Optical equipment

Abstract

To provide a highly reliable optical device that secures the movable bending portion and excess bending portion of a flexible printed circuit board with a simple configuration and is resistant to external impacts. [Solution] The optical device comprises an optical system, a first base member, a second base member held by the first base member, and a flexible printed circuit board arranged across the first and second base members. The flexible printed circuit board includes a movable bending portion, a locking portion, and a hooking portion, arranged sequentially from the first base side to the second base side along the optical axis direction of the optical system. The first base member includes a first holding portion that fixes and holds the locking portion in the thickness direction and the optical axis direction of the flexible printed circuit board. The second base member includes a second holding portion that restricts and holds the hooking portion in the thickness direction and one of the optical axis directions of the flexible printed circuit board. The flexible printed circuit board includes an excess bending portion formed between the locking portion and the hooking portion.

Description

Technical Field

[0001] The present invention relates to an optical device having a flexible printed circuit board.

Background Art

[0002] When a flexible printed circuit board is arranged across two components in a lens barrel, if an impact such as a drop or vibration is applied to the lens barrel, the two components may separate and a gap may form, resulting in a force acting to sever the flexible printed circuit board and a risk of disconnection of the wiring pattern. Patent Document 1 discloses a configuration in which ears provided at two locations of a flexible printed circuit board arranged across two components are inserted into hook shapes arranged on each of the two components and an extra length portion is provided.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the configuration of Patent Document 1, since the position of the flexible printed circuit board in the optical axis direction is not fixed, when a movable bending portion is provided on the flexible printed circuit board, the ears may repeatedly contact and separate from the hook shape. In this case, a contact sound may occur due to the contact between the flexible printed circuit board and the hook shape. Also, when the movable range of the movable bending portion is wide, it becomes difficult to prevent the flexible printed circuit board from falling off the hook shape or to suppress disconnection.

[0005] An object of the present invention is to provide a highly reliable optical device that fixes a movable bending portion and an extra length bending portion of a flexible printed circuit board with a simple configuration and is prepared for external impacts.

Means for Solving the Problems

[0006] An optical device as one aspect of the present invention comprises an optical system, a first base member, a second base member held by the first base member, and a flexible printed circuit board arranged across the first and second base members, wherein the flexible printed circuit board includes a movable bending portion, a locking portion, and a hooking portion arranged sequentially from the side of the first base to the side of the second base along the optical axis direction of the optical system, the first base member includes a first holding portion that holds the locking portion in a fixed position in the thickness direction and the optical axis direction of the flexible printed circuit board, the second base member includes a second holding portion that holds the hooking portion in a restricted position in either the thickness direction or the optical axis direction of the flexible printed circuit board, and the flexible printed circuit board includes an excess bending portion formed between the locking portion and the hooking portion. [Effects of the Invention]

[0007] According to the present invention, it is possible to fix the movable bending portion and excess bending portion of a flexible printed circuit board with a simple structure and to provide a highly reliable optical device that is protected from external impacts. [Brief explanation of the drawing]

[0008] [Figure 1] This is an external view of an interchangeable lens and a digital camera according to an embodiment of the present invention. [Figure 2] This is a block diagram showing the configuration of interchangeable lenses and digital cameras. [Figure 3] This is a cross-sectional view of an interchangeable lens in its retracted state. [Figure 4] This is a cross-sectional view of the interchangeable lens in its extended state. [Figure 5] This is a perspective view of the optical unit. [Figure 6] This is a perspective view of a flexible printed circuit board. [Figure 7] This is a detailed diagram of the locking mechanism in the fixed state of a flexible printed circuit board. [Figure 8] This is a detailed diagram of the hook portion in the fixed state of a flexible printed circuit board. [Figure 9] This is an explanatory diagram of the excess length of the bent section. [Figure 10] This is an enlarged view of the position detection element mounting section. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described in detail below with reference to the drawings. In each drawing, the same reference numeral is used for identical components, and redundant descriptions are omitted.

