Optical instrument

Abstract

To maintain optical performance even when an external force acts on a movable member that holds a lens.SOLUTION: An optical instrument 101 has: a movable member 900 that holds a lens 111 and is movable in an optical axis direction; a guiding member 107 that is arranged on an outer periphery of the movable member, and guides the movable member in an optical axis direction; and a cam member 108 that is rotatable around an optical axis, and is provided with a cam part engaged with a cam follower provided on the movable member to drive the movable member in the optical axis direction. The cam part includes first areas 108B, 108C that drive the movable member, and a second area 08A that does not drive the movable unit. When an external force acts on the movable member from the optical axis direction in a state where the cam follower is located in the second area, a first contact part 900e provided on the movable member is brought into contact, in the optical axis direction, with a second contact part 107e provided on the guiding member, and the cam follower is not brought into contact with the cam part.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present invention relates to optical instruments such as interchangeable lenses and digital cameras. [Background technology]

[0002] In optical instruments, when the lens holding state (position, tilt, etc.) is highly sensitive to optical performance, it is important to adjust the lens holding state with high precision. Patent Document 1 discloses an adjustment mechanism for the holding state of the lens group closest to the object side. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-114847 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the adjustment mechanism of Patent Document 1, if a load is applied to the internal structural members due to an external force, for example, when attaching an exterior member after adjustment, the holding state of the adjusted lens may change or the structural members may deform, making it difficult to maintain optical performance. In order to increase the strength of the structural members in order to maintain optical performance, the adjustment mechanism becomes larger.

[0005] The present invention provides a small optical device capable of maintaining optical performance even when an external force acts on a movable member that holds a lens. [Means for solving the problem]

[0006] An optical device according to one aspect of the present invention includes a movable member that holds a lens and is movable in the optical axis direction, a guide member that is disposed on the outer periphery of the movable member and that guides the movable member in the optical axis direction, and a cam member that is rotatable around the optical axis and that is provided with a cam portion that engages with a cam follower provided on the movable member to drive the movable member in the optical axis direction. The cam portion includes a first region that drives the movable member and a second region that does not drive the movable unit. The optical device is characterized in that, when an external force acts on the movable member from the optical axis direction with the cam follower located in the second region, a first abutment portion provided on the movable member abuts against a second abutment portion provided on the guide member in the optical axis direction, and the cam follower does not come into contact with the cam portion. Effect of the Invention

[0007] According to the present invention, in a small optical device, the optical performance can be maintained even if an external force acts on a movable member that holds a lens. [Brief description of the drawings]

[0008] [Figure 1] 1A and 1B are front and rear perspective views of an interchangeable lens and a digital camera according to an embodiment. [Diagram 2] FIG. 1 is a block diagram showing the configuration of an interchangeable lens and a digital camera according to an embodiment. [Diagram 3] FIG. 2 is a cross-sectional view of the interchangeable lens of the embodiment at the telephoto end. [Figure 4] FIG. 2 is a cross-sectional view of the interchangeable lens of the embodiment at the wide-angle end. [Diagram 5] FIG. 3 is a cross-sectional view of the interchangeable lens of the embodiment in a stored state. [Figure 6] FIG. 2 is an exploded perspective view of an interchangeable lens according to an embodiment. [Figure 7] FIG. 4 is an exploded perspective view of a first zoom group and a linear motion cylinder in the embodiment. [Figure 8] FIG. [Figure 9] FIG. 2 is a cross-sectional view of an interchangeable lens in an embodiment. [Figure 10] FIG. 4 is another cross-sectional view of the interchangeable lens of the embodiment. [Figure 11]FIG. 11 is an enlarged view of a portion of FIG. [Figure 12] FIG. 4 is a development view of the inner diameter side of the cam ring in the embodiment. [Figure 13] FIG. 4 is a development view of the outer diameter side of the cam ring in the embodiment. [Figure 14] FIG. 4 is an exploded perspective view of the second zoom group in the embodiment. [Figure 15] FIG. 4 is a side view of the second zoom group in the embodiment. [Figure 16] FIG. 15 is a cross-sectional view of a portion S in FIG. 14 . [Figure 17] 15 is a cross-sectional view of a T portion in FIG. 14. [Figure 18] 15 and 16 are enlarged partial views of FIG. [Figure 19] FIG. 9 is an enlarged view of the roller portion in FIG. [Figure 20] 4A and 4B are a cross-sectional view and a bottom view of the click mechanism in the embodiment. [Figure 21] FIG. 4 is a perspective view of a zoom operation ring in the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0010] 1(a) and 1(b) show the appearances of an interchangeable lens 101 as an optical device according to an embodiment of the present invention and a digital camera (hereinafter referred to as a camera body) 1 to which the interchangeable lens 101 is detachably attached, as viewed from an oblique front side and an oblique rear side, respectively. As shown in FIG. 1(a), the optical axis direction in which the optical axis of the imaging optical system housed in the interchangeable lens 101 extends is defined as the X-axis direction, and the directions perpendicular to this are defined as the Z-axis direction (horizontal direction) and the Y-axis direction (vertical direction). Hereinafter, the Z-axis direction and the Y-axis direction are collectively referred to as the Z / Y-axis direction. Moreover, the rotation direction around the Z-axis is defined as the pitch direction, and the rotation direction around the Y-axis is defined as the yaw direction. The pitch direction and the yaw direction (hereinafter collectively referred to as the pitch / yaw direction) are the rotation directions around two axes, the Z-axis and the Y-axis, which are perpendicular to each other.

