Lens barrel and imaging device

Abstract

This lens barrel comprises: a lens holding frame that holds a lens; a rotation shaft that is rotated by a motor; a fitting portion that moves in a first direction in accordance with the rotation of the rotation shaft around the first direction; a plurality of bearing members that sandwich a portion of the fitting part; and a straight-moving member that is connected to the lens holding frame, rotatably holds the fitting portion through the plurality of bearing members, and moves in the first direction along with the movement of the fitting portion in the first direction.

Description

Lens barrel and imaging device

[0001] The present invention relates to a lens barrel and an imaging device.

[0002] A drive mechanism has been proposed that uses a lead screw and an engaging member (such as a nut or a rack) that engages with the lead screw to drive a lens holding frame (see, for example, Patent Document 1). There is a demand for reducing the drive noise when driving the lens holding frame.

[0003] Japanese Patent Application Laid-Open No. 2018-205603

[0004] According to a first aspect, the lens barrel includes a lens holding frame that holds a lens, a rotation shaft that is rotated by a motor, a fitting portion that moves in a first direction in response to rotation of the rotation shaft around the first direction, a plurality of bearing members that sandwich a portion of the fitting portion, and a rectilinear member that is connected to the lens holding frame, rotatably holds the fitting portion via the plurality of bearing members, and moves in the first direction in response to movement of the fitting portion in the first direction.

[0005] According to a second aspect, an imaging device includes the lens barrel described above.

[0006] The configurations of the embodiments described below may be modified as appropriate, and at least a portion of the configuration may be replaced with other components. Furthermore, components that are not particularly limited in terms of their placement may be placed in any position that can achieve their function, not limited to the placement disclosed in the embodiments.

[0007] FIG. 1 is a diagram showing a camera including a lens barrel and a camera body according to a first embodiment. FIG. 2 is a perspective view showing the relationship between a second fixed barrel, a lens holding frame, and a drive unit. FIG. 3 is a perspective view for explaining the configuration of the lens holding frame and the drive unit. FIG. 4(A) is a cross-sectional view of the drive unit, and FIG. 4(B) is an enlarged view of the vicinity of a first end of a lead screw. FIG. 5(A) is a front view of a moving unit, FIG. 5(B) is a perspective view of the moving unit, and FIGS. 5(C) and 5(D) are exploded perspective views of the moving unit. FIG. 6 is a cross-sectional view of the moving unit. FIG. 7(A) is a cross-sectional view showing a case where a lid is not fixed to a holding unit, and FIG. 7(B) is a cross-sectional view showing a case where an annular member does not have a protrusion. FIG. 8(A) is a view showing a state before a connecting portion of a main body unit is accommodated in a housing portion of a lens holding frame, and FIG. 8(B) is a view showing a state after the connecting portion of the main body unit is accommodated in a housing portion of a lens holding frame. FIG. 9 is a cross-sectional view taken along line A-A in FIG. 8(B). FIG. 10(A) is a perspective view showing a state in which a lead screw and an output shaft of a stepping motor are connected by a coupling mechanism, and FIGS. 10(B) and 10(C) are perspective views of the coupling mechanism. FIGS. 11(A) and 11(B) are perspective views showing a coupling mechanism and a stepping motor. FIGS. 12(A) and 12(C) are views showing a lead screw and an output shaft of a stepping motor that are not connected by a coupling mechanism, and FIGS. 12(B) and 12(D) are views showing a state in which a lead screw and an output shaft of a stepping motor are connected by a coupling mechanism. FIG. 13(A) is a perspective view showing a state in which a lead screw and an output shaft of a stepping motor are connected by a coupling mechanism according to Modification 1, and FIG. 13(B) is a perspective view for explaining the configuration of the coupling mechanism, and FIGS. 13(C) and 13(D) are views showing a state in which a lead screw and an output shaft of a stepping motor are connected by a coupling mechanism. FIG. 14(A) is a perspective view showing a state in which the lead screw and the output shaft of the stepping motor are connected by a coupling mechanism according to Modification 2, FIG. 14(B) is a perspective view for explaining the configuration of the coupling mechanism, and FIGS. 14(C) and 14(D) are views showing the second member.15(A) and 15(B) are cross-sectional views illustrating the connection relationship between the lead screw, the coupling mechanism, and the output shaft in Modification 2, and FIG. 15(C) is an enlarged view of a first end of the lead screw in Modification 2. FIG. 16 is a perspective view illustrating the relationship between a drive source unit, a lens holding frame, and a second fixed barrel according to a second embodiment. FIG. 17 is a perspective view illustrating the configuration of the lens holding frame and the drive source unit. FIG. 18(A) is a perspective view of a moving section according to the second embodiment, and FIG. 18(B) is an exploded perspective view of the moving section. FIG. 19 is a cross-sectional view illustrating the connection between the lens holding frame and the moving section.

[0008] First Embodiment A lens barrel 100 according to a first embodiment will be described in detail below with reference to the drawings. Note that the scales of the shapes, lengths, thicknesses, and other aspects of the components shown in the embodiments do not necessarily correspond to the actual objects, and in each drawing, some elements may be omitted for ease of understanding. Furthermore, in cross-sectional views, hatching of some elements is omitted.

[0009] Fig. 1 is a diagram showing a camera 1 including a lens barrel 100 according to a first embodiment and a camera body 200. In Fig. 1, the wide-angle state is shown above the center line, and the telephoto state is shown below.

[0010] The camera body 200 includes an image sensor 201 and a control unit (not shown) inside. The image sensor 201 is configured with a photoelectric conversion element such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor), and converts the subject image formed by the imaging optical system (lens barrel 100 attached to the camera body 200) into an electrical signal.

[0011] The control unit includes a CPU (Central Processing Unit) and the like, and controls the overall operation of the camera 1 relating to photography, including zoom driving and focusing driving of the image sensor 201 and the attached lens barrel 100 .

[0012] As shown in FIG. 1 , the lens barrel 100 according to this embodiment includes a first fixed barrel 10, and a second fixed barrel 11 and a third fixed barrel 12, which are disposed radially inward from the first fixed barrel 10. A lens mount LM is attached to the first fixed barrel 10. The lens mount LM engages with a body mount (not shown) of the camera body 200, thereby detachably mounting the lens barrel 100 to the camera body 200. Note that in this embodiment, the lens barrel 100 is detachable from the camera body 200, but this is not limiting, and the lens barrel 100 and the camera body 200 may be integrated. Furthermore, the camera body 200 may not only be capable of capturing still images, but may also be dedicated to video recording.

