Lens barrel and imaging device

Abstract

The lens barrel includes: a moving portion having a first protruding portion; a drive unit that moves the moving unit in a straight direction in the optical axis direction; a first cylinder having a first cam groove and a second cam groove, the first cam groove engaging with the first protrusion; and a first lens holding frame which has a second protruding portion that engages with the second cam groove and holds a first lens, the first cylinder being rotated by the movement portion moving in the optical axis direction, and the first lens holding frame being moved in the optical axis direction by the rotation of the first cylinder.

Description

Technical Field

[0001] The present invention relates to a lens barrel and a photographing device. Background Art

[0002] In a photographing device that performs zooming by linearly moving a plurality of lens groups in the optical axis direction using a cam ring, a mechanism for rotating the cam ring using an actuator has been proposed (for example, Patent Document 1). Quiet operation is desired when rotating the cam ring using an actuator.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2019-133009 Summary of the Invention

[0006] According to a first aspect, a lens barrel includes: a moving part having a first protrusion; a driving part that linearly moves the moving part in the optical axis direction; a first cylinder having a first cam groove and a second cam groove, the first cam groove engaging with the first protrusion; and a first lens holding frame having a second protrusion that engages with the second cam groove and holding a first lens. By moving the moving part in the optical axis direction, the first cylinder rotates, and by the rotation of the first cylinder, the first lens holding frame moves in the optical axis direction.

[0007] According to a second aspect, a photographing device includes the above-described lens barrel.

[0008] In addition, the structure of the embodiments described later can be appropriately modified, and at least a part thereof can be replaced with other structures. Furthermore, structural elements that are not particularly limited in terms of their configuration are not limited to the configurations disclosed in the embodiments and can be arranged at positions where their functions can be achieved. Brief Description of the Drawings

[0009] Figure 1 It is a cross-sectional view showing the structure of a camera including a lens barrel according to one embodiment.

[0010] Figure 2 (A) of is a perspective view of a second fixed cylinder, Figure 2 and (B) of is a perspective view of a zoom cam ring.

[0011] Figure 3 (A) of is a perspective view of a zoom rotation limiting ring, Figure 3 and (B) of is a perspective view showing the relationship between the second fixed cylinder, the zoom cam ring, and the zoom rotation limiting ring.

[0012] Figure 4 (A) of is a perspective view showing the structure of a lens holding frame,Figure 4 Figure (B) is a perspective view showing the relationship among the cam pin, the second fixed cylinder, and the zoom cam ring.

[0013] Figure 5 Figure (A) is a perspective view showing the drive mechanism in an exploded state, Figure 5 Figure (B) is a perspective view showing the drive mechanism in an assembled state.

[0014] Figure 6 Figure (A) is a perspective view illustrating the structure of the connecting portion, Figure 6 Figure (B) is a cross-sectional view illustrating the structure of the connecting portion.

[0015] Figure 7 Figure (A) and Figure 7 Figure (B) are diagrams for explaining the structure of the lead screw support mechanism.

[0016] Figure 8 Figure (A) to Figure 8 Figure (D) are diagrams for explaining the structure of the moving portion.

[0017] Figure 9 is a side view of the drive mechanism.

[0018] Figure 10 Figure (A) is a perspective view of the drive mechanism of Modification 1, Figure 10 Figure (B) and Figure 10 Figure (C) are diagrams for explaining the structure of the drive mechanism of Modification 1.

[0019] Figure 11 Figure (A) is a cross-sectional view of the moving portion of Modification 2, Figure 11 Figure (B) is a cross-sectional view of the connecting portion of Modification 3. Detailed Description of the Embodiment

[0020] Hereinafter, the lens barrel of the embodiment will be described in detail with reference to the drawings. In addition, the scales of the shapes, lengths, thicknesses, etc. of the respective portions shown in the embodiment are not necessarily the same as those of the actual product. Further, in each drawing, for ease of understanding, sometimes the illustration of a part of the elements is omitted. Also, sometimes the hatching of a part of the elements is omitted in the cross-sectional view.

[0021] Figure 1 is a cross-sectional view showing the structure of the camera 1 including the lens barrel 2 of one embodiment. The WIDE (wide-angle) state is shown above the center line, and the TELE (telephoto) state is shown below the center line.

