Lens mechanism and lens device
The lens mechanism addresses play and sliding resistance issues by using a bearing portion with a loosely inserted second part and a cam cylinder system, enhancing stability and precision in optical systems.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- FUJIFILM CORP
- Filing Date
- 2022-09-29
- Publication Date
- 2026-07-09
Smart Images
Figure 0007887330000001 
Figure 0007887330000002 
Figure 0007887330000003
Abstract
Description
Technical Field
[0001] The technology of the present disclosure relates to a lens mechanism and a lens device.
Background Art
[0002] Patent Document 1 discloses a lens barrel having a holding member, a driving member, a first guiding member, a first lens barrel, a second guiding member, a second lens barrel, and an adjusting portion. The holding member holds an optical element and has a first guided portion and a second guided portion. The driving member moves the holding member in the optical axis direction. The first guiding member guides the first guided portion in the optical axis direction. The first lens barrel holds the first guiding portion and is movable in the optical axis direction. The second guiding member guides the second guided portion in the optical axis direction. The second lens barrel holds the second guiding portion. The adjusting portion changes the relative position in a direction orthogonal to the optical axes of the first guiding portion and the second guiding portion.
[0003] Patent Document 2 discloses a lens barrel having a lens holding member, a guiding member, and a cam member rotatable around an optical axis. The guiding member has a straight groove for guiding the movement of the lens holding member in the optical axis direction. The cam member has a cam groove for moving the lens holding member in the optical axis direction. The lens holding member has a plurality of first roller members and a plurality of second roller members. At least one of the plurality of first roller members engages with the straight groove and the cam groove. Each of the plurality of second roller members has the same phase as each of the plurality of first roller members in the circumferential direction of the lens holding member, and is provided at a position separated from each of the plurality of first roller members in the optical axis direction. The diameter of the second roller member provided at the same phase as at least one of the plurality of first roller members is smaller than the diameter of at least one of the plurality of first roller members.
[0004] Patent Document 3 discloses an optical device capable of multiple tilt operations of the optical system. The optical device has multiple driving means, control means, and detection means. The multiple driving means drive multiple tilt operations. The control means controls the multiple driving means to drive the optical system from a tilt state before driving to a target tilt state. The detection means detects the direction of gravity relative to the optical device. The control means sets the driving order and driving direction of the multiple driving means according to the detected direction of gravity. [Prior art documents] [Patent Documents]
[0005] [Patent Document 1] Japanese Patent Publication No. 2015-210490 [Patent Document 2] Japanese Patent Publication No. 2019-040092 [Patent Document 3] Japanese Patent Publication No. 2021-117415 [Overview of the project]
[0006] One embodiment of the technology of this disclosure provides, for example, a lens mechanism and lens device that can achieve both suppression of play in a moving member and reduction of sliding resistance of a moving member. [Means for solving the problem]
[0007] A first aspect of the technology of the present disclosure is a lens mechanism comprising a lens holding member for holding a lens, a movable member connected to the lens holding member and moving in the direction of the optical axis, and a guide shaft for guiding the movement of the movable member, wherein the movable member has a bearing portion into which the guide shaft is inserted, and the bearing portion has a first part and a second part, the first part being in contact with the guide shaft and the second part having the guide shaft loosely inserted.
[0008] A second aspect of the technology of this disclosure is a lens mechanism according to the first aspect, wherein the first part is located on the first side of the bearing portion and the second part is located on the second side of the bearing portion.
[0009] A third aspect of the technology of this disclosure is a lens mechanism according to the second aspect, wherein the first side is the objective side and the second side is the imaging side.
[0010] A fourth aspect of the technology of this disclosure is a lens mechanism according to the first aspect, wherein the first part is a lens mechanism having a convex portion that contacts a guide axis.
[0011] A fifth aspect of the technology of this disclosure is a lens mechanism according to the fourth aspect, wherein the convex portion is formed along the circumferential direction of the guide axis.
[0012] A sixth aspect of the technology of this disclosure is a lens mechanism according to the fourth aspect, wherein the convex portion is formed in a convex curved shape in a vertical cross-sectional view and is in contact with the outer surface of the guide axis.
[0013] A seventh aspect of the technology of the present disclosure is a lens mechanism according to the first aspect, wherein the lens mechanism further comprises a cam cylinder disposed on the outside of a moving member and an operating member connected to the outside of the cam cylinder, the moving member is provided with a cam shaft, the cam cylinder has a cam groove that engages with the cam shaft, and the moving member moves in the optical axis direction as the cam shaft moves along the cam groove in accordance with the rotation of the operating member and the cam cylinder.
[0014] An eighth aspect of the technology of this disclosure is a lens mechanism relating to the seventh aspect, wherein the number of multiple cam shafts is three.
[0015] A ninth aspect of the technology of this disclosure is a lens mechanism according to the seventh aspect, wherein the lens mechanism further comprises a fixed member provided between a movable member and a cam cylinder, and supporting the movable member and the cam cylinder.
[0016] A tenth aspect of the technology of this disclosure is a lens mechanism according to the ninth aspect, wherein the guide axis is provided on a fixed member.
[0017] The eleventh aspect according to the technology of the present disclosure is a lens mechanism according to the first aspect, in which the moving member is a lens mechanism connected to the outside of the lens holding member via an adjustment mechanism of the lens holding member.