[0013] As shown in FIG. 1 , the lens barrel 100 according to this embodiment includes lens groups L1 to L6 arranged sequentially along a common optical axis OA. Lens groups L1 to L6 are held by lens holding frames F1 to F6, respectively. In this embodiment, lens groups L2 and L4 are zoom lens groups that move along the optical axis OA during zooming. Lens group L5 is a focus and zoom lens group. Each of lens groups L1 to L6 may consist of a single lens or multiple lenses. Lens groups L1, L3, and L6 are fixed in position along the optical axis OA during zooming. Fixing lens group L1, which is closest to the subject, is preferable because it fixes the overall length of the lens barrel 100 during zooming and minimizes changes in the center of gravity during use. Furthermore, lens groups L4 and L5 are driven by a drive source (e.g., a stepping motor, a VCM motor, etc.) (not shown) provided in the third fixed barrel 12 to move their positions along the optical axis OA. Therefore, the lens barrel 100 does not have a lens group that is mechanically linked to the zoom ring 13. The lens barrel 100 is provided with, as drive sources, a motor for moving the positions of the lens groups during zooming, and a motor for changing the aperture diameter of the diaphragm member S.

[0014] The lens holding frame F2 is driven by a drive source unit 300. More specifically, when the zoom operation ring 13 is operated (rotated), a drive signal corresponding to the amount of operation (amount of rotation) is output from a control unit (not shown) to the drive source unit 300, and the drive source unit 300 is driven based on the drive signal, thereby moving the lens holding frame F2 in the direction of the optical axis OA. The lens holding frame F2 and the drive source unit 300 will be described in detail below.

[0015] Fig. 2 is a perspective view showing the relationship between the second fixed barrel 11, the lens holding frame F2, and the drive source unit 300. Fig. 3 is a perspective view for explaining the configurations of the lens holding frame F2 and the drive source unit 300. Fig. 4(A) is a cross-sectional view of the drive source unit 300.

[0016] As shown in Fig. 2, the second fixed barrel 11 has a substantially cylindrical shape, and the lens holding frame F2 is disposed on the inner diameter side of the second fixed barrel 11. As shown in Fig. 3, three guide portions 500 are provided on the outer periphery of the lens holding frame F2, spaced apart in the circumferential direction. Each guide portion 500 has a bearing 500a.

[0017] The guide portions 500 are formed on the inner periphery of the second fixed barrel 11 and engage with rectilinear grooves 111 extending in a direction parallel to the optical axis OA. This allows the lens holding frame F2 driven by the drive source unit 300 to be guided in a direction parallel to the optical axis OA. Note that a guide bar extending in a direction parallel to the optical axis OA may be fixed to the second fixed barrel 11, and the lens holding frame F2 may be guided by the guide bar.

[0018] 2, the drive source unit 300 includes a stepping motor 301, a lead screw 302 (rotation shaft), and a rectilinear member 303 that moves along the axis of the lead screw 302 as the lead screw 302 rotates. The drive source unit 300 is attached to the second fixed barrel 11 so that the axis of the lead screw 302 is approximately parallel to the optical axis OA.

[0019] In this embodiment, a part 116 of the second fixed barrel 11 is located between the lead screw 302 and the lens holding frame F2. The part 116 of the second fixed barrel 11 is provided in a position where its outer peripheral surface faces the lead screw 302, and functions as a cover for the lead screw 302. This makes it possible to prevent dust and the like generated by the lead screw 302 from adhering to the lens group L2 and the like.

[0020] In order to connect the rectilinear member 303, which engages with the lead screw 302 arranged on the outside of the second fixed barrel 11, to the lens holding frame F2 arranged on the inside of the second fixed barrel 11, an opening 115 is formed in the second fixed barrel 11 at a position facing the lead screw 302. By inserting the rectilinear member 303 through the opening 115, the rectilinear member 303 engaged with the lead screw 302 can be connected to the lens holding frame F2.

[0021] 3, a mounting member 304 is fixed to the stepping motor 301. A hole 304a is formed in the mounting member 304. The stepping motor 301 is fixed to the second fixed barrel 11 by attaching the mounting member 304 to the second fixed barrel 11 using a screw 305 or the like via the hole 304a.

[0022] The output shaft of the stepping motor 301 and the first end 302a of the lead screw 302 are connected via a joint mechanism 400. The joint mechanism 400 transmits the rotational force of the output shaft of the stepping motor 301 to the lead screw 302. The structure of the joint mechanism 400 will be described later.

[0023] 4B is an enlarged view of the vicinity of the first end 302a of the lead screw 302. The first end 302a of the lead screw 302 includes a cylindrical portion 302d and a flat portion 302c having flat surfaces 302f that are substantially parallel to each other. Because the diameter of the lead screw 302 is larger than the diameter of the output shaft 301a of the stepping motor 301 (see FIGS. 12A and 12C), it is easier to form the flat portion 302c compared to the output shaft 301a.

[0024] 4A, the cylindrical portion 302d of the lead screw 302 is fitted into the inner ring of the bearing 306. The outer ring of the bearing 306 is fitted into the inner wall of the first hole 112 formed in the second fixed barrel 11. This rotatably supports the lead screw 302 and reduces frictional resistance during rotation of the lead screw 302. This reduces the load on the stepping motor 301.

[0025] The outer ring of the bearing 306 has a flange 306a that protrudes radially outward from the outer ring. The flange 306a comes into contact with the periphery of the first hole 112 of the second fixed barrel 11. The flange 306a is held between a first spring bearing member 307a (described later) and the second fixed barrel 11. This prevents the bearing 306 from falling out of the first hole 112.

[0026] 4A, the second end 302b of the lead screw 302 is fitted into the inner ring of a bearing 311. The outer ring of the bearing 311 is fitted into the inner wall of a second hole 113 formed in the second fixed barrel 11. This rotatably supports the lead screw 302 and reduces frictional resistance during rotation of the lead screw 302. This reduces the load on the stepping motor 301.

[0027] As shown in FIG. 4A , the outer ring of the bearing 311 has a flange 311a that protrudes radially outward from the outer ring. The flange 311a contacts the periphery of the second hole 113 of the second fixed barrel 11. The flange 311a of the outer ring of the bearing 311 also contacts a protrusion 312a of the fixing member 312. As shown in FIG. 3 , a hole is formed in the fixing member 312, and the fixing member 312 is fixed to the second fixed barrel 11 via the hole with a screw 313 or the like. This holds the flange 311a of the outer ring of the bearing 311 between the second fixed barrel 11 and the fixing member 312, preventing the bearing 311 from falling out of the second hole 113.

[0028] The drive source unit 300 also includes a backlash elimination mechanism 307. The backlash elimination mechanism 307 includes a compression spring 307b, a first spring bearing member 307a that contacts one end of the compression spring 307b, and a second spring bearing member 307c that contacts the other end of the compression spring 307b. As shown in Fig. 4A, the cylindrical portion 302d of the lead screw 302 is inserted through the first spring bearing member 307a, the compression spring 307b, and the second spring bearing member 307c.

