved, a base member 105 which supports the light shielding member, and a rotation member 107 which is supported to be rotatable around an optical axis by the base member and rotated to move the light shielding member. The rotation member includes an engagement part 115 which is engaged with the moving member and rotates the rotation member by the movement of the moving member and a deformation restriction part 116 which comes into contact with the base member, to restrict the deformation of the rotation member to a side away from the base member in the optical axis direction.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a lens barrel having a light amount adjustment mechanism that adjusts the amount of light as the lens moves.

  The lens barrel has a main stop mechanism in which the aperture diameter is electrically adjusted based on photometric results and user settings, and a sub-stop mechanism in which the open stop diameter is adjusted in conjunction with the zoom operation and the focus operation is there. The sub-diaphragm mechanism has a plurality of light blocking members supported so as to be movable (openable) by the base member, and a rotating member that opens and closes the plurality of light blocking members by rotating around the optical axis. Patent Document 1 discloses a lens barrel in which a cam follower is provided on a rotating member of a sub-diaphragm mechanism, and this cam follower is engaged with a cam provided on a fixed barrel. In this lens barrel, the sub diaphragm mechanism moves in the optical axis direction with respect to the fixed cylinder, and the cam follower moves along the cam, whereby the rotating member is rotated and the light blocking member is moved.

JP 2007-248770 A

  However, when a large external force such as an impact is applied to the lens barrel as described above, the cam follower of the rotating member may fall off the cam. In order to prevent the cam follower from falling off from the cam, there is also a configuration in which a cam follower and a cam for preventing falling off are added, but this leads to an increase in the size of the lens barrel. In addition, even if the cam follower does not come off from the cam, the whole of the rotating member is deformed, the connection of the rotating member with the light shielding member is released, and the light shielding member can not be opened or closed.

  The present invention provides a lens barrel capable of suppressing occurrence of a defect that a cam follower of a rotating member falls off a cam or disconnection between the rotating member and a light shielding member, and an optical apparatus provided with the lens barrel. Do.

  A lens barrel as one aspect of the present invention has at least one movable lens movable in the optical axis direction. The lens barrel includes a light blocking member that can move to adjust the light amount, a moving member that moves in the optical axis direction when the movable lens moves, a base member that supports the light blocking member, and a base member. It is supported rotatably around the optical axis, and has a rotating member that moves the light shielding member by rotating. The rotating member is engaged with the moving member and is engaged with the engaging portion that rotates the rotating member by the movement of the moving member, and the base is abutted against the base member to deform the rotating member away from the base member in the optical axis direction And a deformation limiting portion that restricts.

  The optical apparatus and the imaging apparatus provided with the lens barrel also constitute another aspect of the present invention.

  According to the present invention, it is possible to suppress the occurrence of the problem that the engagement between the engaging portion of the rotating member and the moving member and the connection between the rotating member and the light shielding member are disconnected.

BRIEF DESCRIPTION OF THE DRAWINGS Sectional drawing which shows the structure in the infinite point focusing state of the imaging device which is an Example of this invention. FIG. 2 is a cross-sectional view showing the configuration of the imaging device of the embodiment in the close-in-focus state. The disassembled perspective view of the aperture | diaphragm unit in an Example. FIG. 8 is a view for explaining the operation of the rotary member of the diaphragm unit in the embodiment. The expansion perspective view of the cam follower of the aperture | diaphragm unit in an Example. Sectional drawing of the aperture stop unit in an Example, and a movable lens group. The expanded view of the cam of the movable lens group in an Example.

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

  FIG. 1 shows the configuration of an interchangeable-lens type camera (image pickup apparatus) as an optical apparatus according to an embodiment of the present invention in an infinity in-focus condition. Further, FIG. 2 shows the configuration of the image pickup apparatus of the present embodiment in the close in-focus state. In these figures, the direction in which the lens optical axis AXL extends is taken as the Z direction (hereinafter referred to as the optical axis direction), which is a direction perpendicular to the lens optical axis AXL and parallel to the long side of the rectangular imaging surface of the imaging device 6 The direction is the X direction, and the direction parallel to the short side is the Y direction. The circumferential direction about the lens optical axis AXL is also referred to as the optical axis rotation direction, and all directions (including the X direction and the Y direction) orthogonal to the lens optical axis AXL are referred to as the radial direction.