[0022] As Figure 1As shown in the figure, 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 (base end portion), and is detachably attached to the camera body 3 by engaging with a body mount (not shown) of the camera body 3. In addition, in the present embodiment, the lens barrel 2 can be detached from and attached to the camera body 3, but is not limited thereto, and the lens barrel 2 and the camera body 3 may also be integrated.

[0023] The camera body 3 includes a photographing element IS and a control unit (not shown) inside. The photographing element IS is composed of a photoelectric conversion element such as a CCD (Charge Coupled Device), and converts a subject image imaged by an imaging optical system (the lens barrel 2 attached to the camera body 3) into an electric signal.

[0024] The control unit includes a CPU (Central Processing Unit) and the like, and uniformly controls the operations of the entire camera 1 related to photography, including focus driving, in the camera body 3 and the attached lens barrel 2.

[0025] As Figure 1 shown, the lens barrel 2 of the present 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 cylinder 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 the present embodiment, the lens groups L3 and L4 are zoom lens groups that move in the direction of the optical axis OA during zooming.

[0026] In addition, in the present embodiment, the first fixed cylinder 10 is composed of a plurality of components, but may also be composed of a single component. In addition, each of the lens groups L1 to L4 may be composed of one lens or a plurality of lenses. In addition, a lens barrel having four lens groups is taken as an example for description, but the number of lens groups may be three or less or five or more.

[0027] The lens barrel 2 includes a second fixed cylinder 11, a zoom cam ring 20 disposed on the outer peripheral side of the second fixed cylinder 11, and a zoom rotation limiting ring 30 disposed on the outer peripheral side of the zoom cam ring 20.

[0028] Figure 2 (A) of [Figure number] is a perspective view of the second fixed cylinder 11, Figure 2 and (B) of [Figure number] is a perspective view of the zoom cam ring 20. Figure 3 (A) of [Figure number] is a perspective view of the zoom rotation limiting ring 30, Figure 3 and (B) of [Figure number] is a perspective view showing the relationship between the second fixed cylinder 11, the zoom cam ring 20, and the zoom rotation limiting ring 30.

[0029] AsFigure 2 As shown in (A) of FIG. , the second fixed cylinder 11 has a retraction groove 11a, a first straight groove 11b, and a second straight groove 11c. The retraction groove 11a, the first straight groove 11b, and the second straight groove 11c extend in a direction parallel to the optical axis OA. One retraction groove 11a is provided in the circumferential direction of the second fixed cylinder 11, three first straight grooves 11b are provided in the circumferential direction, and three second straight grooves 11c are provided in the circumferential direction. The number of the first straight grooves 11b and the second straight grooves 11c is not limited to three, and may be two or less or four or more.

[0030] As Figure 2 shown in (B) of FIG. , the zoom cam ring 20 has 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.

[0031] As Figure 3 shown in (A) of FIG. , the zoom rotation limiting ring 30 has a cutout portion 30a.

[0032] As Figure 3 shown in (B) of FIG. , the second fixed cylinder 11, the zoom cam ring 20, and the zoom rotation limiting ring 30 are arranged in order from the inner peripheral side. The zoom cam ring 20 and the zoom rotation limiting ring 30 are arranged such that the zoom rotation limiting pin 20d of the zoom cam ring 20 is located in the cutout portion 30a of the zoom rotation limiting ring 30. That is, when the zoom cam ring 20 rotates by a predetermined amount around the optical axis OA, the zoom rotation limiting pin 20d contacts the end portion of the cutout portion 30a. That is, the rotation of the zoom cam ring 20 around the optical axis OA is restricted by the cutout portion 30a.

[0033] Figure 4 (A) of FIG. is a perspective view showing the structures of the lens holding frames F3 and F4. As Figure 1 shown, the lens holding frames F3 and F4 are arranged inside the second fixed cylinder 11. As Figure 4 shown in (A) of FIG. , on the outer peripheral surface of the lens holding frame F3, three cam pins 41 protruding in a direction crossing the optical axis OA direction are provided in the circumferential direction. In addition, on the outer peripheral surface of the lens holding frame F4, three cam pins 42 protruding in a direction crossing the optical axis OA direction are provided in the circumferential direction. The number of the cam pins 41 and the cam pins 42 is not limited to three, and may be two or less or four or more. Further, the cam pin 41 corresponds to the second protrusion, and the cam pin 42 corresponds to the fourth protrusion.

[0034] Figure 4 (B) of FIG. is a perspective view showing the relationship between the cam pins 41 and 42, the second fixed cylinder 11, and the zoom cam ring 20.