[0018] The twelfth aspect according to the technology of the present disclosure is a lens mechanism according to the first aspect, in which the second portion is a lens mechanism that is separated from the guide shaft by 0.2% or more and 0.6% or less of the diameter of the guide shaft.
[0019] The thirteenth aspect according to the technology of the present disclosure is a lens mechanism according to the first aspect, in which the lens mechanism includes a first guide shaft as a guide shaft and a second guide shaft that guides the movement of the moving member.
[0020] The fourteenth aspect according to the technology of the present disclosure is a lens device including a lens mechanism according to any one of the first to thirteenth aspects, a tilt mechanism that tilts the lens mechanism, a shift mechanism that shifts the lens mechanism, and a rotation mechanism that rotates at least one of the tilt mechanism and the shift mechanism around the optical axis direction.
Brief Description of the Drawings
[0021] [Figure 1] It is a perspective view showing an example of an imaging device. [Figure 2] It is a plan view showing an example of a lens device. [Figure 3] It is a side view showing an example of a lens device. [Figure 4] It is a longitudinal sectional view showing an example of a lens device. [Figure 5] It is a longitudinal sectional view showing an example of a lens mechanism. [Figure 6] It is a sectional view taken along line F6-F6 of FIG. 5. [Figure 7] It is a perspective view including a partial cross section of an example of a lens device. [Figure 8] It is a perspective view including a partial cross section of an example of a lens device. [Figure 9] It is a sectional view showing an example of a first region and a second region in a lens mechanism. [Figure 10] This is an enlarged view of section A in Figure 9. [Figure 11] This is an enlarged view of section B in Figure 9. [Figure 12] This is a cross-sectional view showing an example of the peripheral portion of the first guide shaft and the first bearing. [Modes for carrying out the invention]
[0022] In this specification, “orthogonal” means not only perfect orthogonality but also orthogonality that includes errors generally accepted in the art to which the disclosed art belongs, provided that such errors do not contradict the spirit of the disclosed art. In this specification, “parallel” means not only perfect parallelism but also parallelism that includes errors generally accepted in the art to which the disclosed art belongs, provided that such errors do not contradict the spirit of the disclosed art. In this specification, “equally spaced” means not only perfectly equal spacing but also equal spacing that includes errors generally accepted in the art to which the disclosed art belongs, provided that such errors do not contradict the spirit of the disclosed art.
[0023] First, the configuration of the imaging device 10 according to one embodiment of this disclosure will be described.
[0024] Figure 1 shows an imaging device 10 according to this embodiment in a perspective view. As an example, as shown in Figure 1, the imaging device 10 comprises a lens device 12 and an imaging device body 14. The lens device 12 is located at the front of the imaging device body 14. In Figure 1, the lens device 12 and the imaging device body 14 are schematically shown. The imaging device body 14 incorporates an image sensor (not shown) and a computer (not shown), etc. With respect to the lens device 12, arrow A indicates the objective side, and arrow B indicates the imaging side. The optical axis OA is the optical axis of the lens device 12. Hereinafter, the axial direction of the optical axis OA will be referred to as the "optical axis direction".
[0025] Figure 2 shows the lens device 12 in a plan view, and Figure 3 shows the lens device 12 in a side view. Figure 4 shows the lens device 12 in a longitudinal cross-sectional view (i.e., a side cross-sectional view). As an example, as shown in Figures 2 to 4, the lens device 12 comprises a lens mechanism 16, a tilt mechanism 18, a shift mechanism 20, a revolving mechanism 22, and a mount 24.
[0026] The lens mechanism 16 has a focus ring 26. The focus ring 26 is formed in a ring shape around the optical axis direction. The focus ring 26 is capable of rotating around the optical axis direction.
[0027] The tilt mechanism 18 is a mechanism for tilting the lens mechanism 16. The tilt mechanism 18 includes a tilt base 28, a tilt stage 30, a tilt lock 32, and a tilt knob 34. The boundary 36 is the boundary between the tilt base 28 and the tilt stage 30. The boundary 36 is formed in an arc shape around a tilt axis (not shown) perpendicular to the optical axis OA. The tilt mechanism 18 operates starting from the boundary 36.
[0028] The tilt stage 30 is positioned closer to the objective lens than the tilt base 28. The tilt stage 30 is fixed to the lens mechanism 16. The tilt base 28 supports the tilt stage 30 so that it can tilt. Tilt refers to a rotational movement around a tilt axis. The tilt stage 30 tilts integrally with the lens mechanism 16.
[0029] The tilt lock 32 and the tilt knob 34 are axial members. The axial direction of the tilt lock 32 is positioned parallel to the axial direction of the tilt axis. Similarly, the axial direction of the tilt knob 34 is positioned parallel to the axial direction of the tilt axis. The tilt lock 32 and the tilt knob 34 are provided on the tilt base 28.
[0030] The tilt lock 32 is a component that can take on a locked state that fixes the tilt stage 30 to the tilt base 28 and an unlocked state that allows the tilt stage 30 to tilt. The tilt knob 34 is a component that tilts the tilt stage 30. Between the tilt knob 34 and the tilt stage 30, for example, a rack and pinion mechanism (not shown) is provided, and the tilt stage 30 tilts by an amount of movement corresponding to the amount of rotation of the tilt knob 34.
[0031] The revolving mechanism 22 is a mechanism that rotates the lens mechanism 16, the tilt mechanism 18, and the shift mechanism 20. The revolving mechanism 22 has a revolving stage 38 and a revolving base 40. The boundary 42 is the boundary between the revolving base 40 and the shift base 44, which will be described later. The boundary 42 is formed along a plane perpendicular to the optical axis OA. The revolving mechanism 22 operates starting from the boundary 42.
