Lens barrel and imaging device

Abstract

This lens barrel comprises: a moving part which has a first protrusion; a driving part which moves the moving part straight in an optical axis direction; a first tube which has a first cam groove that engages with the first protrusion, and a second cam groove; and a fist lens holding frame which has a second protrusion that engages with the second cam groove, and holds the first lens. The first tube rotates by the movement of the moving part in the optical axis direction, and the first lens holding frame moves in the optical axis direction by the rotation of the first tube.

Description

Lens barrel and imaging device

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

[0002] In an image pickup apparatus that uses a cam ring to move multiple lens groups linearly in the optical axis direction for zooming, a mechanism for rotating the cam ring using an actuator has been proposed (see, for example, Patent Document 1).It is desirable to reduce noise when rotating the cam ring using an actuator.

[0003] Japanese Patent Application Laid-Open No. 2019-133009

[0004] According to a first aspect, the lens barrel comprises a moving section having a first protrusion, a drive section that moves the moving section in a straight line in the optical axis direction, a first cylinder having a first cam groove that engages with the first protrusion and a second cam groove, and a first lens holding frame that has a second protrusion that engages with the second cam groove and holds a first lens, and the first cylinder rotates as the moving section moves in the optical axis direction, and the rotation of the first cylinder moves the first lens holding frame in the optical axis 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 allows them to achieve their function, not limited to the placement disclosed in the embodiments.

[0007] FIG. 1 is a cross-sectional view showing the configuration of a camera equipped with a lens barrel according to an embodiment. FIG. 2(A) is a perspective view of a second fixed barrel, and FIG. 2(B) is a perspective view of a zoom cam ring. FIG. 3(A) is a perspective view of a zoom rotation limiting ring, and FIG. 3(B) is a perspective view showing the relationship between the second fixed barrel, the zoom cam ring, and the zoom rotation limiting ring. FIG. 4(A) is a perspective view showing the configuration of a lens holding frame, and FIG. 4(B) is a perspective view showing the relationship between a cam pin, the second fixed barrel, and the zoom cam ring. FIG. 5(A) is a perspective view showing the drive mechanism in an exploded state, and FIG. 5(B) is a perspective view showing the drive mechanism in an assembled state. FIG. 6(A) is a perspective view illustrating the configuration of a connecting portion, and FIG. 6(B) is a cross-sectional view illustrating the configuration of the connecting portion. FIGS. 7(A) and 7(B) are diagrams for explaining the configuration of a lead screw support mechanism. FIGS. 8(A) to 8(D) are diagrams for explaining the configuration of a moving portion. Fig. 9 is a side view of the drive mechanism. Fig. 10(A) is a perspective view of the drive mechanism according to Modification 1, and Figs. 10(B) and 10(C) are diagrams for explaining the configuration of the drive mechanism according to Modification 1. Fig. 11(A) is a cross-sectional view of a moving part according to Modification 2, and Fig. 11(B) is a cross-sectional view of a connecting part according to Modification 3.

[0008] The lens barrel according to the embodiment will be described in detail below with reference to the drawings. Note that the scale of the shape, length, thickness, etc. of each part shown in the embodiment does not necessarily correspond to the actual product, and in each drawing, some elements may be omitted for ease of understanding. Also, in cross-sectional views, hatching of some elements may be omitted.

[0009] FIG. 1 is a cross-sectional view showing the configuration of a camera 1 equipped with a lens barrel 2 according to one embodiment, with the wide-angle state shown above the center line and the telephoto state shown below.

[0010] 1, the camera 1 includes a camera body 3 and a lens barrel 2. The lens barrel 2 is provided with a lens mount LM at the rear (proximal end) thereof, and is detachably attached to the camera body 3 by engaging with a body mount (not shown) of the camera body 3. Note that in this embodiment, the lens barrel 2 is detachable from the camera body 3, but this is not limiting, and the lens barrel 2 and the camera body 3 may be integrated.

[0011] The camera body 3 includes an image sensor IS and a control unit (not shown) inside. The image sensor IS is composed of a photoelectric conversion element such as a CCD (Charge Coupled Device), and converts the subject image formed by the imaging optical system (the lens barrel 2 attached to the camera body 3) into an electrical signal.