[0035] The cam pin 41 of the lens holding frame F3 penetrates through the first straight groove 11b of the second fixed cylinder 11 and engages with the second cam groove 20b of the zoom cam ring 20. Thus, when the zoom cam ring 20 rotates, the lens holding frame F3 linearly moves in the direction of the optical axis OA along the first straight groove 11b and the second cam groove 20b.

[0036] The cam pin 42 of the lens holding frame F4 penetrates through the second straight groove 11c of the second fixed cylinder 11 and engages with the third cam groove 20c of the zoom cam ring 20. Thus, when the zoom cam ring 20 rotates, the lens holding frame F4 linearly moves in the direction of the optical axis OA along the second straight groove 11c and the third cam groove 20c.

[0037] Next, the driving (rotation) of the zoom cam ring 20 will be described. The zoom cam ring 20 is driven by a driving mechanism 100 fixed to the inside of the second fixed cylinder 11. Figure 5 FIG. (A) is a perspective view of the driving mechanism 100 showing an exploded state, Figure 5 FIG. (B) is a perspective view of the driving mechanism 100 showing an assembled state.

[0038] As shown in Figure 5 FIG. (A), the driving mechanism 100 includes a main body portion 150 and a support portion 110 that supports the main body portion 150. The support portion 110 includes a motor support portion 111, a guide portion 112, and a lead screw support mechanism 140. The motor support portion 111 supports the motor 131 provided in the main body portion 150. The guide portion 112 engages with a straight groove engaging portion 123 provided in a moving portion 120 to be described later, and has a straight groove 112a that guides the moving portion 120 along the axial direction of the lead screw 135. In addition, the support portion 110 is fixed to the second fixed cylinder 11 such that the axis of the lead screw 135 is parallel to the optical axis OA.

[0039] The main body portion 150 includes a driving portion 130 and a moving portion 120. The driving portion 130 includes a motor 131 and a lead screw 135. As the motor 131, for example, a stepping motor or an ultrasonic motor can be used.

[0040] In the present embodiment, the output shaft of the motor 131 and the lead screw 135 are connected by a connecting portion 136. Figure 6 FIG. (A) is a perspective view illustrating the structure of the connecting portion 136, Figure 6 FIG. (B) is a cross-sectional view illustrating the structure of the connecting portion 136.

[0041] As shown in Figure 6 FIG. (A), the connecting portion 136 includes a connecting portion 136c, a bearing 136b, a housing portion 136a, and an alignment portion 136d. The connecting portion 136c connects the output shaft of the motor 131 and the lead screw 135. Specifically, asFigure 6 As shown in (B) of FIG. [Reference numeral], a connecting member 137 is mounted on the output shaft of the motor 131. By inserting one end portions of the connecting member 137 and the lead screw 135 into the connecting portion 136c, the output shaft of the motor 131 is connected (coupled) to the lead screw 135.

[0042] The outer periphery of the connecting portion 136c is fitted with the inner ring of the bearing 136b, and the outer ring of the bearing 136b is fitted with the inner wall of the housing portion 136a. Thus, the connecting portion 136c is rotatably supported by the housing portion 136a. Accordingly, compared with the case where the connecting portion between the output shaft of the motor 131 and the lead screw 135 is supported without passing through the bearing 136b, the load applied to the motor 131 can be reduced.

[0043] The housing portion 136a is annular and has a through hole 139 penetrating the housing portion 136a. In the present embodiment, six through holes 139 are provided at equal intervals in the circumferential direction of the housing portion 136a, and a centering portion 136d is inserted into each through hole 139. The centering portion 136d is, for example, a bolt. By moving the centering portion 136d in the radial direction of the housing portion 136a, the contact degree between the centering portion 136d and the outer ring of the bearing 136b can be adjusted. By adjusting the contact degree between each centering 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 (to be approximately the same). That is, the connecting portion 136 has a centering mechanism.

[0044] Return Figure 5 In (A) of FIG. [Reference numeral], one end portion of the two end portions of the lead screw 135 that is not connected to the output shaft of the motor 131 is rotatably supported by a lead screw support mechanism 140. Figure 7 In (A) of FIG. [Reference numeral] and Figure 7 (B) of FIG. [Reference numeral] are diagrams for explaining the structure of the lead screw support mechanism 140. Figure 7 (A) of FIG. [Reference numeral] is an exploded view of the lead screw support mechanism 140, Figure 7 and (B) of FIG. [Reference numeral] is a cross-sectional view of the lead screw support mechanism 140.