[0029] The surface of the second spring bearing member 307c opposite to the surface that contacts the compression spring 307b contacts the lead screw 302. More specifically, the surface of the second spring bearing member 307c opposite to the surface that contacts the compression spring 307b contacts a step 302e of the lead screw 302 between a screw portion 302s, on which a thread groove is formed, and the first end 302a.

[0030] The surface of first spring bearing member 307a opposite to the surface that contacts compression spring 307b contacts the inner ring of bearing 306. Because compression spring 307b is disposed between first spring bearing member 307a and second spring bearing member 307c, the inner ring of bearing 306 is biased in the direction indicated by arrow AR2 by first spring bearing member 307a. Furthermore, the inner ring of bearing 311 is biased in the direction indicated by arrow AR1 via second spring bearing member 307c and lead screw 302. This makes it possible to suppress axial play due to axial internal gaps in each of bearing 306 and bearing 311.

[0031] Next, a description will be given of the configuration of the rectilinear member 303 that moves along the axis AX1 of the lead screw 302 as the lead screw 302 rotates. The axis AX1 is the central axis of the lead screw 302.

[0032] Fig. 5(A) is a front view of the rectilinear member 303, Fig. 5(B) is a perspective view of the rectilinear member 303, and Figs. 5(C) and 5(D) are exploded perspective views of the rectilinear member 303. Fig. 6 is a cross-sectional view of the rectilinear member 303.

[0033] As shown in FIGS. 5C and 5D , the linear member 303 includes a main body portion 31 and a lead screw engaging portion 30 .

[0034] The main body 31 includes a holding portion 31a that holds the lead screw engagement portion 30, which will be described later, and a connecting portion 31b that is connected to the lens holding frame F2. In this embodiment, the main body 31 is made of resin.

[0035] The lead screw engaging portion 30 includes an annular member 32 (fitting portion), bearings 33 a and 33 b, a cover portion 34 , and a screw 37 .

[0036] As shown in Fig. 6, a groove 321 that comes into contact with the thread groove of the lead screw 302 is formed on the inner periphery of the annular member 32. In this embodiment, the groove 321 is a circumferential groove that is formed around the entire inner periphery of the annular member 32, but this is not limiting. The groove 321 may be formed on only a portion of the inner periphery of the annular member 32 as long as it can come into contact with the thread groove of the lead screw 302. For example, the groove 321 may be formed on half of the inner periphery of the annular member 32 (e.g., in a C-shape).

[0037] The outer periphery of the annular member 32 is fitted with the inner rings of the bearings 33a and 33b. The bearings 33a and 33b are arranged such that a protrusion 32a (part of the annular member 32) formed on the outer periphery of the annular member 32 is sandwiched between their respective inner rings. The outer rings of the bearings 33a and 33b are fitted with the inner wall of the holding portion 31a of the main body 31. This allows the annular member 32 to be rotatably held on the main body 31 (linear member 303). Note that, in this embodiment, the protrusion 32a is provided continuously in the circumferential direction of the annular member 32, but multiple (two or more) protrusions 32a may be provided spaced apart in the circumferential direction. Furthermore, the protrusion 32a may be provided in only a portion of the circumferential direction of the annular member 32.

[0038] As indicated by arrow AR6 in Fig. 6 , the annular member 32 is urged toward the lead screw 302 by a second urging mechanism 36, which will be described later. Because the annular member 32 is rotatably supported, when the lead screw 302 rotates, the annular member 32 is pushed by the flank surfaces of the thread groove of the lead screw 302 and moves in the direction of the axis AX1 of the lead screw 302 while rotating. As a result, the main body 31, which has the holding portion 31a that holds the annular member 32, also moves in the direction of the axis AX1 of the lead screw 302, and the rectilinear member 303 can be moved in a direction parallel to the optical axis OA. In other words, the direction in which the rectilinear member 303 moves (the direction of the axis AX1) is approximately parallel to the optical axis OA.

[0039] Furthermore, because the annular member 32 moves in the axis AX1 direction of the lead screw 302 while rotating, the friction generated between the annular member 32 and the lead screw 302 becomes rolling friction. This reduces the load on the stepping motor 301 when the linearly-moving member 303 moves in the axis AX1 direction of the lead screw 302. The configurations disclosed in International Publication No. 2023 / 048093 can be applied to the configuration of the groove 321 of the annular member 32 and the configuration of the thread groove of the lead screw 302.

[0040] As shown in FIG. 6 , the annular member 32 is parallel to the lead screw 302 in the biasing direction of the second biasing mechanism 36. However, in directions other than the biasing direction of the second biasing mechanism 36, as shown in FIG. 4A , the annular member 32 is arranged at an inclination that matches the inclination of the teeth (thread grooves) of the lead screw 302. This allows the position of the annular member 32 relative to the lead screw 302 to be stably maintained, as described in International Publication No. 2023 / 048093. Furthermore, frictional resistance between the lead screw 302 and the annular member 32 can be reduced. The annular member 32 may also be parallel to the lead screw 302 in directions other than the biasing direction of the second biasing mechanism 36.

[0041] In this embodiment, the annular member 32 is made of resin, which reduces the driving noise generated when the annular member 32 is pushed by the flank surface of the thread groove of the lead screw 302 and moves in the direction of the axis AX1 of the lead screw 302 while rotating.

[0042] A lid 34 is fixed to the main body 31 with screws 37. As shown in Fig. 5C, the lid 34 is annular, and as shown in Fig. 6, the lid 34 contacts the outer ring of the bearing 33b but not the inner ring. This prevents the outer ring of the bearing 33b from rotating with the rotation of the lead screw 302, but allows the inner ring to rotate.

[0043] Here, we will explain why the annular member 32 has the protrusion 32a, why the two bearings 33a and 33b are arranged with the protrusion 32a sandwiched between them, and why the lid 34, which comes into contact with the outer ring of the bearing 33b, is fixed to the main body 31. Fig. 7(A) is a cross-sectional view showing a case where the lid 34 is not fixed to the main body 31.

[0044] In this embodiment, the main body 31 is made of resin. Therefore, as shown in FIG. 7A , if the lid 34 is not fixed to the main body 31, simply fitting the bearings 33a and 33b into the inner wall of the holder 31a of the main body 31 will not provide enough holding force for the main body 31 to hold the bearings 33a and 33b. When an impact is received, the bearings 33a and 33b may move in the direction indicated by arrow AR3. For example, the bearing 33b may fall out of the holder 31a. Therefore, in this embodiment, the lid 34 is provided to contact the outer ring of the bearing 33b, preventing the bearing 33b from falling out of the holder 31a without interfering with the rotation of the bearing 33b. In other words, the lid 34 maintains the position of the bearings 33a and 33b along the axis AX1.