[0032] The revolving stage 38 is positioned on the imaging side of the tilt base 28. The revolving stage 38 is fixed to the tilt base 28. The revolving base 40 is positioned on the imaging side of the shift base 44. The revolving base 40 supports the shift base 44 so that it can rotate around the optical axis. The lens mechanism 16, tilt mechanism 18, revolving stage 38, and shift mechanism 20 rotate together around the optical axis. The lens mechanism 16, tilt mechanism 18, revolving stage 38, and shift mechanism 20 rotate when a force is applied in the rotational direction by a user or the like. The revolving mechanism 22 is an example of a "rotation mechanism" related to the technology of this disclosure.
[0033] The shift mechanism 20 is a mechanism for shifting the lens mechanism 16 and the tilt mechanism 18. The shift mechanism 20 includes a shift base 44, a shift stage 46, a shift lock 48, and a shift knob 50. The boundary 52 is the boundary between the shift base 44 and the shift stage 46. The boundary 52 is formed along a plane perpendicular to the optical axis OA. The shift mechanism 20 operates starting from the boundary 52.
[0034] The shift stage 46 is positioned on the imaging side of the revolving stage 38. The shift stage 46 is fixed to the revolving stage 38. The shift base 44 is positioned on the imaging side of the shift stage 46. The shift base 44 supports the shift stage 46 so that it can be shifted. Shifting refers to a sliding motion in a direction perpendicular to the optical axis. The shift stage 46 shifts together with the lens mechanism 16, the tilt mechanism 18, and the revolving stage 38. As an example, the direction in which the shift stage 46 shifts (hereinafter referred to as the "shift direction") is set in the vertical direction of the imaging device 10 (see Figure 1).
[0035] The shift lock 48 and the shift knob 50 are axial members. The axial direction of the shift lock 48 is arranged parallel to a direction perpendicular to the optical axis direction and the shift direction. Similarly, the axial direction of the shift knob 50 is arranged parallel to a direction perpendicular to the optical axis direction and the shift direction. The shift lock 48 and the shift knob 50 are provided on the shift stage 46.
[0036] The shift lock 48 is a component that can take on a locked state that fixes the shift stage 46 to the shift base 44 and an unlocked state that allows the shift stage 46 to shift. The shift knob 50 is a component that shifts the shift stage 46. Between the shift knob 50 and the shift base 44, for example, a rack and pinion mechanism (not shown) is provided, and the shift stage 46 shifts by an amount of movement corresponding to the amount of rotation of the shift knob 50.
[0037] The mount 24 is provided at the image-forming end of the lens mechanism 16. The mount 24 is fixed to the revolving base 40. The mount 24 is attached to a mount (not shown) provided on the imaging device body 14 (see Figure 1). By attaching the mount 24 to the mount provided on the imaging device body 14, the lens device 12 is fixed to the front of the imaging device body 14.
[0038] Figure 5 shows the lens mechanism 16 in a longitudinal cross-sectional view. As an example, as shown in Figure 5, the lens mechanism 16 includes a first lens 60, a second lens 62, a third lens 64, a first lens frame 66, a second lens frame 68, a third lens frame 70, a movable frame 72, a fixed member 74, a cam cylinder 76, a rotating cylinder 78, and a focus ring 26.
[0039] As an example, the first lens 60 is an objective lens, the second lens 62 is a focusing lens, and the third lens 64 is a fixed-focus lens. The first lens 60 is positioned closer to the objective lens than the second lens 62, and the third lens 64 is positioned closer to the imaging lens than the second lens 62. The first lens 60 is an example of an "objective lens" according to the technology of this disclosure. The second lens 62 is an example of a "lens" and a "focusing lens" according to the technology of this disclosure.
[0040] The first lens 60 is positioned inside the first lens frame 66, the second lens 62 is positioned inside the second lens frame 68, and the third lens 64 is positioned inside the third lens frame 70. In this specification, “inside” means “radially inside” unless otherwise specified. The first lens frame 66 holds the first lens 60, the second lens frame 68 holds the second lens 62, and the third lens frame 70 holds the third lens 64. The second lens frame 68 is an example of a “lens holding member” relating to the art of this disclosure.
[0041] The first lens frame 66 has a first frame 80 and a second frame 82. The first frame 80 is located on the objective side of the second frame 82. Inside the first frame 80 is lens 60A, which is located on the objective side of the first lens 60, and inside the second frame 82 is lens 60B, which is located on the imaging side of the first lens 60.
[0042] The second lens frame 68 has a third frame 84 and a fourth frame 86. The third frame 84 is located on the objective side of the fourth frame 86. The second lens 62 is positioned inside the fourth frame 86. The second lens 62 and the fourth frame 86 are positioned inside the tilt mechanism 18, the shift mechanism 20, and the revolving mechanism 22 (see Figure 4).
[0043] The third frame 84 is positioned closer to the objective lens than the second lens 62. Furthermore, the third frame 84 is positioned outside the second frame 82 of the first lens frame 66. In this specification, "outside" means "radially outside" unless otherwise specified. The lens 60B located on the imaging side of the first lens 60 is positioned inside the third frame 84. The lens 60B located on the imaging side of the first lens 60 is an example of "at least a portion of the objective lens" according to the technology of this disclosure. The third frame 84 is an example of a "connecting member" according to the technology of this disclosure.