[0012] 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 focusing drive of the camera body 3 and the attached lens barrel 2 .

[0013] 1, the lens barrel 2 according to this embodiment has lens groups L1 to L4 arranged in sequence along a common optical axis OA. The lens groups L1 and L2 are held by a first fixed barrel 10 provided in the lens barrel 2, and the lens groups L3 and L4 are held by lens holding frames F3 and F4, respectively. In this embodiment, each of the lens groups L3 and L4 is a zoom lens group that moves in the direction of the optical axis OA during zooming.

[0014] In this embodiment, the first fixed barrel 10 is composed of multiple components, but it may also be composed of a single component. Furthermore, each of the lens groups L1 to L4 may be composed of a single lens, or multiple lenses. Furthermore, while the lens barrel is described as being composed of four lens groups, the number of lens groups may be three or less, or five or more.

[0015] The lens barrel 2 includes a second fixed barrel 11, a zoom cam ring 20 arranged on the outer circumferential side of the second fixed barrel 11, and a zoom rotation limit ring 30 arranged on the outer circumferential side of the zoom cam ring 20.

[0016] Fig. 2(A) is a perspective view of the second fixed barrel 11, and Fig. 2(B) is a perspective view of the zoom cam ring 20. Fig. 3(A) is a perspective view of the zoom rotation limit ring 30, and Fig. 3(B) is a perspective view showing the relationship between the second fixed barrel 11, the zoom cam ring 20, and the zoom rotation limit ring 30.

[0017] 2A, the second fixed barrel 11 includes an escape groove 11a, a first rectilinear groove 11b, and a second rectilinear groove 11c. The escape groove 11a, the first rectilinear groove 11b, and the second rectilinear groove 11c extend in a direction parallel to the optical axis OA. One escape groove 11a is provided in the circumferential direction of the second fixed barrel 11, three first rectilinear grooves 11b are provided in the circumferential direction, and three second rectilinear grooves 11c are provided in the circumferential direction. The number of first rectilinear grooves 11b and second rectilinear grooves 11c is not limited to three, and may be two or less, or four or more.

[0018] 2B, the zoom cam ring 20 includes a first cam groove 20a, a second cam groove 20b, a third cam groove 20c, and a zoom rotation limiting pin 20d. One first cam groove 20a is provided in the circumferential direction of the zoom cam ring 20, three second cam grooves 20b are provided in the circumferential direction, and three third cam grooves 20c are provided in the circumferential direction.

[0019] As shown in FIG. 3A, the zoom rotation limiting ring 30 has a notch 30a.

[0020] As shown in Figure 3(B), the second fixed barrel 11, zoom cam ring 20, and zoom rotation limiting ring 30 are arranged in this order from the innermost side. The zoom cam ring 20 and the zoom rotation limiting ring 30 are arranged so that the zoom rotation limiting pin 20d of the zoom cam ring 20 is located within the cutout portion 30a of the zoom rotation limiting ring 30. In other words, the zoom rotation limiting pin 20d comes into contact with the end of the cutout portion 30a when the zoom cam ring 20 rotates a predetermined amount around the optical axis OA. In other words, the rotation of the zoom cam ring 20 around the optical axis OA is limited by the cutout portion 30a.

[0021] FIG. 4A is a perspective view showing the configuration of the lens holding frames F3 and F4. As shown in FIG. 1, the lens holding frames F3 and F4 are disposed inside the second fixed barrel 11. As shown in FIG. 4A, three cam pins 41 are provided circumferentially on the outer peripheral surface of the lens holding frame F3, protruding in a direction intersecting the optical axis OA. Furthermore, three cam pins 42 are provided circumferentially on the outer peripheral surface of the lens holding frame F4, protruding in a direction intersecting the optical axis OA. The number of cam pins 41 and 42 is not limited to three, and may be two or less, or four or more. The cam pins 41 correspond to the second protrusion, and the cam pins 42 correspond to the fourth protrusion.

[0022] FIG. 4B is a perspective view showing the relationship between the cam pins 41 and 42, the second fixed barrel 11, and the zoom cam ring 20.

