Optical equipment and camera system

Abstract

To provide optical equipment capable of maintaining optical holding accuracy while constituted to collapse.SOLUTION: Optical equipment includes: a holding member which holds an optical system; a drive part moving the holding member; an intermediate member which includes a first intermediate member abutting on the drive part and a second intermediate member abutting on the first intermediate member and holding member, and transmits the driving force of the drive part to the holding member; and a first energizing member which energizes the first intermediate member to the drive part and also energizes the second intermediate member to the holding member.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to an optical instrument and a camera system. [Background technology]

[0002] In recent years, there has been a demand for improved portability when carrying optical devices such as digital cameras, video cameras, and interchangeable lenses. Patent Document 1 discloses a configuration in which, in a collapsed state in which at least a portion of a plurality of lens groups are collapsed to store the lens groups, the overall length is shortened by narrowing the range of movement of the focus lens holding frame in particular. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-150368 Summary of the Invention [Problem to be solved by the invention]

[0004] In the configuration of Patent Document 1, the focus lens holding frame can be biased in a direction parallel to the optical axis, but cannot be biased in a planar direction perpendicular to the optical axis, which reduces the precision with which the lens is held and may result in a deterioration in the image quality of the captured image.

[0005] An object of the present invention is to provide an optical device that has a retractable configuration and is capable of maintaining optical retention precision. [Means for solving the problem]

[0006] An optical device according to one aspect of the present invention includes a holding member that holds an optical system, a driving unit that moves the holding member, a first intermediate member that abuts the driving unit, and a second intermediate member that abuts the first intermediate member and the holding member, and is characterized by having an intermediate member that transmits the driving force of the driving unit to the holding member, and a first biasing member that biases the first intermediate member toward the driving unit and biases the second intermediate member toward the holding member. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide an optical device that has a retractable configuration and is capable of maintaining optical retention precision. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of a camera system according to a first embodiment. [Figure 2] FIG. 1 is a block diagram of a camera system according to a first embodiment. [Figure 3] 1 is a cross-sectional view of an interchangeable lens of Example 1 (at the wide-angle end during shooting). [Figure 4] 1 is a cross-sectional view of an interchangeable lens of Example 1 (at the telephoto end during shooting). [Figure 5] 1 is a cross-sectional view of the interchangeable lens of Example 1 (at the retracted end when not taking pictures). [Figure 6] 1A and 1B are a perspective view and an exploded perspective view of a collapsing mechanism of Example 1. FIG. [Figure 7] FIG. 2 is a front view of the collapsible mechanism of the first embodiment. [Figure 8] FIG. 2 is a cross-sectional view showing the telephoto end close-up state of the collapsible mechanism of the first embodiment. [Figure 9] 2 is a cross-sectional view showing the retracted end of the retracting mechanism of the first embodiment. FIG. [Figure 10] FIG. 2 is a perspective view showing a holding structure for a focus group at the telephoto end of the first embodiment. [Figure 11] FIG. 2 is a perspective view showing a holding structure for a focus group at the retracted end of the first embodiment. [Figure 12] FIG. 2 is a front perspective view showing a holding structure of a focus group according to the first embodiment. [Figure 13]FIG. 2 is a cross-sectional view showing the holding structure of the rack according to the first embodiment. [Figure 14] FIG. 2 is a perspective view of the lens mount of the first embodiment as seen from the subject side. [Figure 15] FIG. 10 is a perspective view showing a holding structure for a focus group at the telephoto end of Example 2. [Figure 16] FIG. 10 is a perspective view showing a holding structure for a focus group at the retracted end of Example 2. [Figure 17] FIG. 10 is a front perspective view showing a holding structure of a focus group according to a second embodiment. [Figure 18] FIG. 10 is a cross-sectional view showing the holding structure of the rack according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to designate the same components, and redundant explanations will be omitted. Example 1 FIG. 1 is a perspective view of a camera system (imaging device) of this embodiment. The camera system has an interchangeable lens 101 and a digital camera (hereinafter referred to as camera body) 1 to which the interchangeable lens 101 is detachably attached. FIGS. 1(A) and 1(B) are perspective views seen from the front side (subject side) and the back side (imaging surface side), respectively. Note that, although this embodiment describes the interchangeable lens 101, which is an example of an optical device, the present invention is also applicable to integrated lens cameras and the like.

[0010] In this embodiment, as shown in FIG. 1A, the optical axis direction, which is the direction in which the optical axis of the imaging optical system housed in the interchangeable lens 101 extends (the direction along the optical axis), is defined as the X-axis direction, and the directions perpendicular to the X-axis direction 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 also be collectively referred to as the Z / Y-axis direction. Furthermore, the rotation direction around the Z axis will be defined as the pitch direction, and the rotation direction around the Y axis will be defined as the yaw direction. The pitch direction and 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 unit 2 is provided on the left side of the camera body 1 as viewed from the front (the right side as viewed from the rear) for the user to hold the camera body 1 with their hand. A power operation unit 3 is also located on the top surface of the camera body 1. When the user turns on the power operation unit 3 while the camera body 1 is in a power-off state, power is supplied to the camera body 1, the camera body 1 enters a power-on state, and a computer program, such as a focus group origin detection program, is executed, and the camera body 1 enters a shooting standby state. Even when the camera body 1 is in a power-off state, if the camera body 1 detects that the interchangeable lens 101 has been mechanically and electrically connected, power is supplied from the camera body 1 to the interchangeable lens 101, and a focus group origin detection program is executed. On the other hand, when the camera body 1 is in a power-on state and the user turns off the power operation unit 3, the camera body 1 enters a power-off state.

