Optical equipment, lens barrels and imaging devices

Abstract

To provide a compact optical apparatus with high lens position accuracy.SOLUTION: An image stabilization device provided in a lens barrel 102 includes: shift lenses 2a and 2b held by a third group holder 3; and a third group frame 8 that rotatably supports a holder shaft 50 in parallel to an optical axis. The holder shaft 50 has a first fixing portion 50a held by the third group frame 8 and a fitting portion 50b slidably fitting with the third group holder 3, and a center axis of the first fixing portion 50a and a center axis of the fitting portion 50b are eccentric. The holder shaft 50 is supported by the third group frame 8 to be rotatable around the center axis of the first fixing portion 50a. The shift lenses 2a and 2b move between a predetermined position on the optical axis and a retreat position that is separated from the optical axis by rotating around the holder shaft 50.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to an optical device , Re The present invention relates to a lens barrel and an imaging device. [Background technology]

[0002] In recent years, optical devices such as digital cameras, video cameras, and interchangeable lenses (lens barrels) have been required to be more portable when not in use. One known technology for reducing the size of optical devices when not in use is a retractable mechanism that shortens the distance between lenses in the optical axis direction. Another known technology is a lens retraction mechanism that shortens the overall length by retracting a portion of the lens group in a direction perpendicular to the optical axis (radial direction).

[0003] For example, Patent Document 1 discloses an imaging device that can drive with high precision a lens group that is arranged to be rotatable around an axis parallel to the optical axis between a shooting position on the optical axis and a retracted position away from the optical axis, and can easily adjust the position. Patent Document 2 discloses an imaging device that is miniaturized by providing a guide member that moves a movable member in a direction perpendicular to the optical axis, retracting the movable member from the optical axis when the imaging device is not in use, and storing another member in the space occupied by the movable member when the imaging device is in use.

[0004] Patent Document 3 discloses a lens drive device that moves at least one lens frame from a shooting position on the optical axis to a retracted position off the optical axis using a bending retraction mechanism when the lens barrel is retracted. Patent Document 4 discloses an interchangeable lens in which a retractable lens barrel that holds part of the optical system is arranged so that it can be retracted to a position off the optical axis by rotation, and a light intensity adjustment device is arranged on the optical axis so that it can be moved in the optical axis direction. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-233919 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-021993 [Patent Document 3] Japanese Patent Application Laid-Open No. 2007-033961 [Patent Document 4] Japanese Patent Application Laid-Open No. 2006-171079 Summary of the Invention [Problem to be solved by the invention]

[0006] The technology disclosed in Patent Document 1 uses three types of eccentric shafts to adjust the drive unit of the retractable lens group, which requires time for adjustment and results in a complex retraction mechanism, resulting in an increased lens barrel size. The technology disclosed in Patent Document 2 does not restrict the movement of the movable member in the optical axis direction when in the retracted position. Therefore, for example, if a large, heavy lens receives an external impact while retracted, positional accuracy may decrease when the lens is subsequently returned to the use position, potentially resulting in a decrease in optical performance. In the technologies disclosed in Patent Documents 3 and 4, which rotate the lens around an axis perpendicular to the optical axis to retract it from the optical axis, preventing unwanted light from reaching the image sensor during shooting tends to increase the outer diameter of the lens barrel, resulting in an increased size.

[0008] Original Akira is The present invention aims to provide an optical device that can adjust the position of a predetermined lens with a simple configuration that can be made compact without impairing optical performance. 。 [Means for solving the problem]

[0009] Original Clearly The optical device includes a plurality of lens groups arranged to be movable forward and backward along an optical axis; a holding member for holding a predetermined lens group among the plurality of lens groups; 1 fixed part, Holding member and a mating portion that mates with the a first adjustment unit that moves the center of the predetermined lens group relative to the optical axis by an external rotation operation; With and arranged parallel to the optical axis a first shaft; and a support member that rotatably supports the first shaft; a second shaft arranged parallel to the optical axis and having a second fixing portion and an abutment portion that abuts against the holding member to regulate a position in a direction perpendicular to the optical axis; the first shaft is supported by the support member so as to be rotatable around a central axis of the first fixed portion, the second shaft is supported by the support member so as to be rotatable around the central axis of the second fixed portion, a central axis of the first fixing portion and a central axis of the fitting portion are eccentric, a central axis of the second fixing portion and a central axis of the abutting portion are eccentric, and the amount of eccentricity of the second axis is equal to or greater than half of the amount of eccentricity of the first axis; The predetermined lens group The holding member The optical axis is rotated about the first axis to move between a predetermined position on the optical axis and a retracted position away from the optical axis. [Effects of the Invention]

[0012] Original Clearly According to this optical device, it is possible to provide an optical device that can adjust the position of a predetermined lens with a simple configuration that can be made compact without impairing optical performance. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a perspective view of the appearance of a digital camera and its lens barrel according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing the extended state of the lens barrel in the first embodiment. [Figure 3] FIG. 2 is a cross-sectional view showing the retracted state of the lens barrel in the first embodiment. [Figure 4] FIG. 2 is a perspective view of an image stabilization device provided in the lens barrel according to the first embodiment. [Figure 5] FIG. 1 is a front view showing the configuration of an image stabilization device according to a first embodiment. [Figure 6] FIG. 2 is a rear view showing the configuration of the image stabilization device according to the first embodiment. [Figure 7] 3A and 3B are perspective views showing the states of a third group holder and the like that make up the image stabilization device in the first embodiment at a shooting position and at a retracted position. [Figure 8] FIG. 2 is a perspective view showing the relationship between a third group base plate and a third group lever that constitute the image stabilization device in the first embodiment. [Figure 9] 7 is a cross-sectional view taken along the arrow CC in FIG. 6. [Figure 10] FIG. 6 is a cross-sectional view taken along the arrow AA in FIG. 5(a). [Figure 11] 7 is a cross-sectional view taken along the arrow BB in FIG. 6. [Figure 12] 2 is a schematic diagram showing the relationship between a third lens group, a holder shaft, and an abutment shaft that constitute the image stabilization device in the first embodiment. FIG. [Figure 13] FIG. 10 is a perspective view of the appearance of a digital camera according to a second embodiment. [Figure 14] FIG. 10 is a block diagram of a digital camera according to a second embodiment. [Figure 15] FIG. 10 is a cross-sectional view showing the wide-angle end state of the lens barrel in the second embodiment. [Figure 16] FIG. 10 is a cross-sectional view showing the telephoto end state of the lens barrel in the second embodiment. [Figure 17] FIG. 10 is a cross-sectional view showing the retracted state of the lens barrel in the second embodiment. [Figure 18] FIG. 10 is an exploded perspective view showing the configuration of an image stabilization device according to a second embodiment. [Figure 19] FIG. 10 is a front view of an image stabilization device in a shooting state according to a second embodiment. [Figure 20] FIG. 10 is a front view of an image stabilization device according to a second embodiment in a non-photographing state. [Figure 21] 21 is a first cross-sectional view taken along the arrow DD in FIG. 20. [Figure 22] 21 is a second cross-sectional view taken along the arrow DD in FIG. 20. [Figure 23] FIG. 10 is an exploded perspective view showing the configuration of an image stabilization device according to a third embodiment. [Figure 24] FIG. 11 is a front view of an image stabilization device according to a third embodiment in a shooting state. [Figure 25] FIG. 11 is a front view of an image stabilization device according to a third embodiment in a non-photographing state. [Figure 26] 26 is a first cross-sectional view taken along the arrow EE in FIG. 25. [Figure 27] FIG. 10 is a block diagram showing the configuration of a digital camera according to a fourth embodiment. [Figure 28] FIG. 11 is a cross-sectional view showing the wide-angle end state of the lens barrel in the fourth embodiment. [Figure 29] FIG. 11 is a cross-sectional view showing the telephoto end state of the lens barrel in the fourth embodiment. [Figure 30] FIG. 10 is a cross-sectional view showing the retracted state of the lens barrel in the fourth embodiment. [Figure 31] FIG. 11 is a first diagram showing a state of the lens barrel in the fourth embodiment when transitioning from an imaging state to a non-imaging state. [Figure 32] FIG. 13 is a second diagram showing the state of the lens barrel in the fourth embodiment when transitioning from an imaging state to a non-imaging state. [Figure 33] FIG. 13 is a third diagram showing the state of the lens barrel in the fourth embodiment when transitioning from an imaging state to a non-imaging state. [Figure 34] FIG. 10 is a fourth diagram showing the state of the lens barrel in the fourth embodiment when transitioning from an imaging state to a non-imaging state. [Figure 35] 10 is a timing chart showing the state when the lens barrel transitions from an imaging state to a non-imaging state in the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In each of the following embodiments, an imaging device such as a digital camera or digital video camera will be described as an optical device according to the present invention, and the description will focus in particular on the lens barrel of the imaging device. Note that the lens barrel may be detachable from the imaging device body (a so-called interchangeable lens), or may be integrally formed with the imaging device body (not detachable).