[0023] The cam pins 41 of the lens holding frame F3 pass through the first rectilinear grooves 11b of the second fixed barrel 11 and engage with the second cam grooves 20b of the zoom cam ring 20. As a result, when the zoom cam ring 20 rotates, the lens holding frame F3 moves linearly in the direction of the optical axis OA along the first rectilinear grooves 11b and the second cam grooves 20b.

[0024] The cam pin 42 of the lens holding frame F4 passes through the second rectilinear groove 11c of the second fixed barrel 11 and engages with the third cam groove 20c of the zoom cam ring 20. As a result, when the zoom cam ring 20 rotates, the lens holding frame F4 moves linearly in the direction of the optical axis OA along the second rectilinear groove 11c and the third cam groove 20c.

[0025] Next, we will explain the drive (rotation) of the zoom cam ring 20. The zoom cam ring 20 is driven by a drive mechanism 100 fixed to the inside of the second fixed barrel 11. Fig. 5(A) is a perspective view showing the drive mechanism 100 in an exploded state, and Fig. 5(B) is a perspective view showing the drive mechanism 100 in an assembled state.

[0026] 5A, the drive mechanism 100 includes a main body 150 and a support 110 that supports the main body 150. The support 110 includes a motor support 111, a guide 112, and a lead screw support mechanism 140. The motor support 111 supports a motor 131 included in the main body 150. The guide 112 has a linear groove 112a that engages with a linear groove engaging portion 123 included in the moving portion 120 (described later) and guides the moving portion 120 in the axial direction of the lead screw 135. The support 110 is fixed to the second fixed barrel 11 so that the axis of the lead screw 135 is parallel to the optical axis OA.

[0027] The main body 150 includes a drive unit 130 and a movement unit 120. The drive unit 130 includes a motor 131 and a lead screw 135. The motor 131 may be, for example, a stepping motor or an ultrasonic motor.

[0028] In this embodiment, the output shaft of the motor 131 and the lead screw 135 are connected by a connecting portion 136. Fig. 6A is a perspective view illustrating the configuration of the connecting portion 136, and Fig. 6B is a cross-sectional view illustrating the configuration of the connecting portion 136.

[0029] As shown in Fig. 6A, the coupling portion 136 includes a connecting portion 136c, a bearing 136b, a housing portion 136a, and an aligning portion 136d. The connecting portion 136c connects the output shaft of the motor 131 to the lead screw 135. Specifically, as shown in Fig. 6B, a connecting member 137 is attached to the output shaft of the motor 131, and the output shaft of the motor 131 and the lead screw 135 are connected (coupled) by inserting the connecting member 137 and one end of the lead screw 135 into the connecting portion 136c.

[0030] The outer periphery of the connecting portion 136c is fitted into the inner ring of the bearing 136b, and the outer ring of the bearing 136b is fitted into the inner wall of the housing portion 136a. This allows the connecting portion 136c to be rotatably supported in the housing portion 136a. This reduces the load on the motor 131 compared to when the connection portion between the output shaft of the motor 131 and the lead screw 135 is supported without the bearing 136b.

[0031] The housing portion 136a is annular and has through holes 139 penetrating the housing portion 136a. In this embodiment, six through holes 139 are provided at equal intervals around the circumference of the housing portion 136a, and an alignment portion 136d is inserted into each of the through holes 139. The alignment portions 136d are, for example, bolts, and the degree of contact between the alignment portions 136d and the outer ring of the bearing 136b can be adjusted by moving the alignment portions 136d radially around the housing portion 136a. By adjusting the degree of contact between each alignment portion 136d and the outer ring of the bearing 136b, the position of the axis of the output shaft of the motor 131 and the position of the axis of the lead screw 135 can be adjusted (approximately aligned). In other words, the connecting portion 136 has an alignment mechanism.

[0032] Returning to Fig. 5A, of the two ends of the lead screw 135, the end that is not connected to the output shaft of the motor 131 is rotatably supported by a lead screw support mechanism 140. Figs. 7A and 7B are diagrams for explaining the configuration of the lead screw support mechanism 140. Fig. 7A is an exploded view of the lead screw support mechanism 140, and Fig. 7B is a cross-sectional view of the lead screw support mechanism 140.