[0045] Fig. 7(B) is a cross-sectional view showing an annular member 132 according to a comparative example. As shown in Fig. 7(B), the annular member 132 does not have a protrusion 32a. Note that the annular member 132 according to the comparative example is also made of resin, like the annular member 32 according to this embodiment. In Fig. 7(B), a lid portion 34 is provided that comes into contact with the outer ring of the bearing 33b.

[0046] In this case, simply pressing the annular member 132 into the inner rings of the bearings 33a and 33b and engaging the outer periphery of the annular member 132 with the inner rings of the bearings 33a and 33b will not provide enough holding force for the bearings 33a and 33b to hold the annular member 132, and when an impact is received, the annular member 132 may move in the direction of arrow AR4 and fall off the bearings 33a and 33b.

[0047] For this reason, in this embodiment, the bearings 33a and 33b are arranged to sandwich a portion (protrusion 32a) of the annular member 32. As a result, even if the annular member 32 receives a force in the direction of arrow AR5 in Figure 6, the protrusion 32a comes into contact with the bearing 33b, whose position in the direction of axis AX1 is maintained by the cover portion 34. This prevents the annular member 32 from moving in the direction of axis AX1. This prevents the annular member 32 from falling off the bearings 33a and 33b.

[0048] As shown by the dashed arrow in FIG. 3, the rectilinear member 303 is connected to the lens holding frame F2 by accommodating the connecting portion 31b of the main body 31 in the accommodating portion 210 of the lens holding frame F2.

[0049] Fig. 8(A) is a diagram showing a state before the connecting portion 31b of the main body portion 31 is accommodated in the accommodation portion 210 of the lens holding frame F2, and Fig. 8(B) is a diagram showing a state after the connecting portion 31b of the main body portion 31 is accommodated in the accommodation portion 210 of the lens holding frame F2. Fig. 9 is a cross-sectional view taken along line A-A in Fig. 8(B).

[0050] As shown in FIGS. 6 and 9, a first biasing mechanism 35 and a second biasing mechanism 36 are attached to the connecting portion 31b of the main body 31.

[0051] The first biasing mechanism 35 includes a compression spring 35a and a spring receiving portion 35b. As shown in FIG. 9 , one end of the compression spring 35a contacts the main body 31, and the other end of the compression spring 35a is held by the spring receiving portion 35b. A surface 351 of the spring receiving portion 35b opposite the surface that contacts the compression spring 35a contacts the inner wall of the housing portion 210 of the lens holding frame F2. In other words, the spring receiving portion 35b is provided between the compression spring 35a and the lens holding frame F2 and abuts against the lens holding frame F2. The compression spring 35a biases the main body 31 toward the inner wall of the housing portion 210 of the lens holding frame F2, as indicated by the arrow AR11. In other words, the compression spring 35a biases the main body 31 (the rectilinear member 303) in a direction parallel to the optical axis OA. This suppresses play between the main body 31 and the storage section 210 of the lens holding frame F2 in a direction parallel to the optical axis OA, and when the linear member 303 moves along the axis AX1 of the lead screw 302 as the lead screw 302 rotates, the lens holding frame F2 also moves in the direction of the axis AX1 (a direction parallel to the optical axis OA).

[0052] The second biasing mechanism 36 includes a compression spring 36a and a spring receiving portion 36b. As shown in FIG. 9 , the compression spring 36a is housed in a spring receiving portion 31d formed in the connecting portion 31b of the main body 31. One end of the compression spring 36a contacts the main body 31, and the other end of the compression spring 36a contacts the spring receiving portion 36b. A surface 361 of the spring receiving portion 36b opposite the surface that contacts the compression spring 36a contacts the bottom wall of the housing portion 210. That is, the spring receiving portion 36b is provided between the compression spring 36a and the lens holding frame F2 and abuts against the lens holding frame F2. The compression spring 36a biases the main body 31 toward the lead screw 302 in a direction perpendicular to the axis AX1 of the lead screw 302, as indicated by arrow AR12.

[0053] 8B , in this embodiment, the rectilinear member 303 is accommodated in the accommodation portion 210 so that the longitudinal direction of the rectilinear member 303 is approximately perpendicular to the radial direction of the lens holding frame F2. Therefore, in this embodiment, the compression spring 36a biases the main body portion 31 (the rectilinear member 303) in the circumferential direction of the lens holding frame F2.

[0054] As a result, the annular member 32 held by the holding portion 31a of the main body portion 31 is forced toward the lead screw 302, and the groove 321 of the annular member 32 is pressed against the thread groove of the lead screw 302, thereby suppressing play between the annular member 32 and the lead screw 302.

[0055] In this embodiment, two first biasing mechanisms 35 are provided, but the number of first biasing mechanisms 35 may be one, or three or more. In addition, one second biasing mechanism 36 is provided, but the number of second biasing mechanisms 36 may be two or more.

[0056] In this embodiment, the spring receiving portion 35b of the first biasing mechanism 35 and the spring receiving portion 36b of the second biasing mechanism 36 are made of resin. In the first biasing mechanism 35, the other end of the compression spring 35a contacts the spring receiving portion 35b, and a surface 351 of the spring receiving portion 35b contacts the inner wall of the housing portion 210 of the lens retaining frame F2. This reduces the frictional force between the compression spring 35a and the inner wall of the housing portion 210 in a direction perpendicular to the biasing direction of the compression spring 35a (e.g., the direction indicated by arrow AR11) compared to when the other end of the compression spring 35a directly contacts the inner wall of the housing portion 210 of the lens retaining frame F2. This reduces the interference with the force of the second biasing mechanism 36 biasing the main body 31 toward the lead screw 302 compared to when the other end of the compression spring 35a directly contacts the inner wall of the housing portion 210 of the lens retaining frame F2.

[0057] Furthermore, in the second biasing mechanism 36, the other end of the compression spring 36a contacts the spring receiving portion 36b, and a surface 361 of the spring receiving portion 36b contacts the bottom wall of the housing portion 210 of the lens retaining frame F2. As a result, the frictional force between the compression spring 36a and the bottom wall of the housing portion 210, which occurs in a direction perpendicular to the biasing direction of the compression spring 36a (e.g., the direction indicated by arrow AR12), is smaller than when the other end of the compression spring 36a directly contacts the bottom wall of the housing portion 210 of the lens retaining frame F2. Therefore, it is possible to suppress the transmission of the force with which the first biasing mechanism 35 biases the main body portion 31 toward the lens retaining frame F2 from being hindered, compared to when the other end of the compression spring 36a directly contacts the bottom wall of the housing portion 210 of the lens retaining frame F2.

[0058] [Coupling mechanism 400] When the output shaft of the stepping motor 301 and the lead screw 302 are directly connected, if the output shaft of the stepping motor 301 and the axis AX1 of the lead screw 302 are not aligned, a large load is applied to the stepping motor 301 due to misalignment of the axes. In addition, the driving noise of the drive source unit 300 may become louder.