[0017] First Embodiment Fig. 1(a) is an external perspective view of a digital camera 100 according to the first embodiment. The digital camera 100 comprises a camera body 101 and a retractable zoom lens barrel 102 (hereinafter referred to as "lens barrel 102") arranged on the front side of the camera body 101. Fig. 1(b) is an external perspective view of the lens barrel 102. The lens barrel 102 comprises a zoom drive unit 31 that performs extension and retraction operations.

[0018] When the power of the camera body 101 is turned on, the lens barrel 102 performs an extension operation, and the lens barrel 102 transitions from a retracted state (retracted state) to an extended state. In the extended state, the various lenses that make up the lens barrel 102 are positioned on the photographing optical axis (hereinafter referred to as the "optical axis"), which enables photography with the digital camera 100. Furthermore, the lens barrel 102 is configured so that in the extended state, the positions of the various lenses in the optical axis direction are controlled, thereby making it possible to change the photographing magnification. When the power of the camera body 101 is turned off, the lens barrel 102 performs a retraction operation, and the lens barrel 102 transitions from the extended state to the retracted state.

[0019] Fig. 2 is a cross-sectional view including the optical axis of lens barrel 102 in an extended state. Fig. 3 is a cross-sectional view including the optical axis of lens barrel 102 in a retracted state. Note that in Figs. 2 and 3, the left side is the subject side (not shown), and the right side is the camera body 101 side (not shown).

[0020] Lens barrel 102 includes a first group lens 23, a first group holder 24a that holds first group lens 23, a first group barrel 24b that holds first group holder 24a, a second group lens 25, and a second group holder 26 that holds second group lens 25. Lens barrel 102 also includes third group lenses 2a and 2b, a third group holder 3 that holds third group lenses 2a and 2b, a fourth group lens 27, a fourth group holder 28 that holds fourth group lens 27, a fifth group lens 29, and a sensor holder 30 that holds fifth group lens 29.

[0021] The first lens 23, the first holder 24a, and the first lens barrel 24b form the first unit. The second lens 25 and the second holder 26 form the second unit. The third lenses 2a and 2b and the third holder 3 form the third unit. The fourth lens 27 and the fourth holder 28 form the fourth unit. The fifth lens 29 and the sensor holder 30 form the fifth unit. The first lens 23, the second lens 25, the third lenses 2a and 2b, the fourth lens 27, and the fifth lens 29 form the photographic optical system of the lens barrel 102.

[0022] A shutter unit 32 is disposed between the second and third unit groups. The shutter unit 32 adjusts the subject light flux that forms an image on the image sensor 36 by moving a pair of shutter blades (not shown) between a position where they block the optical path and a position where they are retracted from the optical path in a plane perpendicular to the optical axis. In the case of an imaging device with interchangeable lenses, such as a digital single-lens reflex camera, the shutter unit is provided on the camera body.

[0023] The sensor holder 30 supports a focus driver (not shown) and a zoom driver 31. The focus driver moves a fourth lens holder 28, which holds a fourth lens group 27, back and forth along the optical axis, thereby performing a focus operation. The zoom driver 31 moves the first to third lens groups back and forth along the optical axis, thereby performing a zoom operation.

[0024] The zoom mechanism will now be described. A fixed barrel 22 is disposed on the outermost periphery of the lens barrel 102. Cam grooves 22a and linear key grooves 22b are formed on the inner periphery of the fixed barrel 22 at three locations, spaced approximately equally apart in the circumferential direction. An outer cam barrel 34 is also disposed inside the fixed barrel 22, and has followers (not shown) formed on the outer periphery at three locations, spaced approximately equally apart in the circumferential direction. The three cam grooves 22a on the fixed barrel 22 and the three followers on the outer cam barrel 34 are slidably fitted together in a one-to-one relationship. A zoom drive unit 31 drives the outer cam barrel 34 to rotate. When the outer cam barrel 34 is driven to rotate by the zoom drive unit 31, it moves in the optical axis direction along the lift of the cam grooves 22a while rotating relative to the fixed barrel 22.

[0025] An outer rectilinear barrel 35 is disposed inside the outer cam barrel 34. A rectilinear key groove 35a is formed on the inner periphery of the outer rectilinear barrel 35, and a circumferential groove 35b is formed on the outer periphery of the outer cam barrel 35. Bayonet claws (not shown) that engage with the circumferential grooves 35b formed on the outer periphery of the outer cam barrel 34 are formed at multiple locations in the circumferential direction and the optical axis direction on the inner periphery of the outer cam barrel 34. In addition, a rectilinear key (not shown) that engages with the rectilinear key groove 22b of the fixed barrel 22 is formed on the outer periphery of the outer cam barrel 34. Therefore, as the outer cam barrel 34 rotates, the outer rectilinear barrel 35 moves linearly in the optical axis direction along the rectilinear key groove 22b of the fixed barrel 22.

[0026] An inner cam cover 33 is disposed inside the outer linear barrel 35, and the inner cam barrel 20 is disposed inside the inner cam cover 33. Cam grooves 20a, shutter cam grooves 20b, and second-group cam grooves 20c are each formed in three locations at approximately equal intervals in the circumferential direction on the inner peripheral portion of the inner cam barrel 20. First-group cam grooves 20d are formed in three locations at approximately equal intervals in the circumferential direction on the outer peripheral portion of the inner cam barrel 20.

[0027] Followers, inner cam cover engaging portions, and drive keys (not shown) are formed at three locations on the outer periphery of the inner cam barrel 20, at approximately equal intervals in the circumferential direction. The inner cam cover 33 is formed with three engaging claws (not shown) that engage with the inner cam cover engaging portions of the inner cam barrel 20, and three anti-rotation portions (not shown) that fit with the drive keys of the inner cam barrel 20. The drive keys provided on the outer periphery of the inner cam barrel 20 engage with three key grooves (not shown) provided on the inner periphery of the outer cam barrel 34. This causes the inner cam barrel 20 to rotate around the optical axis in the same phase as the outer cam barrel 34. As the inner cam barrel 20 rotates, the inner cam cover 33 moves in the optical axis direction while rotating integrally with the inner cam barrel 20 around the optical axis.

[0028] The inner cam barrel 20 holds the linear barrel 21 on its inner periphery so that it can rotate relative to the inner cam barrel 20. A linear plate 19 is attached integrally to the linear barrel 21. A linear key (not shown) is formed on the linear plate 19, which engages with a linear key groove 35a provided on the inner periphery of the outer linear barrel 35. The linear barrel 21 also has a first group guide key 21b, a second group guide groove (not shown), and a third group guide groove 21d formed thereon. The linear barrel 21 also has a retraction introduction surface (not shown) that abuts against the third group lever 6 (see FIGS. 4 and 5), a retraction completion surface (not shown) that abuts against the third group lever 6, and a flange (not shown). The linear barrel 21 is rotatably held relative to the inner cam barrel 20 by the flange of the linear barrel 21 and the linear plate 19, and moves integrally with the inner cam barrel 20 in the optical axis direction.

[0029] Six first-group followers (not shown) are provided at approximately equal intervals around the circumferential edge of the inner periphery of the first-group barrel 24b. These six first-group followers slidably fit one-to-one into six first-group cam grooves 20d provided on the outer periphery of the inner cam barrel 20, and are guided by first-group guide keys 21b of the linearly moving barrel 21, so that the first-group holder 24a and the first-group barrel 24b move forward and backward together in the optical axis direction.

[0030] Second-group followers (not shown) are provided at three locations at approximately equal intervals in the circumferential direction on the outer periphery of the second-group holder 26. The three second-group followers and three second-group cam grooves 20c provided on the inner periphery of the inner cam barrel 20 slidably fit together in a one-to-one relationship, and the second-group holder 26 is supported so as to be movable back and forth in the optical axis direction by being guided by a second-group guide groove (not shown) of the linearly moving barrel 21.

[0031] Shutter followers 32a are provided at three locations at approximately equal intervals in the circumferential direction on the outer periphery of the shutter unit 32. The three shutter followers 32a slidably fit one-to-one with three shutter cam grooves 20b provided on the inner periphery of the inner cam barrel 20, and the shutter unit 32 is guided by the third group guide groove 21d of the linearly moving barrel 21, so that the shutter unit 32 is supported so as to be able to advance and retreat in the optical axis direction.

