JP2006308821A - Lens drive unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent backlash of a lens frame in a lens drive unit equipped with a guide shaft and a rotation stop shaft. <P>SOLUTION: The lens drive unit includes: lens frames 40 and 50; a guide shaft 20 for guiding the lens frames 40 and 50 in an optical axis direction L; the rotation stop shaft 30 for regulating the rotation of the lens frames 40 and 50; lead screws 60 and 90; nuts 70 and 100 screwed on the lead screws 60 and 90; holding parts 43 and 53 for holding the nuts 70 and 100 not to turn; and a spring 120 for energizing so that the nuts 70 and 100 may be brought into close contact with the holding parts 43 and 53. The nuts 70 and 100 have cam surfaces 72 and 102 applying cam action in a direction where they are nearly perpendicular to the guide shaft 20 and they do not cross therewith to the holding parts 43 and 53. Thus, the backlash of the rotation stop shaft and the lens frame is eliminated. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lens driving device that reciprocates a lens in the optical axis direction, and more particularly to a lens driving device that reciprocates a lens frame while guiding the lens frame in the optical axis direction by a guide shaft and a rotation stop shaft.

  As a conventional lens driving device, a lens frame holding a lens, a slide part provided on one side of the lens frame, a guide hole of the slide part is inserted to guide the lens frame in the optical axis direction, and a screw is provided on the outer periphery. Lead screw, meshing part meshing with the lead screw, coil spring pressing the meshing part against the lens frame, and a U-shaped slide part with a U-shaped notch provided on the other side of the lens frame In addition, there is known one provided with a rotation stop shaft or the like that is inserted into the U-shaped slide portion and restricts rotation of the lens frame around the optical axis (for example, see Patent Document 1).

  However, in this lens driving device, since the backlash is not performed between the rotation stop shaft that restricts the rotation of the lens frame and the U-shaped slide portion of the lens frame, the fluctuation of the rotational driving force generated by the lead screw is not performed. As a result, there is a risk that the lens frame will rattle in a plane perpendicular to the optical axis centering on the lead screw.

  As another lens driving device, the lens frame holding the lens, the two slide portions having guide holes provided in the lens frame, and the two slide portions are respectively inserted to guide the lens frame in the optical axis direction. Two guide shafts, a coil spring that biases the lens frame to one side in the optical axis direction, a cam member that abuts the lens frame by the biasing force of the coil spring and exerts a cam action in the optical axis direction, and rotates the cam member There is known a drive motor that drives the lens frame and moves the lens frame in the optical axis direction against the urging force of the coil spring by the cam action of the cam member (for example, see Patent Document 2).

  However, even in this lens driving device, since the backlash is not performed between the two guide shafts and the guide holes of the lens frame, the lens frame is moved to the optical axis due to fluctuations in the cam driving force generated by the cam member. There is a risk of rattling in a vertical plane.

Japanese Patent Laid-Open No. 10-20177 JP 2004-4903 A

  The present invention has been made in view of the above circumstances, and the object of the present invention is to prevent rattling of the lens frame while simplifying the structure and reducing the number of parts, and is smooth and highly accurate. It is another object of the present invention to provide a lens driving device capable of moving the lens in the optical axis direction.

The lens driving device of the present invention includes a lens frame for holding a lens, a guide shaft for guiding the lens frame in the optical axis direction, a rotation preventing shaft for restricting the rotation of the lens frame, and a lead for moving the lens frame in the optical axis direction. A screw, a nut screwed to the lead screw, a holding portion provided on the lens frame to hold the nut in a non-rotatable manner, and a spring that biases the nut and the holding portion in close contact with each other in the optical axis direction. The nut driving device is characterized in that the nut has a cam surface that exerts a cam action on the holding portion in a direction substantially perpendicular to the guide shaft and not intersecting.
According to this configuration, when the lead screw rotates, the lens frame moves in the optical axis direction together with the nut. At this time, the cam surface of the nut exerts a cam action in a direction substantially perpendicular to the guide shaft and not intersecting the holding portion of the lens frame (for example, a holding portion formed as a protruding portion or a flat portion), The lens frame is urged to rotate about the guide shaft, and a backlash between the rotation stop shaft and the lens frame is performed. Therefore, the lens frame can be moved smoothly with high accuracy without causing backlash in a plane perpendicular to the optical axis.