[0011] A grip section 2 is provided on the left side of the camera body 1 as viewed from the front (right side as viewed from the rear) for the user to hold the camera body 1 with his / her hand. A power supply operation section 3 is also provided on the top surface of the camera body 1. When the user turns on the power supply operation section 3 while the camera body 1 is in a power-off state, electricity is started, the camera body 1 is powered on, and a computer program such as an origin detection process for the focus group in the imaging optical system is executed, and the camera body 1 is placed in an imaging standby state. When the user turns off the power supply operation section 3 while the camera body 1 is in a power-on state, the camera body 1 is powered off.

[0012] Furthermore, a mode dial 4, a release button 5, and an accessory shoe 6 are provided on the top surface of the camera body 1. The user can switch between imaging modes by rotating the mode dial 4. The imaging modes include a manual still image imaging mode in which the user can arbitrarily set imaging conditions such as shutter speed and aperture value, an auto still image imaging mode in which an appropriate exposure amount is automatically obtained, and a video imaging mode for capturing videos. The user can also instruct imaging preparation operations such as autofocus and auto exposure control by half-pressing the release button 5 (imaging preparation operation). In addition, the user can instruct imaging by fully pressing the release button 5 (imaging instruction operation). An accessory such as an external flash is detachably attached to the accessory shoe 6.

[0013] The interchangeable lens 101 is mechanically and electrically connected to a camera mount 7 provided on the camera body 1 via a lens mount 102. An imaging optical system that forms an image of a subject by focusing light from the subject is housed inside the interchangeable lens 101. A zoom ring 103 that can be rotated around an optical axis by a user's operation is provided on the outer periphery of the interchangeable lens 101. When the zoom ring 103 is rotated by the user, the zoom group that constitutes the imaging optical system moves to a predetermined usage position that corresponds to the angle of the zoom ring 103. In this way, imaging at a user-desired angle of view becomes possible.

[0014] As shown in FIG. 1(b), a rear operation unit 8 and a display unit 9 are provided on the rear of the camera body 1. The rear operation unit 8 includes a plurality of buttons and dials to which various functions are assigned. When the camera body 1 is in a power-on state and a still image or video imaging mode is set, a live view image showing a subject being imaged by an imaging element, which will be described later, is displayed on the display unit 9. The display unit 9 also displays imaging parameters showing imaging conditions such as shutter speed and aperture value, and the user can change the setting values ​​of the imaging parameters by operating the rear operation unit 8 while viewing the display. The rear operation unit 8 includes a playback button for instructing playback of a recorded captured image, and the captured image is played back and displayed on the display unit 9 by the user operating the playback button.

[0015] 2 shows the electrical and optical configurations of the interchangeable lens 101 and the camera body 1. The camera body 1 has a power supply unit 10 that supplies power to the camera body 1 and the interchangeable lens 101, and an operation unit 11 including the power operation unit 3, the mode dial 4, the release button 5, the rear operation unit 8, and the touch panel function of the display unit 9. The camera body 1 and the interchangeable lens 101 as a whole system are controlled by a camera control unit 12 provided in the camera body 1 and a lens control unit 104 provided in the interchangeable lens 101 in cooperation with each other. The camera control unit 12 reads out and executes a computer program stored in the storage unit 13. At that time, the camera control unit 12 communicates various control signals, data, and the like with the lens control unit 104 via a communication terminal of an electrical contact 105 provided in the lens mount 102. The electrical contact 105 includes a power terminal that supplies power from the power supply unit 10 to the interchangeable lens 101.

[0016] The imaging optical system of the interchangeable lens 101 has a zoom group 110 that is connected to the zoom operation ring 103 and moves in the optical axis direction to change the angle of view (focal length), and a lens vibration isolation group 112 that includes a shift lens as an anti-vibration element. The lens vibration isolation group 112 reduces image blur by moving (shifting) in the Z / Y axis direction perpendicular to the optical axis in response to camera shake such as hand shake. The imaging optical system also has an aperture group 301 that performs a light amount adjustment operation, and a focus group 114 that moves in the optical axis direction to adjust the focus. Furthermore, the interchangeable lens 101 has an anti-vibration drive unit 201 that moves the lens vibration isolation group 112, an aperture drive unit 302 that drives the aperture group 301, and a focus drive unit 401 that drives the focus group 114.

[0017] The camera body 1 has a shutter unit 14, a shutter drive section 15, an image sensor 16, an image processing section 17, and the camera control section 12 described above. The shutter unit 14 controls the amount of exposure of the image sensor 16 to light from the imaging optical system. The image sensor 16 photoelectrically converts (captures) the subject image formed by the imaging optical system and outputs an imaging signal. The image processing section 17 performs various image processes on the imaging signal to generate an image signal. The display section 9 displays the image signal (live view image) output from the image processing section 17, displays imaging parameters as described above, and reproduces and displays captured images recorded in the storage section 13 or a recording medium (not shown).

[0018] The camera control unit 12 controls the focus driving unit 401 in response to an image capture preparation operation in the operation unit 11. For example, when autofocus is instructed, the focus detection unit 18 determines the focus state of the subject image formed on the image sensor 16 based on the image signal generated by the image processing unit 17, generates a focus signal indicating the focus state, and transmits it to the camera control unit 12. The focus driving unit 401 also transmits information regarding the current position (focus position) of the focus group 114 to the camera control unit 12. The camera control unit 12 calculates a focus drive amount based on the focus state and the current focus position, and transmits it to the lens control unit 104. The lens control unit 104 drives a focus motor in the focus driving unit 401 in response to the focus drive amount to move the focus group 114 to a focus position and obtain a focus state for the subject. As the focus motor, a stepping motor, a DC motor, or a vibration type motor can be used.

