Lens barrel and imaging device

Abstract

To provide a lens barrel in which load on a drive source does not fluctuate.SOLUTION: The lens barrel comprises: a drive source mounted to a mounting portion; a first shaft rotated by the drive source; an engaging member engaging with the first shaft; a second shaft restricting the rotation of the engaging member and supported by the mounting portion; a lens holding frame abutting on the engaging member and holding the lens; an energizing member located between the lens holding frame and the engaging member; and a third shaft inserted into the energizing member and moving in the optical axis direction integrally with the lens holding frame and the energizing member. The first shaft does not penetrate the lens holding frame and penetrates the engaging member, the third shaft penetrates the engaging member, and the engaging member has, in at least an inner circumferential section enclosing the first shaft, a thread groove which engages with the first shaft.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] A mechanism has been proposed that uses a lead screw and a nut that engages with the lead screw to drive a focus lens (for example, see Patent Document 1). The focus lens needs to be moved with high precision. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-007938 Summary of the Invention

[0004] According to a first aspect, the lens barrel includes a drive source, a first shaft rotated by the drive source, an engagement member that engages with the first shaft, a second shaft that restricts the rotation of the engagement member, a lens holding frame that abuts against the engagement member and holds a lens, and a biasing member that is disposed between the lens holding frame and the engagement member.

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

[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. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram showing a camera including a lens barrel and a camera body according to an embodiment. [Figure 2]Figure 2(A) is a plan view of the fifth lens retaining frame and the drive source unit as seen from the camera body side, and Figure 2(B) is a plan view of the fifth lens retaining frame and the drive source unit as seen from the subject side. [Figure 3] Figure 3(A) is a side view of the fifth lens retaining frame and the drive source unit as viewed from the direction of arrow A in Figure 2(A), Figure 3(B) is a schematic plan view of the nut, and Figure 3(C) is a schematic oblique view of the first support part. [Figure 4] Figure 4(A) is a perspective view of the fifth lens retaining frame and the drive source unit as viewed from the direction of arrow B in Figure 2(A), and Figure 4(B) is a perspective view of the fifth lens retaining frame and the drive source unit as viewed from the direction of arrow C in Figure 2(A). [Figure 5] 5(A) and 5(B) are diagrams for explaining the shape of the fork portion of the first support portion. [Figure 6] Figures 6(A) and 6(B) are diagrams for explaining a drive source unit and a fifth lens retaining frame according to a comparative example, and Figures 6(C) and 6(D) are diagrams for explaining a drive source unit and a fifth lens retaining frame according to an embodiment. [Figure 7] 7(A) and 7(B) are schematic diagrams showing the relationship between the threads of the nut and the threads of the lead screw when the nut is not inclined with respect to a plane perpendicular to the axial direction of the lead screw. [Figure 8] 8(A) and 8(B) are schematic diagrams showing the relationship between the threads of the nut and the threads of the lead screw in the embodiment. [Figure 9] 9(A) and 9(B) are diagrams showing other examples of the shape of the fork portion of the first support portion. [Figure 10] 10(A) and 10(B) are diagrams illustrating a case where the fifth lens retaining frame and the sixth lens retaining frame collide with each other. DETAILED DESCRIPTION OF THE INVENTION

[0008] A lens barrel 100 according to one embodiment will be described in detail below with reference to the drawings. Fig. 1 is a diagram showing a camera 103 equipped with a lens barrel 100 according to this embodiment and a camera body 101. Note that in this embodiment, the lens barrel 100 is detachable from the camera body 101, but this is not limiting, and the lens barrel 100 and the camera body 101 may be integrated.

[0009] As shown in Fig. 1, the lens barrel 100 according to this embodiment includes a first lens group L1, a second lens group L2, a third lens group L3, a fourth lens group L4, a fifth lens group L5, and a sixth lens group L6, which are sequentially arranged along a common optical axis OA. In this embodiment, the fifth lens group L5 is a focus lens group. Although Fig. 1 shows each of the first lens group L1, the second lens group L2, the third lens group L3, the fourth lens group L4, the fifth lens group L5, and the sixth lens group L6 as being represented by a single lens, they may each be composed of multiple lenses.