[0044] The movable frame 72 is connected to the outside of the third frame 84. The movable frame 72 is formed of, for example, resin. The fixed member 74 has a fixed frame 88 and a connecting frame 90. The fixed frame 88 is provided on the objective side of the connecting frame 90. The fixed frame 88 is located on the outside of the movable frame 72. The third lens frame 70 is fixed to the image-forming end of the connecting frame 90. The fourth frame 86 and the second lens 62 are located inside the connecting frame 90. The fixed member 74 is fixed to the first lens frame 66. The fixed frame 88 of the fixed member 74 is an example of a “fixed member” according to the technology of this disclosure. The movable frame 72 is an example of a “movable member” according to the technology of this disclosure.
[0045] The cam cylinder 76 is located outside the movable frame 72 and the fixed frame 88. The rotating cylinder 78 is connected to the outside of the cam cylinder 76, and the focus ring 26 is connected to the outside of the rotating cylinder 78. The cam cylinder 76 is an example of a "cam cylinder" according to the technology of this disclosure. The focus ring 26 is an example of an "operating ring" according to the technology of this disclosure.
[0046] The focus ring 26, the rotating cylinder 78, and the cam cylinder 76 are supported by the fixed member 74 so as to be rotatable around the optical axis. The movable frame 72 and the second lens frame 68 are also supported by the fixed member 74 so as to be movable in the optical axis direction.
[0047] A camshaft 92 is provided on the movable frame 72. The camshaft 92 is an axial member extending from the movable frame 72 toward the cam cylinder 76. A fixed frame 88 is provided between the movable frame 72 and the cam cylinder 76. The camshaft 92 passes through the fixed frame 88 and protrudes toward the cam cylinder 76 side relative to the fixed frame 88. A cam groove 94 is formed on the fixed frame 88 side surface of the cam cylinder 76 (i.e., the inner circumferential surface). The cam groove 94 is formed along a helix extending around the optical axis direction. The camshaft 92 is engaged with the cam groove 94.
[0048] The cam shaft 92 and cam groove 94 form a cam mechanism 96 that converts forces acting around the optical axis direction into forces in the optical axis direction. When the focus ring 26 is operated in the rotational direction by a user or the like, the cam shaft 92 moves along the cam groove 94 in accordance with the rotation of the focus ring 26 and the cam cylinder 76, causing the moving frame 72 and the second lens frame 68 to move in the optical axis direction. The cam shaft 92 is an example of a "cam shaft" in the technology of this disclosure. The cam groove 94 is an example of a "cam groove" in the technology of this disclosure.
[0049] Although Figure 5 shows one cam mechanism 96, the lens device 12 is provided with three cam mechanisms 96. In other words, there are three cam shafts 92 in total. The three cam shafts 92 are arranged at equal intervals around the optical axis. The cam grooves 94 of the three cam mechanisms 96 may be independent or connected.
[0050] Figure 6 shows the lens device 12 in a cross-sectional view along the line F6-F6 in Figure 5. Figures 7 and 8 also show the lens device 12 in a perspective view including a partial cross-section. Figure 8 is a perspective view taken from a different angle than Figure 7.
[0051] As an example, as shown in Figures 6 to 8, the lens mechanism 16 has a plurality of lens adjustment shafts 98, a plurality of tilt guides 100, and a sensor 102. The lens adjustment shafts 98 are members that adjust the angle of the second lens frame 68 with respect to the optical axis OA (i.e., the tilt angle), and the tilt guides 100 are members that guide the adjustment of the angle of the second lens frame 68. The specific configurations of the lens adjustment shafts 98 and the tilt guides 100 will be described later. The sensor 102 is a sensor that detects the position of the movable frame 72 in the optical axis direction. Examples of the sensor 102 include a resistive displacement sensor using a resistive element, a magnetic displacement sensor using a combination of a GMR (Giant Magneto Resistive) sensor and a magnetized sheet, and a linear sensor such as an optical displacement sensor using a diffraction grating and an optical pickup.
[0052] For example, there are three lens adjustment axes 98. Similarly, there are three tilt guides 100. The three lens adjustment axes 98 are arranged at equal intervals around the optical axis. Similarly, the three tilt guides 100 are also arranged at equal intervals around the optical axis. The lens adjustment axes 98 and tilt guides 100 are arranged alternately in the direction around the optical axis (i.e., the circumferential direction of the lens mechanism 16). Each tilt guide 100 is positioned between adjacent lens adjustment axes 98.
[0053] The three lens adjustment axes 98 and the three tilt guides 100 constitute the adjustment mechanism 104 of the second lens frame 68. The movable frame 72 is connected to the outside of the second lens frame 68 (specifically, the third frame 84) by the adjustment mechanism 104. The adjustment mechanism 104 is located on the objective side of the fourth frame 86 and the second lens 62 (see Figure 5). In addition, the multiple lens adjustment axes 98, the multiple tilt guides 100, and the sensor 102 are located inside the fixed frame 88.
[0054] The adjustment mechanism 104 is an example of a "lens holding member adjustment mechanism" related to the technology of this disclosure. The lens adjustment shaft 98 is an example of an "adjustment member" related to the technology of this disclosure. The tilt guide 100 is an example of a "guide member" related to the technology of this disclosure. The sensor 102 is an example of a "sensor" related to the technology of this disclosure.