[0019] In addition, the camera control unit 12 controls the aperture drive unit 302 and the shutter drive unit 15 in accordance with the aperture value and shutter speed input by the user from the operation unit 11, thereby driving the aperture 301 to the input aperture value and driving the shutter unit 14 at the input shutter speed.

[0020] The camera body 1 has a pitch shake detection unit 19 and a yaw shake detection unit 20 that detect camera shake in the pitch direction and the yaw direction, respectively. The pitch shake detection unit 19 and the yaw shake detection unit 20 are each composed of an angular velocity sensor (vibration gyro) and an angular acceleration sensor. The camera control unit 12 calculates the shift position of the lens vibration isolation group 112 in the Y-axis direction using the shake signal from the pitch shake detection unit 19, and calculates the shift position of the lens vibration isolation group 112 in the Z-axis direction using the shake signal from the yaw shake detection unit 20. The camera control unit 12 then controls the vibration isolation driving unit 201 according to the calculated shift position in the pitch / yaw direction, thereby moving the lens vibration isolation group 112 to a target position in the Z / Y axis direction and reducing image shake.

[0021] The interchangeable lens 101 has a zoom ring 103 for changing the angle of view of the imaging optical system, and a zoom detection unit 106 for detecting the angle of the zoom ring 103. The zoom detection unit 106 detects the angle of the zoom ring 103 operated by the user as an absolute value, and is composed of a linear potentiometer or the like. Information relating to the angle of view detected by the zoom detection unit 106 is transmitted to the lens control unit 104, and is reflected in various controls by the camera control unit 12 described above. In addition, some of this various information is recorded in the storage unit 13 or a recording medium (not shown) together with the captured image.

[0022] Next, the configuration of the interchangeable lens 101 will be described with reference to Figs. 3 to 13. Figs. 3 to 5 are XY cross sections including the optical axis of the interchangeable lens 101 (and the camera body 1). Figs. 3 and 4 respectively show cross sections of the interchangeable lens 101 at the telephoto end and the wide-angle end. Fig. 5 shows a cross section of the interchangeable lens 101 in a stored state (non-imaging state) in which the overall length in the optical axis direction is the shortest. Fig. 6 shows an exploded view of the interchangeable lens 101, and Fig. 7 shows an exploded view of the first lens group 111 and the rectilinear barrel 950, which will be described later. Figs. 8 show the guide barrel 107, which will be described later. Figs. 9 and 10 show detailed cross sections of the interchangeable lens 101. Figs. 11(a) and 11(b) show enlarged views of the rectilinear barrel 950 and a portion of the cam ring 108 and the first zoom base plate 900, which will be described later. 12 and 13 each show the inner and outer peripheries of a cam ring 108, which will be described later, developed in a circumferential direction (direction around the optical axis) centered on the optical axis.

[0023] In this embodiment, as shown in Figs. 3 and 4, an optical system having a six-group configuration is adopted as the imaging optical system. The imaging optical system has a first lens group 111, a lens vibration isolation group 112 as a second lens group, an aperture group 301, a third lens group 113, a fourth lens group 114 as a focus group, a fifth lens group 115, and a sixth lens group 116, which are arranged in this order from the object side to the image side. The sixth lens group 116 is directly fixed to the guide barrel 107. The zoom group 110 shown in Fig. 2 has a first zoom group constituted by the first lens group 111 and a second zoom group constituted by the second to fifth lens groups 112 to 115, which move independently of each other in the optical axis direction. The imaging optical system may have a group configuration other than the above.

[0024] Guide barrel 107 as a guide member is disposed on the outer periphery of the imaging optical system, and is a fixed component fixed to lens mount 102 via fixed barrel 109. Lens mount 102 is a member that mechanically and electrically engages with the camera mount of camera body 1. As shown in Fig. 8, engagement claws 107a are formed on the outer periphery of guide barrel 107 at multiple locations equally spaced in the circumferential direction. Guide barrel 107 holds cam ring 108 as a cam member on its outer periphery so that it can rotate around the optical axis.

[0025] 9, an engagement groove 108a is provided on the inner periphery of the cam ring 108. The cam ring 108 is connected to the zoom operation ring 103 via a key (not shown). When the zoom operation ring 103 is rotated by the user, the engagement claw 107a engages with the engagement groove 108a, causing the cam ring 108 to rotate around the optical axis.

[0026] As shown in FIG. 6, a first lens group 111 constituting the first zoom group is included in a first zoom unit 1101, and second to fifth lens groups 112 to 115 constituting the second zoom group are included in a second zoom unit 1102.

[0027] As shown in Fig. 8, guide barrel 107 is formed with linear grooves 107b at equal intervals in the circumferential direction to prevent rotation of first zoom unit 1101 and second zoom unit 1102 about the optical axis and guide movement in the optical axis direction. Also, as shown in Fig. 12, cam ring 108 is formed with first cam grooves 108b as a cam portion that drives first zoom unit 1101 in the optical axis direction and second cam grooves 108c as a cam portion that drives second zoom unit 1102 in the optical axis direction, each of which is formed at equal intervals in the circumferential direction.

[0028] As shown in FIG. 7, in the first zoom unit 1101, the first lens group 111 is held by a lens holding frame 1110, and the lens holding frame 1110 is held by a first zoom base plate 900 as a movable member. The first zoom base plate 900 has linear key portions 900b formed at three positions equally spaced in the circumferential direction, and cam followers 900a are provided on each linear key portion 900b. The cam followers 900a may be formed integrally with the first zoom base plate 900 (linear key portion 900b), or may be formed separately and fixed to the first zoom base plate 900. Each cam follower 900a engages with a corresponding first cam groove portion 108b in the cam ring 108, and each linear key portion 900b engages with a corresponding linear groove portion 107b in the guide cylinder 107. The linear key portion 900b is connected to the first zoom base plate 900 by a connecting portion 900f in order to further shorten (make smaller) the overall length when the interchangeable lens 101 is stored.