[0010] The first lens group L1, the second lens group L2, the third lens group L3, the fourth lens group L4, the fifth lens group L5, and the sixth lens group L6 are held by the first lens holding frame F1, the second lens holding frame F2, the third lens holding frame F3, the fourth lens holding frame F4, the fifth lens holding frame F5, and the sixth lens holding frame F6, respectively.

[0011] Lens barrel 100 includes a fixed barrel 110. A lens mount 117 is fixed to fixed barrel 110, allowing lens barrel 100 to be attached to and detached from camera body 101. Fixed barrel 110 includes a first fixed barrel 111, a second fixed barrel 112, and a third fixed barrel 113. Lens barrel 100 also includes a zoom operation ring 150, a cam barrel 170, a first movable barrel 160, and a second movable barrel 180.

[0012] The zoom operation ring 150 is disposed on the outer periphery of the first fixed barrel 111. The zoom operation ring 150 is connected to the cam barrel 170 by a member not shown. When the zoom operation ring 150 is rotated, the cam barrel 170 moves linearly in the direction of the optical axis OA while rotating.

[0013] A first lens retaining frame F1 is fixed to the first movable barrel 160. The first movable barrel 160 is provided with a cam follower 161 that fits into a cam groove (not shown) of the zoom operation ring 150. Due to the fit between the cam groove of the zoom operation ring 150 and the cam follower 161 of the first movable barrel 160, the first lens retaining frame F1 moves linearly in the direction of the optical axis OA as the zoom operation ring 150 rotates. In other words, when the user rotates the zoom operation ring 150, the first lens retaining frame F1 moves in the direction of the optical axis OA.

[0014] The second lens retaining frame F2 and the third lens retaining frame F3 are fixed to the second moving barrel 180. The second moving barrel 180 is provided with cam followers 181 that fit into cam grooves (not shown) of the cam barrel 170. Due to the fit between the cam grooves of the cam barrel 170 and the cam followers 181 of the second moving barrel 180, the second lens retaining frame F2 and the third lens retaining frame F3 move linearly in the direction of the optical axis OA as the cam barrel 170 rotates. In other words, when the user rotates the zoom operation ring 150, the second lens retaining frame F2 and the third lens retaining frame F3 move in the direction of the optical axis OA.

[0015] The cam barrel 170 is provided with a cam groove (not shown) into which a cam follower 171 provided on the outer periphery of the fourth lens retaining frame F4 fits, and a cam groove (not shown) into which a cam follower (not shown) provided on the outer periphery of the sixth lens retaining frame F6 fits. As a result, the fourth lens retaining frame F4 and the sixth lens retaining frame F6 move linearly in the direction of the optical axis OA as the cam barrel 170 rotates. In other words, when the user rotates the zoom operation ring 150, the fourth lens retaining frame F4 and the sixth lens retaining frame F6 move in the direction of the optical axis OA.

[0016] The fifth lens retaining frame F5 is driven by a drive source unit 200. The fifth lens retaining frame F5 and the drive source unit 200 will be described in detail below.

[0017] Fig. 2(A) is a plan view of the fifth lens retaining frame F5 and the drive source unit 200 as viewed from the camera body 101 side, and Fig. 2(B) is a plan view of the fifth lens retaining frame F5 and the drive source unit 200 as viewed from the subject side. Fig. 3(A) is a side view of the fifth lens retaining frame F5 and the drive source unit 200 as viewed from the direction of arrow A in Fig. 2(A), Fig. 3(B) is a schematic plan view of the nut, and Fig. 3(C) is a schematic perspective view of the first support portion 210a. Fig. 4(A) is a perspective view of the fifth lens retaining frame F5 and the drive source unit 200 as viewed from the direction of arrow B in Fig. 2(A), and Fig. 4(B) is a perspective view of the fifth lens retaining frame F5 and the drive source unit 200 as viewed from the direction of arrow C in Fig. 2(A). 5(A) and 5(B) are diagrams for explaining the shape of the first support portion 210a, which will be described later. Note that in each diagram, some elements may be omitted from the illustration in order to make it easier to understand.