[0010] Figure 1 is an external view of an interchangeable lens (optical device) 101 and a digital camera (hereinafter referred to as the camera body) 1 to which the interchangeable lens 101 is detachably attached, according to an embodiment of the present invention. Figures 1(a) and 1(b) are views from the front and rear, respectively. As shown in Figure 1(a), the direction in which the optical axis of the imaging optical system housing 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 will be collectively referred to as the Z / Y-axis direction. The direction of rotation around the Z-axis will be defined as the pitch direction, and the direction of rotation around the Y-axis will be defined as the yaw direction. The pitch direction and the yaw direction (hereinafter collectively referred to as the pitch / yaw direction) are directions of rotation around two axes, the Z-axis and the Y-axis, which are orthogonal to each other.

[0011] In this embodiment, an interchangeable lens is described as an example of an optical device, but the present invention is also applicable to other optical devices such as a camera with an integrated lens.

[0012] A grip section 2 for the user to hold the camera body 1 is provided on the left side (right side when viewed from the rear) when viewed from the front (subject side) of the camera body 1. A power control unit 3 is located on the top surface of the camera body 1. When the camera body 1 is in the power-off state, the user turns on the power control unit 3, which turns on the camera body 1 and enables image capture. Conversely, when the camera body 1 is in the power-on state, the user turns off the power control unit 3, which turns off the camera body 1.

[0013] Furthermore, the top surface of the camera body 1 is equipped with a mode dial 4, a release button 5, and an accessory shoe 6. The user can switch between imaging modes by rotating the mode dial 4. Imaging modes include a manual still image mode in which the user can arbitrarily set imaging conditions such as shutter speed and aperture value, an auto still image mode in which the appropriate exposure amount is automatically obtained, and a video imaging mode for capturing video. By half-pressing the release button 5, the user can instruct preparatory operations for imaging, such as autofocus and automatic exposure control, and by fully pressing it, the user can instruct imaging. Accessories such as an external flash and an external viewfinder (EVF), not shown, can be detachably attached to the accessory shoe 6. In addition, the camera body 1 is equipped with an image sensor that converts (images) the subject image formed by the imaging optical system in the interchangeable lens 101 into photoelectric images.

[0014] The interchangeable lens 101 is mechanically and electrically connected to the camera mount 7 provided on the camera body 1 via the lens mount 102. As mentioned above, the interchangeable lens 101 houses an imaging optical system that uses light from the subject to form an image of the subject. The outer circumference of the interchangeable lens 101 is provided with a zoom operation ring 103 that can be rotated around the optical axis by user operation. The outer circumference of the zoom operation ring 103 is provided with a knurled shape to prevent the user's hand from slipping when operating it. When the zoom operation ring 103 is rotated by the user, the zoom group constituting the imaging optical system moves to a predetermined optical position corresponding to the angle of the zoom operation ring 103. In this way, the user can take pictures at the desired angle of view.

[0015] As shown in Figure 1(b), the rear of the camera body 1 is provided with a rear control panel 8 and a display panel 9. The rear control panel 8 includes multiple buttons and dials to which various functions are assigned. When the camera body 1 is powered on and a still image or video recording mode is set, the display panel 9 displays a through image of the subject being captured by the image sensor. The display panel 9 also displays imaging parameters indicating imaging conditions such as shutter speed and aperture value, and the user can change the settings of these imaging parameters by operating the rear control panel 8 while viewing the display. The rear control panel 8 includes a playback button for instructing playback of recorded images, and when the user operates the playback button, the captured images are displayed on the display panel 9.

[0016] FIG. 2 is a block diagram showing the electrical and optical configurations of the interchangeable lens 101 and the camera body 1. The camera body 1 includes a power supply unit 10 that supplies power to the camera body 1 and the interchangeable lens 101, and an operation unit 11 that includes the touch panel functions of the power operation unit 3, the mode dial 4, the release button 5, the rear operation unit 8, and the display unit 9 described above. Control of the entire system of the camera body 1 and the interchangeable lens 101 is performed by the camera control unit 12 provided in the camera body 1 and the lens control unit 104 provided in the interchangeable lens 101 cooperating with each other. The camera control unit 12 reads and executes a computer program stored in the storage unit 13. At that time, the camera control unit 12 communicates with the lens control unit 104 via the communication terminal of the electrical contact 105 provided on the lens mount 十02 for various control signals, data, etc. The electrical contact 105 includes a power supply terminal that supplies power from the power supply unit 10 described above to the interchangeable lens 101.