[0059] In order to transmit the rotational force of the stepping motor 301 to the lead screw 302 while allowing for misalignment of the axes, it is conceivable to use, for example, an Oldham coupling. However, a typical Oldham coupling takes up space and can only be driven by a motor with a relatively large torque. It is also conceivable to provide an adjustment mechanism or the like for adjusting the position of the output shaft of the stepping motor 301 and the position of the axis AX1 of the lead screw 302, but this would require a lot of adjustment work.

[0060] Therefore, in this embodiment, a coupling mechanism 400 is used to connect the output shaft of the stepping motor 301 and the lead screw 302 .

[0061] Fig. 10(A) is a perspective view showing a state in which the lead screw 302 and the output shaft of the stepping motor 301 are connected by the coupling mechanism 400, and Figs. 10(B) and 10(C) are perspective views of the coupling mechanism 400. Figs. 11(A) and 11(B) are perspective views showing the coupling mechanism 400 and the stepping motor 301. Figs. 12(A) and 12(C) are views showing the lead screw 302 and the output shaft of the stepping motor 301 that are not connected by the coupling mechanism 400, and Figs. 12(B) and 12(D) are views showing a state in which the lead screw 302 and the output shaft of the stepping motor 301 are connected by the coupling mechanism 400.

[0062] The coupling mechanism 400 includes a first member 41 and a second member 42. As shown in Fig. 10(B) , a hole 411 is formed in the first member 41. As shown in Fig. 11(A) , the output shaft 301a of the stepping motor 301 is press-fitted into the hole 411, thereby fixing the first member 41 to the output shaft 301a of the stepping motor 301.

[0063] The second member 42 is formed with a first groove 421 (see FIG. 10C) that engages with the first end 302a (more specifically, the flat portion 302c) of the lead screw 302, and a second groove 422 (see, for example, FIG. 11B) that engages with the first member 41. In addition, in FIGS. 10A to 12D, the direction parallel to the axial direction of the lead screw 302 is the Z1 direction, the extension direction of the second groove 422 is the X1 direction, and the direction perpendicular to the X1 and Z1 directions is the Y1 direction. In other words, when the lead screw 302 is arranged so that the axial direction of the lead screw 302 is parallel to the optical axis OA, the Z1 direction is a direction parallel to the optical axis OA.

[0064] As shown in FIG. 11B and other figures, the second groove 422 extends in the X1 direction and has a T-shape when viewed from the X1 direction. The first member 41 has a T-shape when viewed from the X1 direction so as to engage with the second groove 422. As shown in FIG. 12B , the first member 41 and the second groove 422 engage with each other so as to restrict relative movement in the Y1 direction. Therefore, when the first member 41 and the second member 42 are engaged with each other, the second member 42 can move in the X1 direction (first direction) relative to the first member 41 (movement in the X1 direction is permitted), but movement in the Y1 direction (second direction) is restricted (movement in the Y1 direction is not permitted).

[0065] As shown in FIG. 10C and other drawings, the first groove 421 of the second member 42 is an I-shaped groove extending in the Y1 direction (second direction) when viewed from the Z1 direction (in the X1Y1 plane). In this embodiment, the width (thickness) of the flat portion 302c of the lead screw 302 in the X1 direction is approximately the same as or slightly smaller than the width of the first groove 421 in the X1 direction. Furthermore, the length of the first groove 421 in the Y1 direction of the second member 42 is greater than the width of the flat portion 302c of the lead screw 302 in the Y1 direction. As a result, the second member 42 is movable in the Y1 direction (second direction) relative to the lead screw 302 (movement in the Y1 direction is permitted), but movement in the X1 direction (first direction) is restricted (movement in the X1 direction is not permitted).

[0066] The second member 42 is restricted in its movement in the Y1 direction relative to the first member 41, which is fixed to the output shaft 301a of the stepping motor 301, and restricted in its movement in the X1 direction relative to the lead screw 302. This allows the rotational force of the output shaft 301a of the stepping motor 301 to be transmitted to the lead screw 302. The second member 42 is also movable in the X1 direction relative to the first member 41 and in the Y1 direction relative to the lead screw 302. As a result, even if the output shaft 301a of the stepping motor 301 and the axis AX1 of the lead screw 302 are not aligned, the second member 42 can swing to absorb any misalignment of the axes. This prevents unnecessary load from being applied to the stepping motor 301 and also reduces noise.

[0067] Furthermore, a typical Oldham coupling includes three components: two hub members fixed to the output shaft of the stepping motor 301 and the lead screw 302, respectively, and a slide member disposed between the two hub members. Because the coupling mechanism 400 according to this embodiment is configured from two components, the space required for the coupling can be reduced compared to a typical Oldham coupling. As a result, even when the coupling mechanism 400 is used, the drive source unit 300 can be made more space-saving.

[0068] Furthermore, the length of the lead screw 302 is longer than the length of the output shaft 301a and the lengths of the first member 41 and the second member 42 in the direction of the optical axis OA. Therefore, even if the axis AX1 of the lead screw 302 is arranged at a slight angle with respect to the optical axis OA, the position of the first end 302a of the lead screw 302 will deviate significantly from the design position. In this embodiment, even if the position of the first end 302a of the lead screw 302 deviates from the design position, the coupling mechanism 400 can absorb the deviation of the axis.

[0069] The assembly procedure for the coupling mechanism 400 is as follows: First, the output shaft 301a of the stepping motor 301 is press-fitted into the hole 411 formed in the first member 41, and the first member 41 is fixed to the output shaft 301a of the stepping motor 301. Next, the first member 41 is slid to engage with the second groove 422 of the second member 42 so that the first member 41 and the second member 42 are relatively movable in the X1 direction (first direction).

[0070] With the first member 41 and the second member 42 engaged (with the coupling mechanism 400 attached to the stepping motor 301), the stepping motor 301 is attached to the second fixed barrel 11, and then the flat portion 302c of the lead screw 302 is inserted into the first groove 421 of the second member 42 so that the flat portion 302c of the lead screw 302 and the second member 42 can move relative to each other in the Y1 direction (second direction).

[0071] The drive source unit 300 is fixed to the second fixed barrel 11 as follows. First, the lead screw 302 is rotatably attached to the second fixed barrel 11 together with the fixed member 312, bearings 306 and 311, and backlash-removing mechanism 307. Then, the stepping motor 301 equipped with the coupling mechanism 400 is attached to the second fixed barrel 11. At this time, the lead screw 302 is rotated so that the flat portion 302c of the lead screw 302 can be inserted into the first groove 421 of the second member 42 of the coupling mechanism 400. In this embodiment, the lead screw 302 is disposed on the outside of the second fixed barrel 11, rather than the inside, which facilitates the operation of rotating the lead screw 302 to engage the flat portion 302c of the lead screw 302 with the first groove 421 of the second member 42.

