Lens support mechanism, and lens barrel and camera equipped with the same

Abstract

To provide a lens support mechanism with which it is possible to improve the freedom of design, a lens barrel equipped with the same, and a camera.SOLUTION: A lens support mechanism 10 comprises lens group units 23-27, a substantially cylindrical straight advance barrel 11, and a substantially cylindrical cam barrel 12. The straight advance barrel 11 has a main cam follower 11b including the lens group units 23-27 and protruding from the outer circumferential surface toward the radially outside and a sub-cam groove 11c. The cam barrel 12 has a main cam groove 12b and a sub-cam follower 12c and is arranged on the outer circumferential side of the straight advance barrel 11. The main cam groove 12b engages with the main cam follower 11b and is formed in substantially parallel to the sub-cam groove 11c, causing the lens group units 23-27 to move back and forth in the direction of the optical axis when it rotates relative to the straight advance barrel 11. The sub-cam follower 12c protrudes toward the radially inside and engages with the sub-cam groove 11c.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present disclosure relates to a lens support mechanism included in a lens barrel that is attached to a camera body, and a lens barrel and a camera that are equipped with the same. [Background technology]

[0002] The lens barrel attached to the camera body has multiple frames that support the optical system. A first frame included in the multiple frames has a cam member, and a second frame has a guide groove in which the cam member slides when inserted. When the first and second frames rotate relative to one another, the cam member is guided by the guide groove, and the two frames move relatively in the optical axis direction, thereby achieving a collapsible lens barrel.

[0003] However, when an external force acts on the lens barrel, the external force is transmitted to the frame, and there is a risk that the cam member or the guide groove may be damaged. Therefore, in addition to the cam member and guide groove, the frame is provided with a reinforcing protrusion and a reinforcing groove. Even if an external force acts on the lens barrel, the reinforcing protrusion and the reinforcing groove can also withstand the external force, thereby preventing damage to the cam member and the guide groove.

[0004] However, by providing the frame with a reinforcing groove in addition to the guide groove, it becomes necessary to increase the diameter of the frame or to make the guide groove compact. In other words, there is a risk that the reinforcing groove will reduce the degree of freedom in design. For example, Patent Document 1 discloses a lens barrel that includes a first frame having five grooves spaced apart in the circumferential direction, and a second frame having five protrusions inserted into each of the five grooves, in order to improve strength and design freedom. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2013-224973 A [Patent Document 2] JP 2014-48450 A [Patent Document 3] JP 2009-186529 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, the above-mentioned conventional lens barrel has the following problems. That is, in the lens barrel disclosed in the above publication, five protrusions, including three cam followers and two protrusions for improving strength, are all provided on the same second frame, and similarly, five grooves into which these five protrusions are inserted are all provided on the same first frame, which may impair the freedom of design of the lens barrel.

[0007] An object of the present disclosure is to provide a lens support mechanism that enables greater freedom in design than ever before, and a lens barrel and a camera that are provided with the same. Another object of the present disclosure is to provide a lens barrel that is capable of ensuring a sufficient zoom range while reducing the size of the lens barrel that is detachably attached to the camera body, and a camera equipped with the same. [Means for solving the problem]

[0008] The lens support mechanism according to the present disclosure includes a lens group, a substantially cylindrical fixed barrel, and a substantially cylindrical cam barrel. The substantially cylindrical fixed barrel contains the lens group and has a first cam follower protruding radially outward from its outer circumferential surface, and a second cam groove. The substantially cylindrical cam barrel has the first cam groove and the second cam follower, and is disposed on the outer circumferential side of the fixed barrel. The first cam groove engages with the first cam follower and moves the lens group back and forth in the optical axis direction when the first cam groove rotates relative to the fixed barrel, and is formed substantially parallel to the second cam groove. The second cam follower protrudes radially inward and engages with the second cam groove. Effect of the Invention

[0009] The lens support mechanism according to the present disclosure allows greater freedom in design than ever before. Furthermore, with the lens barrel according to the present disclosure, in a lens barrel that is detachably attached to a camera body, it is possible to ensure a sufficient zoom range while achieving miniaturization. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is an overall perspective view showing the configuration of a camera in which a lens barrel including a lens support mechanism according to an embodiment of the present disclosure is attached to a camera body. [Diagram 2] FIG. 2 is a cross-sectional view of the lens barrel of FIG. 1. [Figure 3A] 3 is a cross-sectional view showing the lens barrel in FIG. 2 in a wide position. [Figure 3B] FIG. 3 is a cross-sectional view showing the lens barrel in FIG. 2 in a Tele position. [Figure 4A] 3B is a cross-sectional view showing a state in which the cam followers of the third, fourth, and seventh group units are engaged with the cam grooves of the cam barrel at the Wide position in FIG. 3A. [Figure 4B] 3C is a cross-sectional view showing a state in which the cam followers of the third, fourth, and seventh group units are engaged with the cam grooves of the cam barrel at the Tele position in FIG. 3B. [Diagram 5] 3 is a perspective view showing a state in which cam followers of each group unit arranged on the inner peripheral surface side of the linear movement barrel of the lens support mechanism included in the lens barrel of FIG. 2 are engaged with grooves of the linear movement barrel. [Figure 6A] 6 is a perspective view showing the positional relationship between the linear motion barrel in FIG. 5, the cam barrel arranged on the outer circumferential surface side thereof, and the cam followers of each group unit in a Wide position. [Figure 6B] 6 is a perspective view showing the positional relationship among the linear motion barrel in FIG. 5, the cam barrel arranged on the outer circumferential surface side thereof, and the cam followers of each group unit at the Tele position. [Figure 7] 11 is a cross-sectional view showing a state in which a sub-cam follower provided on the cam barrel is engaged with a sub-cam groove provided on the linear motion barrel via a predetermined gap. FIG. [Figure 8]FIG. 8 is an enlarged cross-sectional view of part X in FIG. [Figure 9A] 6B is a perspective view showing a configuration in which a first unit and a base frame are arranged on the outer circumferential surface side of the lens support mechanism in FIG. 6A. [Figure 9B] 9B is a perspective view showing a configuration in which a zoom ring is disposed on the outer circumferential surface side of the configuration in FIG. 9A. [Figure 10] FIG. 9C is a perspective view showing the configuration of the zoom ring in FIG. 9B. [Figure 11] 11 is a perspective view showing a process of attaching a zoom drive pin to the zoom ring in FIG. 10 from its outer circumferential surface side. [Figure 12A] 12 is a cross-sectional view showing the configuration in which the zoom drive pin in FIG. 11 has been moved to a Wide position in a state where it is fixed to the cam barrel. [Figure 12B] 12 is a cross-sectional view showing the configuration in which the zoom drive pin in FIG. 11 has been moved to a Tele position in a state where it is fixed to the cam barrel. [Figure 13] 2 is a perspective view showing the positional relationship between a zoom drive pin and a cutout portion for preventing interference with the zoom drive pin, which is formed in a substantially cylindrical main body of the first unit, when the lens barrel in FIG. 1 is in the Wide position. [Figure 14] FIG. 12B is an enlarged view showing a configuration near the zoom ring in FIG. 12A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, the embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed explanation than necessary may be omitted. For example, detailed explanation of already well-known matters or duplicate explanation of substantially the same configuration may be omitted. This is to avoid the following explanation becoming unnecessarily redundant and to facilitate understanding by those skilled in the art. The applicant provides the accompanying drawings and the following description so that those skilled in the art can fully understand the present disclosure, and they are not intended to limit the subject matter described in the claims.