[0029] As will be described in more detail later, the second zoom unit 1102 also has linear key portions and cam followers held thereby at three equally spaced locations in the circumferential direction. Each cam follower of the second zoom unit 1102 engages with a corresponding second cam groove portion 108c in the cam ring 108, and the linear key portion engages with the linear groove portion 107b.

[0030] When the user rotates the zoom operation ring 103 to rotate the cam ring 108, the cam followers of the first and second zoom units 1101, 1102 are pushed in the optical axis direction by the first and second cam groove portions 108b, 108c. At this time, the first and second zoom units 1101, 1102 are guided in the optical axis direction while being prevented from rotating around the optical axis by the engagement between the linear key portions and the linear groove portion 107b. As a result, the first and second zoom units 1101, 1102 are driven in the optical axis direction.

[0031] Next, a method of holding the first lens group 111 in the first zoom unit 1101 will be described. As shown in Fig. 7, the first lens group 111 is held by a first lens frame 1110. The first lens frame 1110 is held by the first zoom base plate 900 by being bayonet-coupled to the first zoom base plate 900, and this bayonet coupling prevents the first lens frame 1110 from moving in the optical axis direction relative to the first zoom base plate 900.

[0032] In addition, rollers 1111 are attached to three equally spaced locations on the outer periphery of the first lens frame 1110 with screws. Each roller 1111 is an eccentric roller. The three rollers 1111 are inserted from the radial outside of the first zoom base plate 900 into rectangular holes 900c provided at three equally spaced locations on the first zoom base plate 900, and are fixed to the first lens frame 1110 with screws. By rotating any one of the rollers 1111 about its axis, the position of the first lens frame 1110 relative to the first zoom base plate 900 (the eccentric position in a plane perpendicular to the optical axis and the tilt position relative to the plane) can be adjusted. In this way, by making the position of the first lens frame 1110 relative to the first zoom base plate 900 adjustable, the deterioration of optical performance due to the miniaturization of the interchangeable lens 101 can be suppressed.

[0033] 9, when the rectilinear cylinder 950 is attached to the first zoom base plate 900 as an exterior member that moves integrally with the first zoom base plate 900, it is impossible to rotate the rollers 1111 from the outside. For this reason, it is necessary to attach the rectilinear cylinder 950 to the first zoom base plate 900 after rotating the rollers 1111 from the outside and adjusting the position of the first lens frame 1110 relative to the first zoom base plate 900.

[0034] 7 and 9, the linear barrel 950 is attached with fastening portions 950a provided at three circumferential locations on the front wall portion on the object side to fastening portions 900d provided at three circumferential locations on the first zoom base plate 900 with screws. The fastening portions 950a and the fastening portions 900d are each disposed at equal intervals of 120 degrees in the circumferential direction, and are disposed in a phase different from the circumferential phase at which the three guide groove portions 107b in the guide barrel 107 shown in FIG.

[0035] After the linear cylinder 950 is attached to the first zoom base plate 900 with screws, a front plate 951 is adhered and fixed to the front end face of the front wall of the linear cylinder 950 with double-sided tape (not shown) as shown in FIG.

[0036] As shown in FIG. 10, three convex portions 950b are provided at equal intervals in the circumferential direction on the inner periphery of the linear barrel 950 as third contact portions. As shown in FIG. 11(a), the convex portions 950b are arranged in the third cam groove portion 108d provided on the outer periphery of the cam ring 108 so that a second gap Y is formed between the convex portions 950b and the cam surface 108f as a fourth contact portion on the mount side (image side). When an external force such as an impact acts on the first zoom unit 1101 from the outside of the front side, the second gap Y disappears and the convex portions 950b come into contact with the cam surface 108f, thereby reducing the external force applied from the cam follower 900a to the first cam groove portion 108b (and the reaction force to the cam follower 900a). This makes it possible to suppress deterioration of optical performance caused by the action of an external force on the interchangeable lens 101.

[0037] Next, a description will be given of how the linear motion cylinder 950 is attached to the first zoom base plate 900. As shown in Fig. 12 and Fig. 13, the first cam groove portion 108b and the third cam groove portion 108d of the cam ring 108 have a continuous groove shape, and have four regions: an assembly region 108A, a storage region 108B, an imaging region 108C, and an introduction region 108D.

[0038] The assembly area 108A has a portion where the width in the optical axis direction of each cam groove portion is wider than other areas. The linear barrel 950 is attached to the first zoom base plate 900 when the cam follower 900a provided on the first zoom base plate 900 and the convex portion 950b provided on the linear barrel 950 are positioned within the assembly area 108A of the first and third cam groove portions 108b, 108d of the cam ring 108. In other words, the assembly area 108A is an area for attaching (assembling) the linear barrel 950 to the first zoom base plate 900, and corresponds to the second area.

[0039] The introduction area 108D is an area that is open on the object side and is used to introduce the cam follower 900a, the cam follower 700a, and the convex portion 950b into the corresponding first cam groove portion 108b, the second cam groove portion 108c, and the third cam groove portion 108d. The cam follower 700a is provided at three locations at equal intervals in the circumferential direction on the second zoom base plate 700, which is the base member of the second zoom unit 1102. By providing the introduction area 108D, the first zoom base plate 900, the second zoom base plate 700, and the linear barrel 950 can be moved in the optical axis direction without rotating the cam ring 108.