[0018] First, we will explain the drive source unit 200. The drive source unit 200 is attached to the fourth lens retaining frame F4. As shown in Figures 1 and 3(A), the drive source unit 200 includes a stepping motor 201, a lead screw 202, a nut 203, an attachment member 205, and a rotation restriction bar 204.

[0019] The mounting member 205 is a U-shaped member and has a first portion 205a fixed to the stepping motor 201, a second portion 205b facing the first portion 205a, and a third portion 205c extending parallel to the lead screw 202 between the first portion 205a and the second portion 205b. A plurality of holes 205d are formed in the third portion 205c as shown in Figures 4(A) and 4(B), and the drive source unit 200 is fixed to the fourth lens retaining frame F4 by fastening the mounting member 205 to the fourth lens retaining frame F4 with screws or the like.

[0020] The rotation restriction bar 204 is supported at one end by the first part 205a of the mounting member 205 and at the other end by the second part 205b of the mounting member 205 so as to be parallel to the lead screw 202, i.e., extend in the direction of the optical axis OA.

[0021] The lead screw 202 is directly connected to the output shaft of the stepping motor 201 and extends in the direction of the optical axis OA. The tip of the lead screw 202 is rotatably supported by the second portion 205b of the mounting member 205. Since the tip of the lead screw 202 is rotatably supported by the second portion 205b of the mounting member 205, runout of the tip is suppressed.

[0022] A nut 203 is threaded onto the lead screw 202. As shown in FIG. 3(B), the nut 203 has a nut portion 203a that engages with the thread groove of the lead screw 202, a fork portion 203b that engages with the rotation restriction bar 204, and a hole 203d that engages with a spring support shaft 230 (described later). The fork portion 203b is bifurcated and holds the rotation restriction bar 204 therebetween. That is, a U-shaped groove is formed by the fork portion 203b, and this U-shaped groove engages with the rotation restriction bar 204. As a result, the rotation of the nut 203 is restricted by the rotation restriction bar 204, and when the lead screw 202 is rotated by the stepping motor 201, the nut 203 moves linearly in the direction of the optical axis OA.

[0023] Next, the configuration of the fifth lens retaining frame F5 will be described. As shown in Figures 2(A) and 2(B), the fifth lens retaining frame F5 has a cylindrical portion 240 that retains the fifth lens group L5, and the outer periphery of the cylindrical portion 240 is provided with a first guide portion 210 for guiding the fifth lens retaining frame F5 in the optical axis OA direction and a second guide portion 220 for suppressing movement of the fifth lens retaining frame F5 in the rotational direction.

[0024] 3(A), 4(A), 4(B), etc., the first guide portion 210 and the second guide portion 220 extend in the optical axis OA direction, and a through hole 211 that passes through the first guide portion 210 and a through hole 221 that passes through the second guide portion 220 in the optical axis OA direction are formed. A guide bar that is fixed to the fourth lens retaining frame F4 and guides the fifth lens retaining frame F5 in the optical axis OA direction is inserted into the through hole 211. In addition, a guide bar that is fixed to the fourth lens retaining frame F4 and suppresses movement of the fifth lens retaining frame F5 in the rotational direction is inserted into the through hole 221.

[0025] 2(A), 2(B), 3(A), and 4(B), the first guide portion 210 has a first support portion 210a and a second support portion 210b extending in the circumferential direction from the first guide portion 210. A spring support shaft 230 inserted through a hole 203d (see FIG. 3(B)) of the nut 203 and the torsion spring 300 is held between the first support portion 210a and the second support portion 210b.

[0026] 3(C), the first support portion 210a has a hole 214 into which the spring support shaft 230 fits, and a fork portion 213 at least a portion of which abuts against the nut 203. The fork portion 213 is bifurcated and sandwiches the lead screw 202. A surface 212 of the fork portion 213 facing the nut 203 is inclined with respect to a plane perpendicular to the axis AX of the lead screw 202 when the drive source unit 200 is assembled. This will be described in detail later.