[0033] The lead screw support mechanism 140 is attached to the guide portion 112. The lead screw support mechanism 140 includes a housing portion 141, a compression spring 142, a backlash-removing member 143, a bearing 144, and a screw 145.

[0034] The housing portion 141 houses a compression spring 142, a backlash-removing member 143, and a bearing 144. A hole 141a into which a screw 145 is inserted is formed in the housing portion 141. The screw 145 is inserted into the hole 141a and prevents the bearing 144 from coming out of the housing portion 141.

[0035] The end of the lead screw 135 fits into the inner ring of the bearing 144, and the outer ring of the bearing 144 fits into the inner wall of the housing portion 141. As a result, the lead screw support mechanism 140 rotatably supports the lead screw 135 and can reduce frictional resistance when the lead screw 135 rotates. As a result, the load on the motor 131 can be reduced.

[0036] The compression spring 142 urges the outer ring of the bearing 144 toward the lead screw 135 via the backlash elimination member 143. More specifically, the backlash elimination member 143 has an outer edge portion 143a that comes into contact with the outer ring of the bearing 144 and an engaging portion 143b that engages with the compression spring 142, and the compression spring 142 urges the backlash elimination member 143 toward the lead screw 135, causing the outer edge portion 143a to urge the outer ring of the bearing 144 toward the lead screw 135. This makes it possible to suppress axial backlash caused by an axial internal gap of the bearing 144.

[0037] Next, the moving unit 120 will be described. As the lead screw 135 rotates, the moving unit 120 moves in the axial direction of the lead screw 135. FIGS. 8A to 8D are diagrams for explaining the configuration of the moving unit 120. Note that FIGS. 8A and 8B are perspective views of the moving unit 120 viewed from different directions, FIG. 8C is an exploded perspective view of the moving unit 120, and FIG. 8D is a cross-sectional view of the moving unit 120.

[0038] The moving portion 120 includes a support portion 121 , a cam groove engaging portion 122 corresponding to the first protrusion, a linear groove engaging portion 123 corresponding to the third protrusion, a lead screw engaging portion 124 , and a biasing portion 125 .

[0039] The support portion 121 supports the cam groove engaging portion 122 , the linear groove engaging portion 123 , the lead screw engaging portion 124 , and the biasing portion 125 .

[0040] The cam groove engaging portion 122 passes through the clearance groove 11a (see FIG. 2A) of the second fixed barrel 11 and engages with the first cam groove 20a (see FIG. 2B) of the zoom cam ring 20 (see FIG. 4B). As a result, when the moving portion 120 (cam groove engaging portion 122) moves in the axial direction of the lead screw 135, the zoom cam ring 20 rotates.

[0041] As shown in FIG. 8D , the cam groove engagement portion 122 includes a fixed portion 122a, an annular member 122b, and a bearing 122c. The fixed portion 122a is fixed to the support portion 121. The outer periphery of the fixed portion 122a is fitted into the inner ring of the bearing 122c. The outer ring of the bearing 122c is fitted into the inner wall of the annular member 122b. This allows the annular member 122b to be rotatably supported on the support portion 121. Because the annular member 122b is rotatable, friction when the cam groove engagement portion 122 moves within the first cam groove 20a of the zoom cam ring 20 is rolling friction. Because rolling friction is much smaller than sliding friction, the load on the motor 131 when the cam groove engagement portion 122 moves within the first cam groove 20a of the zoom cam ring 20 can be reduced compared to when the annular member 122b is not rotatable.

[0042] 9, the rectilinear groove engaging portion 123 engages with the rectilinear groove 112a of the guide portion 112. This allows the moving portion 120 to be guided in the axial direction of the lead screw 135. Note that FIG. 9 is a side view of the drive mechanism 100.

[0043] As shown in FIG. 8C , the linear groove engagement portion 123 includes a bearing 123a and an annular member 123b. The inner ring of the bearing 123a is fitted to the outer periphery of the protrusion 121a of the support portion 121. The outer ring of the bearing 123a is fitted to the inner wall of the annular member 123b. This allows the annular member 123b to be rotatably supported on the support portion 121. Because the annular member 123b is rotatable, the friction generated when the linear groove engagement portion 123 moves within the linear groove 112a is rolling friction. Therefore, compared to when the annular member 123b cannot rotate, the load on the motor 131 when the linear groove engagement portion 123 moves within the linear groove 112a can be reduced.