[0072] After the flat portion 302c of the lead screw 302 is engaged with the first groove 421 of the second member 42, the stepping motor 301 is fixed to the second fixed barrel 11. In this manner, the drive source unit 300 can be fixed to the second fixed barrel 11.

[0073] As described above in detail, according to this embodiment, the lens barrel 100 includes the lens retaining frame F2 that retains the lens group L2, the lead screw 302 that is rotated by the stepping motor 301, the annular member 32 that moves in the direction of the axis AX1 in response to rotation of the lead screw 302 about the axis AX1, a plurality of bearings 33a and 33b that sandwich a portion of the annular member 32, and the rectilinear member 303 that is connected to the lens retaining frame F2, rotatably holds the annular member 32 via the plurality of bearings 33a and 33b, and moves in the direction of the axis AX1 in response to movement of the annular member 32 in the direction of the axis AX1. Because the bearings 33a and 33b sandwich a portion of the annular member 32, it is possible to prevent the annular member 32 from falling off the bearings 33a or 33b due to an impact or the like, even if the annular member 32 is made of resin for noise reduction.

[0074] In this embodiment, the annular member 32 has a protrusion 32a that is sandwiched between the plurality of bearings 33a and 33b, and the positions of the plurality of bearings 33a and 33b in the direction of the axis AX1 relative to the linear-movement member 303 (main body 31) are maintained. This prevents the bearings 33a and 33b from falling out of the holding portion 31a of the main body 31 and the annular member 32 from falling out of the bearings 33a or 33b due to an impact or the like.

[0075] Furthermore, in this embodiment, the inner rings of the plurality of bearings 33 a and 33 b rotate integrally with the annular member 32 in conjunction with the rotation of the lead screw 302. As a result, the annular member 32 moves in the direction of the axis AX1 of the lead screw 302 while rotating, and therefore the friction generated between the annular member 32 and the lead screw 302 becomes rolling friction, making it possible to reduce the load on the stepping motor 301 when the linearly-moving member 303 is moved in a direction parallel to the axis AX1 of the lead screw 302.

[0076] Furthermore, in this embodiment, the linear-movement member 303 has a lid portion 34, and the outer ring of one bearing 33b of the plurality of bearings 33a and 33b abuts against the lid portion 34, so that the bearing 33b does not rotate in conjunction with the rotation of the lead screw 302. This prevents the bearing 33b from falling out of the holding portion 31a without interfering with the rotation of the bearing 33b.

[0077] Furthermore, according to this embodiment, the lens barrel 100 includes a lead screw 302 rotated by a stepping motor 301, a rectilinear member 303 that moves along the lead screw 302 as the lead screw 302 rotates, a lens retaining frame F2 to which the rectilinear member 303 is connected and that moves as the rectilinear member 303 moves, a plurality of compression springs 35a and 36a having one ends in contact with the rectilinear member 303 and biasing the rectilinear member 303 in different directions relative to the lens retaining frame F2, and spring receiving portions 35b and 36b that are provided between the other ends of the plurality of compression springs 35a and 36a and the lens retaining frame F2 and abut against the lens retaining frame F2. As a result, compared to when the compression spring 35a is in direct contact with the lens retaining frame F2, the frictional force between the lens retaining frame F2 and the lens retaining frame F2 in a direction perpendicular to the biasing direction of the compression spring 35a is smaller, and therefore, it is possible to prevent interference with the biasing force of the compression spring 36a. Furthermore, compared to when the compression spring 36a is in direct contact with the lens holding frame F2, the frictional force between the compression spring 36a and the lens holding frame F2 in a direction perpendicular to the force direction of the compression spring 36a is smaller, thereby preventing the transmission of the force of the compression spring 36a from being obstructed.

[0078] According to this embodiment, the drive source unit 300 includes a first member 41 fixed to the output shaft 301 a of the stepping motor 301, a lead screw 302 having a threaded groove and an axis AX1 disposed substantially parallel to the output shaft 301 a, and a second member 42 engaged at one end with the first member 41 and at the other end with a first end 302 a of the lead screw 302. The second member 42 is allowed to move in an X1 direction perpendicular to the output shaft 301 a relative to the first member 41, but is restricted from moving in a Y1 direction substantially perpendicular to the X1 direction. The second member 42 is allowed to move in the Y1 direction relative to the lead screw 302, but is restricted from moving in the X1 direction. Because the second member 42 is restricted from moving in the Y1 direction relative to the first member 41 and is restricted from moving in the X1 direction relative to the lead screw 302, the rotational force of the output shaft 301 a of the stepping motor 301 can be transmitted to the lead screw 302. Furthermore, the second member 42 is movable in the X1 direction relative to the first member 41, and in the Y1 direction relative to the lead screw 302. As a result, even if the output shaft 301a of the stepping motor 301 and the axis AX1 of the lead screw 302 are not aligned, the second member 42 swings and can absorb the misalignment of the axes. This prevents unnecessary load from being applied to the stepping motor 301, and also reduces noise generation. Furthermore, because the coupling mechanism 400 has only two components, which is fewer than a typical Oldham coupling, space can be saved, and the drive source unit 300 can be made smaller.

[0079] In the above embodiment, the annular member 32 is made of resin, but even if the annular member 32 is made of metal, the bearings 33a and 33b can be configured to sandwich a portion of the annular member 32.

[0080] Furthermore, in the above embodiment, the first member 41 of the coupling mechanism 400 is fixed to the output shaft 301a of the stepping motor 301, but the first member 41 may be fixed to the lead screw 302. In this case, a flat portion may be formed on the output shaft 301a of the stepping motor 301, and the flat portion may be engaged with the first groove 421 of the second member 42, and the first member 41 fixed to the lead screw 302 may be engaged with the second groove 422 of the second member 42.

[0081] In addition, in the above embodiment, the second groove 422 that engages with the first member 41 is formed in the second member 42 of the coupling mechanism 400, but a groove that engages with the second member 42 and extends in the X1 direction may be formed in the first member 41.

[0082] 13A to 13D are diagrams illustrating a coupling mechanism 400A according to Modification 1. Fig. 13A is a perspective view illustrating a state in which the lead screw 302A and the output shaft 301a of the stepping motor 301 are connected by the coupling mechanism 400A, Fig. 13B is a perspective view illustrating the configuration of the coupling mechanism 400A, and Figs. 13C and 13D are diagrams illustrating a state in which the lead screw 302A and the output shaft 301a of the stepping motor 301 are connected by the coupling mechanism 400A.

[0083] As shown in FIGS. 13A to 13D, the joint mechanism 400A includes a first member 41A and a second member 42A.