[0027] The spring support shaft 230 extends parallel to the lead screw 202, i.e., in the direction of the optical axis OA. The spring support shaft 230 is inserted through the hole 203d of the nut 203 and the torsion spring 300. The length of the spring support shaft 230 in the direction of the optical axis OA is shorter than that of the lead screw 202.

[0028] The torsion spring 300 is disposed between the nut 203 and the second support portion 210b of the fifth lens retaining frame F5. The torsion spring 300 biases the second support portion 210b and the nut 203 in a direction that separates the second support portion 210b and the nut 203 from each other. As a result, the first support portion 210a is pressed against the nut 203, and the nut 203 is pressed toward the first support portion 210a by the compression load of the torsion spring 300, as shown by arrow A1 in FIG. 5(A).

[0029] Because the first support portion 210a is pressed against the nut 203, when the nut 203 moves in the optical axis OA direction, the fifth lens retaining frame F5 moves together with the nut 203 in the optical axis OA direction. At this time, because the torsion spring 300 is supported by the spring support shaft 230 supported by the first support portion 210a and the second support portion 210b of the fifth lens retaining frame F5, when the fifth lens retaining frame F5 moves in the optical axis OA direction, the torsion spring 300 moves together with the fifth lens retaining frame F5 in the optical axis OA direction. For this reason, even if the position of the fifth lens retaining frame F5 changes, the spring load of the torsion spring 300 does not change. This point will be explained in detail.

[0030] Figures 6(A) and 6(B) are diagrams for explaining a drive source unit 500 and a fifth lens retaining frame F5' according to a comparative example, and Figures 6(C) and 6(D) are diagrams for explaining a drive source unit 200 and a fifth lens retaining frame F5 according to this embodiment. Figures 6(A) and 6(C) show the case where the fifth lens group is at the close position, and Figures 6(B) and 6(D) show the case where the fifth lens group is at the infinity position.

[0031] In Figure 6(A), a drive source unit 500 according to the comparative example has a stepping motor 501, a lead screw 502 rotated by the stepping motor 501, a nut 503 engaged with the lead screw 502, a rotation restriction bar 504 that restricts the rotation of the nut 503, an attachment member 505, and a guide shaft 506.

[0032] The fifth lens retaining frame F5' engages with the guide shaft 506, and a compression spring 507 is disposed between the mounting member 505 and the fifth lens retaining frame F5'. The compression spring 507 biases the fifth lens retaining frame F5' toward the nut 503, so when the nut 503 moves in the direction of the optical axis OA, the fifth lens retaining frame F5' moves integrally with the nut 503 in the direction of the optical axis OA.

[0033] In this case, in the comparative example, as shown in FIGS. 6A and 6B, when the position of the fifth lens group L5′ changes, the length of the compression spring 507 changes, and the spring load of the compression spring 507 fluctuates between the state shown in FIG. 6A and the state shown in FIG. 6B. In the comparative example, the closer the fifth lens group L5′ is to the stepping motor 501, the greater the spring load of the compression spring 507. Therefore, the amount of power required by the stepping motor 501 to move the fifth lens group L5′ when the fifth lens group L5′ is close to the stepping motor 501 differs from the amount of power required by the stepping motor 501 to move the fifth lens group L5′ when the fifth lens group L5′ is far from the stepping motor 501, making it difficult to move the fifth lens group L5′ with precision. Furthermore, depending on the weight of the fifth lens group L5′, it may be difficult to move the fifth lens group L5′ with the torque of the stepping motor 501.

[0034] 6(C) and 6(D), in this embodiment, the torsion spring 300 moves integrally with the fifth lens retaining frame F5, and the length of the torsion spring 300 does not change, so the spring load of the torsion spring 300 does not change with the movement of the fifth lens retaining frame F5. Therefore, the load on the stepping motor 201 is constant, and the fifth lens group L5 can be moved with high precision. Furthermore, even if the fifth lens group L5 is heavy, the fifth lens group L5 can be moved by the stepping motor 201.