[0012] (Embodiment 1) A lens barrel 100 including a lens support mechanism 10 according to an embodiment of the present disclosure will be described below with reference to FIGS. 1 to 14. (1) Configuration of Lens Barrel 100 Hereinafter, the configuration of a lens barrel 100 including a lens support mechanism 10 according to an embodiment of the present disclosure will be described with reference to the drawings. Fig. 1 is a perspective view showing a camera 1 configured by mounting a lens barrel 100 including a lens support mechanism 10 according to this embodiment to a camera body 101.

[0013] Lens barrel 100 is a collapsible lens barrel that is detachably attached to camera body 101, as shown in FIG. As shown in FIG. 2, lens barrel 100 mainly includes a linear barrel (fixed barrel) 11, a cam barrel 12, a first group unit (lens group unit, first lens frame) 21, a second group unit (lens group unit) 22, a third group unit (lens group unit) 23, a fourth group unit (lens group unit) 24, a fifth group unit (lens group unit) 25, a sixth group unit (lens group unit) 26, a seventh group unit (lens group unit) 27, a focus ring 31, a zoom ring 32, and a base frame 40.

[0014] Furthermore, the lens barrel 100 is equipped with a lens support mechanism 10 that includes a linear cylinder 11 and a cam cylinder 12. The detailed configuration of the lens support mechanism 10 will be described later. First unit 21 is a substantially cylindrical member arranged on the outer circumferential surface side of linear cylinder 11, and holds first lens L1 at its end (first end) on the subject side in the direction of optical axis OP, as shown in Fig. 2. First unit 21 is arranged closest to the subject side in the direction of optical axis OP of lens barrel 100.

[0015] As shown in FIG. 2, the first group unit 21 has a substantially cylindrical main body portion 21a and a cam follower 21b provided on the inner circumferential surface of the substantially cylindrical main body portion 21a. Cam follower 21b of first group unit 21 is provided near the subject-side end of the inner peripheral surface of substantially cylindrical main body 21a so as to protrude radially inward from the outer peripheral surface. Cam follower 21b engages with linear groove 11d (see FIG. 5) formed in linear barrel 11 and cam groove 12d (see FIG. 6A) formed in cam barrel 12, and moves first group unit 21 back and forth in the direction of optical axis OP as cam barrel 12 rotates.

[0016] Second unit 22 is a substantially annular member contained within the inner peripheral surface side of linear motion barrel 11, and holds second lens L2 as shown in Fig. 2. Second unit 22 is disposed between first unit 21 and third unit 23 in the direction of optical axis OP of lens barrel 100. Second unit 22 is fixed to the subject-side end surface of linear motion barrel 11 using screws (not shown).

[0017] Third unit 23 is a substantially annular member contained within the inner circumferential surface side of linear cylinder 11, and holds third lens group L3 as shown in Fig. 2. Third unit 23 is disposed between second unit 22 and fourth unit 24 in the direction of optical axis OP of lens barrel 100. The third group unit 23 has a cam follower 23a (see FIG. 4A) provided so as to protrude radially outward from the outer circumferential surface.

[0018] Fourth group unit 24 is a substantially cylindrical member contained within the inner peripheral surface side of linear motion cylinder 11, and holds fourth group lens L4 as shown in Fig. 2. Fourth group unit 24 is disposed between third group unit 23 and fifth group unit 25 in the direction of optical axis OP of lens barrel 100. Fourth group unit 24 has cam followers 24a (see FIG. 4A) provided so as to protrude radially outward from the outer circumferential surface.

[0019] Fifth unit 25 is a substantially annular member contained within the inner peripheral surface side of linear barrel 11, and holds fifth group lens L5 as shown in Fig. 2. Fifth unit 25 is disposed between fourth group unit 24 and sixth group unit 26 in the direction of optical axis OP of lens barrel 100. Fifth unit 25 is attached in a suspended state relative to fourth group unit 24 by a guide shaft 28 (see Fig. 7), one end of which is attached to fourth group unit 24.

[0020] Sixth group unit 26 is a substantially annular member contained within the inner peripheral surface side of linear motion barrel 11, and holds sixth group lens L6 as shown in Fig. 2. Sixth group unit 26 is disposed between fifth group unit 25 and seventh group unit 27 in the direction of optical axis OP of lens barrel 100. Similar to fifth group unit 25, sixth group unit 26 is attached in a suspended state relative to fourth group unit 24 by a guide shaft (not shown).

[0021] Seventh group unit 27 is a substantially annular member contained within the inner peripheral surface side of linear motion cylinder 11, and holds seventh group lens L7 as shown in Fig. 2. Seventh group unit 27 is disposed on the image surface side opposite the subject side in the direction of optical axis OP of lens barrel 100. Seventh group unit 27 has cam followers 27a (see FIG. 4A) provided so as to protrude radially outward from the outer circumferential surface.