[0084] The second member 42A has a guide groove 422A and an engaging portion 427. In Figures 13(A) to 13(D), the direction parallel to the axis of the lead screw 302A is the Z3 direction, the extension direction of the guide groove 422A is the X3 direction, and the direction perpendicular to the X3 direction and the Z3 direction is the Y3 direction.

[0085] As shown in Figures 13(B) and 13(C), the guide groove 422A of the second member 42A extends in the X3 direction and, as shown in Figure 13(C), has a T-shape when viewed from the X3 direction. As shown in Figure 13(B), the first member 41A has a side surface portion 412 that is perpendicular to the Y3 direction and extends in the X3 direction, and engages with the guide groove 422A of the second member 42A. As shown in Figure 13(C), the first member 41A and the guide groove 422A are engaged so as to prevent relative movement in the Y3 direction. As a result, the second member 42A is movable in the X3 direction relative to the first member 41A (movement in the X3 direction is permitted), but movement in the Y3 direction is restricted (movement in the Y3 direction is not permitted).

[0086] As shown in FIG. 13B, the engaging portion 427 of the second member 42A has a side surface 427a that is perpendicular to the X3 direction and extends in the Y3 direction. As shown in FIGS. 13B and 13D, in Modification 1, a groove 302h is formed at the tip of the first end 302a of the lead screw 302A. The groove 302h extends in the Y3 direction when viewed from the -Z3 direction (in the Z3Y3 plane). The engaging portion 427 of the second member 42A is inserted into the groove 302h of the lead screw 302A. As shown in FIG. 13D, the groove 302h of the lead screw 302A and the engaging portion 427 of the second member 42A engage to prevent relative movement in the X3 direction. As a result, the second member 42A is movable in the Y3 direction relative to the lead screw 302A (movement in the Y3 direction is permitted), but movement in the X3 direction is restricted (movement in the X3 direction is not permitted).

[0087] The second member 42A is restricted from moving in the Y3 direction relative to the first member 41A, which is fixed to the output shaft 301a of the stepping motor 301, and restricted from moving in the X3 direction relative to the lead screw 302A. This allows the rotational force of the output shaft 301a of the stepping motor 301 to be transmitted to the lead screw 302A. The second member 42A is also allowed to move in the X3 direction relative to the first member 41A, and in the Y3 direction relative to the lead screw 302A. This allows the second member 42A to oscillate and absorb any misalignment of the axes, even if the output shaft 301a of the stepping motor 301 and the axis of the lead screw 302A are not aligned. This prevents unnecessary loads from being applied to the stepping motor 301, and also reduces noise. Furthermore, since the coupling mechanism 400A in the first modification is made up of only two members, the space required for the coupling mechanism 400A can be reduced compared to a typical Oldham coupling.

[0088] As shown in Modification 1, the groove extending in the Y3 direction may be provided in the lead screw instead of the second member.

[0089] (Variation 2) Figures 14(A) to 15(C) are diagrams illustrating a coupling mechanism 400B according to Variation 2. Figure 14(A) is a perspective view illustrating a state in which the lead screw 302B and the output shaft 301a of the stepping motor 301 are connected by the coupling mechanism 400B. Figure 14(B) is a perspective view illustrating the configuration of the coupling mechanism 400B. Figures 14(C) and 14(D) are diagrams illustrating the second member 42B. Figures 15(A) and 15(B) are cross-sectional views illustrating the connection relationship between the lead screw 302B, the coupling mechanism 400B, and the output shaft 301a. Figure 15(C) is an enlarged view of the first end 302a of the lead screw 302B.

[0090] As shown in FIG. 14B, the joint mechanism 400B includes a first member 41B and a second member 42B.

[0091] The second member 42B has an elongated hole 423 (see FIG. 14C) and a hole 425 (see FIG. 14D). In FIGS. 14A to 14D, the direction parallel to the axis of the lead screw 302B is the Z2 direction, the extension direction of the elongated hole 423 is the Y2 direction, and the direction perpendicular to the Y2 and Z2 directions is the X2 direction.

[0092] As shown in Fig. 14(C), two protrusions 424 facing each other in the X2 direction are formed in the elongated hole 423. Furthermore, as shown in Fig. 14(D), two substantially parallel wall portions 426 facing each other in the Y2 direction are provided in the hole 425.

[0093] The first member 41B has side surfaces 413 that face each other in the Y2 direction and are substantially perpendicular to the Y2 direction. The first member 41A is inserted between the two wall portions 426 of the second member 42B so that the side surfaces 413 face the wall portions 426 of the second member 42B. The diameter of the hole 425 is set to be larger than the maximum length of the first member 41A in the X2 direction. This allows the second member 42B to move in the X2 direction relative to the first member 41B, but restricts (does not allow) movement in the Y2 direction.

[0094] 15B and 15C, a recess 302g is formed in the first end 302a of the lead screw 302B. The recess 302g is disposed between the protrusions 424 formed in the elongated hole 423 of the second member 42B. This allows the second member 42B to move in the Y2 direction relative to the lead screw 302B, but restricts (does not allow) movement in the X2 direction.

[0095] The second member 42B is restricted from moving in the Y2 direction relative to the first member 41B, which is fixed to the output shaft 301a of the stepping motor 301, and restricted from moving in the X2 direction relative to the lead screw 302B. This allows the rotational force of the output shaft 301a of the stepping motor 301 to be transmitted to the lead screw 302B. Furthermore, the second member 42B is allowed to move in the X2 direction relative to the first member 41B, and allowed to move in the Y2 direction relative to the lead screw 302B. This allows the second member 42B to oscillate and absorb any misalignment of the axes, even if the output shaft 301a of the stepping motor 301 and the axis AX1 of the lead screw 302B are not aligned. This prevents unnecessary loads from being applied to the stepping motor 301, and also reduces noise. Furthermore, in the second modification, the coupling mechanism 400B is composed of only two members, which allows for a smaller space for the coupling mechanism 400B compared to a typical Oldham coupling.

[0096] Second Embodiment The configuration of the rectilinear member 303 included in the drive source unit 300 is not limited to that of the first embodiment. Fig. 16 is a perspective view showing the relationship between a drive source unit 300C, a lens holding frame F2C, and a second fixed barrel 11C according to a second embodiment. Fig. 17 is a perspective view for explaining the configuration of the lens holding frame F2C and the drive source unit 300C. Fig. 18(A) is a perspective view of a rectilinear member 303C according to the second embodiment, and Fig. 18(B) is an exploded perspective view of the rectilinear member 303C. Fig. 19 is a cross-sectional view for explaining the connection between the lens holding frame F2C and the rectilinear member 303C.