[0045] The lead screw support mechanism 140 is mounted on the guide portion 112. The lead screw support mechanism 140 includes a housing portion 141, a compression spring 142, a backlash elimination member 143, a bearing 144, and a screw 145.

[0046] The housing portion 141 houses the compression spring 142, the backlash elimination member 143, and the bearing 144. A hole 141a for inserting the screw 145 is formed in the housing portion 141. The screw 145 is inserted into the hole 141a to prevent the bearing 144 from protruding out of the housing portion 141.

[0047] The end of the lead screw 135 is fitted into the inner ring of the bearing 144, and the outer ring of the bearing 144 is fitted into the inner wall of the housing portion 141. Thus, the lead screw support mechanism 140 can rotatably support the lead screw 135 and can reduce the frictional resistance when the lead screw 135 rotates. Therefore, the load applied to the motor 131 can be reduced.

[0048] The compression spring 142 biases the outer ring of the bearing 144 toward the lead screw 135 via the play elimination member 143. More specifically, the play elimination member 143 has an outer edge portion 143a that contacts the outer ring of the bearing 144 and an engagement portion 143b that engages with the compression spring 142. The compression spring 142 biases the play elimination member 143 toward the lead screw 135, so that the outer edge portion 143a biases the outer ring of the bearing 144 toward the lead screw 135. Thus, axial play caused by the axial internal clearance of the bearing 144 can be suppressed.

[0049] Next, the moving portion 120 will be described. As the lead screw 135 rotates, the moving portion 120 moves in the axial direction of the lead screw 135. Figure 8 of (A) to Figure 8 of (D) are diagrams for explaining the structure of the moving portion 120. In addition, Figure 8 of (A) and Figure 8 of (B) are perspective views of the moving portion 120 viewed from different directions, Figure 8 of (C) is an exploded perspective view of the moving portion 120, Figure 8 of (D) is a cross-sectional view of the moving portion 120.

[0050] The moving portion 120 includes a support portion 121, a cam groove engagement portion 122 corresponding to the first protrusion, a straight groove engagement portion 123 corresponding to the third protrusion, a lead screw engagement portion 124, and a biasing portion 125.

[0051] The support portion 121 supports the cam groove engagement portion 122, the straight groove engagement portion 123, the lead screw engagement portion 124, and the biasing portion 125.

[0052] The cam groove engagement portion 122 passes through the retraction groove 11a of the second fixed cylinder 11 (see Figure 2 of (A)), and engages with the first cam groove 20a of the zoom cam ring 20 (see Figure 2 of (B)) (see Figure 4 of (B)). Therefore, when the moving portion 120 (the cam groove engagement portion 122) moves in the axial direction of the lead screw 135, the zoom cam ring 20 rotates.

[0053] As Figure 8As shown in (D), the cam groove engaging portion 122 includes a fixing portion 122a, an annular member 122b, and a bearing 122c. The fixing portion 122a is fixed to the supporting portion 121. The outer periphery of the fixing portion 122a is fitted with the inner ring of the bearing 122c. The outer ring of the bearing 122c is fitted with the inner wall of the annular member 122b. Thus, the annular member 122b is supported by the supporting portion 121 so as to be rotatable. Since the annular member 122b is rotatable, the friction generated when the cam groove engaging portion 122 moves in the first cam groove 20a of the zoom cam ring 20 is rolling friction. Since rolling friction is much smaller than sliding friction, the load applied to the motor 131 can be reduced when the cam groove engaging portion 122 moves in the first cam groove 20a of the zoom cam ring 20 as compared with the case where the annular member 122b cannot rotate.

[0054] As Figure 9 shown, the linear groove engaging portion 123 engages with the linear groove 112a of the guiding portion 112. Thus, the moving portion 120 can be guided along the axial direction of the lead screw 135. In addition, Figure 9 is a side view of the drive mechanism 100.

[0055] As Figure 8 shown in (C), the linear groove engaging portion 123 includes a bearing 123a and an annular member 123b. The inner ring of the bearing 123a is fitted with the outer periphery of the convex portion 121a provided on the supporting portion 121. The outer ring of the bearing 123a is fitted with the inner wall of the annular member 123b. Thus, the annular member 123b is supported by the supporting portion 121 so as to be rotatable. Since the annular member 123b is rotatable, the friction generated when the linear groove engaging portion 123 moves in the linear groove 112a becomes rolling friction. Therefore, the load applied to the motor 131 when the linear groove engaging portion 123 moves in the linear groove 112a can be reduced as compared with the case where the annular member 123b cannot rotate.