[0012] The top surface of the camera body 1 is provided 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. The imaging modes include a manual still image capture mode, in which the user can freely set imaging conditions such as shutter speed and aperture value, an auto still image capture mode, in which the appropriate exposure is automatically obtained, and a video capture mode for capturing videos. The user can also half-press the release button 5 to instruct imaging preparation operations such as autofocus and auto exposure control, and can fully press the button to instruct imaging. An accessory (camera accessory) such as an external flash or other lighting or light-emitting device can be detachably attached to the accessory shoe 6.

[0013] The interchangeable lens 101 includes a lens mount (fixed member) 102 that can be mechanically and electrically connected to a camera mount 7 provided on the camera body 1. The interchangeable lens 101 houses an imaging optical system that forms an image of a subject using light from the subject. A zoom ring (operating member) 103 that can be rotated around the optical axis by a user is provided on the outer periphery of the interchangeable lens 101. When the zoom ring 103 is rotated by the user, the zoom groups that make up the imaging optical system move to predetermined usage positions that correspond to the angle of the zoom ring 103, within a range from the wide-angle end to the telephoto end. This configuration allows the user to capture images at a desired angle of view. In addition, as will be described in detail later, in this embodiment, a retractable end, where imaging is further restricted, is provided after the zoom ring 103 is rotated from the telephoto end to the wide-angle end. The retractable end is the position where the interchangeable lens 101 is most retracted.

[0014] The rear surface of the camera body 1 is provided with a rear operation unit 8 and a display unit 9. The rear operation unit 8 includes a plurality of buttons and dials to which various functions are assigned. When the camera body 1 is powered on and the still image capture mode or video capture mode is set, the display unit 9 displays a through image of a subject captured by an image sensor (described later). The display unit 9 also displays shooting parameters indicating shooting conditions such as shutter speed and aperture value. The user can change the settings of the shooting 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. When the user operates the playback button, the captured image is played back and displayed on the display unit 9. The display unit 9 may be a touch panel type having the same functions as the rear operation unit 8.

[0015] FIG. 2 is a block diagram showing the electrical and optical configuration of the camera system. 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 a power operation unit 3, a mode dial 4, a release button 5, a rear operation unit 8, and a touch panel function of the display unit 9. The entire camera system is 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, which communicate with each other. The camera control unit 12 reads and executes a computer program stored in a memory unit 13. In this case, 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 is equipped with a zoom group 110 connected to a zoom operation ring 103 and moving in the optical axis direction to change the angle of view, and a lens vibration reduction group 112 including a shift lens as an image stabilization element that reduces image blur. The lens vibration reduction group 112 performs vibration reduction operation to reduce image blur by moving (shifting) the shift lens in directions including Z- and Y-axis components orthogonal to the optical axis. The imaging optical system also includes an aperture group 301 that adjusts the amount of light, and a focus group (optical system) 114 including a focus lens that moves in the optical axis direction to adjust the focus. The interchangeable lens 101 also includes an image stabilization driver 201 that drives the lens vibration reduction group 112 to shift the shift lens, an aperture driver 302 that drives the aperture group 301, and a focus driver 401 that drives the focus group 114 to move the focus lens.

[0017] The camera body 1 has a shutter unit 14, a shutter driver 15, an image sensor 16, an image processor 17, and a camera controller 12. The shutter unit 14 controls the amount of light collected by the imaging optical system in the interchangeable lens 101 and exposed to the image sensor 16. The image sensor 16 photoelectrically converts the subject image formed by the imaging optical system and outputs an image signal. The image processor 17 performs various image processes on the image signal and then generates an image signal. The display 9 displays the image signal (through image) output from the image processor 17, displays shooting parameters, and plays back and displays captured images recorded in the memory unit 13 or a recording medium (not shown).

[0018] The camera control unit 12 controls the focus driving unit 401 in response to a shooting preparation operation (such as half-pressing the release button 5) on the operation unit 11. For example, when an 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 sends it to the camera control unit 12. At the same time, the focus driving unit 401 sends information about the current position of the focus group 114 to the camera control unit 12. The camera control unit 12 compares the focus state of the subject image with the current position of the focus group 114, calculates a focus driving amount from the amount of deviation, and sends it to the lens control unit 104. The lens control unit 104 then moves the focus group 114 to a target position in the optical axis direction via the focus driving unit 401, thereby correcting the focus deviation of the subject image.

[0019] As will be described in more detail below, the focus drive unit 401 includes a focus motor 401a that functions as an actuator, and a photointerrupter that detects the origin position of the focus group 114. In this embodiment, the photointerrupter functions as a detector. Generally, a stepping motor, which is a type of actuator, is often used as the focus motor. However, because a stepping motor can only control the relative drive amount, the current position of the focus group 114 becomes undefined when the camera body 1 is powered off. In this case, the current position of the focus group 114 cannot be detected.