[0097] As shown in FIG. 16 , like the first embodiment, the second fixed barrel 11C according to the second embodiment also has an opening 115 formed at a position facing the lead screw 302B. This allows the rectilinear member 303C and the lens holding frame F2 to be connected. Furthermore, a portion 116 of the second fixed barrel 11C is located between the lens holding frame F2C and the lead screw 302B. The portion 116 of the second fixed barrel 11C is disposed so as to face the lead screw 302 in the direction of gravity, and functions as a cover for the lead screw 302. This prevents dust and other particles generated by the lead screw 302 from falling into the second fixed barrel 11C.

[0098] The linear-motion member 303C according to the second embodiment includes a main body 31C, a lead screw engagement portion 30C, and a connecting portion 38. The lead screw engagement portion 30C includes an annular member 32, bearings 33a and 33b, a cover portion 34C, and a screw 37. The lead screw engagement portion 30C is held by a holding portion 31a of the main body 31C. The configuration of the lead screw engagement portion 30C is the same as that of the lead screw engagement portion 30 according to the first embodiment, except for the shape of the cover portion 34C, and therefore detailed description thereof will be omitted.

[0099] The connecting portion 38 includes a connecting member 38a and a screw 38b. The connecting member 38a is fixed to the main body portion 31C with the screw 38b. As shown in FIG. 19 , the connecting member 38a is inserted into a housing portion 210C formed in the lens holding frame F2C. The connecting member 38a has a flange portion 381, and a compression spring 36a is disposed between the flange portion 381 and the lens holding frame F2C. This biases the main body portion 31C in the direction indicated by the arrow AR31, thereby pressing the annular member 32 against the lead screw 302B. This reduces play between the annular member 32 and the lead screw 302B.

[0100] A biasing mechanism 35C is attached to the lens holding frame F2C to bias the connecting member 38a toward the inner wall of the accommodation portion 210C. The biasing mechanism 35C includes a compression spring 35a, a spring receiving portion 35c, a fixing portion 35d, and a screw 35e.

[0101] The fixed portion 35d is fixed to the lens holding frame F2C with a screw 35e. One end of the compression spring 35a contacts the spring receiving portion 35c, and the other end of the compression spring 35a contacts the fixed portion 35d. A surface 352 of the spring receiving portion 35c opposite to the surface that contacts the compression spring 35a contacts the connecting member 38a.

[0102] The compression spring 35a biases the spring receiving portion 35c in the direction indicated by the arrow AR32. As a result, the connecting member 38a is pressed against the inner wall of the accommodation portion 210C, and therefore, when the rectilinear member 303C moves in a direction parallel to the optical axis OA in accordance with the rotation of the lead screw 302B, the lens holding frame F2C also moves in a direction parallel to the optical axis OA.

[0103] In this embodiment, the connecting member 38a and the spring receiving portion 35c are made of resin. This reduces the frictional force between the compression spring 35a and the lens holding frame F2C in a direction perpendicular to the biasing direction of the compression spring 35a compared to when the compression spring 35a is in direct contact with the connecting member 38a. This reduces the interference with the force of the compression spring 35a biasing the main body 31C in the direction indicated by arrow AR31 compared to when the compression spring 35a is in direct contact with the connecting member 38a.

[0104] In the second embodiment, the coupling mechanism 400B of Modification 2 is used as the coupling mechanism that connects the lead screw 302B and the output shaft 301a of the stepping motor 301, but the coupling mechanism 400 of the first embodiment or the coupling mechanism 400A of Modification 1 may also be used. The other configurations are the same as those of the first embodiment, and therefore detailed description thereof will be omitted.

[0105] In the above embodiment and modified example, the stepping motor 301 is used, but instead of the stepping motor 301, for example, an ultrasonic motor or the like may be used.

[0106] In the above embodiment and modified examples, one bearing is provided on each side of the protrusion 32a of the annular member 32, but this is not limited to this. For example, one bearing may be provided on one side of the protrusion 32a and two or more bearings may be provided on the other side. Also, two or more bearings may be provided on each side of the protrusion 32a.

[0107] The above-described embodiment is a preferred example of implementation, but is not limited to this, and various modifications are possible within the scope of the gist, and any constituent elements may be combined.

[0108] REFERENCE SIGNS LIST 1 camera 11 second fixed barrel 32 annular member 32a protrusion 33a, 33b bearing 34 cover 35 first biasing mechanism 35a compression spring 35b spring receiving portion 36 second biasing mechanism 36a compression spring 36b spring receiving portion 41, 41A, 41B first member 42, 42A, 42B second member 100 lens barrel 115 opening 300, 300C drive source unit 301 stepping motor 302, 302A, 302B lead screw 303, 303C linear member 400, 400A, 400B joint mechanism

Claims

1. A lens holder frame that holds the lens, A rotating shaft that is rotated by a motor, A fitting portion that moves in the first direction in accordance with the rotation of the rotation axis in the first direction, Multiple bearing members that sandwich a part of the aforementioned fitting portion, The device comprises a linear member connected to the lens holding frame, which rotatably holds the fitting portion via the plurality of bearing members, and which moves in the first direction as the fitting portion moves in the first direction, Lens barrel.

2. The fitting portion has a protruding portion that is sandwiched between the plurality of bearing members, The positions of the plurality of bearing members with respect to the linear member in the first direction are maintained. The lens barrel according to claim 1.

3. The inner rings of the plurality of bearing members rotate together with the fitting portion as the rotation of the rotating shaft. A lens barrel according to claim 1 or claim 2.

4. The first direction in which the straight-moving member moves is substantially parallel to the optical axis. A lens barrel according to claim 1 or claim 2.

5. The aforementioned straight member has a cover portion, The outer ring of one of the aforementioned bearing members does not rotate in conjunction with the rotation of the rotating shaft by contacting the cover portion. A lens barrel according to claim 1 or claim 2.

6. On the surface that is biased circumferentially with respect to the rotation axis of the lens holding frame, the fitting portion is substantially parallel to the optical axis. A lens barrel according to claim 1 or claim 2.

7. A rotating shaft that is rotated by a motor, A linear member that moves along the rotation axis when the rotation axis rotates, The aforementioned linear member is connected to a lens holding frame that moves in conjunction with the movement of the linear member, A plurality of biasing members, one end of which contacts the straight-moving member, and which bias the straight-moving member in different directions relative to the lens holding frame, The system includes a contact member provided between the other end of each of the plurality of biasing members and the lens holding frame, which contacts the lens holding frame. Lens barrel.

8. The frictional resistance between the contact member and the lens retaining frame is smaller than the frictional resistance between the other end of each of the plurality of biasing members and the lens retaining frame. The lens barrel according to claim 7.

9. At least one of the plurality of biasing members biases the straight-line member toward the circumferential direction of the lens holding frame. The lens barrel according to claim 7 or claim 8.

10. At least one of the plurality of biasing members biases the straight-line member in the direction of the optical axis, The lens barrel according to claim 7 or claim 8.

11. An imaging device comprising a lens barrel according to any one of claims 1, 2, 7, and 8.