The said structure can employ | adopt the structure which has a holding surface inclined so that a holding | maintenance part might surface-contact with the cam surface of a nut.
According to this configuration, since the holding portion of the lens frame is in surface contact with the nut cam surface via the holding surface, a more reliable cam action is obtained and a more reliable backlash is performed.

In the above configuration, the lens frame includes a first lens frame and a second lens frame arranged in the optical axis direction, and the lead screw moves the first lens frame and the second lens frame in the optical axis direction, respectively. The nut includes a lead screw and a second lead screw, and the nut is held in a first nut held in a first holding part provided in the first lens frame and a second holding part provided in the second lens frame. It is possible to adopt a configuration that includes two nuts and the spring is stretched so as to exert a biasing force in a direction in which the first lens frame and the second lens frame are brought close to each other.
According to this configuration, when the first lead screw rotates, the first lens frame moves in the optical axis direction together with the first nut, and when the second lead screw rotates, together with the second nut. The second lens frame moves in the optical axis direction. At this time, the cam surface of the first nut cams in a direction substantially perpendicular to the guide shaft and not intersecting the first holding portion (for example, a holding portion formed as a projecting portion or a flat portion) of the first lens frame. And the cam surface of the second nut is substantially perpendicular to the guide shaft and does not intersect the second holding portion (for example, a holding portion formed as a projecting portion or a flat portion) of the second lens frame. Since the cam action is exerted in the direction, the first lens frame and the second lens frame are urged to rotate around the guide shaft, and the rotation stopping shaft, the first lens frame, and the second lens frame are loosely moved. Therefore, the first lens frame and the second lens frame can be moved with high accuracy and smoothness without causing a backlash in a plane perpendicular to the optical axis.

In the above configuration, the first nut and the second nut each have a cam surface that exerts a cam action so as to rotate the first lens frame and the second lens frame in the same direction with the guide shaft as a rotation center. can do.
According to this configuration, since the first lens frame and the second lens frame are loosely moved in the same rotation direction with the guide shaft as the center of rotation, the optical axis of the lens held in the first lens frame and the second lens Since the axial displacement of the lens held by the frame with respect to the optical axis can be reliably prevented, high optical performance can be maintained while performing backlash.

In the above configuration, the first nut has a cam surface that exerts a cam action so as to rotate the first lens frame in one direction with the guide shaft as the rotation center, and the second nut has the guide shaft as the rotation center. A configuration having a cam surface that exerts a cam action so as to rotate the second lens frame in the other direction can be adopted.
According to this configuration, the first lens frame is rattled in one rotation direction and the second lens frame is rattled in the other rotation direction around the guide shaft as the rotation center. The load (torque load) due to the torque exerted by each of the first lens frame and the second lens frame cancels each other, and the bending or deformation of the rotation-stopping shaft can be surely prevented. It can be moved smoothly.

In the above-described configuration, it is possible to adopt a configuration in which the cam surface of the nut is formed so as to exert a cam action in a direction substantially perpendicular to a straight line passing through the optical axis of the lens and the guide shaft.
According to this configuration, since the rotational torque due to the cam action of the nut acts most efficiently (maximum), the lead screw and the guide shaft are compared with the case where the cam action is formed in a direction other than vertical. The separation distance can be shortened, and the apparatus can be further miniaturized.

In the above configuration, the cam surface of the nut is formed so as to exert a cam action in a direction substantially perpendicular to a straight line passing through the optical axis of the lens and the guide shaft. A configuration can be adopted in which the frame is disposed at a position approximately 180 ° apart in the circumferential direction of the frame.
According to this configuration, the lens frame is guided more smoothly in the direction of the optical axis by preventing inclination and the like, and the torque load due to the cam action of the nut is relative to the straight line passing through the optical axis of the lens and the rotation stop shaft. Since it acts from the vertical direction, the backlash is efficiently performed.

  According to the lens driving device having the above-described configuration, the lens frame can be prevented from rattling while the structure is simplified and the number of parts is reduced, and the lens can be moved smoothly and accurately in the optical axis direction. A lens driving device that can be obtained can be obtained.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, exemplary embodiments of the invention will be described with reference to the accompanying drawings. 1 to 6 show an embodiment of a lens driving device according to the present invention. FIG. 1 is an exploded perspective view of the device, FIG. 2 is a perspective view showing a part of the device, and FIG. FIG. 4 is a partial side view of the configuration shown in FIG. 3, and FIG. 5 is a front view showing the second lens frame forming a part of the apparatus and its peripheral configuration. 6 and 6 are partial side views of the configuration shown in FIG.