[0040] The storage area 108B is an area for driving the first and second zoom units 1101, 1102 between the wide-angle end shown in Fig. 4 and the stored state shown in Fig. 5 via the cam followers 900a, 700a. The imaging area 108C is an area for driving the first and second zoom units 1101, 1102 between the wide-angle end and the telephoto end shown in Fig. 3 via the cam followers 900a, 700a. The storage area 108B and the imaging area 108C correspond to the first area.

[0041] In the following, when the cam follower 900a and the convex portion 950b are positioned within the assembly area 108A, the storage area 108B and the imaging area 108C of the first and third cam groove portions 108b, 108d, it is said that the cam ring 108 is in the phase of the assembly area 108A, the storage area 108B and the imaging area 108C, respectively.

[0042] As shown in Fig. 7 and Fig. 9, a first abutment portion 900e is provided at the mount side end of the three fastening portions 900d of the first zoom base plate 900. The linear key portion 900b is connected to the connecting portion 900f on the mount side in the optical axis direction from the first abutment portion 900e. In addition, three second abutment portions 107e are provided at positions corresponding to the three first abutment portions 900e on the guide barrel 107. When the cam ring 108 is in the phase of the assembly area 108A, the first abutment portion 900e and the second abutment portion 107e can abut against each other as shown in Fig. 9.

[0043] At this time, as shown in Figures 11(b), 12, and 13, a first gap X is formed between the cam follower 900a and the cam surface 108e on the mount side of the first cam groove portion 108b. Therefore, even if a force is applied to the mount side in the optical axis direction when attaching the linear motion cylinder 950 to the first zoom base plate 900, the first abutment portion 900e and the second abutment portion 107e abut against each other, so that the cam follower 900a in the assembly area 108A does not come into contact with the cam surface 108e of the first cam groove portion 108b.

[0044] Therefore, no load is applied to the cam follower 900a, and no load is applied to the connecting portion 900f, so deformation of the first zoom base plate 900 can be suppressed, and it is possible to achieve both miniaturization and prevention of deterioration of the optical performance of the interchangeable lens 101. If the cam surface 108e and the cam follower 900a come into contact with each other before the first contact portion 900e and the second contact portion 107e come into contact with each other, the connecting portion 900f must be reinforced in order to suppress deformation of the first zoom base plate 900, or the size of the connecting portion 900f increases.

[0045] Furthermore, the first contact portion 900e and the second contact portion 107e are disposed on the inner peripheral side of the cam ring 108, in the tube portion of the guide barrel 107. Therefore, it is possible to prevent the interchangeable lens 101 from becoming large, without affecting the lens groups disposed inside the guide barrel 107.

[0046] As shown in FIGS. 11(a) and 11(b), in the assembly area 108A, a first gap X between the cam follower 900a and the cam surface 108e and a second gap Y between the convex portion 950b of the linear cylinder 950 and the cam surface 108f on the mount side of the third cam groove portion 108d are X>Y It is set so that:

[0047] As described above, when the linear barrel 950 is attached to the first zoom base plate 900, the first abutment portion 900e and the second abutment portion 107e abut against each other. In this state, if a large force is applied to the mount side by the linear barrel 950, the guide barrel 107 may be deformed in the optical axis direction. However, even in this case, due to the setting of X>Y, the convex portion 950b of the linear barrel 950 contacts the cam surface 108f of the third cam groove portion 108d before the cam follower 900a contacts the cam surface 108e of the first cam groove portion 108b. As a result, no load is applied to the cam follower 900a, and deterioration of optical performance is unlikely to occur. Note that in this state, the click mechanism 600 described later has not yet been attached.

[0048] Fig. 14 shows an exploded view of the second zoom unit 1102 as viewed from the oblique object side. Fig. 15 shows the second zoom unit 1102 in an assembled state as viewed from the side.

[0049] In the second zoom unit 1102, the second zoom base plate 700 holds the second lens group 112 to the fourth lens group 114 and the aperture group 301. The second zoom base plate 700 is provided with linear key portions 700b at three positions in the circumferential direction, and each linear key portion 700b holds the above-mentioned cam follower 700a. Each cam follower 700a engages with a corresponding second cam groove portion 108c in the cam ring 108, and each linear key portion 700b engages with a corresponding linear groove portion 107a in the guide barrel 107.

[0050] The linear key portions 900b, 700b of the first zoom unit 1101 and the second zoom unit 1102 are engaged with the same linear groove portion 107a, which allows relatively high-precision positioning and reduces the risk of deterioration of optical performance.

[0051] In the second zoom unit 1102, the lens vibration isolation group 112 is held by a vibration isolation lens frame 1120. The vibration isolation lens frame 1120 is held by a vibration isolation base plate 1121 so as to be movable within a plane perpendicular to the optical axis.

[0052] The vibration-isolating base plate 1121 is fixed to the second zoom base plate 700 with a plurality of screws. The aperture group 301 is sandwiched between the vibration-isolating base plate 1121 and the second zoom base plate 700.

[0053] The third lens group 113 as the first lens is held by a third lens frame 1130 as a first holding member. The third lens frame 1130 is held by the second zoom base plate 700 so as to be movable in the optical axis direction and in a direction perpendicular to the optical axis. Rollers 1131 are attached by screws to three equally spaced locations on the outer periphery of the third lens frame 1130. At least one of the three rollers 1131 is an eccentric roller as an adjustment member. The third lens frame 1130 is bayonet-coupled to the second zoom base plate 700 with a position-adjustable gap. The second zoom base plate 700 has rectangular holes 700c at three equally spaced locations in the circumferential direction. The rollers 1131 inserted into the rectangular holes 700c from the radial outside of the second zoom base plate 700 are screwed to the third lens frame 1130, so that the third lens frame 1130 is held by the second zoom base plate 700. At this time, a slight gap is formed between the second zoom base plate 700 and the third lens frame 1130 in the radial direction.