[0032] Next, we will explain the image stabilization device incorporated into the lens barrel 102. Fig. 4(a) is a perspective view showing the image stabilization device provided in the lens barrel 102, as seen from the front side (subject side). Fig. 4(b) is a perspective view showing the image stabilization device, as seen from the rear side (image sensor 36 side). The image stabilization device has third lens group 2a, 2b, third lens group holder 3, holder torsion spring 4, holder shaft 50, abutment shaft 80, third lens group lever 6, third lens group frame 8, and third lens group base plate 9. Note that in Fig. 4, the third lens group 2a, 2b are simply indicated by '2', and this is the same in Figs. 5 to 7 and 12.

[0033] The third group flexible substrate 11 is held by a Hall sensor holder 12, which is fixed to the third group base plate 9. A pair of Hall elements (not shown) are mounted on the third group flexible substrate 11. The pair of Hall elements are arranged in positions facing the pair of magnets 8d (see FIG. 7) in the optical axis direction, and detect changes in the direction and magnitude of the magnetic force of the pair of magnets 8d. A control unit (not shown) provided in the camera body 101 determines the position of the third group frame 8 relative to the Hall sensor holder 12 based on the direction and magnitude of the magnetic force detected by the Hall elements.

[0034] Fig. 5(a) is a front view (viewed from the subject side) of the image stabilization device when the lens barrel 102 is in the extended state. Fig. 5(b) is a front view of the image stabilization device when the lens barrel 102 is in the retracted state. Fig. 6 is a rear view of the image stabilization device when the lens barrel 102 is in the extended state.

[0035] The third lens group holder 3 holds the third lens groups 2a and 2b. The third lens groups 2a and 2b are located on the optical axis (hereinafter referred to as the "shooting position") when the lens barrel 102 is in the extended state, and are located away from the optical axis (hereinafter referred to as the "retracted position") when the lens barrel 102 is in the retracted state. do.As shown in FIG. 3, by moving third lens group 2a and 2b to a retracted position when lens barrel 102 is retracted, the distance between second lens group 25 and fourth lens group 27 in the optical axis direction is shortened, and the overall length of lens barrel 102 in the retracted state can be shortened.

[0036] In the description of this embodiment, for convenience, when the third group lenses 2a and 2b are in the shooting position, the third group holder 3 is also said to be in the shooting position, and when the third group lenses 2a and 2b are in the retracted position, the third group holder 3 is also said to be in the retracted position.

[0037] The third holder 3 is provided with a third mask 17a on the subject side and a third mask 17b on the imaging plane side. The third frame 8 is formed with spring hooks 8c in three locations for hooking one end of a thrust spring 14 (see FIG. 7). The third frame 8 is also provided with bearings 8a that support a holder shaft 50 (first axis). The third frame 8 is a support member that rotatably supports the third holder 3; specifically, the third holder 3 is supported by the bearings 8a provided on the third frame 8 so that it can rotate around the holder shaft 50. The third holder 3 is disposed integrally with the third lenses 2a and 2b so that it can move around the holder shaft 50 in a plane perpendicular to the optical axis between an imaging position and a retracted position.

[0038] Fig. 7(a) is a perspective view from the rear side showing the positional relationship between the third holder 3, the third frame 8, and the third lever 6 when the third holder 3 is in the shooting position. Fig. 7(b) is a perspective view from the rear side showing the positional relationship between the third holder 3, the third frame 8, and the third lever 6 when the third holder 3 is in the retracted position.

[0039] One end of the thrust spring 14 is hooked onto each of three spring hooks 8c formed on the third group frame 8. Three ball receiving surfaces 8b that come into contact with three balls 13 (see FIG. 8) are formed on the third group frame 8. A pair of magnets 8d are also attached to the third group frame 8, spaced apart by approximately 90° in the circumferential direction within a plane perpendicular to the optical axis.

[0040] Fig. 8 is a perspective view showing the positional relationship between the third group base plate 9 and the third group lever 6 as viewed from the front, with the third group holder 3 (not shown) in the retracted position. Fig. 9 is a cross-sectional view taken along the arrow CC in Fig. 6. Ball grooves 9a are formed in three locations on the third group base plate 9, and balls 13 (rolling members) are disposed in each of the ball grooves 9a. Spring hooks 9b are provided in three locations on the third group base plate 9, to which the other ends of three thrust springs 14 are respectively hooked. Each of the three balls 13 is sandwiched between the ball receiving surface 8b of the third group frame 8 and the ball groove 9a of the third group base plate 9 by the biasing force of the thrust spring 14, and can roll within the ball groove 9a in a plane perpendicular to the optical axis.

[0041] The third group base plate 9 is provided with the third group lever shaft 7, a bearing 9d that pivotally supports the third group lever shaft 7 parallel to the optical axis, and a follower 9e that slidably fits into the cam groove 20a (see FIGS. 2 and 3) of the inner cam barrel 20. The third group base plate 9 also has a pair of coils 9c that are arranged in phase with the pair of magnets 8d. When current is applied to the pair of coils 9c, a Lorentz force is generated between the magnetism of the pair of magnets 8d. This Lorentz force allows the third group frame 8 to move relative to the third group base plate 9 in a plane perpendicular to the optical axis. At this time, the third group holder 3 is rotatably supported by the third group frame 8, and therefore moves integrally with the third group frame 8. In other words, the third group lenses 2a and 2b held by the third group holder 3 can move integrally with the third group frame 8.

[0042] The third group lever 6 is provided with a retraction slope 6c that abuts against a retraction introduction surface (not shown) of the linear movement barrel 21, and a retraction completion portion 6d that abuts against a retraction completion surface (not shown) of the linear movement barrel 21. The third group lever 6 is supported by a bearing 9d on the third group base plate 9 so as to be rotatable around the third group lever shaft 7. The third group lever 6 is urged in the direction of the photographing position by a lever torsion spring 18 that is attached around the third group lever shaft 7 so as to abut against a photographing position abutment surface (not shown) provided on the third group base plate 9.

[0043] 10 is a cross-sectional view taken along the line AA in FIG. 5(a). The third group holder 3 has a lens element 4 in the optical axis direction. Orthogonal to A stopper portion 3a is provided to regulate the position at the position, and the stopper portion 3a abuts against an abutment shaft 80 (second shaft).

[0044] 11 is a cross-sectional view taken along the arrow BB in FIG. 6. The holder torsion spring 4 is composed of a torsion spring portion and a compression spring portion, and the compression spring portion is fitted onto the sleeve 3b of the third holder 3. The torsion spring portion of the holder torsion spring 4 urges the third holder 3 toward the third frame 8 so that the stopper portion 3a of the third holder 3 abuts against an abutment shaft 80 provided on the third frame 8. In other words, the holder torsion spring 4 urges the third lens group 2a, 2b (third holder 3) in a direction that moves them from the retracted position to the shooting position. In addition, the compression spring portion of the holder torsion spring 4 urges the third holder 3 toward the subject in the optical axis direction, causing the subject-side tip of the sleeve 3b of the third holder 3 to abut against the subject-side bearing 8a of the third frame 8.

[0045] The image stabilization device configured as described above is controlled by a control unit (not shown) provided in the camera body 101. The control unit controls the voltage applied to the pair of coils 9c based on image shake information from a gyro sensor (not shown) arranged in the camera body 101, and moves the third group frame 8 within a plane perpendicular to the optical axis. In this way, by moving the third group holder 3 that holds the third group lenses 2a and 2b together with the third group frame 8 in a direction in which image shake is corrected, image shake of the subject image formed on the image sensor 36 through the photographing optical system can be corrected, and images and videos with reduced image shake can be obtained.

[0046] Next, the position adjustment mechanism for the third group lenses 2a and 2b will be described. As shown in Fig. 11, the holder shaft 50 is fitted in parallel to the optical axis to the sleeve 3b of the third group holder 3. The holder shaft 50 has a first fixed portion 50a held by the third group frame 8, a fitting portion 50b that slidably fits with the third group holder 3 and serves as the center of rotation when the third group holder 3 is retracted, and a fitting portion 50c that engages an adjustment tool (not shown) when adjusting the positions of the third group lenses 2a and 2b. Let 10, the abutment shaft 80 has a second fixing portion 80a that is held by the third group frame 8, an abutment portion 80b that abuts against the stopper portion 3a when the third group holder 3 is in the shooting position, and a stopper portion 80c that engages an adjustment tool (not shown) when adjusting the lens. Let The second adjustment section 80c has a second adjustment section 80c.