[0020] Also, consider a case where the power to the camera body 1 remains on, but the power to the interchangeable lens 101 is interrupted by, for example, mechanically removing the interchangeable lens 101 from the camera mount 7 of the camera body 1. In this case, the focus group 114 is held in the position it was in when the power was interrupted, making it impossible to detect.

[0021] When the user turns on the power supply operation unit 3 while the current position of the focus group 114 described above is uncertain, the focus group 114 must be moved to the origin position and origin detection processing must be executed before the camera enters a shooting standby state.

[0022] Note that focus motor 401a may be a DC motor with an encoder, an ultrasonic motor, a servo motor, etc. Also, although a photointerrupter directly receives light emitted from a light-emitting unit with a light-receiving unit, a photoreflector that receives light reflected from a reflective surface or a brush that electrically detects a signal by contacting a conductive pattern may be used as the detection unit instead.

[0023] Furthermore, the camera control unit 12 controls the driving of the aperture group 301 and the shutter unit 14 via the aperture drive unit 302 and the shutter drive unit 15 in accordance with the setting values ​​of the aperture value and shutter speed received from the operation unit 11. For example, when an automatic exposure control operation is instructed, the camera control unit 12 receives a luminance signal generated by the image processing unit 17 and performs a photometric calculation. Based on the result of the photometric calculation, the camera control unit 12 controls the aperture drive unit 302 in accordance with a shooting instruction operation on the operation unit 11 (such as a full press of the release button 5). At the same time, the camera control unit 12 controls the driving of the shutter unit 14 via the shutter drive unit 15 and performs an exposure process by the image sensor 16.

[0024] The camera body 1 has a pitch shake detection unit 19 and a yaw shake detection unit 20 as shake detection means capable of detecting image shake caused by a user's hand shake or the like. The pitch shake detection unit 19 and the yaw shake detection unit 20 each use an angular velocity sensor (vibration gyro) and an angular acceleration sensor to detect image shake in the pitch direction (rotation direction around the Z axis) and the yaw direction (rotation direction around the Y axis) and output a shake signal. 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. Similarly, the camera control unit 12 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. Then, the camera control unit 12 controls the drive of the lens vibration isolation group 112 to a target position according to the calculated shift positions in the pitch and yaw directions, and performs vibration isolation operation to reduce image shake during exposure and live view image display.

[0025] 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 is configured using, for example, a resistive linear potentiometer, and detects the angle of the zoom ring 103 operated by the user as an absolute value. Information about the angle of view detected by the zoom detection unit 106 is sent to the lens control unit 104 and reflected in various controls by the camera control unit 12. Some of the information about the various controls is recorded in the memory unit 13 or a recording medium together with the captured image.

[0026] The positional relationships of the main components of the interchangeable lens 101 will be described below with reference to Figures 3 to 5. Figures 3 to 5 are cross-sectional views of the interchangeable lens 101 on an XY plane that includes the optical axis. The center line shown in each figure approximately coincides with the optical axis determined by the imaging optical system, and therefore will be hereinafter referred to as the optical axis. Figure 3 shows the wide-angle end on the short focal length side of the zoom, and Figure 4 shows the telephoto end on the long focal length side of the zoom.

[0027] 3 and 4 both show the imaging optical system of the interchangeable lens 101 in a position where imaging is possible (a state where imaging is possible). On the other hand, Fig. 5 shows the imaging optical system of the interchangeable lens 101 in a stored state (a state where it is in a retracted position) when not taking images. Fig. 5 also shows the retracted end where the overall length in the optical axis direction is shortened to the shortest.

[0028] The retractable end shown in FIG. 5 is located further beyond the wide-angle end shown in FIG. 3. Rotating the zoom operation ring 103 in one direction sequentially transitions from the retractable end shown in FIG. 5 to the wide-angle end shown in FIG. 3, and from the wide-angle end shown in FIG. 3 to the telephoto end shown in FIG. 4. In this embodiment, a state in which the imaging optical system is ready is referred to as a first state, and a state in which the imaging optical system is in a retracted position is referred to as a second state. Note that a state in which imaging is ready means that the camera functions, including the camera body 1 and the interchangeable lens 101, can operate normally at any time. Restricted imaging means that some of the camera functions, including the camera body 1 and the interchangeable lens 101, do not operate normally. For example, when the imaging optical system is in a retracted position, it is possible to take a photograph (e.g., pressing the shutter to capture a subject), but the captured image may be wholly or partially blurred due to factors such as being out of focus.

[0029] As shown in FIGS. 3 and 4 , this embodiment employs a six-group configuration as an example of an imaging optical system. The zoom group 110 moves to different predetermined usage positions at the wide-angle end and the telephoto end to collect light from a subject onto the image sensor 16. The zoom group 110 is composed of a first zoom group 111, a lens vibration reduction group 112 and an aperture group 301 functioning as a second zoom group, a third zoom group 113, a focus group 114 functioning as a fourth zoom group, a fifth zoom group 115, and a sixth zoom group 116. Note that this embodiment does not limit the configuration of the imaging optical system; for example, the lens vibration reduction group 112 and the focus group 114 may function as other zoom groups. Furthermore, some lens groups may be fixed rather than movable.