[0022] Here, the first to seventh lens groups L1-L7 held in the first to seventh unit groups 21-27 are arranged in this order from the subject side with the optical axis OP as the center axis. The lens barrel 100 moves the first, third to seventh unit groups 21, and 23-27 back and forth along the optical axis OP between the Wide position shown in Fig. 3A and the Tele position shown in Fig. 3B by rotating the zoom ring 32 described later.

[0023] That is, the base frame 40 is disposed on the inner peripheral side of the zoom ring 32, and supports the zoom ring 32 so as to be rotatable about the optical axis OP. For this reason, the lens barrel 100 is configured so that, when the zoom ring 32, which is rotatably attached to the outer circumferential surface of the base frame 40, is rotated, the cam barrel 12 rotates in conjunction with the rotation of the zoom ring 32. When the cam barrel 12 rotates, the lens barrel 100 drives the first, third to seventh group units 21, and 23-27 back and forth in the direction of the optical axis OP.

[0024] 4A, the first-group, third-group, fourth-group, and seventh-group units 21, 23, 24, and 27 have a plurality of cam followers (cam followers 21b, 23a, 24a, and 27a) that respectively engage with a plurality of cam grooves formed in the cam barrel 12. The cam follower 21b of the first-group unit 21 engages with a linear groove 11d formed in the linear barrel 11. The cam followers 23a, 24a, and 27a of the third-group, fourth-group, and seventh-group units 23, 24, and 27 engage with a linear groove 11e formed in the linear barrel 11.

[0025] Furthermore, cam follower 21b of first unit 21 engages with cam groove 12d formed in cam barrel 12. Also, cam followers 23a, 24a, 27a of third, fourth, and seventh units 23, 24, 27 engage with cam grooves 12e, 12f, 12g formed in cam barrel 12. As a result, when cam barrel 12 is rotated relative to linear barrel 11, first, third, fourth, and seventh group units 21, 23, 24, and 27 are driven relatively back and forth in the direction of optical axis OP between the Wide position shown in FIG. 4A and the Tele position shown in FIG. 4B.

[0026] (2) Configuration of Lens Support Mechanism 10 Next, the configuration of the lens support mechanism 10 of the present embodiment will be described in detail. As shown in FIG. 2 and other figures, the lens support mechanism 10 includes a linear cylinder 11 and a cam cylinder 12. As shown in Fig. 5, the linear cylinder 11 has a substantially cylindrical main body 11a, a main cam follower (first cam follower) 11b, a sub cam groove (second cam groove) 11c, and linear grooves 11d and 11e. Note that Fig. 5 shows the positions of the cam followers 23a, 24a, and 27a in the Wide position shown in Fig. 3A and the like.

[0027] 5, the substantially cylindrical main body 11a is formed with a linear groove 11d into which the cam follower 21b provided in the first unit 21 engages, and a linear groove 11e into which the cam followers 23a, 24a, and 27a provided in the third, fourth, and seventh units 23, 24, and 27 engage. Three main cam followers 11b are attached in the circumferential direction approximately near the center of the outer circumferential surface of the main body 11a.

[0028] As shown in FIG. 5, the three main cam followers (first cam followers) 11b are attached so as to protrude from the outer circumferential surface of the substantially cylindrical main body portion 11a. In FIG. 5, for ease of explanation, the main cam follower 11b is attached directly to the outer peripheral surface of the linear barrel 11. However, in the actual assembly process of the lens barrel 100, the main cam follower 11b is attached to the outer peripheral surface of the linear barrel 11 with the cam barrel 12 inserted into the outer peripheral surface side of the linear barrel 11.

[0029] As shown in FIGS. 6A and 6B, the main cam follower 11b engages with a main cam groove (first cam groove) 12b formed on the cam barrel 12 side, and moves along the main cam groove 12b as the cam barrel 12 rotates. The sub-cam groove (second cam groove) 11c is a recess (non-through hole) formed obliquely with respect to the optical axis OP direction as shown in Fig. 5, and a sub-cam follower 12c provided so as to protrude radially inward from the inner peripheral surface of the cam barrel 12 engages with the sub-cam groove 11c via predetermined gaps G1, G2, G3 (see Fig. 8). The sub-cam groove 11c is formed so as to be approximately parallel to a main cam groove 12b provided on the cam barrel 12 side, which will be described later, as shown in Figs. 6A and 6B.

[0030] The predetermined gaps G1 to G3 shown in FIG. 8 each have a size of, for example, about 0.1 to 0.2 mm. 6A and 6B, when the cam barrel 12 is rotated relative to the linear barrel 11, the sub cam follower 12c moves along the sub cam groove 11c in a non-contact state, in the same way that the main cam follower 11b moves along the main cam groove 12b. Therefore, due to the engagement of the sub cam follower 12c with the sub cam groove 11c, the rotation of the cam barrel 12 relative to the linear barrel 11 and the movement in the direction of the optical axis OP are not restricted by the frictional force between the sub cam follower 12c and the sub cam groove 11c.

[0031] As described above, the sub-cam groove 11c is formed as a non-through recess. This makes it possible to avoid a decrease in the rigidity of the linear motion barrel 11 caused by the formation of the sub-cam grooves 11c. Further, the sub-cam groove 11c is provided with an insertion opening 11ca on the end surface on the image surface side. As a result, when assembling the lens barrel 100, with the sub-cam follower 12c still attached to the inner peripheral surface of the cam barrel 12, the cam barrel 12 can be inserted from the end face on the image surface side of the linear barrel 11, and the sub-cam follower 12c can be engaged with the sub-cam groove 11c.

[0032] The rectilinear groove 11d is a through hole that moves the first group unit 21 in the direction of the optical axis OP, and is formed linearly along the direction of the optical axis OP at a position closer to the subject side in the direction of the optical axis OP as shown in FIG. The rectilinear groove 11e is a through hole that moves the third, fourth, and seventh group units 23, 24, and 27 in the direction of the optical axis OP, and is engaged with the cam followers 23a, 24a, and 27a of the respective units 23, 24, and 27, as shown in Fig. 5. The rectilinear groove 11e is formed linearly along the direction of the optical axis OP over almost the entirety of the substantially cylindrical main body portion 11a in the direction of the optical axis OP.