[0047] 12 is a schematic diagram showing the relationship between the third group lenses 2a and 2b, the holder shaft 50, and the abutment shaft 80 in the image stabilization device. As shown in Fig. 11, the central axis of the first fixing portion 50a of the holder shaft 50 and the central axis of the fitting portion 50b are offset by a distance E. Therefore, when the first adjustment portion 50c is rotated, the third group holder 3 moves offset, and the center of the third group lens 2 moves along the locus of an ellipse S1 shown in Fig. 12.

[0048] Also, as shown in Figure 10 R As shown, the central axes of the second fixed portion 80a and the abutment portion 80b of the abutment shaft 80 are eccentric by a distance F. Therefore, when the second adjustment portion 80c is rotated, the third group holder 3 moves eccentrically, and moves while describing an arc S2 with the straight-line distance between the holder shaft 50 and the abutment shaft 80 as its radius, with the holder shaft 50 as its center.

[0049] Here, distance F, which is the amount of eccentricity of the abutment shaft 80, is equal to or greater than half of distance E, which is the amount of eccentricity of the holder shaft 50 (F≧E / 2). Therefore, rotation of the abutment shaft 80 enables movement to any position within the ellipse of the elliptical movement S1 of the third lens group 2 caused by rotation of the holder shaft 50. In other words, by combining the elliptical movement caused by rotation of the holder shaft 50 and the arc movement caused by rotation of the abutment shaft 80, it is possible to freely move the third lens group holder 3 within a plane perpendicular to the optical axis.

[0050] In addition, a second fixing portion 80a is provided between the contact portion 80b and the second adjustment portion 80c, and the second fixing portion 80a The third group holder 3 abuts at is located closer to second adjustment portion 80c than contact portion 80b. Therefore, even if a load is applied to second adjustment portion 80c during adjustment, it is possible to perform adjustment while maintaining contact shaft 80 in a stable state. Therefore, by realizing a simple structure with only two adjustment locations, it is possible to achieve a lens barrel 102 that is compact and inexpensive, and that can be easily adjusted without compromising optical performance.

[0051] 12, a line connecting the centers of the holder shaft 50 and the abutment shaft 80 is designated as line H. Lengths H1 and H2 obtained by dividing line H by a perpendicular line G (see FIG. 6 as appropriate) that intersects line H at right angles and passes through the third lens groups 2a and 2b satisfy the relationship 'H1≧H2'. Thus, as the flattening of the elliptical motion of the third lens group 2 caused by rotation of the holder shaft 50 increases, the elliptical motion of the third lens group 2 approaches linear motion that is substantially parallel to line H, making adjustment easier.

[0052] Furthermore, both first adjustment unit 50c and second adjustment unit 80c are provided along the optical axis on the imaging surface side of image sensor 36, rather than on the subject side. This makes it easier to engage adjustment tools with first adjustment unit 50c and second adjustment unit 80c during the manufacturing process of lens barrel 102, allowing for cost reductions due to lower manufacturing costs.

[0053] The third group frame 8, which holds the holder shaft 50 and the abutment shaft 80, is biased toward the image sensor 36 in the optical axis direction by a thrust spring 14 (see FIG. 7 as appropriate), against the third group base plate 9. As a result, even if a large force is applied when an adjustment tool engages with the first adjustment unit 50c and the second adjustment unit 80c during the manufacturing process of the lens barrel 102, the force is applied in the opposite direction to the biasing direction of the thrust spring 14. This prevents damage such as scratches on the ball receiving surface 8b and the ball groove 9a, and allows the balls 13 to roll smoothly, making it possible to maintain high optical performance (image stabilization performance).

[0054] Second Embodiment Fig. 13(a) is an external perspective view from the front side of a digital camera 200 according to the second embodiment. Fig. 13(b) is an external perspective view from the rear side of the digital camera 200. The digital camera 200 has a camera body 210 and a lens barrel 201 (interchangeable lens) that is detachable from the camera body 210.

[0055] For convenience of explanation, X, Y, and Z axes are defined as being orthogonal to one another with respect to digital camera 200, as shown in FIG. 13(a). The direction (optical axis direction) in which the optical axis of the imaging optical system (hereinafter simply referred to as the "optical axis") housed in lens barrel 201 extends is referred to as the Z axis direction. When the Z axis is parallel to the horizontal direction, the axis perpendicular to the Z axis in the horizontal plane is referred to as the X axis, and the axis perpendicular to the horizontal plane is referred to as the Y axis. Note that the X axis direction is the width direction of camera body 210, the Y axis direction is the height direction of camera body 210, and the Z axis direction is the front-to-rear direction of camera body 210. In the following explanation, the rotation direction around the X axis (with the X axis as the center of rotation) is referred to as the pitch direction, and the rotation direction around the Y axis is referred to as the yaw direction.

[0056] Camera body 210 has a grip section 212 on the left side when viewed from the front (right side when viewed from the rear) that allows the user to hold camera body 210 with their hand. A power operation section 213 is located on the top surface of camera body 210. When the user turns on power operation section 213 while camera body 210 is in the power-off state, power begins to flow inside digital camera 200, and camera body 210 enters the power-on state. When camera body 210 enters the power-on state, camera control section 232 (see FIG. 14) executes a predetermined computer program, and digital camera 200 enters a standby state for photographing. Conversely, when the user turns off power operation section 213 while camera body 210 is in the power-on state, camera body 210 enters the power-off state.

[0057] A mode dial 214, a release button 215, and an accessory shoe 216 are provided on the top surface of the camera body 210. The user can switch between shooting modes by rotating the mode dial 214. The shooting modes include a manual still image shooting mode in which the user can arbitrarily set shooting conditions such as shutter speed and aperture value, an auto still image shooting mode in which the appropriate exposure is automatically obtained, and a video shooting mode for shooting videos. The camera control unit 232 performs shooting preparation operations such as autofocus and auto exposure control in response to a half-press of the release button 215, and takes a picture in response to a full-press of the button. An accessory such as an external flash device can be attached to the accessory shoe 216.

[0058] Lens barrel 201 is mechanically and electrically connected to a camera mount 217 provided on camera body 210 via lens mount 202. An imaging optical system is housed inside lens barrel 201, which forms an image of the subject by focusing light from the subject on image sensor 236 (see FIG. 14). A zoom ring 203 is provided on the outer periphery of lens barrel 201 and can be rotated around the optical axis by user operation. When zoom ring 203 is rotated, the zoom group that makes up the imaging optical system moves to a predetermined position corresponding to the angle of zoom ring 203. This allows the user to take pictures at a desired angle of view.

[0059] The rear surface of the camera body 210 is provided with a rear surface operation unit 218 and a display unit 219. The rear surface operation unit 218 includes a plurality of buttons and dials to which various functions are assigned. When the power of the camera body 210 is on and a still image or video shooting mode is set, the display unit 219 displays a through image of the subject image captured by the image sensor 236. The display unit 219 also displays shooting parameters indicating shooting conditions such as shutter speed and aperture value, and the user can change the shooting parameters to desired settings by operating the rear surface operation unit 218 while viewing the display. The rear surface operation unit 218 includes a playback button for instructing playback of recorded captured images. When the playback button is operated, captured images and the like recorded in the storage unit 233 (see FIG. 14 ) are played back and displayed on the display unit 219.

[0060] 14 is a block diagram showing the electrical and optical configuration of the digital camera 200. The camera body 210 has a power supply unit 230 that supplies power to the camera body 210 and the lens barrel 201. The camera body 210 also has an operation unit 231 that includes a power operation unit 213, a mode dial 214, a release button 215, a rear operation unit 218, and a touch panel function of a display unit 219. Overall system control of the digital camera 200 is performed by cooperation between a camera control unit 232 provided in the camera body 210 and a lens control unit 204 provided in the lens barrel 201.

[0061] The camera control unit 232 reads and executes a computer program stored in the storage unit 233. In doing so, the camera control unit 232 communicates various control signals, data, and the like with the lens control unit 204 via a communication terminal of the electrical contact 205 provided on the lens mount 202. The electrical contact 205 includes a power supply terminal that supplies power from the power supply unit 230 to the lens barrel 201.

[0062] The imaging optical system of the lens barrel 201 has a zoom group 220 that is connected to the zoom operation ring 203 and moves in the optical axis direction to change the angle of view, and an image stabilization device 600 that includes a shift lens 222 as an anti-vibration element. The image stabilization device 600 reduces image shake by shifting (moving (displacing)) the shift lens 222 in any direction in an XY plane perpendicular to the optical axis. The configuration of the image stabilization device 600 will be described in detail later.

[0063] The imaging optical system also has an aperture group 350 that adjusts the amount of light, and a focus group 224 that includes a focus lens that moves in the optical axis direction to adjust the focus. Furthermore, the lens barrel 201 has an anti-vibration driver 251 that drives the image stabilization device 600, an aperture driver 302 that drives the aperture group 350, and a focus driver 401 that moves the focus group 224.