[0056] As Figure 8 shown in (D), the lead screw engaging portion 124 includes an annular member 124a and a bearing 124b. The outer periphery of the annular member 124a is fitted with the inner ring of the bearing 124b. A groove 127 that contacts 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 over the entire circumference of the inner periphery of the annular member 124a.

[0057] As Figure 8As shown by arrow A1 in (D), the annular member 124a is biased toward the lead screw 135 in a direction orthogonal to the axial direction of the lead screw 135 by the biasing portion 125 that is a leaf spring. Thereby, the groove 127 of the annular member 124a is pressed against the thread groove of the lead screw 135, and thus loosening between the annular member 124a and the lead screw 135 is suppressed. In addition, a part of the bearing 124b is housed in the housing portion 121b provided in the support portion 121, and thus the support portion 121 is connected to the lead screw engaging portion 124. Further, the annular member 124a can be biased toward the lead screw 135 by other biasing members.

[0058] Since the annular member 124a is supported so as to be rotatable, when the lead screw 135 rotates, the annular member 124a is pressed by the thread surface of the thread groove of the lead screw 135 and moves in the axial direction of the lead screw 135 while rotating. Thereby, the support portion 121 that supports the annular member 124a also moves in the axial direction of the lead screw 135, and thus the moving portion 120 can be moved in the direction of the optical axis OA. In addition, since 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. Thereby, the load applied to the motor 131 when moving the moving portion 120 in the axial direction of the lead screw 135 can be reduced. As the structure of the lead screw engaging portion 124, the structure disclosed in Japanese Patent Application No. 2021-156263 can also be applied.

[0059] The cam groove engaging portion 122 of the moving portion 120 engages with the first cam groove 20a of the zoom cam ring 20. Therefore, when the zoom cam ring 20 is rotated by moving the moving portion 120 in the direction of the optical axis OA, the lens holding frame F3 linearly moves in the direction of the optical axis OA along the first straight groove 11b and the second cam groove 20b, and the lens holding frame F4 linearly moves in the direction of the optical axis OA along the second straight groove 11c and the third cam groove 20c. Since the zoom cam ring 20 is rotated using the first cam groove 20a, quiet operation can be achieved as compared with the case where the zoom cam ring 20 is rotated using a gear.

[0060] As described in detail above, the lens barrel 2 of the present embodiment includes: a moving portion 120 having a cam groove engaging portion 122; a driving portion 130 that linearly moves the moving portion 120 in the optical axis OA direction; a zoom cam ring 20 having a first cam groove 20a and a second cam groove 20b, the first cam groove 20a being engaged with the cam groove engaging portion 122; and a lens holding frame F3 having a cam pin 41 engaged with the second cam groove 20b and holding the lens group L3. By moving the moving portion 120 in the optical axis OA direction, the zoom cam ring 20 rotates, and by the rotation of the zoom cam ring 20, the lens holding frame F3 moves in the optical axis OA direction. Since the zoom cam ring 20 is rotated by using the first cam groove 20a, the sound generated when rotating the zoom cam ring 20 can be reduced compared with the case of rotating the zoom cam ring 20 by using a gear.

[0061] In addition, in the present embodiment, the moving portion 120 includes a linear groove engaging portion 123, and the lens barrel 2 includes a guiding portion 112 having a linear groove 112a engaged with the linear groove engaging portion 123. Thereby, the moving portion 120 can linearly move in the optical axis OA direction.

[0062] In addition, in the present embodiment, the cam groove engaging portion 122 (ring-shaped member 122b) can rotate about the center of the cam groove engaging portion 122. Thereby, compared with the case where the cam groove engaging portion 122 (ring-shaped member 122b) cannot rotate, the load applied to the motor 131 when the cam groove engaging portion 122 moves in the first cam groove 20a can be reduced. Therefore, in the case of rotating the zoom cam ring 20 having the same weight by using the motor 131 having the same output, the zoom cam ring 20 can rotate at a higher speed compared with the case where the cam groove engaging portion 122 (ring-shaped member 122b) cannot rotate (the case of generating sliding friction). In addition, for example, in the case of using the motor 131 having the same output, a heavier zoom cam ring 20 can be rotated compared with the case where the cam groove engaging portion 122 (ring-shaped member 122b) is supported so as not to rotate (the case of generating sliding friction). In addition, in the case of rotating the zoom cam ring 20 having the same weight, a motor 131 having a smaller output can be used compared with the case where the cam groove engaging portion 122 (ring-shaped member 122b) is supported so as not to rotate (the case of generating sliding friction), and thus the drive mechanism 100 can be miniaturized.