[0055] The lens mechanism 16 includes a first guide shaft 110, a first bearing 112, a second guide shaft 114, and a second bearing 116. The first guide shaft 110 and the second guide shaft 114 are pin-shaped and extend in the direction of the optical axis. The first guide shaft 110 and the second guide shaft 114 are mounted on a fixed frame 88. The second guide shaft 114 is positioned on the side opposite to the first guide shaft 110 across the optical axis OA (i.e., on the opposite side from the first guide shaft 110). The first guide shaft 110 and the second guide shaft 114 are formed of, for example, metal.
[0056] The first bearing 112 and the second bearing 116 are formed in the movable frame 72. That is, the movable frame 72 has the first bearing 112 and the second bearing 116. The first bearing 112 is formed in the shape of a hole extending in the direction of the optical axis. The second bearing 116 is formed in the shape of a U-shaped groove extending in the direction of the optical axis. The bottom of the U-shaped groove of the second bearing 116 is located on the optical axis OA side (i.e., radially inside the lens mechanism 16) of the second guide shaft 114, and the open part of the U-shaped groove of the second bearing 116 is located on the opposite side of the optical axis OA from the second guide shaft 114 (i.e., radially outside the lens mechanism 16).
[0057] A first guide shaft 110 is inserted into the first bearing 112, and a second guide shaft 114 is inserted into the second bearing 116. The insertion of the first guide shaft 110 into the first bearing 112 and the second guide shaft 114 into the second bearing 116 guides the movement of the movable frame 72 in the optical axis direction. The first guide shaft 110 is an example of a "guide shaft" and a "first guide shaft" in the technology of this disclosure. The second guide shaft 114 is an example of a "second guide shaft" in the technology of this disclosure. The first bearing 112 is an example of a "bearing" in the technology of this disclosure.
[0058] Figure 9 shows an embodiment in which the lens mechanism 16 is divided into a first region 120 and a second region 122. Figure 9 is a cross-sectional view of the lens mechanism 16 cut at the same position as in Figure 6. As an example, as shown in Figure 9, the first region 120 and the second region 122 are regions divided by a line segment 124 connecting the first guide axis 110 and the second guide axis 114. The first region 120 contains one of the three lens adjustment axes 98 and two of the three tilt guides 100. The second region 122 contains two of the three lens adjustment axes 98 and one of the three tilt guides 100.
[0059] As an example, sensor 102 is located in the first region 120. Sensor 102 is located between the lens adjustment axis 98 and the tilt guide 100 in the circumferential direction of the lens mechanism 16. Sensor 102 is located in a region closer to the second guide axis 114 than to the first guide axis 110.
[0060] Figure 10 shows an enlarged view of part A in Figure 9, and Figure 11 shows an enlarged view of part B in Figure 9. As an example, as shown in Figures 10 and 11, the movable frame 72 has openings 130 and 132 formed at positions corresponding to the adjustment mechanism 104. Opening 130 is formed at a position corresponding to the lens adjustment shaft 98, and opening 132 is formed at a position corresponding to the tilt guide 100. The fixed frame 88 has openings 134 and 136 formed at positions corresponding to the adjustment mechanism 104. Opening 134 is formed at a position corresponding to the lens adjustment shaft 98, and opening 136 is formed at a position corresponding to the tilt guide 100. The cam cylinder 76 has openings 138 and 140 formed at positions corresponding to the adjustment mechanism 104. Opening 138 is formed at a position corresponding to the lens adjustment shaft 98, and opening 140 is formed at a position corresponding to the tilt guide 100.
[0061] The lens adjustment shaft 98 has a support member 98A and a rotating member 98B. The support member 98A is fixed to the third frame 84 of the second lens frame 68. The support member 98A is an axial member that extends outward from the third frame 84. The rotating member 98B is rotatably supported by the support member 98A. The rotating member 98B has an eccentric shape with respect to the central axis of the support member 98A. The rotating member 98B is housed in an opening 130 formed in the movable frame 72 and is in contact with the inner circumferential surface of the opening 130. The angle of the second lens frame 68 is adjusted by changing the distance between the rotation center of the rotating member 98B and the inner circumferential surface of the opening 130 according to the rotation angle of the rotating member 98B.
[0062] The tilt guide 100 has a support member 100A and a guide member 100B. The support member 100A is fixed to the third frame 84 of the second lens frame 68. The support member 100A is an axial member that extends outward from the third frame 84. The guide member 100B is fixed to the support member 100A. The guide member 100B is housed in an opening 132 (i.e., a groove) formed in the movable frame 72. The guide member 100B is engaged with the opening 132 so as to be movable in the optical axis direction. The angle adjustment of the second lens frame 68 is guided by the guide member 100B being guided by the opening 132.
[0063] Figure 12 shows the peripheral portions of the first guide shaft 110 and the first bearing 112 in a cross-sectional view along line F12-F12 in Figure 9. As an example, as shown in Figure 12, the first bearing 112 has a first portion 112A and a second portion 112B. Figure 12 shows enlarged views of the first portion 112A and the second portion 112B, respectively. For example, the first portion 112A is located on the first side of the first bearing 112, and the second portion 112B is located on the second side of the first bearing 112. The first side is the first axial side of the first bearing 112, and the second side is the second axial side of the first bearing 112. For example, the first side is the objective side, and the second side is the imaging side. The first portion 112A is in contact with the first guide shaft 110, and the first guide shaft 110 is loosely inserted into the second portion 112B. The first part 112A has a protrusion 118 that contacts the first guide shaft 110.