[0064] The camera body 210 has a shutter unit 234, a shutter drive unit 235, an image sensor 236, an image processing unit 237, and a camera control unit 232. The shutter unit 234 controls the amount of subject light that passes through the imaging optical system in the lens barrel 201 and forms an image on the image sensor 236. The image sensor 236 photoelectrically converts the optical image of the subject (subject image) formed on the imaging surface and outputs an image signal. The image processing unit 237 performs various image processes on the image signal to generate an image signal. The display unit 219 has already been described with reference to FIG. 13, so a description thereof will be omitted.

[0065] The camera control unit 232 controls the focus driving unit 401 in response to a shooting preparation operation (such as a half-press of the release button 215) performed on the operation unit 231. For example, when an autofocus operation is instructed, the focus detection unit 238 determines the focus state of the subject image formed on the image sensor 236 using the image signal generated by the image processing unit 237, generates a focus signal, and transmits it to the camera control unit 232. In parallel with this, the focus driving unit 401 transmits information regarding the current position of the focus group 224 to the camera control unit 232. The camera control unit 232 then compares the focus state of the subject image with the current position of the focus group 224 to determine the amount of deviation, calculates a focus drive amount from the determined amount of deviation, and transmits it to the lens control unit 204. The lens control unit 204 moves the focus group 224 to a target position in the optical axis direction via the focus driving unit 401 using the obtained focus drive amount. This corrects the focus deviation of the subject image, bringing the subject into focus.

[0066] The focus driver 401 includes a focus motor (not shown) and a photointerrupter (not shown) that detects the origin position of the focus group 224. The focus motor may be a stepping motor or the like, but is not limited to this, and may also be a DC motor with an encoder or an ultrasonic motor (vibration actuator). Also, instead of the photointerrupter, a photoreflector or a brush that contacts a conductive pattern to electrically detect a signal may be used.

[0067] The camera control unit 232 controls the driving of the aperture group 350 and the shutter unit 234 via the aperture drive unit 302 and the shutter drive unit 235 in accordance with the setting values of the aperture value and shutter speed received from the operation unit 231. For example, when an automatic exposure control operation is instructed, the camera control unit 232 receives a luminance signal generated by the image processing unit 237 and performs a photometric calculation. Based on the obtained photometric calculation result, the camera control unit 232 controls the aperture drive unit 302 in accordance with a shooting instruction operation on the operation unit 231 (such as a full press of the release button 215). In parallel with this, the camera control unit 232 controls the driving of the shutter unit 234 via the shutter drive unit 235 and performs an exposure process for the image sensor 236.

[0068] The camera body 210 has a pitch shake detection unit 239 and a yaw shake detection unit 240 as shake detection means capable of detecting image shake caused by the user's hand shake or the like. The pitch shake detection unit 239 and the yaw shake detection unit 240 respectively detect the pitch and yaw shake in the pitch and yaw directions using an angular velocity sensor (vibration gyro) and an angular acceleration sensor. Camera body 210 The camera control unit 232 detects shake and outputs a shake signal. The camera control unit 232 calculates the shift position of the shift lens 222 in the Y-axis direction using the shake signal acquired from the pitch shake detection unit 239, and calculates the shift position of the shift lens 222 in the X-axis direction using the signal acquired from the yaw shake detection unit 240. The camera control unit 232 drives the image stabilization device 600 via the vibration isolation drive unit 251 in accordance with the calculated shift positions in the pitch and yaw directions, and moves the shift lens 222 to target positions in the X-axis and Y-axis directions. This reduces image shake during exposure and while a through-image is displayed.

[0069] The lens barrel 201 has a zoom operation ring 203 for changing the angle of view of the imaging optical system, and a zoom detection unit 206 that detects the angle of the zoom operation ring 203. The zoom detection unit 206 is configured using, for example, a resistive linear potentiometer, and detects the angle of the zoom operation ring 203 operated by the user as an absolute value. Information about the angle of view detected by the zoom detection unit 206 is transmitted to the lens control unit 204, and then reflected in various controls by the camera control unit 232. Note that part of the above-mentioned information is recorded, together with the captured image (image data), in the storage unit 233 or a recording medium (not shown).

[0070] Next, the positional relationships of the main components of lens barrel 201 will be described with reference to Figures 15 to 17. Figures 15 to 17 are YZ cross-sectional views (cross-sectional views perpendicular to the X-axis) of digital camera 200, and are shown in a cross section including the optical axis. Figure 15 shows a state in which lens barrel 201 is set at the wide-angle end on the short focal length side, and Figure 16 shows a state in which lens barrel 201 is set at the telephoto end on the long focal length side. Figure 17 shows a retracted state in which lens barrel 201 is at its shortest overall length.

[0071] The lens barrel 201 is an example of an imaging optical system with a six-group configuration. A configuration in which the aperture group 350 is incorporated into the zoom group 220 By adopting There are. The zoom group 220 moves to different predetermined positions in the optical axis direction at the wide-angle end and the telephoto end, and forms an image of incident light on the image sensor 236. The zoom group 220 includes a first zoom group 221, a shift lens 222 (second zoom group), , th The zoom group 220 is made up of a third zoom group 223, a focus group 224 (fourth zoom group), a fifth zoom group 225, and a sixth zoom group 226. Note that the configuration of the zoom group 220 here does not limit the configuration of the imaging optical system of the lens barrel 201; for example, the shift lens 222 and the focus group 224 may function as other zoom groups. Also, some lens groups may not be movable but may be fixed.

[0072] The lens barrel 201 has a linear guide barrel 207 and a cam barrel 208. A cam follower (not shown) is provided on the inner periphery of the cam barrel 208. The cam barrel 208 is also connected to the zoom operation ring 203 via a key (not shown). When the zoom operation ring 203 is rotated, the cam barrel 208 moves forward and backward in the optical axis direction while rotating about the optical axis due to the slidable engagement between the cam groove and the cam follower.

[0073] The linear guide barrel 207 is disposed on the inner circumferential side of the cam barrel 208, and is fixed to the lens mount 202 via a fixed barrel (not shown). Cam grooves (not shown) are formed at equal intervals on the outer circumferential surface of the linear guide barrel 207. Further, linear guide grooves that restrict movement of the zoom group 220 in the rotational direction and guide linear movement in the optical axis direction are formed at equal intervals on the linear guide barrel 207. Meanwhile, cam grooves with loci at different angles in the rotational direction are formed at equal intervals on the cam barrel 208 to correspond to the zoom group 220.

[0074] The zoom group 220 is provided with a plurality of cam followers that slidably fit into the linear grooves of the linear guide barrel 207 and the cam grooves of the cam barrel 208. When the zoom operation ring 203 is rotated, the cam barrel 208 rotates. Accordingly, the zoom group 220 advances and retreats in the optical axis direction while its rotation about the optical axis is restricted, because the cam followers of the zoom group 220 are fitted into the linear guide grooves of the linear guide barrel 207 and the cam grooves of the cam barrel 208.

[0075] The lens barrel 201 has a retraction mechanism (not shown) and a retraction mechanism for the shift lens 222. When the lens barrel 201 (digital camera 200) is not in use, the retraction mechanism retracts the zoom group 220 further toward the rear side (toward the camera body 210) to shorten the overall length of the lens barrel 201, thereby improving portability. When the lens barrel 201 is set at the wide-angle end as shown in FIG. 15 , the distance between the first zoom group 221 and the shift lens 222 is wide, but when the lens barrel 201 is set at the telephoto end as shown in FIG. 16 , the distance between the fifth zoom group 225 and the sixth zoom group 226 is wide. The retraction mechanism shortens the overall length of the lens barrel 201 in the optical axis direction by narrowing the distance between the zoom groups that are spaced apart when the lens barrel 201 is in use and moving them to a retracted position where they are close to each other when not in use.

[0076] As shown in Fig. 17, in the retracted state of lens barrel 201, zoom groups 220 move to a storage position where they are close to each other. When zoom operation ring 203 is rotated to the wide-angle end in the retracted state, zoom groups 220 extend to the front side (subject side) and move to a predetermined use position, thereby achieving the use state shown in Fig. 15. Note that such a retraction mechanism is well known, so a detailed description will be omitted.