  As shown in FIG. 1, the apparatus includes a case 10 composed of a base 11 and a cover 12, a guide shaft 20 and a rotation stop shaft 30 fixed to the case 10, a first lens frame 40 holding a lens G1, and a lens G2. The second lens frame 50 to be held, the first lead frame 60 that moves the first lens frame 40 in the optical axis direction L, the first nut 70 and the first motor 80, and the second lens frame 50 are moved in the optical axis direction L. The second lead screw 90, the second nut 100, the second motor 110, the spring 120 that urges the first lens frame 40 and the second lens frame 50 toward each other, the first sensor 130, the second sensor 140, etc. It has.

As shown in FIG. 1, the base 11 is formed in a substantially rectangular case shape. The base 11 has a circular opening 11 a formed in the bottom thereof, a fitting hole 11 b of the guide shaft 20, and a fitting of the rotation prevention shaft 30. A pin 11d and a screw hole 11e formed in a portion protruding from the bottom for fixing the joint hole 11c, the first motor 80 and the second motor 110 with the fixing plate 13, and an end surface for fastening the cover 12. A screw hole 11f and the like are provided.
As shown in FIG. 1, the case 12 is formed so as to define a rectangular parallelepiped by being connected to the base 11, a circular opening 12 a formed at the front end thereof, a fitting hole 12 b of the guide shaft 20, A fitting hole 12c of the rotation stop shaft 30 and a through hole 12f through which a screw is passed are provided.

  The guide shaft 20 is formed in a columnar shape extending in the optical axis direction L as shown in FIG. 1 in order to guide the first lens frame 40 and the second lens frame 50 in the optical axis direction L. One end of the guide shaft 20 is fitted into the fitting hole 11 b of the base 11, and the other end is fitted to the fitting hole 12 b of the cover 12, so that the guide shaft 20 is firmly fixed to the case 10.

  The anti-rotation shaft 30 restricts the first lens frame 40 and the second lens frame 50 from rotating in a plane perpendicular to the optical axis L, and extends in the optical axis direction L as shown in FIG. It is formed in a cylindrical shape. One end of the rotation preventing shaft 30 is fitted into the fitting hole 11c of the base 11, and the other end is fitted into the fitting hole 12c of the cover 12, so that it is firmly fixed to the case 10. .

  As shown in FIGS. 1 to 4, the first lens frame 40 is disposed on the front side (close to the subject) in the optical axis direction L, and projects in the radial direction from the cylindrical portion 41 that holds the lens G <b> 1. The two connecting portions 42, the first holding portion 43 that extends from one connecting portion 42 and holds the first nut 70 in a non-rotatable manner, and the spring that is formed extending from one connecting portion 42. A latching piece 44 for latching one end 121 of 120, a substantially U-shaped coupling part 45 projecting in a radial direction from the cylindrical part 41 at a position approximately 180 ° away from the coupling part 42 in the circumferential direction, and a coupling part 45 The detected piece 46 etc. which protruded from the vicinity of is provided.

The two connecting portions 42 have guide holes 42a that are formed coaxially in the optical axis direction L and through which the guide shaft 20 is slidably inserted.
The first holding portion 43 includes an inclined holding surface 43 a that comes into surface contact with a cam surface 72 (described later) of the first nut 70, a through hole 43 b that allows the first lead screw 60 to be inserted in a non-contact state, and rotation of the first nut 70. A restriction piece 43c for restriction and a protrusion 43d for restricting the first nut 70 from falling off are provided.
The connecting portion 45 has inner side surfaces 45a and 45b that define a substantially U-shaped notch that opens outward. The interval defined by the inner side surfaces 45 a and 45 b is formed to have a dimension slightly larger than the outer diameter dimension of the rotation stop shaft 30.
Here, the connecting portion 42 and the connecting portion 45 are disposed at positions that are separated from each other by 180 ° in the circumferential direction of the first lens frame 40, that is, the guide shaft 20 and the rotation stop shaft 30 are arranged in the first lens frame 40. Therefore, the first lens frame 40 is prevented from tilting and is guided smoothly in the optical axis direction L.