[0063] In addition, in the present embodiment, the straight groove engaging portion 123 (ring-shaped member 123b) can rotate about the center of the straight groove engaging portion 123. Thus, compared with the case where the straight groove engaging portion 123 (ring-shaped member 123b) cannot rotate, the load applied to the motor 131 when the straight groove engaging portion 123 moves in the straight groove 112a can be reduced. Therefore, when rotating the zoom cam ring 20 of the same weight using a motor 131 with the same output, the zoom cam ring 20 can rotate at a higher speed compared with the case where the straight groove engaging portion 123 (ring-shaped member 123b) cannot rotate (the case of sliding friction). In addition, for example, when using a motor 131 with the same output, a heavier zoom cam ring 20 can be rotated compared with the case where the straight groove engaging portion 123 (ring-shaped member 123b) is supported so as not to rotate (the case of sliding friction). In addition, when rotating the zoom cam ring 20 of the same weight, a motor 131 with a smaller output can be used compared with the case where the straight groove engaging portion 123 (ring-shaped member 123b) is supported so as not to rotate (the case of sliding friction), and thus the drive mechanism 100 can be miniaturized.

[0064] In addition, in the present embodiment, the moving portion 120 has a plurality of straight groove engaging portions 123. Thus, the moving portion 120 can be stably guided in the direction of the optical axis OA.

[0065] In the present embodiment, the zoom cam ring 20 further has a third cam groove 20c. And the lens barrel 2 includes a lens holding frame F4 which has a cam pin 42 engaged with the third cam groove 20c and holds the lens group L4. By the rotation of the zoom cam ring 20, the lens holding frame F4 moves in the direction of the optical axis OA. Thus, a single motor 131 can be used to move a plurality of lens groups L3 and L4 in the direction of the optical axis OA. Therefore, compared with the case where a plurality of motors are respectively provided to drive a plurality of lens groups, the power consumption can be reduced.

[0066] In addition, in the present embodiment, the drive portion 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 portion 136, and the connecting portion 136 has a centering mechanism for adjusting the positions of the axes of the output shaft of the motor 131 and the axis of the lead screw 135. Thus, the vibration and noise caused by the positional deviation between the axis of the output shaft of the motor 131 and the axis of the lead screw 135 can be reduced.

[0067] In addition, in the above embodiment, as the mechanism for guiding the moving portion 120 along the direction of the optical axis OA, the mechanism shown in (A) to Figure 10 of Figure 10 (C) may also be used. Figure 10(A) is a perspective view of the drive mechanism 100A of Modification 1. Figure 10 (B) of Figure 10 (C) is a perspective view showing the guide portion 112A, the moving portion 120A, and the lead screw support mechanism 140A of Modification 1.

[0068] As Figure 10 As shown in (A), the guide portion 112A includes a guide rod 112b extending parallel to the axial direction of the lead screw 135. The guide rod 112b is supported by the lead screw support mechanism 140A.

[0069] As Figure 10 As shown in (B), two through holes 121c are provided in the support portion 121A of the moving portion 120A, and the guide rods 112b are respectively inserted through the through holes 121c. Thus, the moving portion 120A is guided by the guide rods 112b along the axial direction of the lead screw 135 (i.e., the optical axis OA direction).

[0070] Further, in the above-described embodiment, the zoom cam ring 20 is disposed on the outer peripheral side of the second fixed cylinder 11, but it is not limited thereto. The zoom cam ring 20 may be disposed on the inner peripheral side of the second fixed cylinder 11.

[0071] Additionally, in the above-described embodiment, a lens holding frame that holds a lens group different from the lens groups L3 and L4 may be connected to the moving portion 120, and the lens holding frame may be moved in the optical axis OA direction by the moving portion 120. That is, the moving portion 120 and the lens holding frame may also move integrally in the optical axis OA direction. Thus, three lens holding frames can be linearly moved in the optical axis OA direction by one motor 131.