[0077] 15 and 16, when the lens barrel 201 is in use (when taking pictures with the digital camera 200), each group of the zoom group 220 is positioned at a predetermined position on the optical axis. When the lens barrel 201 is rotated from a state set at the wide-angle end (FIG. 15) until the zoom operation ring 203 is in a retracted state, the zoom group 220 begins to retract toward the rear side, and at the same time, the shift lens 222 retracts from the optical axis. In other words, when the lens barrel 201 transitions from an in-use state to a retracted state when not in use, the shift lens 222 moves from a predetermined position on the optical axis when in use (shooting position) to a predetermined position (retracted position) a predetermined distance away from the optical axis in a direction perpendicular to the optical axis (radial direction). The movement of the shift lens 222 between the shooting position and the retracted position is performed in the same manner as the retraction of the third group holder 3 (third group lenses 2a and 2b) in the first embodiment. By retracting the first zoom group 221 into the space created by the retraction of the shift lens 222 and storing them so as not to interfere with each other, the lens barrel 201 reaches the state shown in FIG. 17, where the overall length is at its shortest.

[0078] Fig. 18 is an exploded perspective view showing the image stabilization device 600 including the shift lens 222, as viewed from the front side. Fig. 19 is a front view of the image stabilization device 600 with the shift lens 222 in the shooting position. Fig. 20 is a front view of the image stabilization device 600 with the shift lens 222 in the retracted position.

[0079] The image stabilization device 600 has a shift lens 222, a lens frame 602, a base member 603, a shift member 604, a torsion spring 605, a retraction lever 606, three balls 607 (rolling members), and three springs 608. The lens frame 602 is a holding member that holds the shift lens 222. The lens frame 602 is rotatably supported by a bearing of the shift member 604 via a rotation shaft 603e that is press-fitted into the base member 603 parallel to the optical axis. During image stabilization, the shift lens 222 and the lens frame 602 move integrally with the shift member 604 within a plane perpendicular to the optical axis.

[0080] The torsion spring 605 is an urging member that is extrapolated onto the base member 603 and urges the lens frame 602 in a direction that moves it relative to the shift member 604 from the retracted position to the shooting position. The shift member 604 is provided with three ball receiving surfaces 604c (see FIG. 21) that come into contact with the three balls 607, respectively, and spring hook portions 604b to which one ends of three springs 608 are respectively hooked. In addition, a pair of magnets 609 are arranged on the shift member 604, spaced apart by approximately 90° from each other in the circumferential direction in a plane perpendicular to the optical axis.

[0081] The base member 603 is provided with spring hook portions 603b on which the other ends of the three springs 608 are respectively hooked. The three balls 607 are supported rollably within a plane perpendicular to the optical axis in a state where they are sandwiched between a ball receiving surface 604c of the shift member 604 and a ball receiving surface 603c (see FIG. 21) of the base member 603 by the biasing forces of the three springs 608 in the optical axis direction.

[0082] A pair of coils 610 is disposed on the base member 603 and is arranged in phase with the pair of magnets 609. When current is applied to the pair of coils 610, a Lorentz force is generated between the pair of magnets 609, and the shift member 604 moves relative to the base member 603 within a plane perpendicular to the optical axis due to the generated Lorentz force.

[0083] The movement of the shift member 604 in a plane perpendicular to the optical axis is restricted by a part of the outer periphery of the shift member 604 abutting against a part of the inner periphery of the base member 603. For example, a part of the side surface of the proximity shape portion 603a of the base member 603 (see FIGS. 18 and 19) can be configured to be used to restrict the movement of the shift member 604.

[0084] The retraction lever 606 is attached to the outer periphery of the base member 603 at a position close to a groove (not shown) provided in the cam barrel 208. When the cam barrel 208 rotates toward the retracted position, a part of the retraction lever 606 engages with the groove of the cam barrel 208 in accordance with the linear movement of the cam barrel 208 relative to the linear guide barrel 207. As a result, the retraction lever 606 rotates about the rotation axis 603e in a plane perpendicular to the optical axis in accordance with the movement of the cam barrel 208, and a tip end 606a of the retraction lever 606 presses against the lens frame 602. As a result, the lens frame 602 rotates against the spring force of the torsion spring 605, and the shift lens 222 moves to the retracted position.

[0085] FIG. 21 is a first cross-sectional view taken along the arrow DD in FIG. 20, showing the relationship between the lens frame 602 and the base member 603 when the shift lens 222 is in the retracted position. When the shift lens 222 is in the retracted position as viewed from the optical axis direction, a portion of the shift lens 222 protrudes outward from the outer periphery of the base member 603. The lens frame 602 is provided with a protrusion 602a that protrudes toward the base member 603. The base member 603 is provided with a proximity shape portion 603a (see FIGS. 18 and 19) that is in proximity to the protrusion 602a of the lens frame 602 when the shift lens 222 is in the retracted position. In other words, the protrusion 602a of the lens frame 602 and the proximity shape portion 603a of the base member 603 are located in proximity to each other when the shift lens 222 is in the retracted position.

[0086] As a result, when an external force such as a drop impact is applied while the shift lens 222 is in the retracted position, the protruding portion 602a near the center of gravity of the lens collides with the proximity shape portion 603a, and receives the external force. This prevents the external force acting on the ball 607 and the ball receiving surfaces 603c, 604c from becoming too large, reducing the risk of damage such as dents being caused to the ball 607 and the ball receiving surfaces 603c, 604c. As a result, deterioration in the rolling performance of the ball 607 is suppressed, and deterioration in image stabilization performance can be suppressed.

[0087] Incidentally, although the configuration has been described in which the protrusion 602a provided on the lens frame 602 and the proximity shape portion 603a provided on the base member 603 are close to each other when the shift lens 222 is in the retracted position, they may be partially in contact with each other in the optical axis direction.

[0088] When the protruding portion 602a and the proximal portion 603a are configured to come into contact with each other, it is desirable to form the proximal portion 603a in a sloped shape that approaches the lens frame 602 in the optical axis direction as it moves away from the optical axis toward the outer periphery, as shown in Fig. 21. This allows the protruding portion 602a to move smoothly by riding on the slope of the proximal portion 603a when the lens frame 602 moves from the shooting position in Fig. 19 to the retracted position in Fig. 20.

[0089] Fig. 22 is a second cross-sectional view taken along the arrow DD in Fig. 20, and shows a state in which the shift member 604 holding the lens frame 602 is tilted at an angle θ with respect to a plane perpendicular to the optical axis as a result of the protrusion 602a riding on and moving to the proximity shape portion 603a. Note that in Fig. 21, the shift member 604 is parallel to the plane perpendicular to the optical axis.

[0090] In the state shown in FIG. 22, an external force (impact) applied when the shift lens 222 is in the retracted position can be reliably received by the protrusion 602a and the proximity shape portion 603a. Also, a gap is created between at least one of the three balls 607 and the ball receiving surface 604c of the shift member 604 and the ball receiving surface 603c of the base member 603. Therefore, even if the lens frame 602 receives an impact, the risk of damage such as dents occurring on the ball 607 and the ball receiving surfaces 603c, 604c can be reduced by receiving the impact on the protrusion 602a and the proximity shape portion 603a. This effect can be significantly achieved by the ball 607 and its ball receiving surface, which are located closest to the protrusion 602a near the center of gravity of the optical element when the shift lens 222 is in the retracted position.

[0091] As explained above, in the second embodiment, the image stabilization device 600 can reduce the risk of damage, such as dents, occurring on the ball 607 and the ball receiving surfaces 603c, 604c even if an external force, such as an impact, is applied when the shift lens 222 is in the retracted position. This makes it possible to suppress a decrease in image stabilization performance during shooting. Furthermore, in the second embodiment, damage to the ball 607 and the ball receiving surfaces 603c, 604c can be avoided simply by changing the shapes of some of the components of conventional image stabilization devices, and there is no need to provide new members or the like. This makes it possible to avoid an increase in the size of the image stabilization device 600, and furthermore, to avoid an increase in the size of the lens barrel 801.

[0092] Third Embodiment In the third embodiment, an image stabilization device having a different configuration from the image stabilization device 600 described in the second embodiment will be described. Fig. 23 is an exploded perspective view showing an image stabilization device 700 according to the third embodiment, as viewed from the front side. Fig. 24 is a front view of the image stabilization device 700 with the shift lens 222 in the shooting position. Fig. 25 is a front view of the image stabilization device 700 with the shift lens 222 in the retracted position. Fig. 26 is a cross-sectional view taken along arrow EE in Fig. 25.

[0093] The image stabilization device 700 has a shift lens 222, a lens frame 602, a base member 703, a shift member 704, a torsion spring 605, a retraction lever 606, three balls 707 (rolling members), three springs 608, and a rolling assist member 720. The shift lens 222, the lens frame 602, the torsion spring 605, the retraction lever 606, the three springs 608, the pair of magnets 609, and the pair of coils 610 are the same as those constituting the image stabilization device 600 in the second embodiment, and therefore description thereof will be omitted. Furthermore, spring hooks 703b and 704b correspond to the spring hooks 603b and 604b in the image stabilization device 600, respectively.