  As shown in FIGS. 1, 2, 5, and 6, the second lens frame 50 is disposed on the rear side in the optical axis direction L, and holds the lens G <b> 2, and the radial direction from the cylindrical portion 51. Two connecting portions 52 projecting from each other, formed from one connecting portion 52, a second holding portion 53 for holding the second nut 100 in a non-rotatable manner, and extending from the other connecting portion 52. A latch piece 54 for latching the other end 122 of the spring 120, a substantially U-shaped coupling portion 55 projecting radially from the cylindrical portion 51 at a position approximately 180 ° away from the coupling portion 52 in the circumferential direction, A detected piece 56 or the like protruding from the vicinity of the connecting portion 55 is provided.

The two connecting portions 52 have guide holes 52a that are formed coaxially in the optical axis direction L and through which the guide shaft 20 is slidably inserted.
The second holding portion 53 includes an inclined holding surface 53a that comes into surface contact with a cam surface 102 described later of the second nut 100, a through hole 53b that allows the second lead screw 90 to be inserted in a non-contact state, and rotation of the second nut 100. A restriction piece 53c for restriction and a protrusion 53d for restricting the second nut 100 from falling off are provided.
The connecting portion 55 has inner side surfaces 55a and 55b that define a substantially U-shaped notch that opens outward. The interval defined by the inner side surfaces 55 a and 55 b is formed to be slightly larger than the outer diameter of the rotation stop shaft 30.
Here, the connecting portion 52 and the connecting portion 55 are disposed at positions 180 degrees apart in the circumferential direction of the second lens frame 50, that is, the guide shaft 20 and the rotation stop shaft 30 are the second lens frame 50. Therefore, the second lens frame 50 is prevented from tilting and guided smoothly in the optical axis direction L.

The first lead screw 60 is directly connected to the first motor 80 and is driven to rotate, and is screwed into a first nut 70 that is held in the first lens frame 40 so as not to rotate.
As shown in FIGS. 1 to 4, the first nut 70 is in surface contact with the female screw 71 screwed into the first lead screw 60 and the holding surface 43 a of the first lens frame 40 and is perpendicular to the optical axis L. It has a cam surface 72 that exerts a cam action in the plane.
As shown in FIGS. 3 and 4, the cam surface 72 is perpendicular to the guide shaft 20 and does not intersect, that is, the first lens frame 40 is rotated clockwise CW (one direction around the guide shaft 20 as a rotation center). ) To act as a cam.
As a result, the connecting portion 45 of the first lens frame 40 is in a state in which its inner side surface 45a is in contact with the outer peripheral surface of the anti-rotation shaft 30 by a predetermined biasing force F1 (a load due to the rotational torque T1 obtained by the cam action). Is maintained and the backlash is performed.
Further, as shown in FIG. 3, the cam surface 72 exerts a cam action in a direction perpendicular to the optical axis L of the lens G1 and a straight line SL passing through the guide shaft 20, and therefore, the cam face 72 is caused by the cam action of the first nut 70 ( The rotational torque T1 (with the arm length H1) works most efficiently (maximally). Therefore, the separation distance H1 between the first lead screw 60 and the guide shaft 20 can be shortened and the apparatus can be miniaturized compared to the case where the cam action is formed in a direction other than the vertical direction.
As the first motor 80, a DC motor or a stepping motor is employed.

The second lead screw 90 is directly connected to the second motor 110 and is rotationally driven, and is screwed into a second nut 100 that is held non-rotatably by the second lens frame 50.
As shown in FIGS. 1, 2, 5, and 6, the second nut 100 is in surface contact with the female screw 101 screwed into the second lead screw 90 and the holding surface 53 a of the second lens frame 50. The cam surface 102 exerts a cam action in a plane perpendicular to the optical axis L.
As shown in FIGS. 5 and 6, the cam surface 102 is perpendicular to the guide shaft 20 and does not intersect, that is, the second lens frame 50 is rotated clockwise CW (one direction around the guide shaft 20 as a rotation center). ) To act as a cam. As a result, the connecting portion 55 of the second lens frame 50 has its inner side surface 55a caused by a predetermined urging force F2 (a load obtained by the rotational torque T2 having an arm length H2 obtained by the cam action of the second nut 100). The state is maintained in contact with the outer peripheral surface of the rotation stop shaft 30, and the backlash is performed.
As the second motor 110, a DC motor or a stepping motor is employed.