[0033] As shown in Figures 6A and 6B, the cam barrel 12 is arranged on the outer peripheral surface side of the above-mentioned approximately cylindrical linear barrel 11, and has an approximately cylindrical main body portion 12a, a main cam groove (first cam groove) 12b, a sub cam follower (second cam follower) 12c, and cam grooves 12d, 12e, 12f, and 12g. In the lens barrel 100 of this embodiment, the linear cylinder 11 and the cam cylinder 12 are inserted into the inner surface side of the base frame 40, and the linear cylinder 11 is fixed to the base frame 40 using screws (not shown), thereby indirectly fixing the linear cylinder 11 to the camera body 101.

[0034] As a result, the cam barrel 12 moves back and forth in the direction of the optical axis OP on the outer circumferential surface side of the rectilinear barrel 11 fixedly disposed relative to the base frame 40 fixed to the camera body 101, as shown in FIGS. 6A and 6B. As shown in FIG. 6A, the substantially cylindrical main body portion 12a is formed with a plurality of cam grooves including a main cam groove 12b and cam grooves 12d, 12e, 12f, and 12g.

[0035] 6A and 6B, three main cam grooves (first cam grooves) 12b are provided approximately near the center of the approximately cylindrical main body portion 12a so as to correspond to the three main cam followers 11b provided on the above-mentioned linear cylinder 11. The three main cam grooves 12b are provided as approximately linear through holes formed obliquely with respect to the optical axis OP direction. The main cam groove 12b does not have to be substantially straight, and may be formed along a free curve.

[0036] Thereby, when the cam barrel 12 is rotated relative to the linear motion barrel 11, the main cam follower 11b provided on the linear motion barrel 11 side moves along the main cam groove 12b, and the cam barrel 12 moves back and forth in the direction of the optical axis OP. As shown in FIG. 6A, the main cam groove 12b is disposed at a position overlapping a portion of the sub cam groove 11c when viewed from the outer circumferential surface side.

[0037] Such an arrangement would be impossible to achieve in a configuration in which main cam groove 12b and sub cam groove 11c are provided in the same component. Therefore, compared to the conventional configuration in which main cam groove 12b and sub cam groove 11c are provided in the same frame, it is possible to improve the degree of freedom in design and achieve a compact, high-performance lens barrel 100. As shown in Fig. 7, the sub cam follower (second cam follower) 12c is provided so as to protrude radially inward from the inner peripheral surface of the cam barrel 12. As shown in Fig. 8, the sub cam follower 12c engages with the sub cam groove 11c provided on the above-mentioned linear motion barrel 11 side via a predetermined gap G1.

[0038] That is, as shown in FIG. 8, the sub-cam follower 12c and the sub-cam groove 11c are engaged with each other via a predetermined gap G1 in a steady state. Here, in an emergency in which an external force is applied from the outside, such as a drop impact, if the components that make up lens barrel 100 are deformed, sub cam follower 12c and sub cam groove 11c, which are engaged with each other in a non-contact state under normal conditions, come into contact.

[0039] This makes it possible to suppress deformation of the components constituting lens barrel 100, and effectively prevent damage, deformation, etc., of the components. As shown in FIG. 8, the sub cam follower 12c has a substantially conical main body portion 12ca and a flange portion 12cb that protrudes radially outward from the outer circumferential surface of the substantially conical shape.

[0040] The main body portion 12ca is formed in a substantially conical shape to match the groove shape of the sub-cam groove 11c, as shown in Fig. 8. This allows the sub-cam follower 12c to engage with the sub-cam groove 11c without coming into contact with the surface of the sub-cam groove 11c. 8, the flange portion 12cb is a substantially annular portion provided on the base side of the substantially conical main body portion 12ca, and is disposed substantially parallel to the outer circumferential surface of the linear motion cylinder 11 in a cross-sectional view along the optical axis OP. The flange portion 12cb is attached so as to be embedded in the inner circumferential surface of the cam cylinder 12.

[0041] This improves the strength of the sub cam follower 12c that comes into contact with the sub cam groove 11c when an external force is applied to the lens barrel 100. Also, the flange portion 12cb can disperse the force applied to the sub cam follower 12 when an impact is applied. Furthermore, from the viewpoint of workability, when the sub cam follower 12 is fitted into a through hole, the flange portion 12cb can prevent the sub cam follower 12 from slipping out to the outside.

[0042] In this embodiment, the sub cam follower 12c is molded separately from the cam barrel 12 and then attached so as to be embedded in the inner circumferential surface of the cam barrel 12, but the sub cam follower 12c may also be molded integrally with the cam barrel 12. Cam groove 12d is a through hole formed in a direction intersecting the direction of optical axis OP at a position from the end of cam barrel 12 on the subject side to approximately the center, as shown in Figure 6A and Figure 6B, and is engaged with cam follower 21b of first group unit 21 as shown in Figure 2. In cam groove 12d at the Wide position shown in Figure 6A, cam follower 21b of first group unit 21 is located at the right end (image surface side), and in the Tele position shown in Figure 6B, cam follower 21b of first group unit 21 is located at the left end (subject side).

[0043] As a result, when the cam barrel 12 is rotated relative to the linear barrel 11, the cam follower 21b of the first unit 21 moves along the cam groove 12d of the cam barrel 12 while engaging with the linear groove 11d of the linear barrel 11, thereby allowing the first unit 21 to move back and forth in the direction of the optical axis OP. 6A and 6B, cam groove 12e is a through hole formed in a direction intersecting the direction of optical axis OP near the end of cam barrel 12 on the subject side, and is engaged with cam follower 23a of third group unit 23. In cam groove 12e at the Wide position shown in Fig. 6A, cam follower 23a of third group unit 23 is located at the right end (image surface side), and in the Tele position shown in Fig. 6B, cam follower 23a of third group unit 23 is located at the left end (subject side).