[0094] The image stabilization device 700 differs from the image stabilization device 600 described in the second embodiment in that a rolling assist member 720 is arranged near the retracted position of the shift lens 222, and the following description will focus on this point.

[0095] When the shift lens 222 is in the retracted position, the center of gravity of the three balls 707 is unbalanced. Therefore, when an external force such as an impact is applied, there is a risk that dents or the like will be formed on one of the three balls 707 that is closest to the retracted position of the shift lens 222 and on its ball receiving surfaces 703c, 704c. To solve this problem, a rolling assist member 720 is arranged near the retracted position of the shift lens 222. The rolling assist member 720 is a ball (sphere) arranged between an auxiliary ball receiving surface 703f provided on the base member 703 and an auxiliary ball receiving surface 704f provided on the shift member 704.

[0096] The rolling assist member 720 may be held in contact with the auxiliary ball receiving surfaces 703f, 704f, or a small gap may be provided between the rolling assist member 720 and the auxiliary ball receiving surfaces 703f, 704f in the optical axis direction. In other words, the distance between the auxiliary ball receiving surfaces 703f, 704f in the optical axis direction may be greater than the distance between the ball receiving surfaces 703f, 704f. This is because it is desirable for the three balls 707 to determine a plane when photography is possible.

[0097] If an external force such as an impact is applied from the outside while the shift lens 222 is in the retracted position, the rolling assist member 720 and the auxiliary ball receiving surfaces 703f, 704f receive the external force because of the arrangement of the rolling assist member 720. As a result, it is possible to prevent the external force acting on the ball 707 and its ball receiving surfaces 703c, 704c from increasing, thereby reducing the risk of damage such as dents being caused to the ball 707 and its ball receiving surfaces 703c, 704c. As a result, it is possible to prevent a decrease in the rolling performance of the ball 707, and to prevent a decrease in image stabilization performance.

[0098] The auxiliary ball receiving surface 703f can be formed of a different material from the base member 703 using known techniques such as insert molding or bonding, and the same applies to the auxiliary ball receiving surface 704f. In this case, by forming the auxiliary ball receiving surfaces 703f, 704f from a material (e.g., metal, ceramics, etc.) that is harder than the ball receiving surfaces 703c, 704c, the risk of damage to the ball 707 and its ball receiving surfaces 703c, 704c can be further reduced.

[0099] As explained above, in the third embodiment, as in the second embodiment, even if the shift lens 222 is subjected to an external force such as an impact while in the retracted position, the risk of damage such as dents occurring to the ball 707 and the ball receiving surfaces 703c, 704c can be reduced.

[0100] <Fourth embodiment> FIG. 27 is a block diagram showing the electrical and optical configuration of a digital camera 800 according to the fourth embodiment. The appearance of the digital camera 800 is substantially the same as the appearance of the digital camera 200 according to the second embodiment (see FIG. 13), and therefore is not shown in the drawings. The digital camera 800 also differs from the digital camera 200 according to the second embodiment, which is equipped with the lens barrel 201, in that it is equipped with a lens barrel 801. Compared to the lens barrel 201 according to the second embodiment, the lens barrel 801 is characterized by an image stabilization device 900 and an aperture group 350, with the other components being equivalent to those of the lens barrel 201. Therefore, in the following, components of the digital camera 800 that are substantially the same as those of the digital camera 200 will be assigned the same reference numerals and their description will be omitted, and the image stabilization device 900 and the aperture group 350 will be mainly described. The code used for the shift lens is changed from '222' to '822a'.

[0101] Figures 28 to 30 are YZ cross-sectional views (cross-sectional views perpendicular to the X-axis) of digital camera 800, and are shown in a cross section including the optical axis. Figure 28 shows a state in which lens barrel 801 is set at the wide-angle end on the short focal length side, and Figure 29 shows a state in which lens barrel 801 is set at the telephoto end on the long focal length side. Figure 30 shows a retracted state in which lens barrel 801 is at its shortest overall length.

[0102] When the digital camera 800 is in a state where it can take pictures as shown in FIG. 28 or FIG. 29, all lens is disposed on an optical axis perpendicular to the imaging surface of the imaging element 236. When the zoom operation ring 103 is rotated from the state shown in FIG. 28 to the retracted end, First zoom group 221 and third to sixth zoom groups 223 to 226 begins to retract toward the rear side (camera body 210 side), and at the same time, shift lens 822a retracts from the optical axis. The first zoom group 221 further retracts into the space thus created, and the first and second zoom groups are stored so as not to interfere with each other, and the lens barrel 801 reaches the state shown in FIG. 30, where its overall length is at its shortest. Although not shown in the second embodiment (FIGS. 14 to 16), FIG. 28 shows key 209 that connects cam barrel 108 and zoom operation ring 103.

[0103] Image stabilization device 900 is defense a shift lens 822a as a vibration element, Shift Lens 822a It functions as a second zoom group. The image stabilization device 900 reduces image blur by shifting the shift lens 822a in a plane perpendicular to the optical axis. In the description of the fourth embodiment, the state in which the shift lens 822a is in an imaging position on the optical axis will be referred to as "the image stabilization device is in an imaging state" as appropriate. In addition, the state in which the shift lens 822a is in a retracted position away from the optical axis will be referred to as "the image stabilization device is in a non-imaging state" as appropriate.

[0104] The image stabilization device 900 has a shift lens 822a, a lens frame 822f, a retraction base plate 822b, an vibration-isolating base plate 822c, multiple coils 822d, and multiple magnets 822e. When a current is applied to the coil 822d, a Lorentz force is generated between the coil 822d and the magnet 822e, causing the shift lens 822a to move in any direction within a plane perpendicular to the optical axis.

[0105] In the second embodiment, the image stabilization device 600 is configured to move the shift lens 222 to the retracted position by rotating the lens frame 602 that holds the shift lens 222 about an axis parallel to the optical axis (Z axis). In contrast, the image stabilization device 900, which will be described in detail later, is configured to move the shift lens 822a to the retracted position by rotating the lens frame 822f that holds the shift lens 822a about an axis parallel to the X axis.

[0106] 31 to 35, a description will be given of the transition between the imaging state and the non-imaging state of the image stabilization device 900 and the aperture group 350 in the lens barrel 801. Figures 31 to 34 are diagrams illustrating the states of the lens barrel 801, the image stabilization device 900, and the aperture group 350 at specific stages when transitioning from the imaging state to the non-imaging state. Figure 35 is a timing chart showing the states of the first zoom group 221, the image stabilization device 900, and the aperture group 350 when transitioning from the imaging state to the non-imaging state.

[0107] Figure 31(a) is a cross-sectional view of lens barrel 801 when image stabilization device 900 is in a shooting state. Figure 31(b) is a perspective view of image stabilization device 900 and aperture group 350 corresponding to the state shown in Figure 31(a). The state shown in Figure 31 corresponds to state (1) in Figure 35.

[0108] 31(b), the aperture group 350 has an aperture group frame 301, an aperture drive unit 302, a drive ring 320, and multiple aperture blades 330. The aperture drive unit 302 is attached to the aperture group frame 301, and the drive ring 320 and multiple aperture blades 330 are movably supported by the aperture group frame 301. Driving the aperture drive unit 302 drives the drive ring 320, and the aperture blades 330 form the intended aperture shape, thereby adjusting the amount of light incident on the image sensor 236. A cutout portion 301a is provided in the outermost periphery of the aperture group frame 301, with a portion cut out.

[0109] When the image stabilization device 900 is in a shooting state, the shift lens 822a is arranged on the optical axis, just like the other groups. The diaphragm blade 330 is driven to an arbitrary aperture diameter by the diaphragm drive unit 302 and the drive ring 320 to adjust the amount of light incident on the image sensor 236. Furthermore, a light-shielding portion 320a, which is part of the drive ring 320, and a portion of the diaphragm blade 330 protrude from the cutout portion 301a to block harmful light. In FIG. 31(b), the portion of the diaphragm blade 330 protruding from the cutout portion 301a is indicated by a dashed line because it is on the +Z side of the light-shielding portion 320a protruding from the cutout portion 301a.

[0110] Fig. 32(a) is a cross-sectional view showing a state in which the zoom operation ring 103 is rotated from the wide-angle end position toward the retracted end position, which is the first stage in the transition of the image stabilization device 900 from the imaging state to the non-imaging state. Fig. 32(b) is a perspective view of the image stabilization device 900 and the aperture group 350 corresponding to the state of Fig. 32(a). The state of Fig. 32 corresponds to state (2) in Fig. 35.