[0017] It should be noted that there seems to be an error in the original text where "十02" is likely a misrepresentation. I've translated it as "102" as it seems more appropriate based on the context. If this is incorrect, please adjust accordingly.The camera body 1 also includes a shutter unit 14, a shutter drive unit 15, an image sensor 16, an image processing unit 17, and a focus detection unit 18. The shutter unit 14 controls the amount of light that is focused by the imaging optical system in the interchangeable lens 101 and exposed by the image sensor 16. The image sensor 16 converts the subject image formed by the imaging optical system into an image signal. The image processing unit 17 performs various image processing on the image signal and then generates an image signal. The display unit 9 displays the image signal (through image) output from the image processing unit 17, displays imaging parameters as described above, and plays back and displays captured images recorded in the storage unit 13 or a recording medium (not shown). The camera control unit 12 controls the driving of the aperture group 401 and the shutter unit 14 via the aperture drive unit 402 and the shutter drive unit 15 according to the aperture value and shutter speed settings received from the operation unit 11. Furthermore, the camera control unit 12 controls the drive of the focus group 501 in response to the image preparation operation (half-press operation) on the operation unit 11 (release button 5). For example, when autofocus operation is instructed, the focus detection unit 18 determines the focus state of the subject image formed by the image sensor 16 based on the image signal generated by the image processing unit 17, generates a focus signal, and transmits it to the camera control unit 12. In parallel, the focus drive unit 502 detects the current position of the focus group 501 and transmits the detection signal to the camera control unit 12 via the lens control unit 104. The camera control unit 12 compares the focus state of the subject image with the current position of the focus group 501, calculates the focus drive amount from the amount of deviation, and transmits it to the lens control unit 104. The lens control unit 104 then drives the focus group 501 to the target position via the focus drive unit 502 and corrects the focus deviation of the subject image.

[0018] Furthermore, the camera body 1 has a pitch shake detection unit 19 and a yaw shake detection unit 20 to detect image shakes such as hand shakes by the user. The pitch shake detection unit 19 and the yaw shake detection unit 20 use an angular velocity sensor (vibration gyro) or an angular acceleration sensor to detect image shakes in the pitch direction (rotation direction around the Z axis) and the yaw direction (rotation direction around the Y axis), respectively, and output shake signals. The camera control unit 12 calculates the shift position in the Y-axis direction of the lens anti-shake group 301 (shift lens) using the shake signal from the pitch shake detection unit 19. Similarly, the camera control unit 12 calculates the shift position in the Z-axis direction of the lens anti-shake group 301 using the shake signal from the yaw shake detection unit 20. Then, the camera control unit 12 drives and controls the lens anti-shake group 301 to the target position according to the calculated shift positions in the pitch / yaw directions, and performs an anti-shake operation to reduce image shakes during exposure or during through-image display.

[0019] The imaging optical system of the interchangeable lens 101 is connected to the zoom operation ring 103 and has a zoom group 200 that moves along the optical axis to change the angle of view, and a lens anti-shake group 301 including a shift lens as an anti-shake element for reducing image shakes. The lens anti-shake group 301 performs an anti-shake operation to reduce image shakes by moving (shifting) the shift lens in the Z / Y-axis directions orthogonal to the optical axis. Further, the imaging optical system has an aperture group 401 that performs a light amount adjustment operation, and a focus group 501 including a focus lens that moves along the optical axis to perform focus adjustment. Furthermore, the interchangeable lens 101 has an anti-shake drive unit 302 that drives the lens anti-shake group 301 to shift the shift lens, an aperture drive unit 402 that drives the aperture group 401, and a focus drive unit 502 that drives the focus group 501 to move the focus lens.

[0020] The interchangeable lens 101 includes a zoom operation 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 operation ring 103. The zoom detection unit 106 detects the angle of the zoom operation ring 103 operated by the user as an absolute value. For example, a resistive linear potentiometer can be used as the zoom detection unit 106. The information regarding the angle of view detected by the zoom detection unit 106 is transmitted to the lens control unit 104 and reflected in various controls by the camera control unit 12. Some of this information is also recorded in the storage unit 13 or recording medium along with the captured image.