[0030] The linear guide barrel 107 is a fixed component that is fixed to the lens mount 102 via a fixed barrel (not shown). Cam grooves (not shown) are formed at equal intervals on the outer peripheral surface of the linear guide barrel 107. Meanwhile, cam followers (not shown) are provided on the inner peripheral side of the cam barrel 108. The cam barrel 108 is also connected to the zoom operation ring 103 via a key (not shown). When the zoom operation ring 103 is rotated, the cam barrel 108 moves forward and backward in the optical axis direction while rotating about the optical axis due to the engagement between the cam grooves and the cam followers.

[0031] The linear guide barrel 107 has linear guide grooves formed at equal intervals that restrict movement of the zoom group 110 in the rotational direction and guide linear movement in the optical axis direction. Cam grooves, each with a different angle in the rotational direction, are formed at equal intervals in the cam barrel 108 to correspond to the zoom group 110. The zoom group 110 is provided with a plurality of cam followers, each of which is fitted into a corresponding linear guide groove and cam groove. When the user rotates the zoom operation ring 103, the cam barrel 108 rotates, and the cam followers, due to the fit between the linear guide grooves and the cam grooves, move the zoom group 110 forward and backward in the optical axis direction while restricting movement in the rotational direction.

[0032] The interchangeable lens 101 of this embodiment has a retractable mechanism, which will be described in detail later, and a retraction mechanism for the lens vibration isolation group (second zoom group) 112. This configuration makes it possible to retract the zoom group 110 further to the rear side (image capture surface side) when not taking pictures. This reduces the overall length of the interchangeable lens 101, making it possible to improve the portability of the interchangeable lens 101 and the camera body 1.

[0033] At the wide-angle end shown in FIG. 3, the distance between the first zoom group 111 and the lens vibration reduction group (second zoom group) 112 is wide, and at the telephoto end shown in FIG. 4, the distance between the fifth zoom group 115 and the sixth zoom group 116 is wide. The retractable mechanism narrows these distances, moves the zoom groups to a retracted position closer to each other, and shortens the overall length in the optical axis direction. As shown in FIG. 5, at the retracted end when not shooting, the zoom groups 110 are moved to a retracted position closer to each other. From this state, for example, when a user rotates the zoom operation ring 103 to the wide-angle end, the zoom groups 110 extend to the front side (subject side) and move to a predetermined usage position, thereby achieving the state in which shooting is possible, as shown in FIG. 3.

[0034] 3 and 4, all of the zoom groups 110 are arranged on the same optical axis, but at the retracted end when not shooting as shown in Fig. 5, the lens vibration reduction group (second zoom group) 112 retracts in a direction perpendicular to the optical axis (radial direction). When the user rotates the zoom operation ring 103 toward the retracted end from the wide-angle end where shooting is possible as shown in Fig. 3, the zoom groups 110 begin to retract toward the rear side (image plane side), and at the same time, the lens vibration reduction group (second zoom group) 112 retracts from the optical axis. The first zoom group 111 retracts further into the space thus created and is stored so as not to interfere with each other, resulting in the state in which the overall length is shortened to its shortest as shown in Fig. 5.

[0035] Fig. 6(A) is a perspective view of the members (components) that make up the retractable mechanism of this embodiment, and Fig. 6(B) is an exploded perspective view showing some of the components shown in Fig. 6(A). Fig. 7 is a front view of the retractable mechanism of this embodiment, and Figs. 8 and 9 are cross-sectional views taken along line S1-S1 in Fig. 7. Fig. 8 shows the telephoto end of the interchangeable lens 101, the same as Fig. 4. Fig. 9 shows the retracted end of the interchangeable lens 101, the same as Fig. 5.

[0036] The rear group base tube 118 houses a focus drive unit 401 including a focus motor 401a and a feed screw (meshing portion) 401b, a focus group holding frame (holding member) 141 that holds the focus group 114, and the fifth zoom group 115. The rear group base tube 118 moves integrally with the components in the optical axis direction during zooming from the wide-angle end to the telephoto end. Three cam followers 120 are provided at equal intervals on the outer periphery of the rear group base tube 118.

[0037] The cam follower 120 engages with a tapered inner circumferential cam groove provided on the inner periphery of the cam barrel 108. A cam barrel engaging portion 120a of the cam follower 120 is conical and configured to contact (for example, line contact) the slope of the inner circumferential cam groove. Furthermore, a guide barrel engaging portion 120b of the cam follower 120 engages with a rectilinear guide groove provided in the rectilinear guide barrel 107. When the zoom operation ring 103 is rotated, the cam barrel 108, which is connected by a key (not shown), rotates, and the rear group base barrel 118 moves in conjunction with the zoom operation ring 103. When the rear group base barrel 118 moves in the optical axis direction in this way, the system transitions from a first state in which photography is possible as shown in FIG. 8 to a second state in which photography is restricted as shown in FIG. 9, in which the movement of the focus group holding frame 141 is restricted.

[0038] 10 and 11 are perspective views showing the holding structure of the focus group 114. FIG. 10 shows the same telephoto end as FIGS. 4 and 8, and FIG. 11 shows the same retracted end as FIGS. 5 and 9. A first guide bar (guide member) 142 is a metal member fixed to the rear group base tube 118, and engages with a slide hole 141a on the imaging surface side and a slide hole 141b on the subject side formed in the focus group holding frame 141. Similarly, a second guide bar 143 fixed to the rear group base tube 118 engages with a U-shaped groove 141c provided in the focus group holding frame 141. This holds the focus group holding frame 141 so that it can move freely in the optical axis direction relative to the rear group base tube 118.