  1 is a camera body. An interchangeable lens (optical apparatus) 2 is removably mounted on the camera body 1. First, the configuration of the camera 1 will be described.

  In the state shown in the figure, the main mirror 3 is disposed on the light path of the light flux from the interchangeable lens 2, reflects a part of the light flux, guides it to the finder optical system (7, 8), and transmits the remaining light flux.

  A sub mirror 4 is disposed behind the main mirror 3 (image plane), and reflects the light flux transmitted through the main mirror 3 to guide it to the focus detection unit 5. The main mirror 3 and the sub mirror 4 can be retracted from the optical path by a drive mechanism (not shown). The focus detection unit 5 performs focus detection (detection of the focus state of the interchangeable lens 2) by the phase difference detection method. A control unit (not shown) controls the autofocus (AF) of the interchangeable lens 2 according to the result of focus detection.

  An image sensor 6 is a CCD sensor or a CMOS sensor. On the light receiving surface (image plane) of the image sensor 6, an object image formed by the light flux from the interchangeable lens 2 is formed. The imaging device 6 photoelectrically converts an object image and outputs an imaging signal. An image processing unit (not shown) performs various processes on the imaging signal to generate image data. A display panel 9 displays an image corresponding to image data and various other information.

  The camera body 1 may be a mirrorless type that does not have the main mirror 3, the sub mirror 4 and the focus detection unit 5. In addition, the sub mirror 4 and the focus detection unit 5 may not be provided, and the AF may be performed by a phase difference detection method or a contrast detection method using a signal from the imaging device 6.

  The interchangeable lens 2 has a first lens unit 101, a second lens unit 102, an aperture unit AS as light amount adjusting means, a third lens unit 103 and a fourth lens unit 104 in order from the object side to the image side. An imaging optical system is configured by the first to fourth lens units 101 to 104 and the aperture unit AS, and is held by a lens barrel whose configuration will be described below.

  Reference numeral 105 denotes an iris base which is a base member of the iris unit AS, and numeral 106 denotes a main iris wind turbine which rotates around the optical axis to turn the main iris. Reference numeral 107 denotes a sub-aperture windmill as a rotating member that rotates (moves) the sub-aperture blade by rotating in a direction around the optical axis. The detailed configuration and operation of the aperture unit AS will be described later.

  The first lens unit 101, the second lens unit 102, the third lens unit 103, and the fourth lens unit 104 respectively include a first lens holding frame 111, a second lens holding frame 112, a third lens holding frame 113, and a fourth lens. It is held by a holding frame 114. The second lens unit 102 and the third lens unit 103 are movable lenses movable in the optical axis direction together with the second lens holding frame 112 and the third lens holding frame 113, respectively. The aperture unit AS is disposed between the second lens unit 102 and the third lens unit 103, and adjusts the amount of light incident on the camera body 1. A control substrate 109 mounted with a control circuit including the aperture unit AS and a lens microcomputer and the like is connected to each other by a flexible printed circuit (not shown).

  Reference numeral 20 denotes a guide cylinder, which is fixed to a tilt cover 34 of a TS mechanism unit described later. Reference numeral 21 denotes a cam ring, which is disposed on the outer periphery of the guide cylinder 20, and is rotatably supported in the direction around the optical axis at a fixed position in the optical axis direction. Reference numeral 23 denotes a fixed cylinder fixed to the guide cylinder 20. A hood attachment portion for attaching a hood, a filter, a cap, and the like is provided in the vicinity of the end of the fixed cylinder 23 on the subject side.

  An MF (manual focus) operation ring 24 is disposed on the outer periphery of the fixed barrel 23 and supported rotatably in the direction around the optical axis at a fixed position in the optical axis direction. The MF operation ring 24 is connected to the cam ring 21 via a key mechanism (not shown). When the MF operation ring 24 is rotated, the cam ring 21 is also rotated by the same amount. The position of the MF operation ring 24 in the rotational direction is detected by a sensor (not shown) and input to the control board 109.