[0021] The positional relationship between the interchangeable lens 101 and the components in the camera body 1 will be explained below with reference to Figures 3 and 4. Figures 3 and 4 are cross-sectional views on the XY plane containing the optical axis of the interchangeable lens 101 in the zoom-retracted and extended states, respectively. The center line O shown here substantially coincides with the optical axis determined by the imaging optical system, and therefore will be considered synonymous with the optical axis hereafter.

[0022] In this embodiment, a zoom configuration is employed as an example of an imaging optical system. Each group, moved to a predetermined optical position according to the angle of view, guides light from the subject to the imaging surface of the image sensor 16. At this time, the lens vibration stabilization group 301, the aperture group 401, and the focus group 501 are each positioned in predetermined locations.

[0023] Furthermore, the present invention is not limited to the lens group configuration of this embodiment, and some of the lens groups may be fixed rather than movable.

[0024] The straight guide tube 107 is a fixed component that is fixed to the lens mount 102 via the fixed tube 109. Bayonet claws (not shown) are arranged at equal intervals on the outer circumferential surface of the straight guide tube 107. On the other hand, a circumferential groove (not shown) is provided on the inner circumferential surface of the cam tube 108. Furthermore, the cam tube 108 is connected to the zoom operating ring 103. When the zoom operating ring 103 is rotated, the cam tube 108 rotates around the optical axis due to the engagement of the bayonet claws and the circumferential groove.

[0025] The linear guide cylinder 107 has linear guide grooves formed therein that restrict the rotational movement of each zoom group and guide it to move in a straight line in the optical axis direction. The cam cylinder 108 has cam grooves formed therein that correspond to each zoom group and have trajectories at different angles in the rotational direction. Each zoom group is provided with a cam follower, and each cam follower engages with the corresponding linear guide groove and cam groove. When the user rotates the zoom operating ring 103, the cam cylinder 108 rotates, and the cam follower, through engagement with the linear guide groove and cam groove, moves the optical unit 600 (lens vibration damping group 301, aperture group 401, focus group 501, etc.) forward and backward in the optical axis direction.

[0026] As shown in Figure 4, the optical unit 600 is arranged on the inner circumferential surface of the straight guide cylinder 107 and consists of a front fixing cylinder (second base member) 610, a rear fixing cylinder (first base member) 620, and groups arranged on the inner circumferential surfaces of the front fixing cylinder 610 and the rear fixing cylinder 620. The front fixing cylinder 610 and the rear fixing cylinder 620 are made up of cylindrical parts. The optical unit 600 moves forward and backward along the optical axis when the user operates the zoom operation ring 103.

[0027] The front fixed cylinder 610 includes a focusing group 501 and supports the focusing group 501 so that it can move along the optical axis. The rear fixed cylinder 620 includes a lens image stabilization group 301 and an aperture group 401.

[0028] The holding configuration of the flexible printed circuit board in this embodiment will be described below. Figure 5 is a perspective view of the optical unit 600. Figures 5(a) and 5(b) are a view from the front and a side view, respectively.

[0029] The front fixing cylinder 610 is secured to the rear fixing cylinder 620 by fixing cylinder fixing screws 630.

[0030] The flexible printed circuit board 700 is a single-sided flexible printed circuit board that is flexible. The flexible printed circuit board 700 has a structure in which a wiring pattern made of copper foil is sandwiched between a base film and a coverlay film made of an insulating film such as polyimide, and bonded together using a thermosetting adhesive. Although the degree of freedom in wiring is limited because the wiring pattern is formed on only one side of the single-sided flexible printed circuit board, it has the advantage of lower manufacturing costs compared to multilayer flexible printed circuit boards.

[0031] The flexible printed circuit board 700 is electrically connected to the main board, which is the lens control unit 104, via a connector.

[0032] The motor 701 is electrically connected to the flexible printed circuit board 700 by soldering. The motor retaining plate 702, which is integrally attached to the motor 701, is screwed to the front fixing cylinder 610 by motor fixing screws 703. In this embodiment, the motor 701 is a stepping motor.

[0033] The movable bending portion 710 extends in the direction of the optical axis and swings with the movement of at least a part of the imaging optical system. The locking portion 711 is provided at a position extending from the movable bending portion 710 and is locked (fixed) by a hook portion (first holding portion) 621 integrally formed with the rear fixing cylinder 620. Furthermore, as shown in Figure 5(a), depending on the length and shape of the flexible printed circuit board 700, in addition to the locking portion 711, a locking portion 712 or multiple locking portions may be provided.

