Optical equipment

Abstract

To provide an optical instrument that achieves miniaturization, while capable of accurate detection of a lens position.SOLUTION: An optical instrument comprises: a guide barrel (107) that holds a lens group movably in an optical axis direction; a cam barrel (108) that is rotatably held by the guide barrel; a detection member (106) that includes a detection engagement part (106a) and detects the position of the lens group through movement of the detection engagement part; and a stationary barrel (109) that has the guide barrel, the cam barrel, and the detection member arranged therein. The detection engagement part is engaged with detection engaged parts (108c, 107b) provided on the cam barrel, and the detection member is movable in the optical axis direction with respect to the cam barrel.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to optical instruments. [Background technology]

[0002] 2. Description of the Related Art Optical devices such as digital cameras, video cameras, and interchangeable lenses are required to be small in both the diameter and overall length of the lens barrel while still being capable of varying magnification.

[0003] Patent documents 1 and 2 disclose a lens barrel with variable magnification, in which a position detection groove is provided in a cam barrel that holds a lens group movably in the optical axis direction or in an operating ring connected to the cam barrel, and a detection part of a position detector fixed to a fixed barrel engages with the groove, in order to detect the lens position of the lens barrel. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-242356 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-142905 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in Patent Document 1, it is necessary to provide a lift amount equivalent to the detection range of the position detector in the position detection groove provided in the operation ring, which hinders miniaturization of the lens barrel.

[0006] Furthermore, in Patent Document 2, it is necessary to provide a lift amount equivalent to the detection range of the position detector in the position detection groove provided in the cam barrel, which hinders miniaturization of the lens barrel.

[0007] The present invention provides an optical device that can detect the lens position with high accuracy while achieving miniaturization. [Means for solving the problem]

[0008] An optical device according to one aspect of the present invention comprises a guide barrel that holds a lens group so that it can move in the optical axis direction, a cam barrel that is rotatably held on the guide barrel, a detection member that has a detection engagement portion and detects the position of the lens group by movement of the detection engagement portion, and a fixed barrel that has the guide barrel, the cam barrel, and the detection member arranged inside, wherein the detection engagement portion engages with a detection engageable portion provided on the cam barrel, and the detection member is movable in the optical axis direction relative to the cam barrel.

[0009] Another aspect of the present invention is an optical device comprising a guide barrel that holds a lens group so that it can move in the optical axis direction, a cam barrel that is rotatably held on the guide barrel, a detection member that has a detection engagement portion and detects the position of the lens group by movement of the detection engagement portion, and a fixed barrel that is arranged inside the guide barrel, the cam barrel, and the detection member, wherein the detection engagement portion engages with a detection engageable portion provided on the guide barrel, and the detection member is movable in the optical axis direction relative to the guide barrel.

[0010] Other objects and features of the present invention will be described in the following embodiments. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide an optical device that can be made compact while still being capable of detecting the lens position with high accuracy. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 2A is a front perspective view and FIG. 2B is a rear perspective view of the interchangeable lens and the digital camera. [Figure 2] FIG. 2 is a block diagram showing the configuration of an interchangeable lens and a digital camera. [Figure 3] FIG. 2 is a cross-sectional view of the interchangeable lens at the wide-angle end. [Figure 4] FIG. 2 is a cross-sectional view of the interchangeable lens at the telephoto end. [Figure 5]FIG. 2 is a cross-sectional view of the interchangeable lens at the retracted end. [Figure 6] FIG. 2 is an exploded perspective view of the vibration isolation drive unit and peripheral members of the interchangeable lens. [Figure 7] FIG. 2 is a cross-sectional view showing the relationship between a zoom detection unit and a cam barrel. [Figure 8] 10A and 10B are diagrams illustrating a movement range of a detection knob of a zoom detection unit. [Figure 9] FIG. [Figure 10] FIG. 2 is a cross-sectional view showing the relationship between a zoom detection unit and a linear guide barrel. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each drawing, the same components are given the same reference numerals, and duplicated explanations will be omitted. In each embodiment, an interchangeable lens will be described as an example of an optical device, but a lens-integrated camera or the like may also be used.