[0054] The fifth lens group 115 as the second lens is held by the fifth lens frame 1150 as the second holding member. The fifth lens frame 1150 is also held by the second zoom base plate 700 so as to be movable in the optical axis direction and in a direction perpendicular to the optical axis. The fifth lens frame 1150 has rectangular holes 1150a at three equally spaced locations in the circumferential direction. The fifth lens frame 1150 is held by the second zoom base plate 700 by screwing the rollers 701 inserted into the rectangular holes 1150a from the radial outside of the fifth lens frame 1150 to the second zoom base plate 700. At this time, a slight gap is formed between the second zoom base plate 700 and the fifth lens frame 1150 in the radial direction. Two of the three rollers 701 are eccentric rollers serving as adjustment members.

[0055] By rotating the eccentric rollers 1131, 701 about their axes, the positions of the third lens frame 1130 and the fifth lens frame 1150 relative to the second zoom base plate 700 (eccentric positions in a plane perpendicular to the optical axis) can be adjusted. Note that the rotation of the eccentric rollers may be made to adjust the tilt positions of the third lens frame 1130 and the fifth lens frame 1150 relative to the plane perpendicular to the optical axis. In this way, by making the positions of the third and fifth lens groups 113, 115 relative to the second zoom base plate 700 adjustable, it is possible to suppress deterioration of optical performance that accompanies miniaturization of the interchangeable lens 101.

[0056] The fourth lens group 114 as the third lens is held by a fourth lens frame 1140 as a third holding member. The second zoom base plate 700 and the vibration isolation base plate 1121 hold a first guide shaft 710 extending in the optical axis direction, and the second zoom base plate 700 holds a second guide shaft portion (not shown) extending in the optical axis direction. The fourth lens frame 1140 is held by the first guide shaft 710 and the second guide shaft so as to be movable in the optical axis direction in an area sandwiched between the third lens frame 1130 and the fifth lens frame 1150 in the second zoom base plate 700. A focus motor 402 as an actuator for driving the fourth lens frame 1140 in the optical axis direction and a focus drive unit 401 including a flexible board for supplying electricity to the focus motor 402 are fixed to the second zoom base plate 700. The focus motor 402 is disposed inside the second zoom base plate 700, and the flexible board is disposed outside the second zoom base plate 700.

[0057] Two pairs of hook portions 1130b, 1150b are provided at two locations on the outer periphery of each of the third lens frame 1130 and the fifth lens frame 1150, and both ends of an elastic member 800, which is a tension coil spring, are hooked onto each pair of hook portions 1130b, 1150b.

[0058] FIG. 16 shows a cross section of the second zoom unit 1102 seen from the image side when cut along the SS line in FIG. 15. FIG. 17 shows a cross section of the second zoom unit 1102 seen from the image side when cut along the TT line in FIG. 15. As shown in FIG. 16 and FIG. 17, two pairs of hook parts 1130b, 1150b (i.e., two elastic members 800) are provided in two of the three phase regions between the rollers 1131, 701 attached in threes each to the third lens frame 1130 and the fifth lens frame 1150. The focus driving unit 401 is disposed in the remaining phase region of the second zoom base plate 700 that is not one of the two phase regions in which the elastic member 800 is disposed. This configuration allows the diameter of the second zoom unit 1102 to be made smaller than when the focus driving unit 401 is disposed in the same phase region as the elastic member 800 so as to avoid the elastic member 800.

[0059] 15, each pair of hook portions 1130b, 1150b are provided at different phases, and the elastic member 800 is disposed so as to be inclined with respect to the optical axis direction. The elastic member 800 urges the third lens frame 1130 and the fifth lens frame 1150 in directions in which they approach each other in the optical axis direction, and also urges the third lens frame 1130 and the fifth lens frame 1150 in opposite directions in the circumferential direction.

[0060] Fig. 18(a) shows an enlarged view of the periphery of roller 1131 circled in Fig. 16, and Fig. 18(b) shows an enlarged view of the periphery of roller 701 circled in Fig. 17. Also, Fig. 19 shows a cross section of the periphery of rollers 1131 and 701 in the second zoom unit 1102 as viewed from the side.

[0061] 16, 17, and 19, the second zoom base plate 700 is provided with a first contact portion 700d facing the object side. Also, as shown in Fig. 19, the second zoom base plate 700 is provided with a second contact portion 700e facing the image side.

[0062] 19, due to the biasing force in the optical axis direction generated by the elastic member 800, the abutment portion 1130c provided on the third lens frame 1130 abuts (presses) against the first abutment portion 700d of the second zoom base plate 700. In addition, the abutment portion 1150c provided on the fifth lens frame 1150 abuts against the second abutment portion 700e of the second zoom base plate 700. This makes it possible to position the third lens frame 1130 and the fifth lens frame 1150 relative to the second zoom base plate 700 in the optical axis direction.

[0063] 18(a), the biasing force generated by the elastic member 800 around the optical axis causes the roller 1131 attached to the third lens frame 1130 to abut (press) against the third abutment portion 700f in the rectangular hole portion 700c in the second zoom base plate 700. Furthermore, as shown in Fig. 18(b), the biasing force of the elastic member 800 around the optical axis causes the abutment portion 1150d in the rectangular hole portion 1150a of the fifth lens frame 1150 to abut against the roller 701 attached to the second zoom base plate 700. This makes it possible to position the third lens frame 1130 and the fifth lens frame 1150 relative to the second zoom base plate 700 in the circumferential direction.