[0039] In this embodiment, the rack holder (second intermediate member) 144 and the rack (first intermediate member) 146 constitute an intermediate member that transmits the driving force of the focus driver 401 to the focus group holding frame 141. A through hole into which the first guide bar 142 is inserted is formed in the rack holder 144. The rack holder 144 is supported on the first guide bar 142 so as to be movable in the axial direction and rotatable on a plane perpendicular to the optical axis. A boss 144a of the rack holder 144 engages with an elongated hole 141d formed in the focus group holding frame 141, thereby preventing the rack holder 144 from rotating around the through hole. A compression coil spring (second biasing member) 145 is disposed in the space between the focus group holding frame 141 and the rack holder 144. One end of the compression coil spring 145 urges the focus group holding frame 141 toward the imaging surface in the optical axis direction, and the other end urges the rack holder 144 toward the slide hole 141b (subject side) of the focus group holding frame 141. Therefore, when the rack holder 144 moves in the optical axis direction, the focus group holding frame 141 moves integrally (linked) in the same direction.

[0040] The rack 146 meshes with a feed screw 401b provided on the rotation shaft of the focus driver 401, and a rotation shaft portion 146a is engaged with a fitting hole 144c of the rack holder 144, allowing rotation only around the fitting hole 144c. A torsion coil spring (first biasing member) 147 has a coil portion inserted into the boss 144a. One end of the arm of the torsion coil spring 147 abuts against the rack 146 to bias the rack 146 against the feed screw 401b, and the other end abuts against the rack holder 144 to bias the rack holder 144 against an elongated hole 141d provided in the focus group holding frame 141.

[0041] The propagation path of the biasing force acting on focus group 114 will be described below with reference to FIG. 12. FIG. 12 is a front cross-sectional view showing the holding structure of focus group 114. One end of torsion coil spring 147 applies biasing force C1 to rack 146 via abutment portion 147a with rack 146, generating a moment around fitting hole 144c in rack 146. The moment around fitting hole 144c applies biasing force D to lead screw 401b via meshing teeth 146b of rack 146. This allows stable meshing between rack 146 and lead screw 401b without separation, even if lead screw 401b vibrates due to variations in component precision.

[0042] At the other end of the torsion coil spring 147, abutment portion 147b with the rack holder 144 applies a biasing force C2 to the rack holder 144, generating a moment on the rack holder 144 about the first guide bar 142. The moment on the first guide bar 142 applies a biasing force E to an elongated hole 141d provided in the focus group holding frame 141 via boss 144a. The biasing force E generates a moment on the focus group holding frame 141 about the first guide bar 142, which applies a biasing force F to the second guide bar 143 engaged with U-shaped groove 141c provided in the focus group holding frame 141. As a result, the focus group holding frame 141 is always biased to one side with respect to the gap between the first guide bar 142 and the second guide bar 143, thereby stabilizing the position and tilt of the focus group holding frame 141 in a plane perpendicular to the optical axis.

[0043] 13 is a cross-sectional view showing the holding structure of the rack 146. Both ends of the rotation shaft 146a of the rack 146 are engaged with the fitting holes 144c of the rack holder 144. One side of the rotation shaft 146a of the rack 146 has a conical contact portion that contacts the fitting hole 144c of the rack holder 144, and is in line contact with the fitting hole 144c. A spring 148 is inserted between the other side of the rotation shaft 146a of the rack 146 and the fitting hole 144c of the rack holder 144, and biases the rack 146 toward the rack holder 144. When the rotation shaft of the rack 146 and the feed screw 401b of the focus drive unit 401 are inclined in different directions, the rack holder 144 tilts around the conical shape of the rack holder 144 in accordance with the inclination of the feed screw 401b. Furthermore, the conical shape of rack holder 144 and fitting hole 144c are always in contact with each other without separation due to the biasing force of spring 148. This ensures that rack 146 and feed screw 401b mesh reliably, and the rotational driving force of focus motor 401a can be stably converted into propulsion force in the optical axis direction.

[0044] 14 is a perspective view of the lens mount 102 as seen from the subject side, showing the location of contact portion 102a that comes into contact with contact portion 141e of focus group holding frame 141 when the lens mount is retracted. At the telephoto end, the biasing force of compression coil spring 145 causes end portion 144b to come into contact with slide hole 141b on the subject side, and rack holder 144 and focus group holding frame 141 move together.

[0045] Meanwhile, at the retracted end, the rear group base tube 118 moves in the optical axis direction toward the imaging surface, opposite the subject side, causing abutment portion 141e provided on the focus group holding frame 141 to abut against abutment portion 102a provided on the lens mount 102. At this time, the rack 146 engages with the feed screw 401b and does not move, so the compression coil spring 145 is compressed, allowing the focus group holding frame 141 to move relative to the rear group base tube 118. At this time, the focus group holding frame 141 can be separated from the rack holder 144 against the biasing force of the compression coil spring 145. By separating the focus group holding frame 141 from the rack holder 144, the state changes from the first state to the second state.