[0064] The protrusion 118 is formed in a convex curved shape in a longitudinal cross-sectional view and is in contact with the outer circumferential surface of the first guide shaft 110. The longitudinal cross-section refers to a cross-section cut along the height direction of the protrusion 118, as shown in Figure 12. The protrusion 118 is formed along the circumferential direction of the first guide shaft 110. As an example, the protrusion 118 is formed in an annular shape along the circumferential direction of the first guide shaft 110. Because the protrusion 118 is formed in a convex curved shape in a longitudinal cross-sectional view and is formed along the circumferential direction of the first guide shaft 110, it is in line contact with the outer circumferential surface of the first guide shaft 110.
[0065] For example, the second part 112B is separated from the first guide shaft 110 by a distance of 0.2% to 0.6% of the diameter of the first guide shaft 110. The second part 112B has the function of maintaining the posture of the movable frame 72 by coming into contact with the first guide shaft 110 as the posture of the movable frame 72 changes.
[0066] Part 112A is an example of the "Part 1" relating to the technology of this disclosure. Part 212B is an example of the "Part 2" relating to the technology of this disclosure. The objective side is an example of the "Part 1" relating to the technology of this disclosure. The imaging side is an example of the "Part 2" relating to the technology of this disclosure. The protrusion 118 is an example of the "protrusion" relating to the technology of this disclosure.
[0067] Next, the effects of this embodiment will be described.
[0068] In the lens device 12 according to this embodiment, the lens mechanism 16 includes a second lens frame 68 that holds the second lens 62, a movable frame 72 connected to the second lens frame 68, a cam cylinder 76 positioned outside the movable frame 72, and a focus ring 26 connected to the outside of the cam cylinder 76. The movable frame 72 is provided with a cam shaft 92, and the cam cylinder 76 has a cam groove 94 that engages with the cam shaft 92. Therefore, when the focus ring 26 is operated in the rotational direction by a user or the like, the cam shaft 92 moves along the cam groove 94 in accordance with the rotation of the focus ring 26 and the cam cylinder 76, thereby moving the movable frame 72 and the second lens frame 68 in the optical axis direction. This allows a user or the like to manually focus on the subject.
[0069] Furthermore, there are three cam shafts 92. Therefore, when the focus ring 26 is operated in the rotational direction by the user or the like, a moving force in the optical axis direction can be applied to the movable frame 72 at the three locations where the three cam shafts 92 are located.
[0070] Furthermore, the lens mechanism 16 includes a first guide shaft 110 and a second guide shaft 114 that guide the movement of the movable frame 72. Therefore, even if the position of the cam cylinder 76 changes in conjunction with the rotation of the focus ring 26, the movement of the movable frame 72 is guided by the first guide shaft 110 and the second guide shaft 114, thereby suppressing play in the movable frame 72. This also suppresses play in the second lens frame 68 connected to the movable frame 72.
[0071] Furthermore, the movement of the movable frame 72 can be guided at two locations where the first guide axis 110 and the second guide axis 114 are located. This allows for more stable guidance of the movement of the movable frame 72 compared to a structure that guides the movement of the movable frame 72 at only one location.
[0072] Furthermore, the movable frame 72 has a first bearing 112 into which the first guide shaft 110 is inserted. The first bearing 112 has a first portion 112A and a second portion 112B. The first portion 112A is in contact with the first guide shaft 110, and the first guide shaft 110 is loosely inserted into the second portion 112B. Therefore, compared to, for example, the case in which the first guide shaft 110 is in contact with the first bearing 112 over the axial direction, it is possible to suppress play in the movable frame 72 and reduce the sliding resistance of the movable frame 72.
[0073] Furthermore, the first portion 112A is located on the first axial side of the first bearing 112, and the second portion 112B is located on the second axial side of the first bearing 112. Therefore, the first portion 112A can suppress play in the movable frame 72, and the second portion 112B can reduce the sliding resistance of the movable frame 72.
[0074] Furthermore, the first side where the first portion 112A is located is the objective side, and the second side where the second portion 112B is located is the imaging side. Here, the objective side of the lens device 12 is the free end side, and the imaging side of the lens device 12 is the fixed end side that is fixed to the imaging device body 14. Therefore, on the objective side, where rigidity is lower than on the imaging side, the first portion 112A contacts the first guide shaft 110, thereby effectively suppressing the play of the moving frame 72. In other words, the play of the moving frame 72 can be suppressed compared to the case where the second portion 112B into which the first guide shaft 110 is loosely inserted is provided on the objective side.
[0075] Furthermore, the first portion 112A has a protrusion 118 that contacts the first guide shaft 110. Therefore, in a longitudinal cross-sectional view of the protrusion 118, the protrusion 118 is in point contact with the first guide shaft 110, so that the first portion 112A can also suppress play in the movable frame 72 and reduce the sliding resistance of the movable frame 72. In other words, compared to a structure in which the first portion 112A is in surface contact with the first guide shaft 110 over the axial direction of the first guide shaft 110 (i.e., a structure with a larger contact area than the protrusion 118), the first portion 112A can suppress play in the movable frame 72 while reducing the sliding resistance of the movable frame 72.