[0014] FIG. 1 shows the appearance of an interchangeable lens 101 and a digital camera (hereinafter referred to as camera body) 1 to which the interchangeable lens 101 is detachably attached. FIG. 1(a) is a perspective view of the front side of the camera body 1, and FIG. 1(b) is a perspective view of the rear side of the camera body 1. As shown in FIG. 1(a), the optical axis direction along which the optical axis of the imaging optical system housed in the interchangeable lens 101 extends is defined as the X-axis direction, and two 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. Furthermore, 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 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 perpendicular to each other.

[0015] A grip section 2 is provided on the left side of the camera body 1 as viewed from the front (right side as viewed from the rear) for the user to hold the camera body 1 with their hand. A power operation section 3 is also located on the top surface of the camera body 1. When the user turns on the power operation section 3 while the camera body 1 is in the power-off state, power begins to flow and the camera body 1 enters the power-on state. In the power-on state, computer programs such as the focus group origin detection process are executed, and the camera body 1 enters a standby state for shooting. Conversely, when the user turns off the power operation section 3 while the camera body 1 is in the power-on state, the camera body 1 enters the power-off state.

[0016] Furthermore, 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 shooting modes by rotating the mode dial 4. Shooting modes include a manual still image shooting mode, in which the user can freely set shooting conditions such as shutter speed and aperture value; an auto still image shooting mode, in which the camera automatically obtains the appropriate exposure; and a video shooting mode for shooting videos. Furthermore, by half-pressing the release button 5, the user can instruct the camera body 1 to perform shooting preparation operations such as autofocus and auto exposure control. By fully pressing the release button 5, the user can instruct the camera body 1 to take a picture. Accessories such as an external flash can be detachably attached to the accessory shoe 6.

[0017] The interchangeable lens 101 is mechanically and electrically connected to a camera mount 7 provided on the camera body 1 via a lens mount 102. The interchangeable lens 101 houses an imaging optical system that forms an image of a subject by focusing light from the subject. A zoom ring 103 that can be rotated around the optical axis by user operation is provided on the outer periphery of the interchangeable lens 101. When the zoom ring 103 is rotated by the user, the zoom group that makes up the imaging optical system moves to a predetermined position that corresponds to the angle of the zoom ring 103. In this way, the user can take pictures at a desired angle of view.

[0018] As shown in FIG. 1(b), 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 the image sensor 16 (described below). The display unit 9 also displays shooting parameters indicating shooting conditions such as shutter speed and aperture value, and 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, and when the user operates the playback button, the captured image is played back and displayed on the display unit 9.

[0019] FIG. 2 is a block diagram showing the electrical and optical configurations of the interchangeable lens 101 and camera body 1. The camera body 1 includes a power supply unit 10 that supplies power to the camera body 1 and interchangeable lens 101, and an operation unit 11 that includes the power operation unit 3, mode dial 4, release button 5, rear operation unit 8, and the touch panel function of the display unit 9. The camera body 1 and interchangeable lens 101 as a whole are controlled by a camera control unit 12 provided in the camera body 1 and a lens control unit 104 provided in the interchangeable lens 101, which communicate with each other. The camera control unit 12 reads and executes a computer program stored in the memory unit 13. In this process, 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.

[0020] The imaging optical system of the interchangeable lens 101 includes a zoom group 110 that is connected to the zoom operation ring 103 and moves in the optical axis direction to change the angle of view from a wide-angle position to a telephoto position, and a lens vibration reduction group 112 that includes a shift lens as a vibration reduction element. Image blur is reduced by moving (shifting) the lens vibration reduction group 112 in the Z / Y axis directions perpendicular to the optical axis. The imaging optical system also includes an aperture group 301 that adjusts the amount of light, and a focus group 114 that includes a focus lens that moves in the optical axis direction to adjust the focus. The interchangeable lens 101 also includes an image vibration reduction driver 201 that moves the lens vibration reduction group 112, an aperture driver 302 that drives the aperture group 301, and a focus driver 401 that moves the focus group 114. The interchangeable lens 101 has a zoom operation ring 103 for changing the angle of view of the imaging optical system, and a zoom detection unit (detection member) 106 that detects the position of the zoom group 110 by detecting the angle of a cam barrel 108 ring driven by the zoom operation ring 103.