[0044] As a result, when the cam barrel 12 is rotated relative to the linear barrel 11, the cam follower 23a of the third group unit 23 moves along the cam groove 12e while engaging with the linear groove 11e of the linear barrel 11, thereby allowing the third group unit 23 to move back and forth in the direction of the optical axis OP. 6A and 6B, cam groove 12f is a through hole formed along a direction intersecting the optical axis OP direction at a position adjacent to cam groove 12e formed near the end of cam barrel 12 on the subject side, and is engaged with cam follower 24a of fourth group unit 24. In cam groove 12f at the Wide position shown in Fig. 6A, cam follower 24a of fourth group unit 24 is located at the right end (image surface side), and in the Tele position shown in Fig. 6B, cam follower 24a of fourth group unit 24 is located at the left end (subject side).

[0045] As a result, when the cam barrel 12 is rotated relative to the linear barrel 11, the cam follower 24a of the fourth group unit 24 moves along the cam groove 12f while engaging with the linear groove 11e of the linear barrel 11, thereby allowing the fourth group unit 24 to move back and forth in the direction of the optical axis OP. 6A and 6B, cam groove 12g is a through hole formed in a position near the end of cam barrel 12 on the image surface side along a direction intersecting the direction of optical axis OP, and is engaged with cam follower 27a of seventh group unit 27. In cam groove 12g at the Wide position shown in Fig. 6A, cam follower 27a of seventh group unit 27 is located at the right end (image surface side), and in the Tele position shown in Fig. 6B, cam follower 27a of seventh group unit 27 is located at the left end (subject side).

[0046] As a result, when the cam barrel 12 is rotated relative to the linear barrel 11, the cam follower 27a of the seventh group unit 27 moves along the cam groove 12g while engaging with the linear groove 11e of the linear barrel 11, thereby allowing the seventh group unit 27 to move back and forth in the direction of the optical axis OP. 6A and 6B, the zoom drive pin 33 is already attached to the outer circumferential surface of the cam barrel 12. However, in an actual assembly process, the zoom drive pin 33 is inserted through a pin insertion hole (attachment hole) 32b (described later) and fixed to the outer circumferential surface of the cam barrel 12 with the base frame 40 and the zoom ring 32 assembled to the outer circumferential surface side of the cam barrel 12.

[0047] Furthermore, as shown in FIGS. 6A and 6B, the cam barrel 12 is shorter than the rectilinear barrel 11 in the direction of the optical axis OP. When the zoom ring 32 is rotated, the main cam follower 11b provided on the above-mentioned linear cylinder 11 moves along the main cam groove 12b, so that the cam barrel 12 moves back and forth in the direction of the optical axis OP between the end (first end) on the subject side and the end (second end) on the image plane side of the linear cylinder 11.

[0048] As a result, for example, compared to a configuration in which the cam barrel 12 has approximately the same length in the optical axis OP direction as the rectilinear barrel 11, the angle of the cam grooves formed in the cam barrel 12 can be made gentler. That is, in this embodiment, the length of the cam barrel 12 in the direction of the optical axis OP is shorter than that of the rectilinear barrel 11, so that, for example, if the number of cam grooves formed in the cam barrel 12 is the same, the angle of the cam grooves will be gentle.

[0049] As a result, the cam barrel 12 itself moves back and forth in the direction of the optical axis OP relative to the linear movement barrel 11, so that a sufficient zoom range can be ensured even if the angle of the cam groove is gentle. As a result, while ensuring a sufficient zoom range, the rotational torque, frictional resistance, etc. required to drive the 1st, 3rd-7th group units 21, 23-27 that are generated when the zoom ring 32 is rotated is reduced, making it possible to more smoothly drive the 1st, 3rd-7th group units 21, 23-27 back and forth in the direction of the optical axis OP.

[0050] <Assembly of the lens barrel 100> The process for assembling the lens barrel 100 including the lens support mechanism 10 of this embodiment will be described below with reference to FIGS. 9A to 12B. That is, as described above, the cam barrel 12 is disposed on the outer circumferential surface side of the linear motion barrel 11, and the linear motion barrel 11 and the cam barrel 12 are fitted together in the radial direction of a circle centered on the optical axis OP.

[0051] First, with the cam barrel 12 inserted on the outer circumferential surface side of the linear-movement barrel 11, the main cam follower 11b of the linear-movement barrel 11 is fixed to the outer circumferential surface of the linear-movement barrel 11 from the radially outer side using a screw (not shown), as shown in FIG. 6A. Similarly, with the cam barrel 12 inserted into the outer circumferential surface side of the linear motion barrel 11, the cam followers 23a, 24a, 27a of the third-group, fourth-group, and seventh-group units 23, 24, and 27 are fixed to the main bodies and the like of the third-group, fourth-group, and seventh-group units 21, 23, 24, and 27 from the radially outer side using screws (not shown).

[0052] At this time, when the cam barrel 12 is rotated relative to the linear barrel 11, the first, third, fourth and seventh group units 21, 23, 24 and 27 are restricted in rotation by the linear grooves 11d and 11e, and therefore move in the direction of the optical axis OP along the trajectories of the cam grooves 12d, 12e, 12f and 12g. The cam barrel 12 itself also moves in the direction of the optical axis OP while rotating along the trajectory of the main cam groove 12b in which the main cam follower 11b on the linear motion barrel 11 side is engaged.

[0053] In this manner, with the configuration in which cam barrel 12 is extended relative to linear barrel 11 shown in Figures 6A and 6B, the total amount of movement of the first, third to seventh group units 21-27 matches the total amount of movement of the cam grooves 12d, 12e, 12f, and 12g in the direction of the optical axis OP and the length of the locus of main cam groove 12b in the direction of the optical axis OP. Next, linear motion barrel 11 and cam barrel 12, with first to seventh group units 21 to 27 assembled, are inserted into base frame 40 as shown in FIG. 9A, and linear motion barrel 11 is fixed to base frame 40 using screws (not shown).