[0076] Furthermore, the protrusions 118 are formed along the circumferential direction of the first guide shaft 110. Therefore, the protrusions 118 can be made to make line contact along the circumferential direction of the first guide shaft 110. This makes it possible to reduce the sliding resistance of the movable frame 72 and suppress the play of the movable frame 72, compared to, for example, a structure in which multiple protrusions 118 are scattered along the circumferential direction of the first guide shaft 110.
[0077] Furthermore, the protrusion 118 is formed in a convex curved shape when viewed in a vertical cross-section and contacts the outer surface of the guide shaft. This makes it possible to achieve a state in which the protrusion 118 is in point contact with the first guide shaft 110 when viewed in a vertical cross-section.
[0078] Furthermore, the second part 112B is separated from the first guide shaft 110 by a distance of 0.2% to 0.6% of the diameter of the first guide shaft 110. Here, if the distance between the second part 112B and the first guide shaft 110 is less than 0.2% of the diameter of the first guide shaft 110, there is a risk that the second part 112B may interfere with the first guide shaft 110 due to the difference in linear expansion accompanying the decrease in temperature, especially if the first bearing 112 is made of resin and the first guide shaft 110 is made of metal. On the other hand, if the distance between the second part 112B and the first guide shaft 110 exceeds 0.6% of the diameter of the first guide shaft 110, contact with the first guide shaft 110 will become impossible as the posture of the moving frame 72 changes.
[0079] Therefore, if the second portion 112B is separated from the first guide shaft 110 by 0.2% to 0.6% of the diameter of the first guide shaft 110, the second portion 112B can prevent interference with the first guide shaft 110 due to the difference in linear expansion accompanying the decrease in temperature, while the posture of the movable frame 72 can be maintained by the second portion 112B coming into contact with the first guide shaft 110 as the posture of the movable frame 72 changes.
[0080] Furthermore, the lens mechanism 16 has a fixed frame 88. The fixed frame 88 is provided between the movable frame 72 and the cam cylinder 76, and supports the movable frame 72 and the cam cylinder 76. Therefore, since the movable frame 72 and the cam cylinder 76 are supported by a common fixed frame 88, the lens mechanism 16 can be made smaller compared to, for example, a case where a first support frame supporting the movable frame 72 and a second support frame supporting the cam cylinder 76 are provided separately.
[0081] Furthermore, the first guide shaft 110 and the second guide shaft 114 are provided on the fixed frame 88 (i.e., a fixed member). Therefore, compared to a structure in which, for example, the first guide shaft 110 and the second guide shaft 114 are provided on a movable member, the play of the movable frame 72 can be suppressed.
[0082] Furthermore, the second bearing 116 is formed in a U-shaped groove extending in the direction of the optical axis. The bottom of the U-shaped groove of the second bearing 116 is located on the optical axis OA side of the second guide shaft 114, and the open part of the U-shaped groove of the second bearing 116 is located on the opposite side of the optical axis OA from the second guide shaft 114. Therefore, even if the distance between the first bearing 112 and the second bearing 116 becomes shorter than the design value due to manufacturing errors and / or deformation, the second guide shaft 114 can move away to the open part of the U-shaped groove of the second bearing 116. This makes it possible to suppress an increase in the sliding resistance of the moving frame 72 compared to, for example, the case where the second bearing 116 has the same configuration as the first bearing 112.
[0083] Furthermore, the movable frame 72 is connected to the outside of the second lens frame 68 via the adjustment mechanism 104 of the second lens frame 68. Therefore, the angle of the second lens frame 68 relative to the movable frame 72 can be adjusted by the adjustment mechanism 104.
[0084] Furthermore, the lens device 12 includes a lens mechanism 16, a tilt mechanism 18 for tilting the lens mechanism 16, and a shift mechanism 20 for shifting the lens mechanism 16. Therefore, tilt imaging, in which imaging is performed with the lens mechanism 16 tilted by the tilt mechanism 18, and shift imaging, in which imaging is performed with the shift mechanism 20 shifted by the shift mechanism 20, can be performed.
[0085] Furthermore, the lens device 12 includes a revolving mechanism 22 that rotates the tilt mechanism 18 and the shift mechanism 20 around the optical axis. Therefore, by rotating the tilt mechanism 18 with the revolving mechanism 22, the direction in which the lens mechanism 16 is tilted can be changed. Also, by rotating the shift mechanism 20 with the revolving mechanism 22, the direction in which the lens mechanism 16 is shifted can be changed.
[0086] Next, a modified example of this embodiment will be described.
[0087] In the above embodiment, the first side where the first portion 112A of the first bearing 112 is located is the object side, and the second side where the second portion 112B of the first bearing 112 is located is the image-forming side. However, the first side where the first portion 112A of the first bearing 112 is located is the image-forming side, and the second side where the second portion 112B of the first bearing 112 is located may also be the object side.
[0088] Furthermore, in the above embodiment, the protrusion 118 is formed in an annular shape along the circumferential direction of the first guide shaft 110, but it may also be formed by a plurality of protrusions extending along the circumferential direction of the first guide shaft 110.
[0089] Furthermore, in the above embodiment, the number of camshafts 92 is three, but it may be other than three.
[0090] Furthermore, in the above embodiment, the lens mechanism 16 has a first guide shaft 110 and a second guide shaft 114 that guide the movable frame 72, but the number of guide shafts that guide the movable frame 72 may be one or three or more.
[0091] Furthermore, in the above embodiment, the revolving mechanism 22 is a mechanism that rotates the tilt mechanism 18 and the shift mechanism 20 around the optical axis direction, but it may also be a mechanism that rotates either the tilt mechanism 18 or the shift mechanism 20 around the optical axis direction.