As shown in FIGS. 1 and 2, the spring 120 is a coil spring that exerts an urging force Fs attracted in the optical axis direction L. One end 121 of the spring 120 is hooked on the hooking piece 44 of the first lens frame 40. The end 122 is hooked on the hooking piece 54 of the second lens frame 50.
The spring 120 brings the first nut 70 (cam surface 72) and the holding portion 43 (holding surface 43a) of the first lens frame 40 into close contact, and the second nut 100 (cam surface 102) and the second lens. A biasing force is exerted in the direction of bringing the first lens frame 40 and the second lens frame 50 closer to each other in the optical axis direction L so that the holding portion 53 (holding surface 53a) of the frame 50 is brought into close contact.

The first sensor 130 is composed of a transmissive optical sensor having a light emitting element and a light receiving element, and detects the initial position of the first lens frame 40 by detecting the presence or absence of the detection piece 46 of the first lens frame 40. It is like that.
As described above, the second sensor 140 includes a transmissive optical sensor having a light emitting element and a light receiving element, and detects the presence or absence of the detection piece 56 of the second lens frame 50, thereby initializing the second lens frame 50. The position is detected.

  In the above configuration, the first nut 70 and the second nut 100 have a cam action so as to rotate the first lens frame 40 and the second lens frame 50 in the same direction (clockwise CW) with the guide shaft 20 as the rotation center. Therefore, it is possible to reliably prevent the axial deviation between the optical axis of the lens G1 held in the first lens frame 40 and the optical axis of the lens G2 held in the second lens frame 50. While performing, high optical performance can be maintained.

  Next, the operation of this apparatus will be briefly described. When the first lens frame 40 and the second lens frame 50 are in the initial positions (rest positions) retracted rearward in the optical axis direction L, the first sensor 130 and The second sensor 140 detects that each of the first lens frame 40 and the second lens frame 50 is located at the initial position, that is, the control start reference position.

  When the first lead screw 60 is rotated by the first motor 80 from the initial position, the first lens frame 40 moves in the optical axis direction L together with the first nut 70. When the second lead screw 90 is rotated by the second motor 110, the second lens frame 50 moves in the optical axis direction L together with the second nut 100.

At this time, the first lens frame 40 (lens G1) and the second lens frame 50 (lens G2) are moved in the optical axis direction L by appropriately controlling the amount and direction of rotation of the first motor 80 and the second motor 110. The zooming operation and the focusing operation are performed by relatively moving in FIG.
In this operation, the cam surface 72 of the first nut 70 exerts a cam action in a direction substantially perpendicular to the guide shaft 20 and not intersecting the first holding portion 43 (holding surface 43a) of the first lens frame 40. The cam surface 102 of the second nut 100 exerts a cam action on the second holding portion 53 (holding surface 53a) of the second lens frame 50 in a direction substantially perpendicular to the guide shaft 20 and not intersecting.

As a result, the first lens frame 40 and the second lens frame 50 are urged to rotate around the guide shaft 20, and the anti-rotation shaft 30, the first lens frame 40 (connecting portion 45), and the second lens frame 50 (connecting portion). 55).
Therefore, the first lens frame 40 and the second lens frame 50 can be moved with high accuracy and smoothness without causing rattling in a plane perpendicular to the optical axis L.

FIGS. 7A and 7B show another embodiment of the lens driving device according to the present invention, except that a part of the second lens frame 50 ′ and the second nut 100 ′ is changed. Since it is the same as that of the above-mentioned embodiment, the same code | symbol is attached | subjected about the same structure and the description is abbreviate | omitted.
In this apparatus, as shown in FIGS. 7A and 7B, the holding surface 53a ′ of the second holding portion 53 ′ and the cam surface 102 ′ of the second nut 100 ′ formed on the second lens frame 50 ′. The cam surface 102 ′ is rotated in the counterclockwise CCW (other direction) around the guide shaft 20 in the direction perpendicular to and not intersecting with the guide shaft 20. It is formed so as to exert a cam action.
As a result, the connecting portion 55 of the second lens frame 50 has a predetermined biasing force F2 ′ (a load obtained by the rotational torque T2 ′ having an arm length H3 obtained by the cam action of the second nut 100 ′). The side surface 45b is maintained in contact with the outer peripheral surface of the rotation stop shaft 30, and rattling is performed.