[0054] Next, as shown in FIG. 9B, the substantially cylindrical zoom ring 32 is inserted onto the outer circumferential surface side of the main body portion 40a of the substantially cylindrical base frame 40. As shown in FIG. 10, the zoom ring 32 has a substantially cylindrical main body portion 32a, a pin insertion hole (mounting hole) 32b, and a rectilinear restriction groove 32c. The pin insertion hole (attachment hole) 32b is a through hole formed in the main body portion 32a, and when the zoom drive pin 33 is attached to the outer circumferential surface of the cam barrel 12, the zoom drive pin 33 is inserted into the pin insertion hole (attachment hole) 32b.

[0055] The straight-line restriction groove 32c is formed along the optical axis OP direction so that the head of the zoom drive pin 33, which is inserted from the pin insertion hole 32b and attached to the outer peripheral surface of the cam barrel 12 through the pin clearance hole (through groove) 41 (see Figure 9A) of the base frame 40, engages with and moves. The pin clearance hole (through groove) 41 is formed to avoid interference with the zoom drive pin (drive pin) 33 when the zoom ring 32 is rotated. Specifically, the pin clearance hole 41 is formed in a direction intersecting the optical axis direction on the outer circumferential surface of the base frame 40, as shown in FIG. 9A.

[0056] 11, the zoom drive pin 33 is inserted from the outer circumferential surface side through the pin insertion hole 32b of the zoom ring 32 and the pin clearance hole 41 (see FIG. 9A) of the base frame 40. The zoom drive pin 33 is then fixed to the outer circumferential surface of the cam barrel 12 from the outer circumferential surface side using a screw (not shown). At this time, as shown in FIGS. 12A and 12B, the head of the zoom drive pin 33 engages with the rectilinear restriction groove 32c, and the zoom drive pin 33 is supported so as to be movable in the direction of the optical axis OP relative to the zoom ring 32.

[0057] Here, when the zoom ring 32 is rotated, a rotational force in the circumferential direction is applied to the zoom drive pin 33 engaged with the zoom ring 32, and the cam barrel 12 is rotated. Then, the main cam follower 11b provided on the above-mentioned linear motion cylinder 11 side moves along the main cam groove 12b, so that the cam barrel 12 moves in the direction of the optical axis OP while rotating.

[0058] At this time, the zoom drive pin 33 slides in the direction of the optical axis OP while remaining engaged with the rectilinear movement restricting groove 32c. As shown in FIG. 14, the zoom ring 32 has a first sliding portion 34a and a second sliding portion 34b near the front and rear ends of the approximately cylindrical shape in the direction of the optical axis OP, which rotate relative to one another with a portion of the inner circumferential surface of the zoom ring 32 abutting against a portion of the outer circumferential surface of the base frame 40.

[0059] As shown in FIG. 14, the zoom drive pin 33 is positioned between a first sliding portion 34a and a second sliding portion 34b provided at the end opposite the first sliding portion 34a in the optical axis OP direction so as to move back and forth in the optical axis OP direction. This makes it possible to prevent the zoom drive pin 33 from interfering with the first and second sliding portions 34a, 34b, while also preventing the grease applied near the first and second sliding portions 34a, 34b from seeping into the vicinity of the zoom drive pin 33.

[0060] Here, after the zoom drive pin 33 is fixed to the outer peripheral surface of the cam barrel 12 with a screw, a roughly cylindrical zoom ring rubber (cover member) 32d made of rubber is attached to the outer peripheral surface of the zoom ring 32, as shown in Figures 12A and 12B. The zoom ring rubber 32d is made of a rubber material, and is wound around the outer circumferential surface of the zoom ring 32 so as to cover it.

[0061] In this way, by closing the pin insertion hole 32b with the zoom ring rubber 32d, it is possible to make the zoom drive pin 33 invisible from the outside. 10, an uneven shape 32da is formed on the outer peripheral surface of the zoom ring 32 to improve moldability. As a result, even if the zoom ring 32 has a thickness equal to or greater than a predetermined thickness, the uneven shape 32da reduces the thickness of the zoom ring 32, thereby improving moldability when molding the resin zoom ring 32.

[0062] In addition, as shown in FIG. 14, a substantially cylindrical PET film (sheet-like member) 32e having the same size as the zoom ring rubber 32d is provided between the outer peripheral surface of the zoom ring 32 and the inner peripheral surface of the zoom ring rubber 32d. The PET film 32e is a sheet-like member made of PET (polyethylene-terephthalate) resin, and is attached so as to cover the outer circumferential surface of the zoom ring 32. Note that a sheet-like member made of another material may be used instead of the PET film 32e.

[0063] This prevents the portion of the zoom ring 32 where the pin insertion hole 32b is formed from being easily dented when pressed from the outer circumferential surface side, thereby improving usability. Furthermore, when the zoom ring 32 is rotated and the first unit 21 etc. moves back and forth in the direction of the optical axis OP, a notch 21c is formed in the end of the main body 21a on the image surface side so that the zoom drive pin 33 does not interfere with the approximately cylindrical main body portion (cylindrical portion) 21a of the first unit 21.

[0064] 13, when viewed from the image surface side (the right side in the figure), the notch portion 21c has a shape in which a part of an end portion of the substantially cylindrical main body portion 21a of the first unit 21 is cut out into a substantially trapezoidal shape. Such a substantially trapezoidal shape is set so that the zoom drive pin 33 and the main body portion 21a do not interfere with each other according to the movement range of the zoom drive pin 33 with respect to the main body portion 21a when the zoom ring 32 is rotated.

[0065] Here, as shown in FIG. 13, in the Wide position, the zoom drive pin 33 is positioned closer to the subject (first end) in the direction of the optical axis OP than the cam follower 21b that protrudes radially inward from the inner circumferential surface of the first group unit 21. According to the configuration of this embodiment, a notch 21c is provided at the end of the main body 21a of the first group unit 21 on the image surface side, so that when the zoom ring 32 is rotated and at least a portion of the first, third-seventh group units 21, 23-27 move back and forth in the direction of the optical axis OP, it is possible to prevent the zoom drive pin 33 attached to the outer peripheral surface of the cam barrel 12 from interfering with the end of the main body 21a of the first group unit 21 on the image surface side (second end side).