  An adjustment base 26 is attached to the end of the guide cylinder 20 on the object side. A rotation ring 27 is rotatably held between the guide cylinder 20 and the adjustment base 26 in the direction around the optical axis with the first lens holding frame 111 and the guide cylinder 20 as an axis. When the rotation ring 27 is rotated, the first lens holding frame 111 is decentered on the surface in contact with the rotation ring 27 while moving in the optical axis direction. Thus, optical adjustment of the first lens unit 101 is performed. Reference numeral 28 denotes a front ring, which is an appearance part attached to the fixed barrel 23 after the optical adjustment of the first lens unit 101.

  The fourth lens unit 104 and the fourth lens holding frame 114 are fixed to the guide cylinder 20. The cam follower 40 screwed to the second lens holding frame 112 is engaged with a second cam groove formed on the inner surface of the cam ring 21. Therefore, when the cam ring 21 rotates and the second cam groove pushes the cam follower 40 in the optical axis direction, the second lens unit 102 and the second lens holding frame 112 move in the optical axis direction.

  Reference numeral 29 denotes a connecting ring as a moving member having a cylindrical shape. The connecting ring 29 is fixed to the third lens holding frame 113 near the end on the image side. A cam follower (not shown) engaged with the third cam groove of the cam ring 21 is fixed near the end of the connecting ring 29 on the subject side. Therefore, when the cam ring 21 rotates and the third cam groove pushes the cam follower in the optical axis direction, the connection ring 29, the third lens unit (movable lens) 103 and the third lens holding frame 113 move in the optical axis direction. Moving.

  With such a configuration, when the user rotates the MF operation ring 24, the second lens unit 102 and the third lens unit 103 move in the optical axis direction and change their intervals. Thereby, it is possible to obtain the in-focus state with respect to the subject from infinity (INF) to close proximity (MOD). In the infinity in-focus condition shown in FIG. 1, the second lens unit 102 and the third lens unit 103 are farthest apart, and in the in-focus condition shown in FIG. 2, the second lens unit 102 and the third lens unit 103 are closest. ing.

  Reference numeral 120 denotes an iris fixing screw for fixing the iris base 105, that is, the iris unit AS to the guide cylinder 20.

  The TS mechanism has a revolver unit 30, a shift unit 33, and a tilt unit 35. The revolver unit 30 has a function of rotating the whole of the lens barrel on the subject side of the revolver unit 30 in the direction around the optical axis. The revolving unit 30 is rotatably connected to a fixing unit 31 fixed to a mount 25 which is a connecting unit with the camera body 1 in the interchangeable lens 2. The shift unit 33 has a function of shifting the whole of the lens barrel closer to the subject than the shift unit 33 in parallel to the X direction and the Y optical axis. The shift unit 33 is connected to the revolving unit 30 so as to be parallel shiftable. The tilt unit 35 has a function of tilting the entire object side of the lens barrel with respect to the tilt unit 35 about an axis orthogonal to the lens optical axis AXL. The tilt cover 34 is fixed to the subject side of the tilt unit 35 and fixes the guide cylinder 20 as described above.

  In the camera system having the above configuration, the user operates the release button (not shown) provided on the camera body 1 in a state in which the imaging optical system is focused on the subject at an arbitrary distance by the MF operation. Exposure of the image sensor 6 and generation and recording of image data are performed. At this time, the user can obtain various photographing effects by setting the interchangeable lens 2 to any of the revolving state, the shifting state and the tilting state by using the TS mechanism.

  Next, the configuration of the aperture unit AS will be described in more detail with reference to FIG. Reference numeral 108 denotes a plurality of main aperture blades. Each main aperture blade 108 has blade pins 108 a on the object side and the image side. Reference numeral 105 a denotes a plurality of main aperture cams provided on the aperture base 105. Reference numeral 106 a denotes a plurality of main throttle holes formed in the main throttle wind turbine 106. The plurality of main aperture blades 108 are disposed between the aperture base 105 and the main aperture windmill 106, the respective image side blade pins 108a engage with the corresponding main aperture cams 105a, and the subject side blade pins 108a correspond. The main throttle hole 106a is inserted.