[0034] The flexible printed circuit board 700 is held by a linear guide tube 107 (not shown). By positioning a movable bending portion 710 between the linear guide tube 107 and the rear fixed tube 620, the optical unit 600 can move along the optical axis.

[0035] In this embodiment, a configuration in which the locking portion 711 is fixed by a hook portion 621 provided on the rear fixing cylinder 620 has been described, but other configurations are acceptable as long as the locking portion 711 can be fixed. For example, the locking portion 711 may be fixed to the rear fixing cylinder 620 by screwing it in, applying adhesive, or using adhesive tape. However, in the configuration of this embodiment, no additional parts are required, so the number of parts and assembly man-hours can be reduced by simplifying the assembly process.

[0036] The flexible printed circuit board 700 is equipped with a hook portion 720 for holding onto the front fixing cylinder 610. The hook portion 720 is held in place by a float suppression portion (second holding portion) 611 which is integrally formed with the front fixing cylinder 610. This suppresses the lifting of the flexible printed circuit board 700. After the flexible printed circuit board 700 is held onto the front fixing cylinder 610, the assembly is carried out in the order of screwing the rear fixing cylinder 620 to the front fixing cylinder 610. Therefore, when the rear fixing cylinder 620 is screwed to the front fixing cylinder 610, the hook portion 720 is sandwiched between the front fixing cylinder 610 and the rear fixing cylinder 620 and is contained within the space without coming loose.

[0037] The locking portion 711 is fixed to the rear fixing cylinder 620, and the hooking portion 720 is in contact with the front fixing cylinder 610. In this way, the flexible printed circuit board 700 is positioned across the front fixing cylinder 610 and the rear fixing cylinder 620. The excess length bent portion 730 is formed by pre-setting a longer distance between the locking portion 711 and the hooking portion 720.

[0038] In the interchangeable lens 101, if inertial force or external force is applied, for example, due to an impact caused by the photographer dropping the camera, the front fixing cylinder 610 and the rear fixing cylinder 620 may deform. Also, the front fixing cylinder 610 and the rear fixing cylinder 620 may temporarily separate due to the impact. If the flexible printed circuit board 700 is fixed to the front fixing cylinder 610 and the rear fixing cylinder 620 respectively, the above deformation may apply force to the flexible printed circuit board 700, potentially causing disconnection of the wiring pattern or fracture of the outer shape.

[0039] Another method involves allowing the flexible printed circuit board 700 to float while still being fixed in place. However, this raises concerns about interference with other components, and ensuring sufficient space between the flexible printed circuit board 700 and other components may lead to an increase in the size of the interchangeable lens 101.

[0040] In this embodiment, by providing an excess bent portion 730 between the locking portion 711 and the hooking portion 720, the deformation of the excess bent portion 730 absorbs the impact when an external force is applied, thereby suppressing the fracture of the flexible printed circuit board 700. Furthermore, an increase in size is suppressed, and an impact-resistant interchangeable lens 101 can be provided with a simple configuration.

[0041] As in conventional technology, there is also a method in which the flexible printed circuit board 700 is not fixed to the front fixing cylinder 610 and the rear fixing cylinder 620. However, if the flexible printed circuit board 700 is provided with a movable bending portion 710, there is a concern that a protruding shape such as a hooking portion 720 will repeatedly come into contact with and separate from a hook shape such as a float-preventing portion 611. In such a case, even if an excess bending portion 730 is provided, there is a risk of wire breakage or collision noise occurring in the flexible printed circuit board 700.

[0042] In this embodiment, since the movable bend portion 710 side of the excess bend portion 730 is fixed by the locking portion 711, the excess bend portion 730 does not deform even when the movable bend portion 730 moves, thus suppressing the aforementioned wire breakage and collision noise. Furthermore, the locking portion 711 serves both to hold the movable bend portion 710 and to hold the flexible printed circuit board 700 for forming the excess bend portion 730. Therefore, in this embodiment, it is possible to achieve both the movable bending of the flexible printed circuit board 700 and protection against external impacts in a space-saving manner.