[0021] The camera body 1 has a shutter unit 14, a shutter driver 15 that drives the shutter unit 14, an image sensor 16, an image processor 17, and the camera controller 12 described above. The shutter unit 14 controls the amount of light that is formed by the imaging optical system within the interchangeable lens 101 and that is 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 processing 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 as described above, and plays back and displays captured images stored in the memory unit 13 or a recording medium (not shown).

[0022] 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 on 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. This corrects the focus deviation of the subject image.

[0023] The focus drive unit 401 includes a focus motor (not shown) and a photointerrupter (not shown) that detects the origin position of the focus group 114. A stepping motor, a type of actuator, is typically used as the focus motor. However, because a stepping motor can only control a relative drive amount, the current position of the focus group 114 is undefined when the camera body 1 is powered off. Even if the camera body 1 remains powered on, if the interchangeable lens 101 is mechanically removed from the camera mount 7 of the camera body 1 and power is interrupted, the focus group 114 remains in the position it was in when power was cut off. This leaves the current position of the focus group 114 undefined. If the user turns on the power control unit 3 while the current position of the focus group 114 is undefined, the focus group 114 must first be moved to the origin position and an origin detection process must be performed before the camera enters a shooting standby state. Control of this origin detection process is a well-known technology that has been adopted in many optical devices, so a description thereof will be omitted here. A DC motor or ultrasonic motor equipped with an encoder may also be used as the actuator. A photointerrupter directly receives light emitted from a light-emitting element with a light-receiving element, but instead, a photoreflector that receives light reflected from a reflective surface or a brush that contacts a conductive pattern to electrically detect a signal may also be used.

[0024] Furthermore, camera control unit 12 controls the driving of aperture group 301 and shutter unit 14 via aperture drive unit 302 and shutter drive unit 15 in accordance with the aperture value and shutter speed settings received from operation unit 11. For example, when an automatic exposure control operation is instructed, camera control unit 12 receives a luminance signal generated by image processing unit 17 and performs a photometric calculation. Based on the result of this photometric calculation, camera control unit 12 controls aperture drive unit 302 in accordance with a shooting instruction operation such as fully pressing release button 5 on operation unit 11. At the same time, camera control unit 12 controls the driving of shutter unit 14 via shutter drive unit 15 and performs exposure processing by image sensor 16.

[0025] 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 moves the lens vibration isolation group 112 to a target position in the Z / Y axis direction via the vibration isolation drive unit 201 according to the calculated shift position in the pitch / yaw direction, thereby reducing image shake during exposure or live view image display.

[0026] Next, the positional relationships of the main components of the interchangeable lens 101 will be described using Figures 3, 4, and 5. Figures 3 to 5 are cross-sectional views of the interchangeable lens 101 on an XY plane including the optical axis. The center line shown here roughly coincides with the optical axis of the imaging optical system, and therefore will be synonymous with the optical axis hereinafter. Figure 3 shows a cross-sectional view of the interchangeable lens 101 at the wide-angle end on the short focal length side during shooting. Figure 4 shows a cross-sectional view of the interchangeable lens 101 at the telephoto end on the long focal length side during shooting. Both Figures 3 and 4 show states where shooting is possible. Figure 5 is a cross-sectional view of the interchangeable lens 101 in a retracted state when not shooting, showing the retracted end at which the overall lens length is shortened to the shortest in the optical axis direction.

[0027] As shown in FIGS. 3 and 4 , each embodiment employs a six-group configuration as an example of an imaging optical system. The zoom group 110 moves to different predetermined positions at the wide-angle end and the telephoto end, and forms an image of light from a subject on the image sensor 16. The zoom group 110 is composed of a first zoom group 111, a lens vibration reduction group 112 functioning as a second zoom group, an aperture group 301, 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 each embodiment is not limited to the above configuration; 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.

[0028] The linear guide barrel (guide barrel) 107 is a fixed component fixed to the lens mount 102 via a fixed barrel 109, and holds the zoom group 110 movably in the optical axis direction. The cam barrel 108 is connected to a zoom operation ring (operation ring) 103 held on the outer periphery of the fixed barrel 109 via a key (not shown). The cam barrel 108 is rotatably held by the linear guide barrel 107. When the zoom operation ring 103 is rotated, the cam barrel 108 rotates about the optical axis while its position in the optical axis direction is restricted by the linear guide barrel 107.