[0044] As shown in Fig. 8(D), the lead screw engagement portion 124 includes an annular member 124a and a bearing 124b. The outer periphery of the annular member 124a is fitted into the inner ring of the bearing 124b. A groove 127 that comes into contact with the thread groove of the lead screw 135 is formed on the inner periphery of the annular member 124a. The groove 127 is a circumferential groove formed around the entire inner periphery of the annular member 124a.

[0045] The annular member 124a is urged toward the lead screw 135 in a direction perpendicular to the axial direction of the lead screw 135, as shown by arrow A1 in FIG. 8D , by the urging portion 125, which is a leaf spring. As a result, the groove 127 of the annular member 124a is pressed against the thread groove of the lead screw 135, thereby suppressing backlash between the annular member 124a and the lead screw 135. Furthermore, a portion of the bearing 124b is housed in the housing portion 121b of the support portion 121, thereby connecting the support portion 121 and the lead screw engaging portion 124. Note that the annular member 124a may be urged toward the lead screw 135 by another urging member.

[0046] Because the annular member 124a is rotatably supported, when the lead screw 135 rotates, the annular member 124a is pushed by the flank surface of the thread groove of the lead screw 135 and moves in the axial direction of the lead screw 135 while rotating. As a result, the support portion 121 supporting the annular member 124a also moves in the axial direction of the lead screw 135, allowing the moving portion 120 to move in the direction of the optical axis OA. Furthermore, because the annular member 124a moves in the axial direction of the lead screw 135 while rotating, the friction generated between the annular member 124a and the lead screw 135 becomes rolling friction. This reduces the load on the motor 131 when moving the moving portion 120 in the axial direction of the lead screw 135. The structure disclosed in Japanese Patent Application No. 2021-156263 may be applied to the structure of the lead screw engagement portion 124.

[0047] Because the cam groove engaging portion 122 of the moving portion 120 is engaged with the first cam groove 20a of the zoom cam ring 20, when the moving portion 120 moves in the direction of the optical axis OA, causing the zoom cam ring 20 to rotate, the lens holding frame F3 moves linearly in the direction of the optical axis OA along the first linear groove 11b and the second cam groove 20b, and the lens holding frame F4 moves linearly in the direction of the optical axis OA along the second linear groove 11c and the third cam groove 20c. Because the zoom cam ring 20 is rotated using the first cam groove 20a, noise can be reduced compared to when the zoom cam ring 20 is rotated using gears.

[0048] As described above in detail, the lens barrel 2 according to this embodiment includes a moving unit 120 having a cam groove engaging portion 122, a driving unit 130 that moves the moving unit 120 linearly in the direction of the optical axis OA, a zoom cam ring 20 having a first cam groove 20a and a second cam groove 20b that engage with the cam groove engaging portion 122, and a lens retaining frame F3 that holds a lens group L3 and has cam pins 41 that engage with the second cam groove 20b. Movement of the moving unit 120 in the direction of the optical axis OA causes the zoom cam ring 20 to rotate, and the rotation of the zoom cam ring 20 causes the lens retaining frame F3 to move in the direction of the optical axis OA. Because the zoom cam ring 20 is rotated using the first cam groove 20a, noise generated when rotating the zoom cam ring 20 can be reduced compared to when the zoom cam ring 20 is rotated using gears.

[0049] In this embodiment, the moving section 120 includes a rectilinear groove engaging section 123, and the lens barrel 2 includes a guide section 112 having a rectilinear groove 112a that engages with the rectilinear groove engaging section 123. This allows the moving section 120 to move linearly in the direction of the optical axis OA.