[0072] Additionally, in the above-described embodiment, the bearing 124b included in the lead screw engaging portion 124 of the moving portion 120 is not limited to a bearing, and any rotating rolling body such as a bearing can be used. Further, the bearing 124b and the annular member 124a may be integral.

[0073] Additionally, in the above-described embodiment, the lead screw engaging portion 124 of the moving portion 120 includes the annular member 124a and the bearing 124b, but it is not limited thereto. For example, the lead screw engaging portion 124 may include only the annular member 124a. That is, the annular member 124a may not rotate.

[0074] Additionally, in the above-described embodiment, the lead screw engaging portion 124 of the moving portion 120 may be a nut or a rack. Figure 11 (A) is a cross-sectional view of the moving portion 120B of Modification 2. As Figure 11 As shown in (A), 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.

[0075] In addition, in the above-described embodiment, the linear groove engaging portion 123 of the moving portion 120 may not include the bearing 123a. That is, the annular member 123b may also be supported so as not to rotate.

[0076] In addition, in the above-described embodiment, the output shaft of the motor 131 is connected to the lead screw 135 by the connecting portion 136 having the centering mechanism, but it is not limited thereto. Figure 11 (B) of FIG. is a cross-sectional view showing the connecting portion 136A of the modified example 3.

[0077] As Figure 11 shown in (B) of FIG., the output shaft of the motor 131 and the lead screw 135 may also be directly connected, for example, by the connecting portion 136A that does not have a centering mechanism. In addition, an existing coupling (shaft joint) may be used to connect the output shaft of the motor 131 and the lead screw 135.

[0078] The above-described embodiment is a preferred example. However, it is not limited thereto, and various modifications can be made without departing from the gist, and any structural elements can also be combined.

[0079] Reference Numeral Explanation

[0080] 1 Camera

[0081] 2 Lens Barrel

[0082] 11 Second Fixed Cylinder

[0083] 20 Zoom Cam Ring

[0084] 20a First Cam Groove

[0085] 20b Second Cam Groove

[0086] 20c Third Cam Groove

[0087] 41 Cam Pin

[0088] 42 Cam Pin

[0089] 120 Moving Portion

[0090] 112 Guide Portion

[0091] 112a Linear Groove

[0092] 122 Cam Groove Engaging Portion

[0093] 123 Linear Groove Engaging Portion

[0094] 130 Driving Portion

[0095] 131 Motor

[0096] 135 Lead Screw

[0097] 136 connecting part

[0098] L3 and L4 lens groups

[0099] F3 and F4 lens retaining frames

[0100] OA optical axis

Claims

1. A lens barrel, comprising: A moving part having a first protrusion; A driving part that linearly moves the moving part in the optical axis direction; A first cylinder having a first cam groove and a second cam groove, the first cam groove engaging with the first protrusion; and A first lens holding frame having a second protrusion that engages with the second cam groove and holding a first lens, By moving the moving part in the optical axis direction, the first cylinder rotates, By the rotation of the first cylinder, the first lens holding frame moves in the optical axis direction.

2. The lens barrel according to claim 1, Wherein, The moving part has a third protrusion, The lens barrel includes a guiding part having a linear groove that engages with the third protrusion.

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

4. The lens barrel according to claim 2 or 3, Wherein, The third protrusion can rotate about the center of the third protrusion.

5. The lens barrel according to any one of claims 1 to 4, Wherein, The first protrusion can rotate about the center of the first protrusion.

6. The lens barrel according to any one of claims 1 to 5, Wherein, The first cylinder further has a third cam groove, The lens barrel includes a second lens holding frame having a fourth protrusion that engages with the third cam groove and holding a second lens, By the rotation of the first cylinder, the second lens holding frame moves in the optical axis direction.

7. The lens barrel according to any one of claims 1 to 6, Wherein, The lens barrel includes a second cylinder provided on one of the outer peripheral side or the inner peripheral side of the first cylinder.

8. The lens barrel according to any one of claims 1 to 7, Wherein, The lens barrel includes a third lens holding frame that holds a third lens, The third lens holding frame moves integrally with the moving part along the optical axis direction.

9. The lens barrel according to any one of claims 1 to 8, Wherein, The driving part includes a motor and a lead screw, the motor having an output shaft, The output shaft is connected to the lead screw through a connecting part, The connecting part has an alignment mechanism that adjusts the axial position of the output shaft and the axial position of the lead screw.

10. A photographing device, comprising the lens barrel according to any one of claims 1 to 9.

Images