[0035] As shown in Fig. 5(A), one end 300a of torsion spring 300 is engaged with notch 203e formed on the outer surface of nut 203. The other end of torsion spring 300 is engaged with, for example, a spring retainer formed on second support portion 210b. As a result, nut 203 is pressed toward lead screw 202 by the torsional load of torsion spring 300, as shown by arrow A2 in Fig. 5(A).

[0036] 5(A), surface 212 of fork portion 213 on the nut 203 side has a slope that is inclined with respect to a plane perpendicular to the direction of axis AX of lead screw 202, and the tip of fork portion 213 does not abut on nut 203 but is spaced apart from nut 203. More specifically, as shown in FIG. 5(B), if, on surface 212 of first support portion 210a, the tip of fork portion 213 is defined as P1 and the position where fork portion 213 contacts nut 203 is defined as P2, the angle θ formed by a straight line LN1 that passes through P1 and is perpendicular to axis AX of lead screw 202 and a straight line LN2 that connects P1 and P2 is larger than the lead angle β of the thread groove of lead screw 202. As a result, a moment acts on the nut 203 with P2 as a fulcrum, as indicated by arrow A3, and the nut 203 engages with the lead screw 202 in a state inclined relative to the lead screw 202 (a state inclined relative to a direction perpendicular to the lead screw 202). This reduces play between the nut 203 and the lead screw 202, improving the accuracy of position control of the fifth lens group L5, which moves in conjunction with movement of the nut 203 in the direction of the optical axis OA. This point will be described in detail below.

[0037] 7(A) and 7(B) are schematic diagrams showing the relationship between the threads of the nut 203 and the threads of the lead screw 202 when the nut 203 is not inclined with respect to a plane perpendicular to the axis AX direction of the lead screw 202. Also, Figures 8(A) and 8(B) are schematic diagrams showing the relationship between the threads of the nut 203 and the threads of the lead screw 202 in this embodiment.

[0038] For example, a case will be described in which nut 203 is moved in the direction indicated by arrow A15 in FIG. 7A and then moved in the opposite direction to arrow A15 (the direction indicated by arrow A16 in FIG. 7B). In this case, when nut 203 is moved in the direction indicated by arrow A15, the surface of the thread of nut 203 facing the camera body 101 and the surface of the thread of lead screw 202 facing the subject are in contact with each other above and below axis AX of lead screw 202, as indicated by ellipse C1 in FIG. 7A. This means that there is no delay in the movement of nut 203 relative to the output of stepping motor 201. At this time, a gap is generated between the surface of the thread of nut 203 facing the subject and the surface of the thread of lead screw 202 facing the camera body 101, as indicated by ellipse C2 in FIG. 7A. Therefore, when the direction in which the nut 203 is moved is reversed (when the rotation of the lead screw is reversed), even if the lead screw 202 rotates, the nut 203 does not start moving in the direction of arrow A16 until the surface of the thread of the nut 203 facing the subject and the surface of the thread of the lead screw 202 facing the camera body 101 come into contact as shown by ellipse C3 in Figure 7(B). As a result, the movement of the nut 203 is delayed relative to the output of the stepping motor 201. In other words, because there is play between the nut 203 and the lead screw 202 as shown by ellipse C2, a delay occurs when the movement direction of the nut 203 is reversed.