[0092] Furthermore, in the above embodiment, the lens device 12 has a tilt mechanism 18, a shift mechanism 20, and a revolving mechanism 22, but at least one of the tilt mechanism 18, the shift mechanism 20, and the revolving mechanism 22 may be omitted.
[0093] The descriptions and illustrations presented above are detailed explanations of the technical aspects of this disclosure and are merely examples of the technical aspects. For example, the above descriptions of the structure, function, operation, and effect are examples of the structure, function, operation, and effect of the technical aspects of this disclosure. Therefore, it goes without saying that you may delete unnecessary parts, add new elements, or replace elements in the descriptions and illustrations presented above, as long as you do not deviate from the essence of the technical aspects of this disclosure. Furthermore, in order to avoid confusion and facilitate understanding of the technical aspects of this disclosure, explanations of common technical knowledge and the like that do not require special explanation to enable the implementation of the technical aspects of this disclosure have been omitted from the descriptions and illustrations presented above.
[0094] In this specification, "A and / or B" is synonymous with "at least one of A and B." That is, "A and / or B" means that it may be A alone, or B alone, or a combination of A and B. Furthermore, in this specification, the same concept as "A and / or B" applies when expressing three or more things linked by "and / or."
[0095] All documents, patent applications, and technical standards described herein are incorporated by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually noted as being incorporated by reference. [Explanation of Symbols]
[0096] 10 Imaging device 12 Lens device 14. Imaging device body 16 Lens mechanism 18 Tilt mechanism 20 Shift mechanism 22 Revolving Mechanism 24 Mount 26 Focus Ring 28 Tilt Base 30 Tilt Stage 32 Tilt Lock 34 Tilt knob 36 Boundary 38 Revolving Stages 40 Revolving Bass 42 Boundary 44 Shift base 46 Shift Stages 48 Shift Lock 50 Shift knob 52 Boundary 60 First Lens 62 Second Lens 64 Third Lens 66 First lens frame 68 Second lens frame 70 Third lens frame 72 Movement slots 74 Fixing member 76 Cam cylinder 78 Rotating Cylinder 80, Slot 1 82. Second slot 84. Third slot 86, 4th slot 88 Fixed Frames 90 Connecting frame 92 Camshaft 94 cam groove 96 Cam mechanism 98 Lens adjustment axis 98A Support Member 98B Rotating Member 100 Guides to Dragging 100A Support Member 100B Guide Member 102 Sensors 104 Adjustment mechanism 110 First guide axis 112 First bearing 112A Part 1 112B 2nd part 114 Second guide axis 116 Second bearing 118 Convex part 120 1st area 122 Second area 124 line segments 130 Aperture 132 Aperture 134 Aperture 136 Aperture 138 Aperture 140 Aperture
Claims
1. A lens holding member that holds the lens, A movable member connected to the lens holding member and moving in the direction of the optical axis, A guide shaft that guides the movement of the aforementioned moving member, Equipped with, The moving member has a bearing portion into which the guide shaft is inserted, The bearing portion has a first portion and a second portion located at a distance from the first portion in the optical axis direction. The first portion has a protrusion that contacts the outer circumferential surface of the guide shaft, The aforementioned protrusion is formed in a convex curved shape when viewed in a vertical cross-sectional view from a direction perpendicular to the optical axis, The guide shaft is loosely inserted into the second part. The second part is a portion that maintains the orientation of the moving member by contacting the guide axis in response to changes in the orientation of the moving member with respect to the optical axis. Lens mechanism.
2. The first part is located on the first side of the bearing portion, The second portion is located on the second side of the bearing portion. The lens mechanism according to claim 1.
3. The first side is the object side, The second side is the image-forming side. The lens mechanism according to claim 2.
4. The protrusion is formed along the circumferential direction of the guide shaft. The lens mechanism according to claim 1.
5. The lens mechanism is A cam cylinder positioned on the outside of the aforementioned moving member, An operating member connected to the outside of the cam cylinder, Furthermore, The moving member is provided with a camshaft. The cam cylinder has a cam groove that engages with the cam shaft, The moving member moves in the optical axis direction as the cam shaft moves along the cam groove in response to the rotation of the operating member and the cam cylinder. The lens mechanism according to claim 1.
6. The number of the multiple cam shafts is three. The lens mechanism according to claim 5.
7. The lens mechanism further comprises a fixing member provided between the moving member and the cam cylinder, which supports the moving member and the cam cylinder. The lens mechanism according to claim 5.
8. The guide shaft is provided on the fixing member. The lens mechanism according to claim 7.
9. The movable member is connected to the outside of the lens holding member via an adjustment mechanism for the lens holding member. The lens mechanism according to claim 1.
10. The second portion is separated from the guide shaft by 0.2% or more and 0.6% or less of the diameter of the guide shaft. The lens mechanism according to claim 1.
11. The lens mechanism is The first guide shaft, which serves as the guide shaft, A second guide shaft that guides the movement of the aforementioned moving member, Equipped with The lens mechanism according to claim 1.
12. A lens mechanism according to any one of claims 1 to 11, A tilt mechanism for tilting the aforementioned lens mechanism, A shift mechanism for shifting the aforementioned lens mechanism, A rotation mechanism that rotates at least one of the tilt mechanism and the shift mechanism around the optical axis, A lens device equipped with the following features.