[0043] Figure 6 is a perspective view of the flexible printed circuit board 700. The flexible printed circuit board 700 has a motor 701 and a position detection element 706 soldered to it and is electrically conductive. The motor 701 and the position detection element 706 are positioned in the front fixing cylinder 610.

[0044] The position detection element 706 is a photointerrupter and is arranged along the optical axis. In this embodiment, there are two position detection elements 706a and 706b, but there may be two or more, and the present invention is not limited to this. Furthermore, when the flexible printed circuit board 700 is unfolded, it has a substantially linear shape except for the arms extending to the motor 701. Therefore, there are fewer constraints on the placement of the flexible printed circuit board 700, and the degree of freedom in the layout of the optical unit 600 can be increased.

[0045] Figure 7 is a detailed view of the locking portion 711 in the fixed state of the flexible printed circuit board 700. The locking portion 711 has protrusions that project in directions perpendicular to the thickness direction and the optical axis direction. The protrusions are composed of first ears 713a, 713b and second ears 714a, 714. The first ears 713a, 713b and the second ears 714a, 714b are arranged to straddle the hook portion 621 along the optical axis. This configuration restricts the movement of the flexible printed circuit board 700 in the optical axis direction.

[0046] Furthermore, the hook portion 621 overlaps with the flexible printed circuit board 700 in the direction of the paper. Therefore, the flexible printed circuit board 700 is configured in such a way that it cannot be lifted up and removed.

[0047] The first ear portions 713a and 713b have a semicircular shape to facilitate assembly to the hook portion 621. The second ear portions 714a and 714b have a rectangular shape and are positioned to abut linearly against the contact surface of the hook portion 621. The second ear portions 714a and 714b are configured to ensure a contact surface and to fix their position relative to the optical axis direction, as a force acting against the hook portion 621 is always applied by the reaction force of the flexible printed circuit board 700.

[0048] Furthermore, the locking portion 711 needs to be fixed in order to prevent collision noise caused by displacement in the direction of the paper plane or perpendicular to the paper plane at the movable bending portion 710.

[0049] Figure 8 is a detailed view of the hook portion 720 in the fixed state of the flexible printed circuit board 700.

[0050] The hook portion 720 is formed by a third lug portion 721. The third lug portion 721 is held by the float-preventing portion 611 of the front fixing cylinder 610, but is not completely fixed.

[0051] The hook portion 720 may be fixed in the same way as the locking portion 711, but in this embodiment, it is not fixed in consideration of the assembly procedure and required functions. The hook portion 720 is formed between the locking portion 711 and the rear fixing cylinder 620 and the front fixing cylinder 610 by screw fastening them together, thereby forming an excess length bent portion 730. Therefore, the hook portion 720 abuts against the float suppression portion 611 of the front fixing cylinder 610 and is positioned to fit in the space between the front fixing cylinder 610 and the rear fixing cylinder 620.

[0052] Furthermore, the hook portion 720 may be equipped with a reinforcing plate to increase its rigidity. The reinforcing plate is made of a material such as LCP resin, polyimide, or PET, and is bonded to the flexible printed circuit board 700 using a thermosetting adhesive.

[0053] Figure 9 is an explanatory diagram of the excess length bent portion 730. Figure 9(a) is a cross-sectional view taken along line A-A' in Figure 5(b) with the flexible printed circuit board 700 in a fixed state. Figure 9(b) is an enlarged view of the excess length bent portion 730. With respect to the placement surface 722 of the flexible printed circuit board 700, the side away from the optical axis is the outer diameter side B, and the side closer to the optical axis is the inner diameter side C.

[0054] If the excess bent portion 730 bulges outward towards the outer diameter side B relative to the placement surface 722, it may come into contact with the moving straight guide tube 107 (not shown), potentially causing a break in the wire. Therefore, the excess bent portion 730 must be restricted to bulge outward towards the inner diameter side C.

[0055] In this embodiment, the contact surface 612 with the hook portion 720 of the front fixing cylinder 610 is positioned on the inner diameter side C from the placement surface 722. In this configuration, when the hook portion 720 is assembled to the contact surface 612, the excess bent portion 730 is configured to bulge out on the inner diameter side C.