[0064] In this way, the third lens frame 1130 and the fifth lens frame 1150 are positioned in both the optical axis direction and the circumferential direction with respect to the second zoom base plate 700. This eliminates the need to provide an engagement portion (hook portion) with an elastic member on each of the third lens frame 1130 and the fifth lens frame 1150 and the second zoom base plate 700, making it possible to reduce the size of the second zoom unit 1102 while maintaining optical performance. Even if an external force such as an impact is applied to the interchangeable lens 101 and the third lens frame 1130 and the fifth lens frame 1150 move once with respect to the second zoom base plate 700, they return to their original positions due to the biasing force of the elastic member 800, so deterioration of optical performance can be suppressed.

[0065] In order to generate such a biasing force in the elastic member 800, it is desirable to arrange the elastic member 800 so as to have an inclination of 30° to 60° with respect to the optical axis direction.

[0066] 15 to 17, the elastic member 800 is disposed so as to be housed inside a recess 700h provided on the outer periphery of the second zoom base plate 700. Therefore, the outer diameter of the second zoom unit 1102 can be made smaller than when the elastic member 800 is provided along the outer periphery of the second zoom base plate 700.

[0067] Next, a description will be given of the zoom operation of the interchangeable lens 101. The cam ring 108 and the zoom operation ring 103 are connected by a connecting member 1080, and when the user rotates the zoom operation ring 103, the cam ring 108 also rotates around the optical axis. At this time, a click feeling is imparted by the click mechanism 600 in response to the rotation of the zoom operation ring 103.

[0068] Fig. 20(a) shows a cross section of the periphery of the click mechanism 600 as viewed from the side, and Fig. 20(b) shows a cross section of the periphery of the click mechanism 600 as viewed from the optical axis side. These figures show the click mechanism 600 in the vicinity of the wide-angle end of the imaging area of ​​the interchangeable lens 101. Fig. 21 shows the zoom operation ring 103.

[0069] The pin member 601 is held by the fixed cylinder 109 so as to be movable in the optical axis direction. As shown in FIG. 20(b), the side surface of the tip 601a of the pin member 601 on the object side has a tapered shape. Also, as shown in FIG. 21, a tapered protrusion 103a is provided on the inner periphery of the zoom operation ring 103 at a position at the same distance (radius) from the optical axis as the tip 601a of the pin member 601. The protrusion 103a is disposed so as to come into contact with the tip 601a of the pin member 601 at the boundary with the storage region 108B of the imaging region 108C of the cam ring 108 shown in FIG. 12 and FIG. 13.

[0070] A cylindrical portion is provided at the rear of the pin member 601 on the image side relative to the tip portion 601a, and a urging member 602, which is a compression coil spring, is inserted into the cylindrical portion. The urging member 602 in a compressed state urges the pin member 601 against the zoom operation ring 103 by having its object side end abut against the pin member 601 and its image side end abut against the fixed cylinder 109.

[0071] When the zoom ring 103 is rotated, the tapered surface of the protrusion 103a comes into contact with the tapered surface of the tip 601a of the pin member 601. When the zoom ring 103 is further rotated, the pin member 601 moves toward the image side along the tapered surface of the protrusion 103a. When the tip 601a of the pin member 601 gets over the protrusion 103a moving in the rotational direction, the pin member 601 moves toward the object side (returns to its original position) due to the biasing force of the biasing member 602.

[0072] In this way, when the protrusion 103a comes into contact with the tip 601a of the pin member 601 and presses the pin member 601 toward the image side against the biasing force of the biasing member 602, the rotational load of the zoom operation ring 103 increases, and the rotational load is relieved when the pin member 601 overcomes the protrusion 103a. This produces a clicking sensation in response to the rotation of the zoom operation ring 103. This clicking sensation allows the user to recognize the end of the cam ring 108 on the storage region 108B side in the imaging region 108C of the cam ring 108, among the phases in which the zoom operation ring 103 can be rotated.

[0073] By changing the angle of the tapered surface of the protrusion 103a and the tip 601a of the pin member 601 and the magnitude of the biasing force generated by the biasing member 602, a suitable clicking sensation can be set in response to the rotation operation of the zoom operation ring 103.

[0074] 21, a first abutment portion 103b and a second abutment portion 103c are provided on both sides of the protrusion 103a in the circumferential direction at a position on the inner periphery of the zoom operation ring 103 that is the same distance from the optical axis as the tip end 601a of the pin member 601. When the tip end 601a of the pin member 601 serving as a rotation preventing member abuts against the first abutment portion 103b and the second abutment portion 103c, further rotation of the zoom operation ring 103 is prevented, and at the same time, rotation of the cam ring 108 is also prevented.

[0075] The first contact portion 103b is provided in a phase corresponding to the boundary between the assembly area 108A and the storage area 108B of the cam ring 108 shown in FIG. 12 and FIG. 13. Therefore, the rotation of the cam ring 108 from the storage area 108B to the assembly area 108A by the rotation operation of the zoom operation ring 103 is prevented. The second contact portion 103c is provided in a phase corresponding to the boundary between the imaging area 108C and the introduction area 108D of the cam ring 108. Therefore, the rotation of the cam ring 108 from the imaging area 108C to the introduction area 108D by the rotation operation of the zoom operation ring 103 is prevented. In this way, the zoom operation ring 103 is allowed to be rotated only when the cam ring 108 is in the phase between the storage area 108B and the imaging area 108C.