[0039] 8(A) and 8(B), the nut 203 is inclined with respect to the lead screw 202, thereby reducing backlash between the nut 203 and the lead screw 202. That is, in FIG. 8(A), the surface of the thread of the nut 203 facing the subject and the surface of the thread of the lead screw 202 facing the camera body 101 come into contact with each other above the axis AX, as shown by the ellipse C5, and the surface of the thread of the nut 203 facing the camera body 101 come into contact with the surface of the thread of the lead screw 202 facing the subject, as shown by the ellipse C6, below the axis AX. As a result, when the nut 203 is moved in the direction of arrow A11, the surface of the thread of the nut 203 facing the camera body 101 and the surface of the thread of the lead screw 202 facing the subject come into contact with each other below the axis AX, as shown by the ellipse C6 in FIG. 8(A), so there is no delay in the movement of the nut 203 relative to the output of the stepping motor 201. 8(B), the surface of the thread of the nut 203 facing the camera body 101 and the surface of the thread of the lead screw 202 facing the subject are in contact with each other above the axis AX, so there is no delay in the movement of the nut 203 relative to the output of the stepping motor 201. In other words, whether the nut 203 is moved in the direction of arrow A11 or arrow A12, there is a portion where the thread of the nut 203 and the thread of the lead screw 202 are in contact with each other, so there is no delay in the movement of the nut 203 relative to the output of the stepping motor 201. This improves the accuracy of position control of the fifth lens group L5.

[0040] Note that surface 212 does not have to be an inclined surface as long as it is located farther from nut 203 than the plane defined by the straight line LN2 connecting P1 and P2. For example, surface 212 may be formed in a stepped shape as shown in Fig. 9(A). Furthermore, surface 212 may be formed in a multi-step stepped shape as shown in Fig. 9(B).

[0041] As described above in detail, the lens barrel 100 according to this embodiment includes a stepping motor 201, a lead screw 202 rotated by the stepping motor 201, a nut 203 engaged with the lead screw 202, a rotation restriction bar 204 restricting rotation of the nut 203, a fifth lens retaining frame F5 that abuts against the nut 203 and holds the fifth lens group L5, and a torsion spring 300 disposed between the fifth lens retaining frame F5 and the nut 203. This allows the fifth lens retaining frame F5 and the torsion spring 300 to move integrally, so that even if the fifth lens retaining frame F5 moves (even if the position of the fifth lens retaining frame F5 changes), the compression load of the torsion spring 300 does not fluctuate. This allows the load on the stepping motor 201 to be constant. Furthermore, even if the fifth lens group L5 is heavy, the fifth lens group L5 can be moved by the stepping motor 201.

[0042] Furthermore, in this embodiment, lens barrel 100 includes spring support shaft 230 that is inserted through torsion spring 300 and moves in the direction of optical axis OA together with fifth lens retaining frame F5 and torsion spring 300. This allows torsion spring 300 to be stably supported.

[0043] In addition, in this embodiment, the nut 203 has a nut portion 203a that engages with the lead screw 202. It is also possible to use a lead screw and a rack member with teeth that mesh with the lead screw as a mechanism for driving a camera lens. However, when a rack member is used, impact may cause teeth to jump or the teeth of the rack member to come off the lead screw. On the other hand, in this embodiment, the nut 203 is threadedly engaged with the lead screw 202 via the nut portion 203a. Therefore, for example, even if the fourth lens frame F4 and the sixth lens frame F6, which are arranged before and after the fifth lens frame F5, collide with the fifth lens frame F5, teeth will not jump due to the impact. Furthermore, the nut 203 will not come off the lead screw 202. This improves reliability when the fifth lens frame F5 is subjected to an impact.

[0044] In this embodiment, the lens barrel 100 includes a fourth lens frame F4 and a sixth lens frame F6 that are movable in the optical axis OA direction. When the fourth lens frame F4 or the sixth lens frame F6 collides with the fifth lens frame F5, the fifth lens frame F5 is movable relative to the nut 203. Specifically, suppose that a camera user turns off the camera in the state shown in FIG. 10(A) and then operates the zoom operation ring 150, causing the sixth lens frame F6 to collide with the fifth lens frame F5, as shown in FIG. 10(B). In this case, the torsion spring 300 disposed between the nut 203 and the fifth lens frame F5 contracts, causing the fifth lens frame F5 to move relative to the nut 203. This prevents damage to the fifth lens frame F5. Although a force is applied from the torsion spring 300 to the nut 203 upon collision, this does not affect the stepping motor 201 because the camera is turned off.