[0056] Figure 10 is an enlarged view of the position detection element mounting section. Position detection elements 706a and 706b (not shown in Figure 10) are mounted on the flexible printed circuit board 700 and are fixed to the front fixing cylinder 610 in a position-restricted manner. The position detection elements 706a and 706b are positioned along the optical axis from the excess length bend section 730. Specifically, the position detection elements 706a and 706b are positioned on the opposite side of the hook section 720 from the excess length bend section 730. However, if the extension from the excess length bend section 730 to the position detection elements 706a and 706b is the shortest possible distance, then if the position detection elements 706a and 706b are misaligned during soldering due to differences in land shape and electrode shape, misalignment will occur in fixing to the front fixing cylinder 610. This misalignment of the position detection elements 706a and 706b can cause stress concentration in the solder, potentially leading to damage such as solder cracks.

[0057] In this embodiment, a first displacement absorption section 741, a second displacement absorption section 742, and a third displacement absorption section 743 are provided between the excess length bent section 730 and the position detection element 706a. The first displacement absorption section 741 is cranked 90 degrees from the excess length bent section 730. The second displacement absorption section 742 is cranked 90 degrees from the first displacement absorption section 741. The third displacement absorption section 743 is cranked 90 degrees from the second displacement absorption section 742. With this configuration, by intentionally bypassing the path, each displacement absorption section twists and functions as an excess length section, which can suppress solder cracks and the like caused by positional misalignment that occurs when soldering the position detection element 706a. Furthermore, by providing the first displacement absorption section 741, the second displacement absorption section 742, and the third displacement absorption section 743, the twisting of the flexible printed circuit board 700 in the thickness direction caused by the displacement of the position detection element 706a can also be absorbed.

[0058] In this embodiment, the circuit is detoured in a crank shape, but it may also be U-shaped, S-shaped, or other shapes. Furthermore, the displacement absorption section does not need to detour every 90 degrees, and may be composed of a semicircular shape. In addition, by providing a fourth displacement absorption section 744 arranged in line with the third displacement absorption section 743 in the optical axis direction, the displacement of the position detection element 706b can be absorbed.

[0059] In this embodiment, the excess length bending portion 730, the first displacement absorption portion 741, and the position detection elements 706a and 706b are arranged on a single straight line. This allows for high reliability in suppressing solder cracks while saving space for each function (excess length bending portion 730 and multiple displacement absorption portions). Furthermore, as shown in Figure 5, the movable bending portion 710, the excess length bending portion 730, and the position detection elements 706a and 706b are arranged in a straight line along the optical axis.

[0060] As described above, according to the configuration of this embodiment, the flexible printed circuit board 700 is equipped with a locking portion 711 that serves both to hold the movable bending portion 710 and to hold the flexible printed circuit board 700 for forming the excess bending portion 730. This makes it possible to realize an impact-resistant interchangeable lens 101. Furthermore, by providing multiple misalignment absorption portions that take into account the mounting misalignment of the position detection elements 706a and 706b, the flexible printed circuit board 700 is provided with excess length having three types and three functions in total, including the movable bending portion 710 and the excess bending portion 730.

[0061] In this embodiment, the configuration of the flexible printed circuit board 700 in the focus drive unit 502 has been described, but the present invention is also applicable to the configuration of the flexible printed circuit board in the vibration damping drive unit 302 and the aperture drive unit 402. In this case, the vibration damping drive unit 302 is equipped with a position detection element such as a Hall element, and the aperture drive unit 402 is equipped with a position detection element such as a photointerrupter.