  Reference numeral 112 denotes a main diaphragm motor configured by a stepping motor, and reference numeral 113 denotes a diaphragm FPC, which energizes the main diaphragm motor 112 from the control substrate 109. Further, a photo interrupter (not shown) is mounted on the stop FPC 113, whereby the rotational position of the main stop wind turbine 106 is detected. An aperture cover 110 holds the main aperture motor 112 and the aperture FPC 113, and rotatably holds the main aperture windmill 106. A pinion gear 111 is fixed to the output shaft of the main throttle motor 112 and engages with a gear portion provided on a part of the outer peripheral portion of the main throttle wind turbine 106. When the main throttle motor 112 is driven and the main throttle wind turbine 106 is rotated via the pinion gear 111, the object side blade pins 108a of each of the plurality of main throttle blades 108 rotate with the main throttle wind turbine 106, and the image side blade pins 108a moves along the main throttle cam 105a. For this reason, the plurality of main diaphragm blades 108 pivot in the opening and closing direction, and increase or decrease the diameter of the main diaphragm opening formed by these.

  A blind sheet 114 is a component for making the main diaphragm motor 112 and the diaphragm FPC 113 invisible from the outside through the first and second lens units 101 and 102 of the interchangeable lens 2.

  Reference numeral 109 denotes a plurality of sub diaphragm blades (light shielding members). Each sub-aperture blade 109 has blade pins 109 a on the subject side and the image side. Reference numeral 107 a denotes a plurality of sub throttle cams provided on the sub throttle windmill 107. The plurality of sub-aperture blades 109 are disposed between the diaphragm base 105 and the sub-aperture windmill 107, each image-side blade pin 109a is engaged with the corresponding sub-diaphragm cam 107a, and the object-side blade pin 109a is a diaphragm base It is inserted into the corresponding hole among the holes (not shown) formed in plurality at 105.

  An arm portion 119 extends radially from a disk portion provided with a plurality of sub-throttling cams 107a in the sub-throttling wind turbine 107, and a cam follower 115 as an engaging portion is provided at the tip in the radial direction. It is provided. A hook 116 is provided as a deformation limiting portion provided in the vicinity of the cam follower 115 (the same phase in the rotational direction of the sub-aperture wind turbine 107) of the arm portion 119.

  FIG. 6 shows a cross section of the stop unit AS, the third lens unit 103, the third lens holding frame 113, and the connecting ring 29. Reference numeral 29a denotes a wind turbine rotating cam provided on the connection ring 29 and engaged by the cam follower 115. As described above, the aperture unit AS is fixed to the guide cylinder 20. On the other hand, the connection ring 29 moves in the optical axis direction together with the third lens holding frame 113 and the third lens unit 103 as the MF operation ring 24 rotates. The sub-aperture windmill 107 is rotated by the relative movement of the diaphragm unit AS and the coupling ring 29 in the optical axis direction and the cam follower 115 moving along the windmill rotational cam 29 a. When the sub-aperture windmill 107 rotates, each of the plurality of sub-aperture blades 109 centers the object-side blade pin 109a inserted in the hole of the diaphragm base 105 by the image-side blade pin 109a moving along the sub-aperture cam 107a. As in the opening and closing direction. As a result, the diameter of the sub-aperture opening formed by the plurality of sub-aperture blades 109 increases or decreases.

  FIG. 7 shows the wind turbine rotating cam 29a provided on the connection ring 29 developed in the circumferential direction. The windmill rotational cam 29a shown in the figure has a linear shape, but may have a non-linear shape. In the close focusing state, the cam follower 115 is positioned at the close position in the drawing. Further, in the infinity in-focus condition, the cam follower 115 is positioned at the infinity position in the figure. In the normal focusing operation, the cam follower 115 moves within a movable range (hereinafter referred to as an infinite distance-close movement range) between these infinity positions and the close positions. Reference numeral 29 b denotes an inlet, which serves as an inlet for introducing the cam follower 115 into the wind turbine rotary cam 29 a when the throttle unit AS is incorporated inside the connection ring 29. The introduction port 29b is connected from the end face on the object side of the connection ring 29 to a cam installation position outside the normal operation range (outside of the infinite distance position) in the wind turbine rotating cam 29a.