[0111] When the zoom operation ring 103 is rotated from the wide-angle end position toward the retracted end position, the diaphragm group 350, the third zoom group 223, the focus group 224, and the fifth zoom group 225 are retracted from their original positions toward the rear side by the action of the linear guide barrel 107 and the cam barrel 108. This causes the lens barrel 801 to transition to a non-photographing state.

[0112] At the same time that the aperture group 350 is retracted to the rear side, the drive ring 320 is mechanically driven to rotate by the action of the adjacent group or the linear guide barrel 107 and the cam barrel 108, and is driven to a small aperture state with a small opening diameter of the aperture blades 330. At this time, the light-shielding portion 320a of the drive ring 320 and part of the aperture blades 330 that were protruding from the cutout portion 301a are housed in the aperture group frame 301.

[0113] Fig. 33(a) is a cross-sectional view showing a state in which the zoom operation ring 103 has been rotated further from the first stage toward the retracted end position, as the second stage in which the image stabilization device 900 transitions from the imaging state to the non-imaging state. Fig. 33(b) is a perspective view of the image stabilization device 900 and the aperture group 350 corresponding to the state shown in Fig. 33(a). The state shown in Fig. 33 corresponds to state (3) in Fig. 35.

[0114] When the zoom operation ring 103 is further rotated from the first stage position (FIG. 32) toward the retracted end, the first zoom group 221 retracts toward the shift lens 822a due to the action of the linear guide barrel 107 and the cam barrel 108. At this time, the third zoom group 223 to the fifth zoom group 225 have retracted toward the rear side, creating space behind the shift lens 822a. This space is then used to mechanically rotate the lens frame 822f of the image stabilization device 900 about an axis parallel to the X axis. As a result, the shift lens 822a moves to a retracted position a certain distance away from the optical axis in the +Y direction, and the image stabilization device 900 enters a non-photographing state.

[0115] Fig. 34(a) is a cross-sectional view showing a state in which the zoom operation ring 103 has been rotated further from the second stage toward the retracted end position, as the third stage in which the image stabilization device 900 transitions from the imaging state to the non-imaging state. Fig. 34(b) is a perspective view of the image stabilization device 900 and the aperture group 350 corresponding to the state of Fig. 34(a). The state of Fig. 34 corresponds to state (4) in Fig. 35.

[0116] When the zoom operation ring 103 is further rotated from the second stage (FIG. 33) position toward the retracted end, the first zoom group 221 and the image stabilization device 900, which are close to each other, move toward the rear side while maintaining a distance from each other due to the action of the linear guide barrel 107 and the cam barrel 108. At this time, the aperture group 350 has already moved toward the rear side, and the light-shielding portion 320a of the drive ring 320 and part of the aperture blades 330 are housed in the aperture group frame 301. Therefore, part of the lens frame 822f (shift lens 822a), which was retracted in the second stage, is inserted into the cutout portion 301a, bringing the image stabilization device 900 and the aperture group 350 into the closest position in the optical axis direction.

[0117] Note that on the rear side of the aperture group 350, the transition of the third zoom group 223 to the non-photographing state has already been completed. Therefore, a portion of the shift lens 822a is stored side by side with the third zoom group 223 in a plane perpendicular to the optical axis (so that a portion of the shift lens 822a overlaps with the third zoom group 223 when viewed from the +Y side). When the zoom operation ring 103 is further rotated from the state in FIG. 34 toward the retracted end, the state becomes (5) in FIG. 35 (see FIG. 30 as appropriate). The transition operation of the lens barrel 801 from the non-photographing state to the photographing state (from (5) to (1) in FIG. 35) is the reverse operation of the transition operation from the photographing state to the non-photographing state, and therefore will not be described here.

[0118] As explained above, in the fourth embodiment, aperture blades 330 are set to a small aperture state when not capturing images, reducing the amount of light incident on image sensor 236, thereby making it possible to prevent image sensor 236 from burning out. Furthermore, when not capturing images, part of shift lens 822a constituting image stabilization device 900 is inserted into notch 301a of aperture group frame 301 and retracted from the optical axis. This makes it possible to shorten the overall length of lens barrel 801 in the retracted state without increasing the outer diameter of lens barrel 801.

[0119] In the fourth embodiment, the overall length of the lens barrel 801 in the non-photographing state is shortened by inserting the shift lens 822a provided in the image stabilization device 900 adjacent to the aperture group 350 into the notch 301a provided in the aperture group 350. However, as long as it is possible to shorten the overall length of the lens barrel 801 in the non-photographing state, the component inserted into the notch 301a is not limited to the shift lens 822a. For example, an actuator (such as a stepping motor or a vibration-type actuator (ultrasonic motor)) that drives the focus group 224 or a guide bar that guides the focus group 224 in the optical axis direction may be inserted. Furthermore, the operation of setting the aperture blades 330 to the small aperture state in the non-photographing state can also be applied to a configuration in which the lens frame 602 is rotated about an axis parallel to the optical axis, as in the lens barrel 201 in the second embodiment. This reduces the risk of burning the image sensor 236 of the camera body 210 to which the lens barrel 201 is attached.

[0120] While the present invention has been described in detail above based on preferred embodiments thereof, the present invention is not limited to these specific embodiments, and various forms within the scope of the gist of the present invention are also included in the present invention. Furthermore, each of the above-described embodiments merely represents one embodiment of the present invention, and each embodiment can be combined as appropriate.

[0121] For example, in each of the above embodiments, the optical device according to the present invention has been described as being embodied as a lens barrel of an imaging device, but the optical device according to the present invention is not limited to this and can be applied to observation devices such as binoculars, telescopes, and field scopes. [Explanation of symbols]

[0122] 2a, 2b 3-group lens 3 3rd group holder 8 3-group frame 50 holder shaft 50a 1st fixed part 50b Mating part 50c 1st adjustment section 80 Contact axis 80c 2nd adjustment section 100, 200, 800 digital cameras 102,201,801 Lens barrel 301a Notch 330 aperture blades 350 aperture group 600,700,900 Image stabilization device 602 Lens frame 602a Protrusion 603 Base material 603a Proximal shape part 607 Ball 703f, 704f Auxiliary ball receiving surface 720 Rolling auxiliary parts 822a Shift Lens

Claims

1. a plurality of lens groups arranged to be movable forward and backward along an optical axis; a holding member for holding a predetermined lens group among the plurality of lens groups; a first axis that includes a first fixing portion, a fitting portion that fits with the holding member, and a first adjustment portion that moves the center of the predetermined lens group relative to the optical axis by an external rotation operation, and that is disposed parallel to the optical axis; a support member that rotatably supports the first shaft; an optical device including a second shaft arranged parallel to the optical axis and having a second fixing portion and an abutment portion that abuts against the holding member to regulate a position in a direction perpendicular to the optical axis, the first shaft is supported by the support member so as to be rotatable around the central axis of the first fixed portion, the second shaft is supported by the support member so as to be rotatable around the central axis of the second fixed portion, a central axis of the first fixing portion and a central axis of the fitting portion are eccentric, a central axis of the second fixing portion and a central axis of the abutting portion are eccentric, and the eccentricity of the second axis is equal to or greater than half of the eccentricity of the first axis; an optical device characterized in that the predetermined lens group moves between a predetermined position on the optical axis and a retracted position away from the optical axis by rotating the holding member about the first axis;

2. When a straight line connecting the center of the first axis and the center of the second axis in a plane perpendicular to the optical axis is divided by a perpendicular line passing through the center of the predetermined lens group, 2. The optical device according to claim 1, wherein the length of the straight line from the center of the first axis to the perpendicular line is equal to or greater than the length of the straight line from the center of the second axis to the perpendicular line.

3. 3. The optical device according to claim 1, wherein the second shaft has a second adjustment portion that moves the center of the predetermined lens group relative to the optical axis by an external rotation operation.

4. The optical device according to claim 3 , wherein the second fixing portion is provided between the contact portion and the second adjustment portion.

5. 5. The optical device according to claim 3, wherein the first adjustment unit and the second adjustment unit are provided in the same direction along the optical axis.

6. A base plate member facing the support member via a ball in the optical axis direction; a biasing member that biases the support member toward the base plate member in the optical axis direction; 6. The optical device according to claim 1, further comprising: a driving unit that drives the support member relative to the base plate member in a direction perpendicular to the optical axis direction.

7. The optical instrument according to any one of claims 1 to 6, The lens barrel is characterized in that the plurality of lens groups included in the optical device form an image of incident light at a predetermined position on the optical axis.

8. An optical device according to any one of claims 1 to 6; An imaging device comprising: The imaging device is characterized in that the optical device forms an image of incident light on the imaging element.

Images