[0029] The linear guide barrel 107 is formed with linear guide grooves 107a at equal intervals to restrict movement of the zoom group 110 in the rotational direction and guide linear movement of the zoom group 110 in the optical axis direction. The cam barrel 108 is also formed with cam grooves 108b at equal intervals to correspond to the zoom group 110, each having a locus at a different angle in the rotational direction. The zoom group 110 is provided with a plurality of cam followers, each of which is fitted into a corresponding linear guide groove 107a and cam groove 108b. 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 107a and cam grooves 108b, move the zoom group 110 forward and backward in the optical axis direction while restricting movement of the zoom group 110 in the rotational direction.

[0030] 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 (detection member) 106 for detecting the position of the zoom group 110 by detecting the angle of a cam barrel 108 driven by the zoom operation ring 103. The zoom detection unit 106 detects the angle of the cam barrel 108 as an absolute value and is configured using, for example, a direct-acting displacement sensor such as a linear potentiometer, which is a resistive sensor. In the configuration of Example 1 described below, a detection knob (detection engaging portion) 106a provided on the zoom detection unit 106 engages with a detection groove (detection engaged portion) 108c provided on the inner periphery of the cam barrel 108 (FIG. 7). This moves the detection knob 106a, detecting the rotation angle of the cam barrel 108. Because the zoom operation ring 103 does not have the detection groove 108c, the length of the zoom operation ring 103 in the optical axis direction can be made shorter than that of the zoom detection unit 106. Information relating to the angle of view detected by the zoom detection unit 106 is sent to the lens control unit 104 and is reflected in the various controls by the camera control unit 12 described above. Meanwhile, some of this information is recorded together with the captured image in the storage unit 13 or a recording medium (not shown). The linear guide barrel 107, cam barrel 108, and zoom detection unit 106 are disposed inside the fixed barrel 109.

[0031] FIG. 6 is an exploded perspective view of the vibration-proof drive unit and peripheral components of the interchangeable lens 101, showing some of the components disassembled. The third zoom group (lens group) 113 has a linear guide 113a, which is a linear key, and a cam follower 113b. A linear guide groove 107a is provided on the inside of the linear guide barrel 107 and engages with the linear guide 113a to restrict rotation of the third zoom group 113 about the optical axis. A base member 501 is connected to the third zoom group 113. A coil 502 is connected to the base member 501 and is wired to the lens control unit 104 (not shown). A shielding case 503 is connected to the base member 501, covering the imaging surface side of the coil 502 and leaving the objective side open. A ball 504 is housed in the base member 501. A lens 505, which is an vibration-proof lens, is a component of the lens vibration-proof group 112. The shift member 506 holds the lens 505 and is in contact with the ball 504. The magnet 507 is connected to the shift member 506 and is disposed opposite the coil 502 in the optical axis direction. The yoke 508 is connected to the magnet 507. The spring hook portion of the base member 501 extends from the base member 501. The spring hook portion of the shift member 506 extends from the shift member 506. The spring 509 is an elastic tension spring having a first hook and a second hook. The first hook of the spring 509 engages with the spring hook portion of the base member 501. The second hook of the spring 509 engages with the spring hook portion of the shift member 506. The spring 509 is disposed so that the longitudinal direction of the spring 509 forms an angle of 75° with the optical axis direction. As a result, the shift member 506 is biased against the base member 501 and is disposed at a position where the tension of the spring 509 is balanced. Furthermore, when the lens control unit 104 applies a current to the coil 502, the shift member 506 can be moved in a direction perpendicular to the optical axis relative to the base member 501 as a voice coil type actuator. The anti-float member 510 restricts the shift member 506 from floating up in the optical axis direction, thereby reducing inadvertent movement of the shift member 506 due to impact from a drop or the like. Example 1 FIG. 7 is a cross-sectional view showing the relationship between the zoom detection unit 106 and the cam barrel 108. FIG. 7(a) is a cross-sectional view at a non-photographing state standby position, FIG. 7(b) is a cross-sectional view at a photographing state wide-angle position, and FIG. 7(c) is a cross-sectional view at a photographing state telephoto position. The zoom detection unit 106 is attached to the third zoom group 113. The zoom detection unit 106 is provided with a detection knob 106a, which engages with a detection groove 108c provided in the cam barrel 108. The movement range of the detection knob 106a is divided into a non-photographing state detection range 106j and a photographing state detection range 106k (FIG. 8). As the cam barrel 108 rotates in conjunction with the rotation of the zoom operation ring 103, the cam follower 113b engages with the cam groove 108b, and the third zoom group 113 moves along the optical axis relative to the fixed barrel 109. As a result, because the zoom detector 106 is attached to the third zoom group 113, the zoom detector 106 and the third zoom group 113 move together in the optical axis direction relative to the linear guide barrel 107 and the cam barrel 108. As a result, the detection knob 106a is moved in the optical axis direction by the lift amount of the cam groove 108b, which is the movement amount of the third zoom group 113. If the detection groove 108c has a lift amount in the optical axis direction, the detection knob 106a moves in the optical axis direction by that lift amount, and therefore the combined lift amount with the lift amount of the cam groove 108b, which is the movement amount of the third zoom group 113, becomes the movement amount of the detection knob 106a in the optical axis direction.