[0076] In this embodiment, the linear barrel 950 is attached to the first zoom base plate 900 in an assembly area 108A where rotation of the cam ring 108 due to rotation of the zoom operation ring 103 is prevented. In the assembly area 108A, the cam follower 900a does not contact the first cam groove portion 108b of the cam ring 108, so that deterioration of optical performance due to attachment of the linear barrel 950 to the first zoom base plate 900 can be suppressed.

[0077] In the above embodiment, the interchangeable lens 101 is described as an optical device, but the internal configuration of the interchangeable lens 101 described in the embodiment can also be applied to a lens barrel portion in a lens-integrated camera (optical device). In the above embodiment, the case where a groove-shaped cam portion (cam groove portion) is provided on the cam ring 108 is described, but a cam portion having a protruding shape may be provided on the cam member.

[0078] The above embodiment includes the following configurations.

[0079] (Configuration 1) a movable member that holds a lens and is movable in the direction of an optical axis; a guide member disposed on an outer periphery of the movable member and configured to guide the movable member in the optical axis direction; a cam member that is rotatable around the optical axis and has a cam portion that engages with a cam follower provided on the movable member to drive the movable member in the optical axis direction; the cam portion includes a first region that drives the movable member and a second region that does not drive the movable unit, An optical device characterized in that, when an external force acts on the movable member from the optical axis direction while the cam follower is positioned in the second region, a first abutment portion provided on the movable member abuts against a second abutment portion provided on the guide member in the optical axis direction, and the cam follower is configured not to contact the cam portion. (Configuration 2) The cam portion is formed as a cam groove portion, 2. The optical device according to configuration 1, wherein a width of the cam groove portion in the second region in the optical axis direction is greater than a width of the cam groove portion in the first region in the optical axis direction. (Configuration 3) 3. The optical device according to configuration 1 or 2, further comprising an exterior member that is attached to the movable member from the optical axis direction when the cam follower is located in the second region. (Configuration 4) when the cam follower is located in the second region, the cam follower is disposed such that a first gap is provided in the optical axis direction relative to the cam portion, and a third contact portion provided on the exterior member is disposed such that a second gap is provided in the optical axis direction relative to a fourth contact portion provided on the cam member, When the external force acts on the exterior member, the third contact portion contacts the fourth contact portion, 4. The optical device according to configuration 3, wherein the first gap is larger than the second gap. (Configuration 5) a mechanism for adjusting a holding state of the lens relative to the movable member, 5. The optical device according to configuration 3 or 4, wherein the exterior member is attached to the movable member after the holding state is adjusted. (Configuration 6) 6. The optical device according to any one of configurations 1 to 5, further comprising a rotation preventing member that prevents the cam member from rotating when the cam follower moves from a state in which it is located in the first region to a state in which it is located in the second region. (Configuration 7) 7. The optical device according to any one of configurations 1 to 6, wherein the first contact portion and the second contact portion are provided on an inner peripheral side of the cam member. (Configuration 8) an optical system including the lens, 8. The optical device according to any one of configurations 1 to 7, wherein the movable member holds the lens arranged closest to the object side in the optical system.

[0080] The embodiments described above are merely representative examples, and various modifications and alterations are possible for each embodiment when implementing the present invention. [Explanation of symbols]

[0081] 101 Interchangeable Lenses 103 Zoom ring 107 Guide tube 108 Cam ring 108b First cam groove portion 108c Second cam groove 108d Third cam groove 108A Assembly Area 108B Storage area 108C Imaging area 900 1st zoom base plate 900a Cam Follower 950 Straight tube 1101 1st zoom unit 1102 2nd zoom unit

Claims

1. a movable member that holds a lens and is movable in the direction of an optical axis; a guide member disposed on an outer periphery of the movable member and configured to guide the movable member in the optical axis direction; a cam member that is rotatable around the optical axis and has a cam portion that engages with a cam follower provided on the movable member to drive the movable member in the optical axis direction; the cam portion includes a first region that drives the movable member and a second region that does not drive the movable unit, An optical device characterized in that, when an external force acts on the movable member from the optical axis direction while the cam follower is positioned in the second region, a first abutment portion provided on the movable member abuts against a second abutment portion provided on the guide member in the optical axis direction, and the cam follower is configured not to contact the cam portion.

2. The cam portion is formed as a cam groove portion, 2 . The optical device according to claim 1 , wherein a width of the cam groove portion in the second region in the optical axis direction is larger than a width of the cam groove portion in the first region in the optical axis direction.

3. 2 . The optical device according to claim 1 , further comprising an exterior member that is attached to the movable member in the optical axis direction when the cam follower is located in the second region.

4. when the cam follower is located in the second region, the cam follower is disposed such that a first gap is provided in the optical axis direction relative to the cam portion, and a third contact portion provided on the exterior member is disposed such that a second gap is provided in the optical axis direction relative to a fourth contact portion provided on the cam member, When the external force acts on the exterior member, the third contact portion contacts the fourth contact portion, The optical device according to claim 3 , wherein the first gap is larger than the second gap.

5. a mechanism for adjusting a holding state of the lens relative to the movable member, 4. The optical device according to claim 3, wherein the exterior member is attached to the movable member after the holding state is adjusted.

6. 2. The optical device according to claim 1, further comprising a rotation preventing member that prevents the cam member from rotating when the cam follower moves from a state in which the cam follower is located in the first region to a state in which the cam follower is located in the second region.

7. The optical device according to claim 1 , wherein the first contact portion and the second contact portion are provided on an inner peripheral side of the cam member.

8. an optical system including the lens, 2. The optical device according to claim 1, wherein the movable member holds the lens that is disposed closest to the object side in the optical system.

Images