[0045] Furthermore, in this embodiment, the nut 203 is inclined with respect to a plane perpendicular to the axis AX direction of the lead screw 202. This reduces play between the nut 203 and the lead screw 202, improving the accuracy of the response of the nut 203 to the output of the stepping motor 201. This improves the accuracy of position control of the fifth lens group L5. This point will be described in detail.

[0046] In the above embodiment, the first guide portion 210 includes the first support portion 210a and the second support portion 210b. However, the first guide portion 210 does not necessarily have to include the first support portion 210a and the second support portion 210b. For example, the outer periphery of the tube portion 240 of the fifth lens retaining frame F5 may be provided with the second support portion 210b extending radially outward from the tube portion 240, and an extension portion extending from the second support portion 210b in the optical axis OA direction may be provided, and the first support portion 210a may be provided extending from the extension portion so as to face the second support portion 210b. Furthermore, for example, the outer periphery of the tube portion 240 of the fifth lens retaining frame F5 may be provided with a substantially U-shaped member including the first support portion 210a and the second support portion 210b.

[0047] 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. [Explanation of symbols]

[0048] 100 Lens barrel 101 Camera Body 103 Camera 201 Stepping motor 202 lead screw 203 Nut 203a Nut part 204 Rotation control bar 210 1st Information Department 210a 1st support part 210b Second support part 230 Spring support shaft 300 Torsion Spring L5 Fifth lens group F4 4th lens holder F5 5th lens holder F6 6th lens holder

Claims

1. a drive source attached to the attachment portion; a first shaft rotated by the drive source; an engaging member that engages with the first shaft; a second shaft that restricts rotation of the engaging member and is supported by the mounting portion; a lens holding frame that abuts against the engaging member and holds a lens; a biasing member disposed between the lens holding frame and the engaging member; a third shaft that is inserted into the biasing member and moves in the optical axis direction together with the lens holding frame and the biasing member; Equipped with the first shaft does not pass through the lens holding frame but passes through the engaging member; the third shaft passes through the engagement member, The engaging member has a thread groove that engages with the first shaft on at least a portion of an inner circumferential surface surrounding the first shaft.

2. A driving source; a first shaft rotated by the drive source; an engaging member that engages with the first shaft; a cylindrical second shaft that restricts rotation of the engaging member; a lens holding frame that abuts against the engaging member and holds a lens; a biasing member disposed between the lens holding frame and the engaging member; a third shaft that is inserted into the biasing member and moves in the optical axis direction together with the lens holding frame and the biasing member; Equipped with the first shaft does not pass through the lens holding frame but passes through the engaging member; the third shaft passes through the engagement member, the second axis is disposed outside the first axis in a radial direction of a circle centered on the optical axis of the lens, The engaging member has a thread groove around the entire circumference that engages with the first shaft.

3. The lens holding frame moves in the optical axis direction, The biasing member moves in the optical axis direction together with the lens holding frame.

3. The lens barrel according to claim 1 or 2.

4. The third axis is shorter than the first axis. The lens barrel according to any one of claims 1 to 3.

5. the lens holding frame engages with the third shaft; The lens barrel according to any one of claims 1 to 4.

6. The engaging member has a hole that engages with the first shaft, a second engaging portion that engages with the second shaft, and a third engaging portion through which the third shaft passes. The lens barrel according to any one of claims 1 to 5.

7. The hole does not have a notch. The lens barrel according to claim 6.

8. a moving frame that is movable in the optical axis direction, When the moving frame collides with the lens holding frame, the lens holding frame is movable relative to the engaging member. The lens barrel according to any one of claims 1 to 7.

9. In the lens holding frame, a contact portion that contacts the engaging member has a slope that is inclined with respect to a plane perpendicular to the axial direction of the first shaft. The lens barrel according to any one of claims 1 to 8.

10. the first shaft has a screw groove; The inclination angle of the inclined surface is larger than the lead angle of the thread groove. The lens barrel according to claim 9.

11. The engaging member is inclined with respect to a plane perpendicular to the axial direction of the first shaft. The lens barrel according to any one of claims 1 to 10.

12. An imaging device comprising the lens barrel according to any one of claims 1 to 11.

Images