[0066] <Major feature 1> The lens support mechanism 10 of this embodiment includes the first to seventh group units 21 to 27, a substantially cylindrical linear cylinder 11, and a substantially cylindrical cam cylinder 12. The linear cylinder 11 contains the first to seventh group units 21 to 27 and has a main cam follower 11b and a sub cam groove 11c that protrude from the outer circumferential surface toward the outside in the radial direction. The cam cylinder 12 has a main cam groove 12b and a sub cam follower 12c, and is disposed on the outer circumferential side of the linear cylinder 11. The main cam groove 12b engages with the main cam follower 11b and is formed substantially parallel to the sub cam groove 11c, and when rotated relative to the linear cylinder 11, moves the lens group units 21 to 27 back and forth in the optical axis direction. The sub cam follower 12c protrudes toward the inside in the radial direction and engages with the sub cam groove 11c.

[0067] That is, in the lens support mechanism 10 of this embodiment, the linear cylinder 11 is provided with a main cam follower 11b and a sub cam groove 11c, and the cam cylinder 12 is provided with a main cam groove 12b and a sub cam follower 12c. As a result, since the main cam groove 12b and the sub cam groove 11c are provided in different frames (the linear barrel 11 and the cam barrel 12), it is possible to avoid a decrease in the strength of the frame compared to a configuration in which the main cam groove 12b and the sub cam groove 11c are provided in the same frame. Furthermore, it is possible to improve the degree of freedom in the arrangement of each groove with respect to the linear barrel 11 and the cam barrel 12 and the degree of freedom in the design of the trajectory. Therefore, it is possible to realize a small-sized, high-performance lens barrel 100.

[0068] Furthermore, as described above, since main cam groove 12b and sub cam groove 11c are provided in separate frames, main cam groove 12b and sub cam groove 11c can be arranged in a position where they overlap when viewed from the outer circumferential surface side, as shown in Fig. 6A. This arrangement is not possible in a configuration in which main cam groove 12b and sub cam groove 11c are provided in the same component. This improves the degree of freedom in the arrangement of each groove and the design freedom of the trajectory, making it possible to realize a compact, high-performance lens barrel 100.

[0069] Furthermore, for example, when lens barrel 100 is accidentally dropped and an impact is applied from the outside, each frame and each cam follower elastically deforms. At this time, sub cam follower 12c and sub cam groove 11c, which are engaged with each other, come into contact and receive the impact, thereby dispersing the impact force and improving the impact resistance of lens barrel 100. For the above reasons, by adopting a configuration such as that of this embodiment, the freedom in the arrangement of the grooves formed in the linear barrel 11 and the cam barrel 12 is improved, making it possible to achieve both a compact lens barrel 100 and good impact resistance.

[0070] <Major feature 2> The lens barrel 100 of this embodiment is a lens barrel that is detachably attached to the camera body 101, and includes the first to seventh group units 21 to 27, a substantially cylindrical linear barrel 11, a substantially cylindrical cam barrel 12, a substantially cylindrical zoom ring 32, and a zoom drive pin 33. The linear barrel 11 has a main cam follower 11b that protrudes in the radial direction, and holds the first to seventh group units 21 to 27 on the inner peripheral surface side. The cam barrel 12 has a main cam groove 12b that is formed in a direction intersecting the optical axis OP direction and engages with the main cam follower 11b in order to move the first, third to seventh group units 21 and 23 to 27 in the optical axis OP direction, and rotates relative to the linear barrel 11 with the main cam follower 11b engaged with the main cam groove 12b to move the first, third to seventh group units 21 and 23 to 27 in the optical axis OP direction. The substantially cylindrical zoom ring 32 has a rectilinear restriction groove 32c formed along the optical axis OP direction, and when rotated to perform a zoom operation, the main cam follower 11b moves along the main cam groove 12b, thereby moving the cam barrel 12 back and forth in the optical axis OP direction relative to the rectilinear barrel 11. The drive pin 33 is fixed to the outer circumferential surface of the cam barrel so as to protrude radially outward, and transmits the rotation of the zoom ring 32 to the cam barrel 12, and engages with the rectilinear restriction groove 32c of the zoom ring 32.

[0071] As a result, in the lens barrel 100 which is attached to the camera body 101 in an interchangeable state, by rotating the zoom ring 32, the cam barrel 12 can be moved back and forth in the direction of the optical axis OP relative to the linear barrel 11 which is fixedly disposed relative to the camera body 101 without the zoom drive pin 33 interfering with each component. Therefore, the cam barrel 12 itself, which has multiple cam grooves formed therein for moving the 1st, 3rd to 7th group units 21, 23-27 back and forth in the direction of the optical axis OP, moves back and forth in the direction of the optical axis OP, thereby expanding the drive range (zoom range) of the 1st, 3rd to 7th group units 21, 23-27 in the direction of the optical axis OP and reducing the rotational load of the zoom ring 32, thereby enabling smooth zoom operation.

[0072] As a result, in lens barrel 100 that is detachably attached to camera body 101, it is possible to ensure a sufficient zoom range while achieving miniaturization. [Other embodiments] Although one embodiment of the present disclosure has been described above, the present disclosure is not limited to the above embodiment, and various modifications are possible without departing from the gist of the disclosure.

[0073] (A) In the above embodiment, an example has been described in which the sub-cam follower 12c provided on the cam barrel 12 side and the sub-cam groove 11c provided on the rectilinear barrel 11 side are engaged with each other via a predetermined gap G1 during normal operation, as shown in Fig. 8. However, the present disclosure is not limited to this.

[0074] For example, in a steady state, a part of the sub cam follower (second cam follower) may be in contact with a part of the sub cam groove (second cam groove) and engaged with each other. In other words, in the present disclosure, it is not essential that the sub cam follower and the sub cam groove are completely out of contact in a steady state, and they may be in partial contact. (B) In the above embodiment, an example has been described in which one sub-cam groove 11c and one sub-cam follower 12c that engages with the same are provided in each of the linear barrel 11 and the cam barrel 12 in order to improve the impact resistance of the lens barrel 100. However, the present disclosure is not limited to this.

[0075] For example, there may be two or more combinations of sub-cam followers and sub-cam grooves provided to improve the impact resistance of the lens barrel. (C) In the above embodiment, an example has been described in which the cam barrel 12 arranged on the outer periphery of the fixedly arranged linear barrel 11 is driven back and forth in the direction of the optical axis OP. However, the present disclosure is not limited to this.