  FIG. 4 shows how the sub-aperture blade 109 opens and closes as the sub-aperture windmill 107 rotates. In the leftmost view, the sub-throttling wind turbine 107 is located at a cam incorporating rotational position in which the cam follower 115 is introduced from the introducing port 29 b described above to the cam incorporating position in the windmill rotational cam 29 a. Reference numeral 117 denotes an outer peripheral surface of the disk portion of the sub throttle windmill 107, which is fitted to an inner peripheral surface of a ring-shaped wind turbine holding portion 105d provided on the throttle base 105. Thus, the sub-aperture windmill 107 is rotatably held by the diaphragm base 105 in the direction around the optical axis.

  In the second diagram from the left, the sub-aperture windmill 107 is located at an infinite rotation position slightly rotated from the cam installation rotation position. At this time, the cam follower 115 is positioned at an infinite distance in the wind turbine rotation cam 29a. In the normal focusing operation, the sub-aperture windmill 107 rotates in an infinite distance-close rotation range from this infinity rotation position to a close rotation position described later.

  In the third view from the left, the sub-aperture windmill 107 is located at the closest rotation position further rotated from the infinity rotation position. At this time, the cam follower 115 is located at the close position in the wind turbine rotation cam 29a.

  In the rightmost view, the sub-aperture wind turbine 107 is further rotated from the near rotation position and located at the wind turbine built-in rotation position outside the infinite distance-close rotation range. The wind turbine built-in rotational position is a position where the sub throttle wind turbine 107 is built into the throttle base 105 (wind turbine holding portion 105 d).

  Reference numeral 105 b denotes pressing claws provided at three positions in the circumferential direction of the aperture base 105 at intervals of 120 °. Numeral 107b is a claw gate provided at three intervals in the circumferential direction of the auxiliary throttle wind turbine 107 at intervals of 120 °, and when the auxiliary throttle wind turbine 107 is incorporated into the throttle base 105 at the wind turbine installation rotational position, the holding claw 105b is a claw gate Go through 107b. After that, when the sub throttle windmill 107 is rotated within the infinite distance-close rotation range, the pressing claw portion 105b abuts the surface on the opposite side to the throttle base 105 in the vicinity of the outer periphery of the sub throttle windmill 107 It becomes a press which prevents falling off from the aperture | diaphragm base 105 of 107. By such a so-called bayonet structure, the sub throttle windmill 107 is supported by the throttle base 105, and the position in the optical axis direction is also determined.

  FIG. 5 shows the periphery of the cam follower 115 in an enlarged manner. Denoted at 118 is a deformation preventing rib as a projecting portion provided on the throttle base 105 so as to extend in the circumferential direction (the rotational direction of the sub throttle wind turbine 107). The deformation preventing rib 118, as shown in FIG. 6, enters between the hook 116 and the arm portion 119 of the sub throttle windmill 107 when the sub throttle windmill 107 is positioned within the infinite distance-close rotation range. The diaphragm base 105 has a hook gate portion 105 as a built-in gate portion for inserting the deformation preventing rib 118 between the hook 116 and the arm portion 119. As shown in FIG. 5, in the wind turbine built-in rotational position, the hook 116 can pass over the deformation preventing rib 118 to the opposite side (hereinafter referred to as the throttle base side) to the sub-throttling wind turbine 107 side (rotation member side). It is.

  The hook 116 is prevented from deformation when an external force such as an impact acting to move the sub throttle windmill 107 away from the diaphragm base 105 to the image side is applied to the interchangeable lens 2 when the sub throttle windmill 107 is within the infinite distance-close rotation range. The rib 118 abuts on the surface of the rib 118 opposite to the side of the sub throttle windmill 107. Therefore, it is possible to limit (prevent) the secondary throttle wind turbine 107 from being deformed or displaced to the side away from the throttle base 105.

  As described above, the hook 116 is located near the tip of the arm portion 119 extending from the disc portion of the sub-aperture windmill 107, that is, at a position farther from the lens optical axis AXL than the outer peripheral surface 117 of the disc portion of the sub-aperture windmill 107 It is provided near the cam follower 115. On the other hand, the disc portion of the sub-aperture windmill 107 is held down by three pressing claws 105b provided on the diaphragm base 105 at a position from the lens optical axis AXL substantially the same as the outer peripheral surface. However, for example, when the cam follower 115 receives an external force from the windmill rotary cam 29a of the coupling ring 29 at a position away from the lens optical axis AXL from the outer peripheral surface 117 of the disc portion The deformation or the like of the wind turbine 107 can not be suppressed.