[0050] Furthermore, in this embodiment, the cam groove engaging portion 122 (annular member 122b) is rotatable about the center of the cam groove engaging portion 122 as an axis. This reduces the load on the motor 131 when the cam groove engaging portion 122 moves within the first cam groove 20a, compared to when the cam groove engaging portion 122 (annular member 122b) is not rotatable. This allows the zoom cam ring 20 to rotate faster than when the cam groove engaging portion 122 (annular member 122b) is not rotatable (when sliding friction occurs) when using a motor 131 with the same output to rotate a zoom cam ring 20 of the same weight. Furthermore, for example, when using a motor 131 with the same output, it is possible to rotate a heavier zoom cam ring 20 than when the cam groove engaging portion 122 (annular member 122b) is supported so as not to rotate (when sliding friction occurs). Furthermore, when rotating a zoom cam ring 20 of the same weight, a motor 131 with a smaller output can be used than when the cam groove engagement portion 122 (annular member 122b) is supported so that it cannot rotate (when sliding friction occurs), and therefore the drive mechanism 100 can be made smaller.

[0051] Furthermore, in this embodiment, the linear groove engagement portion 123 (annular member 123b) is rotatable about the center of the linear groove engagement portion 123 as an axis. This reduces the load on the motor 131 when the linear groove engagement portion 123 moves within the linear grooves 112a, compared to when the linear groove engagement portion 123 (annular member 123b) is not rotatable. This allows the zoom cam ring 20 to rotate faster than when the linear groove engagement portion 123 (annular member 123b) is not rotatable (when sliding friction occurs) when using a motor 131 with the same output to rotate a zoom cam ring 20 of the same weight. Furthermore, for example, when using a motor 131 with the same output, it is possible to rotate a heavier zoom cam ring 20 than when the linear groove engagement portion 123 (annular member 123b) is supported so as not to rotate (when sliding friction occurs). Furthermore, when rotating a zoom cam ring 20 of the same weight, a motor 131 with a smaller output can be used than when the linear groove engagement portion 123 (annular member 123b) is supported so that it cannot rotate (when sliding friction occurs), and therefore the drive mechanism 100 can be made smaller.

[0052] Furthermore, in this embodiment, the moving part 120 has a plurality of linear groove engaging parts 123. This allows the moving part 120 to be stably guided in the optical axis OA direction.

[0053] In this embodiment, the zoom cam ring 20 further has a third cam groove 20c. The lens barrel 2 has a cam pin 42 that engages with the third cam groove 20c, and is equipped with a lens holder frame F4 that holds the lens group L4, and the lens holder frame F4 moves along the optical axis OA with rotation of the zoom cam ring 20. This allows the multiple lens groups L3 and L4 to be moved along the optical axis OA with a single motor 131, thereby reducing power consumption compared to when multiple motors are provided to drive multiple lens groups.

[0054] In this embodiment, the drive unit 130 includes a motor 131 having an output shaft and a lead screw 135. The output shaft and the lead screw 135 are connected by a connecting unit 136. The connecting unit 136 has an alignment mechanism that adjusts the position of the axis of the output shaft and the position of the axis of the lead screw 135. This makes it possible to reduce vibrations and noise caused by misalignment between the axis of the output shaft of the motor 131 and the axis of the lead screw 135.

[0055] In the above embodiment, the mechanisms shown in Figures 10(A) to 10(C) may be used as the mechanism for guiding the moving unit 120 in the direction of the optical axis OA. Figure 10(A) is a perspective view of a drive mechanism 100A according to Modification 1, and Figures 10(B) and 10(C) are perspective views showing a guide unit 112A, a moving unit 120A, and a lead screw support mechanism 140A according to Modification 1.

[0056] 10A, the guide portion 112A includes a guide bar 112b extending parallel to the axial direction of the lead screw 135. The guide bar 112b is supported by a lead screw support mechanism 140A.

[0057] 10B, two through holes 121c are provided in the support portion 121A of the moving portion 120A, and a guide bar 112b is inserted into each of the through holes 121c. As a result, the moving portion 120A is guided by the guide bars 112b in the axial direction of the lead screw 135 (i.e., the direction of the optical axis OA).

[0058] In the above embodiment, the zoom cam ring 20 is disposed on the outer periphery of the second fixed barrel 11, but this is not limitative. The zoom cam ring 20 may also be disposed on the inner periphery of the second fixed barrel 11.