[0076] For example, the linear movement barrel may be driven back and forth in the optical axis direction relative to the cam barrel. (D) In the above embodiment, an example has been described in which the sub-cam groove 11c provided in the linear barrel 11 to improve the impact resistance of the lens barrel 100 is provided as a non-through recess provided on the outer circumferential surface of the linear barrel 11. However, the present disclosure is not limited to this.

[0077] For example, the sub-cam groove (second cam groove) provided in the linearly-moving barrel (fixed barrel) may be a through hole that connects the outer peripheral surface and the inner peripheral surface of the linearly-moving barrel. However, in order to minimize the decrease in rigidity of the linear motion cylinder due to the provision of the sub-cam grooves (second cam grooves), it is preferable to make the sub-cam grooves (second cam grooves) non-through, as in the above embodiment.

[0078] (E) In the above embodiment, an example has been described in which an insertion port 11ca is provided on the end face on the image surface side of the sub-cam groove 11c in order to insert the cam barrel 12 from the end face on the image surface side of the linear motion barrel 11 in a state in which the sub-cam follower 12c is attached to the inner peripheral surface side of the cam barrel 12. However, the present disclosure is not limited to this.

[0079] For example, the position where the insertion opening is provided is not limited to the end surface of the sub-cam groove (second cam groove) on the image surface side, but may be the end surface on the subject side. (F) In the above embodiment, an example has been described in which the sub-cam follower 12c provided on the cam barrel 12 to improve the impact resistance of the lens barrel 100 has a substantially conical shape and a flange portion. However, the present disclosure is not limited to this.

[0080] For example, it may be a sub cam follower (second cam follower) that does not have a flange portion. Furthermore, the shape is not limited to a substantially conical shape, and may be, for example, a sub cam follower (second cam follower) having a substantially cylindrical shape. (G) In the above embodiment, an example has been described in which the present disclosure is applied to a lens barrel 100 that is detachable from a camera body 101. However, the present disclosure is not limited to this.

[0081] For example, the present disclosure may be applied to a lens barrel that is integrated with a camera body and cannot be detached, rather than to a detachable lens barrel. [Industrial Applicability]

[0082] The lens support mechanism of the present disclosure has the effect of enabling greater freedom in design than ever before, and is therefore widely applicable to lens barrels and the like that include lens support mechanisms. [Explanation of symbols]

[0083] 1 Camera 10 Lens support mechanism 11 Straight-moving tube (fixed tube) 11a Main body 11b Main cam follower (first cam follower) 11c Sub cam groove (second cam groove) 11ca Insertion port 11d Straight groove 11e Straight groove 12 Cam barrel 12a Main body 12b Main cam groove (first cam groove) 12c Sub Cam Follower (Second Cam Follower) 12ca Main unit 12cb flange 12d Cam groove 12e Cam groove 12f Cam groove 12g Cam groove 21 1st group unit (lens group unit, 1st lens frame) 21a Main body (cylindrical part) 21b Cam follower 21c Notch 22 2nd group unit (lens group unit) 23 3rd group unit (lens group unit) 23a Cam follower 24 4th group unit (lens group unit) 24a Cam follower 25 5th group unit (lens group unit) 26 6-group unit (lens group unit) 27 7th group unit (lens group unit) 27a Cam follower 28 Guide shaft 31 Focus ring 32 Zoom ring 32a Main body 32b Pin insertion hole (mounting hole) 32c Straight-line restriction groove (straight-line groove) 32d Zoom ring rubber (cover part) 32da uneven shape 32e PET film (sheet-shaped material) 33 Zoom drive pin (drive pin) 34a First sliding part 34b Second sliding part 40 Base Frame 40a Main body 41 Pin clearance hole (through groove) 100 Lens barrel 101 Camera body G1~G3 Gap L1~L7 1st to 7th lens groups (lens groups) OP optical axis

Claims

1. A lens group unit; a substantially cylindrical fixed barrel that contains the lens group unit and has a first cam follower protruding radially outward from an outer circumferential surface and a second cam groove; a substantially cylindrical cam barrel arranged on the outer periphery side of the fixed barrel, the first cam groove being engaged with the first cam follower and being formed substantially parallel to the second cam groove, and moving the lens group unit back and forth in the optical axis direction when the fixed barrel rotates relative to the fixed barrel, and a second cam follower protruding radially inward and engaging with the second cam groove; Equipped with When the first cam follower engages with the first cam groove and slides, the second cam follower engages with the second cam groove in a non-contact state, and in an emergency in which an external force is applied from the outside, if at least one of the fixed barrel, the cam barrel, the first cam follower and the second cam follower is deformed, the second cam follower and the second cam groove, which have engaged with each other in a non-contact state in a steady state, come into contact with each other. Lens support mechanism.

2. the first cam follower provided on the fixed barrel moves along the first cam groove, so that the cam barrel moves in the optical axis direction of the lens group unit while rotating relatively to the fixed barrel. The lens support mechanism according to claim 1 .

3. The first cam groove communicates an inner peripheral surface and an outer peripheral surface of the cam barrel, The second cam groove does not pass through the fixed barrel.

3. The lens support mechanism according to claim 1.

4. the second cam groove is formed to a front end face or a rear end face in the optical axis direction of the fixed barrel, and has an insertion opening in the end face into which the second cam follower is inserted during assembly; The lens support mechanism according to claim 1 .

5. The first cam groove and the second cam groove are arranged in a position where they partially overlap when viewed from a direction perpendicular to the optical axis direction. The lens support mechanism according to claim 1 .

6. the second cam follower has a substantially annular flange portion formed substantially parallel to an outer circumferential surface of the fixed barrel in a cross-sectional view taken along the optical axis direction, The lens support mechanism according to claim 1 .

7. The second cam follower has a generally conical shape. The lens support mechanism according to claim 1 .

8. A lens barrel comprising the lens support mechanism according to any one of claims 1 to 7.

9. The lens barrel according to claim 8 ; a camera body to which the lens barrel is attached; A camera equipped with.

Images