[0046] In this way, by applying a biasing force from the torsion coil spring 147 between the rack 146 and the rack holder 144, the rack 146 and the feed screw 401b do not separate, and a stable contact state can always be maintained. This improves the responsiveness and accuracy of the movement amount of the rack 146 in the optical axis direction relative to the rotational drive amount by the focus motor 401a. Furthermore, the focus group holding frame 141 is always pulled to one side with respect to the first guide bar 142 and the second guide bar 143, eliminating any gap, thereby stabilizing the position and tilt of the focus group holding frame 141 in a plane perpendicular to the optical axis. As a result, even if the orientation of the interchangeable lens 101 changes and the direction of gravity changes, the position of the focus group holding frame 141 does not change, and high positional accuracy can be maintained. Furthermore, the compression coil spring 145 between the focus group holding frame 141 and the rack holder 144 allows the focus group holding frame 141 to be separated from the rack holder 144. That is, the first state can be transitioned to the second state. In a region not restricted by the first or second state, when the rack holder 144 moves in the optical axis direction, the focus group holding frame 141 can move integrally (in conjunction) in the same direction. This ensures high tracking performance between the rack holder 144 and the focus group holding frame 141. Furthermore, in the event of an impact due to a fall or vibration, the compression coil spring 145 contracts, absorbing the impact on the focus group 114 and reducing the load on the rack 146, thereby suppressing tooth skipping and preventing damage to the focus group 114 and the rack 146. Furthermore, the rack 146 is rotatable relative to the rack holder 144 and follows the inclination of the feed screw 401b of the focus drive unit 401, ensuring reliable engagement between the rack 146 and the feed screw 401b. This prevents tooth skipping and localized wear of the rack 146. Therefore, an interchangeable lens (optical device) 101 that maintains optical retention precision can be provided in a collapsible configuration.

[0047] Although the present embodiment shows a holding structure for the focus group 114, similar holding structures may be provided for other lens groups that make up the imaging optical system, such as the zoom group 110 and the lens vibration isolation group 112. Furthermore, the zoom operation ring 103 can be rotated by the user to switch between a state where photography is possible and a retracted state, but the present invention is not limited to this, and a method other than manual operation, such as an electric actuator, may also be used. <Example 2> The basic configuration of the camera system of this embodiment is the same as that of the camera system of embodiment 1. In this embodiment, only the configuration that differs from embodiment 1 will be described, and a description of the common configuration will be omitted.

[0048] 15 and 16 are perspective views showing the holding structure of the focus group 114. FIG. 15 shows the same telephoto end as FIGS. 4 and 8, and FIG. 16 shows the same retracted end as FIGS. 5 and 9. The first guide bar 142 is a metal member fixed to the rear group base tube 118, and engages with a slide hole 541a on the imaging surface side and a slide hole 541b on the subject side formed in the focus group holding frame 541. Similarly, the second guide bar 143 fixed to the rear group base tube 118 engages with a U-shaped groove 541c provided in the focus group holding frame 541. This holds the focus group holding frame 541 so that it can move freely in the optical axis direction relative to the rear group base tube 118.

[0049] In this embodiment, the rack holder (second intermediate member) 544 and the rack (first intermediate member) 546 constitute an intermediate member that transmits the driving force of the focus driver 401 to the focus group holding frame 141. A through hole into which the first guide bar 142 is inserted is formed in the rack holder 544. The rack holder 544 is supported on the first guide bar 142 so as to be movable in the axial direction and rotatable on a plane perpendicular to the optical axis. A protrusion 544a of the rack holder 544 abuts against an abutment surface 541d provided on the focus group holding frame 541, thereby preventing the rack holder 544 from rotating around the through hole. A compression coil spring (second biasing member) 145 is disposed in the space between the focus group holding frame 541 and the rack holder 544. One end of the compression coil spring 145 urges the focus group holding frame 541 toward the imaging surface in the optical axis direction, and the other end urges the rack holder 544 toward the sliding hole 541b side (subject side) of the focus group holding frame 541. Therefore, when the rack holder 544 moves in the optical axis direction, the rack 546 moves integrally (linked) in the same direction.

[0050] The rack 546 meshes with a feed screw 401b provided on the rotation shaft of the focus driver 401, and a rotation shaft portion 546a is engaged with a fitting hole 544c of the rack holder 544, and is allowed to rotate only about the fitting hole 544c. A torsion coil spring (first biasing member) 547 has a coil portion inserted into the rotation shaft portion 546a of the rack 546. One end of an arm of the torsion coil spring 547 abuts against the rack 546 to bias the rack 546 against the feed screw 401b, and the other end abuts against the rack holder 544 to bias the rack holder 544 against an abutment surface 541d provided on the focus group holding frame 541.

[0051] The propagation path of the biasing force acting on focus group 114 will be described below with reference to FIG. 17. FIG. 17 is a front cross-sectional view showing the holding structure of focus group 114. One end of torsion coil spring 547 applies biasing force G1 to rack 546 via abutment portion 547a with rack 546, generating a moment around fitting hole 544c in rack 546. The moment around fitting hole 544c applies biasing force H to lead screw 401b via meshing teeth 546b of rack 546. This allows stable meshing between rack 546 and lead screw 401b without separation, even if lead screw 401b vibrates due to variations in component precision.