[0062] This embodiment includes the following configuration. (Composition 1) Optical system and The first base member and A second base member held by the first base member, The device includes a flexible printed circuit board that spans the first and second base members, The flexible printed circuit board comprises a movable bending portion, a locking portion, and a hooking portion, which are arranged in order from the first base side to the second base side along the optical axis direction of the optical system. The first base member includes a first holding portion that holds the locking portion in a fixed position in the thickness direction and the optical axis direction of the flexible printed circuit board, The second base member includes a second holding portion that restricts and holds the hook portion at one of the positions of the flexible printed circuit board in the thickness direction and in the optical axis direction, The optical device is characterized in that the flexible printed circuit board has an excess length bent portion formed between the locking portion and the hooking portion. (Configuration 2) The locking portion includes a projection that protrudes in a direction perpendicular to the thickness direction and the optical axis direction, The optical device according to configuration 1, characterized in that the protruding portion is configured to sandwich the first holding portion in the optical axis direction. (Composition 3) The optical device according to configuration 2, characterized in that the protruding portions are arranged in at least two locations. (Composition 4) The protruding portion comprises a first lug portion positioned on the side of the first base member, and a second lug portion positioned on the side of the second base member, sandwiching the first lug portion and the first holding portion. The first ear portion has a semicircular shape, The optical device according to configuration 2 or 3, characterized in that the second ear portion has a rectangular shape. (Composition 5) The optical device according to any one of configurations 1 to 3, characterized in that the second holding portion holds the hook portion in the thickness direction at a position different from the arrangement surface on which the second base member of the flexible printed circuit board is arranged. (Composition 6) The optical instrument according to any one of configurations 1 to 5, characterized in that the first and second base members are composed of cylindrical parts. (Composition 7) The optical device according to any one of configurations 1 to 6, characterized in that the flexible printed circuit board is positioned on the side opposite to the excess length bending portion with respect to the hook portion and includes a detection element for detecting the movement of the optical system. (Composition 8) The optical device according to configuration 7, characterized in that the flexible printed circuit board is provided with a displacement absorbing portion that deviates in a direction perpendicular to the optical axis direction between the hooking portion and the detection element. (Composition 9) The optical device according to configuration 7 or 8, characterized in that two or more detection elements are arranged. (Composition 10) The optical instrument according to any one of configurations 7 to 9, characterized in that the detection element, the excess length bent portion, and the movable bent portion are arranged in a straight line along the optical axis direction.

[0063] Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of its gist. [Explanation of symbols]

[0064] 101 Interchangeable Lenses (Optical Instruments) 610 Front fixing cylinder (second base member) 611 Float-retaining section (second holding section) 620 Rear fixing cylinder (first base member) 621 Hook portion (first holding portion) 700 Flexible Printed Circuit Boards 710 Movable bending part 711 Locking part 720 Hook part 730 Extra length bending part

Claims

1. Optical system and First base member, A second base member is held by the first base member, It comprises a flexible printed circuit board that is positioned across the first and second base members, The flexible printed circuit board comprises a movable bending portion, a locking portion, and a hooking portion, which are arranged in order from the side of the first base to the side of the second base along the optical axis of the optical system. The first base member includes a first holding portion that holds the locking portion in a fixed position in the thickness direction and the optical axis direction of the flexible printed circuit board, The second base member includes a second holding portion that restricts and holds the hook portion at one of the positions of the flexible printed circuit board in the thickness direction and in the optical axis direction, The optical device is characterized in that the flexible printed circuit board has an excess length bent portion formed between the locking portion and the hooking portion.

2. The locking portion includes a projection that protrudes in a direction perpendicular to the thickness direction and the optical axis direction, The optical device according to claim 1, characterized in that the protruding portion is configured to sandwich the first holding portion in the optical axis direction.

3. The optical device according to claim 2, characterized in that the protruding portions are arranged in at least two locations.

4. The protruding portion comprises a first lug portion positioned on the side of the first base member, and a second lug portion positioned on the side of the second base member, sandwiching the first lug portion and the first holding portion. The first ear portion has a semicircular shape, The optical device according to claim 2, characterized in that the second ear portion has a rectangular shape.

5. The optical device according to claim 1 or 2, characterized in that the second holding portion holds the hook portion in the thickness direction at a position different from the arrangement surface on which the second base member of the flexible printed circuit board is arranged.

6. The optical device according to claim 1 or 2, characterized in that the first and second base members are composed of cylindrical parts.

7. The optical device according to claim 1 or 2, characterized in that the flexible printed circuit board is positioned on the side opposite to the excess length bending portion with respect to the hook portion and includes a detection element for detecting the movement of the optical system.

8. The optical device according to claim 7, characterized in that the flexible printed circuit board is provided with a displacement absorbing portion between the hooking portion and the detection element, which deviates in a direction perpendicular to the optical axis direction.

9. The optical device according to claim 7, characterized in that two or more detection elements are arranged.

10. The optical device according to claim 7, characterized in that the detection element, the excess length bent portion, and the movable bent portion are arranged in a straight line along the optical axis direction.

Images