[0032] FIG. 9 is a developed view of the inner diameter of the cam barrel 108. The relationship between the cam groove 108b and the detection groove 108c will be described using FIG. 9. The cam follower 113b engages with the cam groove 108b at position 108j on the cam barrel 108 in the non-photographing state standby position. The cam follower 113b engages with the cam groove 108b at position 108k on the cam barrel 108 in the photographing state wide-angle position, and engages with the cam groove 108b at position 108m on the cam barrel 108 in the photographing state telephoto position. The detection knob 106a engages with the detection groove 108c at position 108n on the cam barrel 108 in the non-photographing state standby position. The detection knob 106a engages with the detection groove 108c at position 108p on the cam barrel 108 in the photographing state wide-angle position, and engages with the detection groove 108c at position 108q on the cam barrel 108 in the photographing state telephoto position.

[0033] FIG. 9(a) is a developed view of the inner diameter of the cam barrel 108 when the movement amount of the third zoom group 113 in the shooting state is approximately the same as the detection amount of the zoom detector 106 in the shooting state. If the movement amount of the third zoom group 113 in the shooting state in the optical axis direction is Y, the detection amount of the shooting state detection range 106k of the zoom detector 106 is S, and the lift amount of the detection groove 108c of the cam barrel 108 in the shooting state in the optical axis direction is X, then Y=S, and therefore X=0. In other words, the lift amount of the detection groove 108c in the optical axis direction is 0. If the cam barrel 108 is a molded part, the detection groove 108c will be formed in the inner diameter slide, but because the lift amount is 0, there is no need to provide a large mold draft angle. This enables high-precision position detection.

[0034] 9(b) is a developed view of the inner diameter of the cam barrel 108 when the movement amount of the third zoom group 113 in the shooting state is greater than the detection amount in the shooting state of the zoom detector 106. If the movement amount of the third zoom group 113 in the optical axis direction in the shooting state is Y1, the detection amount of the shooting state detection range 106k of the zoom detector 106 is S, and the lift amount in the shooting state of the detection groove 108c of the cam barrel 108 in the optical axis direction is X1, then Y1-X1=S.

[0035] 9(c) is a developed view of the inner diameter of the cam barrel 108 when the movement amount of the third zoom group 113 in the shooting state is smaller than the detection amount in the shooting state of the zoom detector 106. If the movement amount of the third zoom group 113 in the shooting state in the optical axis direction is Y2, the detection amount of the shooting state detection range 106k of the zoom detector 106 is S, and the lift amount in the shooting state of the detection groove 108c of the cam barrel 108 in the optical axis direction is X2, then Y2 + X2 = S.

[0036] As a result, the lift amounts X, X1, and X2 of detection groove 108c in the optical axis direction in the shooting state can be set to be smaller than shooting state detection range 106k, making it possible to reduce the size of cam barrel 108. Also, there is no need to provide detection groove 108c on zoom operation ring 103, and the overall length of zoom operation ring 103 in the optical axis direction can be shorter than the overall length of zoom detection unit 106 in the optical axis direction, making it possible to reduce the size of the lens barrel. Also, the detection amount of shooting state detection range 106k of zoom detection unit 106 is a combination of lift amount Y of cam groove 108b, which is the movement amount of third zoom group 113, the position of which is to be detected, and lift amount X of detection groove 108c of cam barrel 108 in the shooting state. This enables highly accurate position detection.