[0052] At the other end of torsion coil spring 547, a biasing force G2 is applied to rack holder 544 by a contact portion 547b with rack holder 544. In response to the reaction forces of biasing forces G1 and G2, a biasing force I is applied from the coil portion of torsion coil spring 547 to rotation shaft portion 546a of rack 546, and a moment about first guide bar 142 is generated in rack holder 544. The moment about first guide bar 142 applies a biasing force J to a contact surface 541d provided on focus group holding frame 541 via protrusion 544a. The biasing force J generates a moment about first guide bar 142 in focus group holding frame 541, and applies a biasing force K to second guide bar 143 engaged with U-shaped groove 541c provided in focus group holding frame 541. This ensures that the focus group holding frame 514 is always biased to one side relative to the gap between the first guide bar 142 and the second guide bar 143, stabilizing the position and tilt of the focus group holding frame 514 in a plane perpendicular to the optical axis.

[0053] 18 is a cross-sectional view showing the holding structure of the rack 546. The rack 546 has both ends of a rotation shaft 546a engaged with the fitting holes 544c of the rack holder 544. One side of the rotation shaft 546a of the rack 546 has a conical contact portion that contacts the fitting hole 544c of the rack holder 544, and is in line contact with the fitting hole 544c. A torsion coil spring 547 is inserted between the other side of the rotation shaft 546a of the rack 546 and the fitting hole 544c of the rack holder 544, and biases the rack 546 toward the rack holder 544. When the rotation shaft of the rack 546 and the feed screw 401b of the focus drive unit 401 are inclined in different directions, the rack holder 544 tilts around the conical shape of the rack holder 544 in accordance with the inclination of the feed screw 401b. Moreover, the conical shape of rack holder 544 and fitting hole 544c are always in contact with each other without separation due to the biasing force of torsion coil spring 547. This ensures that rack 546 and feed screw 401b mesh reliably, and the rotational driving force of focus motor 401a can be stably converted into propulsion force in the optical axis direction.

[0054] In this way, by applying a biasing force from the torsion coil spring 547 between the rack 546 and the rack holder 544, the rack 546 and the feed screw 401b do not separate, and a stable contact state can always be maintained. This improves the responsiveness and accuracy of the movement amount of the rack 546 in the optical axis direction relative to the rotational drive amount by the focus motor 401a. Furthermore, the focus group holding frame 541 is always pulled to one side with respect to the first guide bar 142 and the second guide bar 143, eliminating any gap, thereby stabilizing the position and tilt of the focus group holding frame 541 in a plane perpendicular to the optical axis. This prevents the position of the focus group holding frame 541 from changing, thereby maintaining high positional accuracy even if the orientation of the interchangeable lens 101 changes and the direction of gravity changes. Furthermore, the compression coil spring 145 between the focus group holding frame 541 and the rack holder 544 allows the focus group holding frame 541 to be separated from the rack holder 544. That is, the first state can be transitioned to the second state. In a region not restricted by the first or second state, when the rack holder 544 moves in the optical axis direction, the focus group holding frame 541 can move integrally (in conjunction) in the same direction. This ensures high tracking performance between the rack holder 544 and the focus group holding frame 541. Furthermore, in the event of an impact due to a fall or vibration, the compression coil spring 145 contracts, absorbing the impact on the focus group 114 and reducing the load on the rack 546, thereby suppressing tooth skipping and preventing damage to the focus group 114 and the rack 546. Furthermore, the rack 546 is rotatable relative to the rack holder 544 and follows the inclination of the feed screw 401b of the focus drive unit 401, ensuring reliable engagement between the rack 546 and the feed screw 401b. This prevents tooth skipping and localized wear of the rack 546. Therefore, an interchangeable lens (optical device) 101 that maintains optical retention precision can be provided in a collapsible configuration.

[0055] Although the present embodiment shows a holding structure for the focus group 114, similar holding structures may be provided for other lens groups that make up the imaging optical system, such as the zoom group 110 and the lens vibration isolation group 112. Furthermore, the zoom operation ring 103 can be rotated by the user to switch between a state where photography is possible and a retracted state, but the present invention is not limited to this, and a method other than manual operation, such as an electric actuator, may also be used.