[0059] In the above embodiment, a lens holding frame that holds a lens group different from lens groups L3 and L4 may be connected to the moving unit 120, and the lens holding frame may be moved in the direction of the optical axis OA by the moving unit 120. In other words, the moving unit 120 and the lens holding frame may be moved in the direction of the optical axis OA as a unit. In this way, the three lens holding frames can be moved linearly in the direction of the optical axis OA by a single motor 131.

[0060] In the above embodiment, the bearing 124b provided in the lead screw engagement portion 124 of the moving portion 120 is not limited to a bearing, and may be a rotatable rolling element like a bearing. Also, the bearing 124b and the annular member 124a may be integrated.

[0061] In the above embodiment, the lead screw engagement portion 124 of the moving portion 120 includes the annular member 124a and the bearing 124b, but this is not limited to this. The lead screw engagement portion 124 may include, for example, only the annular member 124a. In other words, the annular member 124a does not have to rotate.

[0062] In the above embodiment, the lead screw engaging portion 124 of the moving portion 120 may be a nut or a rack. Fig. 11A is a cross-sectional view of a moving portion 120B according to Modification 2. As shown in Fig. 11A, for example, a thread groove 128 that engages with the thread groove of the lead screw 135 over the entire circumference may be formed in the support portion 121B.

[0063] In the above embodiment, the linear groove engaging portion 123 of the moving portion 120 does not have to include the bearing 123a. That is, the annular member 123b may be supported so as not to rotate.

[0064] In the above embodiment, the output shaft of the motor 131 and the lead screw 135 are connected by the connecting portion 136 having an alignment mechanism, but this is not limited to this. Fig. 11(B) is a cross-sectional view showing a connecting portion 136A according to Modification 3.

[0065] 11B, the output shaft of the motor 131 and the lead screw 135 may be directly connected by, for example, a connecting portion 136A that does not have an alignment mechanism. Alternatively, the output shaft of the motor 131 and the lead screw 135 may be connected using an existing coupling (shaft joint).

[0066] 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.

[0067] REFERENCE SIGNS LIST 1 camera 2 lens barrel 11 second fixed barrel 20 zoom cam ring 20a first cam groove 20b second cam groove 20c third cam groove 41 cam pin 42 cam pin 120 moving portion 112 guide portion 112a rectilinear groove 122 cam groove engaging portion 123 rectilinear groove engaging portion 130 driving portion 131 motor 135 lead screw 136 connecting portion L3, L4 lens group F3, F4 lens holding frame OA optical axis

Claims

1. A moving part having a first protrusion; A drive unit that moves the moving unit linearly in the optical axis direction; a first cylinder having a first cam groove that engages with the first protrusion and a second cam groove; a first lens holding frame having a second protrusion that engages with the second cam groove and that holds a first lens; Equipped with The moving part moves in the optical axis direction to rotate the first cylinder, The first lens holding frame moves in the optical axis direction by the rotation of the first cylinder. Lens barrel.

2. The moving portion has a third protrusion, a guide portion having a linear groove that engages with the third protrusion, The lens barrel according to claim 1 .

3. The moving portion has a plurality of the third protrusions. The lens barrel according to claim 2 .

4. The third protrusion is rotatable about a center of the third protrusion. The lens barrel according to claim 2 or 3.

5. The first protrusion is rotatable about a center of the first protrusion. The lens barrel according to any one of claims 1 to 3.

6. The first cylinder further has a third cam groove, a second lens holding frame having a fourth protrusion that engages with the third cam groove and that holds a second lens; The second lens holding frame moves in the optical axis direction by the rotation of the first cylinder. The lens barrel according to any one of claims 1 to 3.

7. A second tube is provided on one of the outer circumferential side and the inner circumferential side of the first tube. The lens barrel according to any one of claims 1 to 3.

8. a third lens holding frame that holds a third lens; the third lens holding frame moves along the optical axis direction integrally with the moving portion; The lens barrel according to any one of claims 1 to 3.

9. the drive unit includes a motor having an output shaft and a lead screw; the output shaft and the lead screw are connected by a connection portion, The connection portion has an alignment mechanism for adjusting an axial center position of the output shaft and an axial center position of the lead screw. The lens barrel according to any one of claims 1 to 3.

10. An imaging device comprising the lens barrel according to any one of claims 1 to 3.