[0037] In this embodiment, the case where the zoom detection unit 106 is integrated with the third zoom group 113 has been described. However, a configuration in which the zoom detection unit 106 is held by an independent holding frame (not shown) that moves in the optical axis direction, and the detection knob 106a engages with the detection groove 108c of the cam barrel 108, also makes it possible to reduce the size of the lens barrel and detect its position with high accuracy. Furthermore, a configuration in which the zoom detection unit 106 is held by a fixed frame (not shown) that does not move in the optical axis direction, and the detection knob 106a engages with the detection groove 108c of the cam barrel 108, also makes it possible to reduce the size of the lens barrel and detect its position with high accuracy. Example 2 In the first embodiment, a case has been described in which the detection groove 108c, which is the detection engaged portion, is provided in the cam barrel 108. In the second embodiment, the detection hole 107b, which is the detection engaged portion, is provided in the linear guide barrel 107. In the following, a description of the parts common to the first embodiment will be omitted, and only the parts that are different from the first embodiment will be described.

[0038] FIG. 10 is a cross-sectional view showing the relationship between the zoom detector 106 and the linear guide barrel 107. The zoom detector 106 is attached to the third zoom group 113. A detection knob (detection engaging portion) 106a of the zoom detector 106 engages with a detection hole (detection engaged portion) 107b provided in the linear guide barrel 107. The movement range of the detection knob 106a is divided into a non-photographing state detection range 106j and a photographing state detection range 106k. When the cam barrel 108 rotates in conjunction with the rotation of the zoom operation ring 103, the cam follower 113b engages with the cam groove 108b, and the third zoom group 113 moves along the optical axis relative to the fixed barrel 109. As a result, the zoom detector 106 and the third zoom group 113 move together in the optical axis direction relative to the linear guide barrel 107 and the cam barrel 108. As a result, detection knob 106a is moved in the optical axis direction by the lift amount of cam groove 108b, which is the amount of movement of third zoom group 113. With this configuration, there is no need to form detection groove 108c in cam barrel 108, allowing for the miniaturization of cam barrel 108. Also, there is no need to provide detection groove 108c in zoom operation ring 103, allowing the overall length of zoom operation ring 103 in the optical axis direction to be shorter than the overall length of zoom detection unit 106 in the optical axis direction, allowing for the miniaturization of the lens barrel. Furthermore, highly accurate position detection is possible by directly detecting the amount of movement of third zoom group 113.

[0039] In this embodiment, the case where the zoom detection unit 106 is integrated with the third zoom group 113 has been described. However, a configuration in which the zoom detection unit 106 is held by an independent holding frame (not shown) that moves in the optical axis direction, and the detection knob 106a engages with the detection hole 107b of the linear guide barrel 107, also makes it possible to reduce the size of the lens barrel and detect its position with high accuracy. Furthermore, a configuration in which the zoom detection unit 106 is held by a fixed frame (not shown) that does not move in the optical axis direction, and the linear guide barrel 107 moves in the optical axis direction, and the detection knob 106a engages with the detection hole 107b, also makes it possible to reduce the size of the lens barrel and detect its position with high accuracy.

[0040] With the above configuration, it is possible to achieve further miniaturization of the lens barrel diameter direction and overall length of an optical device such as the interchangeable lens 101, and to obtain an optical device that is capable of detecting the lens position with high accuracy.