[0056] The disclosure of this embodiment includes the following configuration. (Configuration 1) a holding member for holding the optical system; a drive unit that moves the holding member; an intermediate member including a first intermediate member in contact with the drive unit and a second intermediate member in contact with the first intermediate member and the holding member, the intermediate member transmitting the drive force of the drive unit to the holding member; a first biasing member that biases the first intermediate member toward the drive portion and biases the second intermediate member toward the holding member. (Configuration 2) 2. The optical device according to configuration 1, wherein the first biasing member biases the first intermediate member and the second intermediate member in a direction perpendicular to the optical axis of the optical system. (Configuration 3) a second biasing member that biases the holding member relative to the second intermediate member in a direction along the optical axis of the optical system; The optical device described in configuration 1 or 2 is characterized in that it has a first state in which a portion of the holding member is abutted against the second intermediate member in accordance with the biasing force of the second biasing member, and a second state in which the holding member is separated from the second intermediate member against the biasing force of the second biasing member. (Configuration 4) 4. The optical device according to configuration 3, wherein the first state is a state in which the optical system is in a position where photography is possible. (Configuration 5) 5. The optical device according to configuration 3 or 4, wherein the second state is a state in which the optical system is in a retracted position and image capturing is restricted. (Configuration 6) a base cylinder that holds the holding member so as to be movable in a direction along the optical axis of the optical system; 6. The optical device according to any one of configurations 3 to 5, wherein the optical device transitions from the first state to the second state by the base tube moving in a direction along the optical axis. (Configuration 7) a fixing member having an abutment portion that abuts against the holding member; The optical device described in configuration 6 or 7, characterized in that when the base tube moves toward the imaging surface in a direction along the optical axis, the abutment portion moves the holding member away from the second intermediate member against the biasing force of the second biasing member. (Configuration 8) an operating member that is rotatable in a radial direction around an optical axis of the optical system; 7. The optical device according to configuration 6, wherein the base tube moves in a direction along the optical axis in conjunction with the rotation of the operating member. (Configuration 9) a guide member that guides the holding member in a direction along the optical axis of the optical system, The optical device described in any one of configurations 1 to 8, characterized in that the guide member supports the second intermediate member so that it can rotate on a plane perpendicular to the optical axis and guides it in a direction along the optical axis. (Configuration 10) The optical device described in configuration 9, characterized in that at least a portion of the area in which the guide member supports the second intermediate member overlaps with the area in which the guide member holds the holding member in the direction along the optical axis. (Configuration 11) the first intermediate member engages with a screw provided on a rotation shaft of the drive unit, The optical device according to any one of configurations 1 to 10, wherein the second intermediate member moves in a direction along the optical axis of the optical system in conjunction with the movement of the first intermediate member. (Configuration 12) the optical system includes a focus lens; 12. The optical device according to any one of configurations 1 to 11, wherein the drive unit adjusts focus by moving the focus lens in a direction along the optical axis of the optical system. (Configuration 13) 13. The optical device according to any one of configurations 1 to 12, wherein the optical device is an interchangeable lens. (Configuration 14) a camera body including a camera mount and a power supply; and the optical device according to any one of configurations 1 to 13, comprising a lens mount connectable to the camera mount; The power supply unit supplies power to the camera body and the optical device.

[0057] Although the 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 the gist of the present invention. [Explanation of symbols]

[0058] 101 Interchangeable lenses (optical equipment) 114 Focus group (optical system) 141 Focus group holding frame (holding member) 144 Rack holder (second intermediate member) 146 Rack (first intermediate member) 147 Torsion coil spring (first biasing member) 401 Focus drive unit (drive unit)

Claims

1. a holding member for holding the optical system; a drive unit that moves the holding member; an intermediate member including a first intermediate member in contact with the drive unit and a second intermediate member in contact with the first intermediate member and the holding member, the intermediate member transmitting the drive force of the drive unit to the holding member; a first biasing member that biases the first intermediate member toward the drive portion and biases the second intermediate member toward the holding member.

2. 2. The optical device according to claim 1, wherein the first biasing member biases the first intermediate member and the second intermediate member in a direction perpendicular to the optical axis of the optical system.

3. a second biasing member that biases the holding member relative to the second intermediate member in a direction along the optical axis of the optical system, 3. The optical device according to claim 1, further comprising: a first state in which a portion of the holding member is brought into contact with the second intermediate member in accordance with the biasing force of the second biasing member; and a second state in which the holding member is moved away from the second intermediate member against the biasing force of the second biasing member.

4. 4. The optical device according to claim 3, wherein the first state is a state in which the optical system is in a photographing position.

5. 4. The optical device according to claim 3, wherein the second state is a state in which the optical system is in a retracted position and photography is restricted.

6. a base cylinder that holds the holding member so as to be movable in a direction along the optical axis of the optical system; 4. The optical device according to claim 3, wherein the transition from the first state to the second state occurs when the base tube moves in a direction along the optical axis.

7. a fixing member having an abutment portion that abuts against the holding member; The optical device according to claim 6, characterized in that when the base tube moves toward the imaging surface in a direction along the optical axis, the abutment portion separates the holding member from the second intermediate member against the biasing force of the second biasing member.

8. an operating member that is rotatable in a radial direction around an optical axis of the optical system; 7. The optical device according to claim 6, wherein the base tube moves in a direction along the optical axis in conjunction with the rotation of the operation member.

9. a guide member that guides the holding member in a direction along the optical axis of the optical system, 3. The optical device according to claim 1, wherein the guide member supports the second intermediate member so as to be rotatable on a plane perpendicular to the optical axis and guides the second intermediate member in a direction along the optical axis.

10. 10. The optical device according to claim 9, wherein at least a portion of the area in which the guide member pivotally supports the second intermediate member overlaps with an area in which the guide member holds the holding member in the direction along the optical axis.

11. the first intermediate member engages with a screw provided on a rotation shaft of the drive unit, 3. The optical device according to claim 1, wherein the second intermediate member moves in a direction along the optical axis of the optical system in conjunction with the movement of the first intermediate member.

12. the optical system includes a focus lens; 3. The optical device according to claim 1, wherein the drive unit adjusts focus by moving the focus lens in a direction along the optical axis of the optical system.

13. 3. The optical device according to claim 1, wherein the optical device is an interchangeable lens.

14. a camera body including a camera mount and a power supply; and the optical device according to claim 1 or 2, which includes a lens mount connectable to the camera mount, The power supply unit supplies power to the camera body and the optical device.

Images