  When the sub throttle windmill 107 is deformed by a predetermined amount or more, there is a possibility that the cam follower 115 may drop from the wind turbine rotation cam 29a or the blade pin 109a may drop from the sub throttle cam 107a. The hook 116 is in contact with the surface of the deformation preventing rib on the opposite side to the side of the sub throttle windmill 107 so that such deformation of the sub throttle windmill 107 does not occur.

  The hook 116 and the deformation preventing rib 118 can be provided within the range of the thickness of the diaphragm base 105 between the main diaphragm windmill 106 and the sub diaphragm windmill 107 in the optical axis direction, and inside the outer diameter of the diaphragm base 105 It can be provided. Therefore, the deformation of the sub throttle windmill 107 can be suppressed while keeping the throttle unit AS small.

  In the present embodiment, the hook 116 and the deformation preventing rib 118 are disposed so as to be separated by a predetermined amount in the optical axis direction in the state where the above deformation does not occur. It may be set according to the allowable deformation amount. For example, when the pressing claws 105b are provided on the aperture base 105 at an interval larger than 120 °, it is desirable that the distance between the hook 116 and the deformation preventing rib 118 be closer. Furthermore, the hook 116 and the deformation preventing rib 118 may be in contact with each other even in the state where the above-mentioned deformation does not occur.

  Further, in the present embodiment, the main throttle wind turbine 106 is driven by the throttle motor 112, but when it is rotated by a cam mechanism similar to the sub throttle wind turbine 107, the main throttle wind turbine is provided with a hook to prevent deformation in the throttle base Ribs may be provided.

  Furthermore, although the case where the hook 116 and the deformation preventing rib 118 are provided in the diaphragm unit AS in the lens barrel of the interchangeable lens 2 has been described in this embodiment, a lens mirror in the lens integrated imaging device has the same configuration. You may provide in the aperture unit in a pipe | tube.

  The embodiments described above are only representative examples, and various modifications and changes can be made to the embodiments when the present invention is implemented.

DESCRIPTION OF SYMBOLS 2 Interchangeable lens 29 Connection ring 29a Wind turbine rotating cam 105 Aperture base (base member)
107 Sub aperture windmill 109 Sub aperture blade (light shielding member)
115 cam follower 116 hook 118 deformation preventing rib

Claims (8)

A lens barrel having at least one movable lens movable in an optical axis direction, comprising:
A light blocking member movable to adjust the amount of light;
A moving member that moves in the optical axis direction when the movable lens moves;
A base member supporting the light shielding member;
It is rotatably supported around the optical axis by the base member, and has a rotating member for moving the light shielding member by rotation.
The rotating member is
An engaging portion which engages with the moving member and rotates the rotating member by the movement of the moving member;
A lens barrel characterized by comprising: a deformation limiting portion which restricts the deformation of the rotating member away from the base member in the optical axis direction by coming into contact with the base member.   The lens barrel according to claim 1, wherein the deformation limiting portion is provided in the same phase as the engagement portion in the rotation direction of the rotation member. The rotating member extends in a direction orthogonal to the optical axis, and has an extending portion provided with the engaging portion at a tip thereof.
The lens barrel according to claim 1, wherein the deformation limiting portion is provided to the extension portion. The base member has a projection extending in the rotational direction of the rotating member,
The lens barrel according to claim 1, wherein the deformation limiting portion is in contact with a surface of the protrusion opposite to the rotating member.   The base member has a built-in gate portion which can pass the deformation limiting portion of the rotary member in the built-in rotational position with respect to the base member beyond the projection and on the opposite side to the rotary member side. The lens barrel according to claim 4, characterized in that   The said base member is characterized by having a claw part which contacts the surface on the opposite side to the said base member in the said rotation member, and prevents drop-off | omission from the said base member of the said rotation member. The lens barrel according to any one of the above.   An optical apparatus comprising the lens barrel according to any one of claims 1 to 6. An optical device according to claim 7;
An image pickup apparatus comprising: a camera main body holding an image pickup device for receiving light from the optical device.