[0041] The disclosure of each of the above embodiments includes the following configurations. (Configuration 1) The optical device includes a guide barrel that holds a lens group movably in the optical axis direction, a cam barrel that is rotatably held by the guide barrel, a detection member that has a detection engagement portion and detects the position of the lens group by movement of the detection engagement portion, and a fixed barrel that has the guide barrel, cam barrel, and detection member disposed therein. The detection engagement portion engages with a detection engaged portion provided on the cam barrel. The detection member is movable in the optical axis direction relative to the cam barrel. (Configuration 2) The optical device includes a guide barrel that holds a lens group movably in the optical axis direction, a cam barrel that is rotatably held on the guide barrel, a detection member that has a detection engagement portion and detects the position of the lens group by movement of the detection engagement portion, and a fixed barrel that has the guide barrel, cam barrel, and detection member disposed inside. The detection engagement portion engages with a detection engaged portion provided on the guide barrel. The detection member is movable in the optical axis direction relative to the guide barrel. (Configuration 3) In the optical device according to configuration 1, the detection engagement portion is provided on the inner periphery of the cam barrel. (Configuration 4) In the optical device according to the first or third aspect, the detection engagement portion provided on the cam barrel is a detection groove. (Configuration 5) In the optical device according to configuration 2, the detection engagement portion provided on the guide tube is a detection hole. (Configuration 6) The optical device according to any one of configurations 1 to 5 further includes an operating ring held on the outer periphery of the fixed barrel. The cam barrel rotates in accordance with the rotation of the operating ring. (Configuration 7) In the optical apparatus according to any one of configurations 1 to 6, the detection member is provided in the lens group. (Configuration 8) In the optical device according to any one of configurations 1 to 7, the detection member is movable in the optical axis direction relative to the fixed barrel. (Configuration 9) In the optical apparatus according to any one of configurations 1 to 8, the lens group and the detection member move together. (Configuration 10) In the optical device according to any one of configurations 1 to 9, the lift amount of the detection engaged portion in the optical axis direction in the photographing state is smaller than the detection range of the detection member. (Configuration 11) In the optical device according to configuration 6, the length of the operation ring in the optical axis direction is shorter than the length of the detection member in the optical axis direction. (Configuration 12) In the optical instrument according to any one of configurations 1 to 11, the detection member is a resistive sensor. (Configuration 13) In the optical device according to any one of configurations 1 to 12, the detection member is a linear displacement sensor.

[0042] 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]

[0043] Optical equipment 101 Guide tube 107 Cam barrel 108 Detection engagement portion 106a Detection member 106 Fixed tube 109 Detected engaged parts 108c, 107b

Claims

1. a guide barrel that holds the lens group movably in the optical axis direction; a cam barrel rotatably held by the guide barrel; a detection member having a detection engagement portion and detecting the position of the lens group by movement of the detection engagement portion; a fixed cylinder having the guide cylinder, the cam cylinder, and the detection member disposed therein, the detection engaging portion engages with a detection engaged portion provided on the cam barrel, The optical device according to claim 1, wherein the detection member is movable in the optical axis direction relative to the cam barrel.

2. a guide barrel that holds the lens group movably in the optical axis direction; a cam barrel rotatably held by the guide barrel; a detection member having a detection engagement portion and detecting the position of the lens group by movement of the detection engagement portion; a fixed cylinder having the guide cylinder, the cam cylinder, and the detection member disposed therein, the detection engaging portion engages with a detection engaged portion provided on the guide tube, The optical device is characterized in that the detection member is movable in the optical axis direction relative to the guide tube.

3. 2. The optical device according to claim 1, wherein the detection engagement portion is provided on an inner periphery of the cam barrel.

4. 2. The optical device according to claim 1, wherein the detection engagement portion provided on the cam barrel is a detection groove.

5. 3. The optical device according to claim 2, wherein the detection engagement portion provided on the guide tube is a detection hole.

6. Further, an operating ring is held on the outer periphery of the fixed barrel, 3. The optical device according to claim 1, wherein the cam barrel rotates in response to a rotational operation of the operation ring.

7. 3. The optical device according to claim 1, wherein the detecting member is provided in the lens group.

8. 3. The optical device according to claim 1, wherein the detection member is movable in the optical axis direction relative to the fixed barrel.

9. 3. The optical device according to claim 1, wherein the lens group and the detection member move together.

10. 3. The optical device according to claim 1, wherein a lift amount of the detection engagement portion in the optical axis direction in a photographing state is smaller than a detection range of the detection member.

11. 7. The optical device according to claim 6, wherein the length of the operation ring in the optical axis direction is shorter than the length of the detection member in the optical axis direction.

12. 3. The optical device according to claim 1, wherein the detecting member is a resistance sensor.

13. 3. The optical device according to claim 1, wherein the detection member is a linear displacement sensor.

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