  Further, since the cam surface 102 ′ exerts a cam action in a direction perpendicular to the optical axis L of the lens G2 and the straight line SL passing through the guide shaft 20, the cam face 102 ′ is caused by the cam action of the second nut 100 ′ (the arm length is The rotational torque T2 '(of H3) works most efficiently (maximum). Therefore, when the separation distance between the second lead screw 90 and the guide shaft 20 is made the same as compared with the embodiment shown in FIG. 5 formed so as to exert a cam action in a direction other than the vertical direction, it is larger. When the urging force F2 ′ (F2 ′> F2) is obtained and the same urging force F2 ′ (F2 ′ = F2) is obtained, the separation distance between the second lead screw 90 and the guide shaft 20 is obtained. Can be shortened and the apparatus can be miniaturized.

Furthermore, in this embodiment, the cam surface 72 of the first nut 70 exerts a cam action so as to rotate the first lens frame 40 clockwise CW (one direction) around the guide shaft 20 as the rotation center, and the second The cam surface 102 'of the nut 100' exerts a cam action so as to rotate the second lens frame 50 'counterclockwise CCW (in the other direction) with the guide shaft 20 as the rotation center.
Accordingly, the first lens frame 40 is rattled in one rotation direction CW and the second lens frame 50 'is rattled in the other rotation direction CCW with the guide shaft 20 as the rotation center. On the other hand, the loads F1 and F2 ′ (torque loads) due to the torque exerted by the first lens frame 40 and the second lens frame 50 ′ act in a direction to cancel each other. As a result, the rotation stop shaft 30 can be reliably prevented from being bent or deformed, and the first lens frame 40 and the second lens frame 50 'can be moved more smoothly.

  In the above embodiment, the case where the present invention is adopted in the configuration including the two lens frames (the first lens frame 40 and the second lens frames 50 and 50 ′) moving in the optical axis direction L is shown. However, the present invention can be applied to a configuration including one lens frame that moves in the optical axis direction L or three or more lens frames.

  In the embodiment described above, the spring 120 stretched between the first lens frame 40 and the second lens frames 50 and 50 'is used as a spring that urges the nut and the lens frame holding portion to closely contact each other. As shown, the first lens frame 40 and the first nut 70 are urged so as to be in close contact with each other, and the first spring, the second lens frames 50 and 50 ', and the second nuts 100 and 100' move together. A second spring that urges and moves together may be employed. In this case, a constant biasing force can be obtained by the first spring and the second spring regardless of the relative distance between the first lens frame 40 and the second lens frames 50 and 50 ', so that the backlash is always constant. Force is obtained and more stable movement is possible.

  As described above, the lens driving device of the present invention can prevent the lens frame from rattling while achieving simplification of the structure, reduction in the number of parts, and the like, and smoothly and accurately moves the lens in the optical axis direction. Therefore, it can be used as a lens driving device for a portable ordinary digital camera or a silver salt film camera, and is also useful as a lens driving device for a fixed camera or other lens optical system. .

It is a disassembled perspective view which shows one Embodiment of the lens drive device which concerns on this invention. It is a fragmentary perspective view which shows a part of apparatus shown in FIG. It is a front view which shows the 1st lens frame which makes a part of apparatus shown in FIG. 1, and its periphery structure. It is sectional drawing in E1-E1 in FIG. It is a front view which shows the 2nd lens frame which makes a part of apparatus shown in FIG. 1, and its periphery structure. It is sectional drawing in E2-E2 in FIG. 2 shows another embodiment of the lens driving device according to the present invention, in which (a) is a front view showing a second lens frame and a peripheral configuration forming a part of the device, and (b) is a diagram in (a). It is sectional drawing in E3-E3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Case 11 Base 12 Cover 20 Guide shaft 30 Anti-rotation shaft 40 1st lens frame 41 Cylindrical part 42 Connection part 42a Guide hole 43 First holding part 43a Holding surface 43b Through-hole 43c Restriction piece 43d Projection 44 Latching piece 45 Connection part 45a, 45b Inner side surface 46 Detected piece 50, 50 'Second lens frame 51 Cylindrical part 52 Connecting part 52a Guide hole 53, 53' Second holding part 53a, 53a 'Holding surface 53b Through hole 53c Restricting piece 53d Protrusion 54 Hanging Stop piece 55 Connecting portion 55a, 55b Inner side surface 56 Detected piece 60 First lead screw 70 First nut 71 Female screw 72 Cam surface 80 First motor 90 Second lead screw 100, 100 'Second nut 101 Female screw 102, 102 'cam surface 110 second motor 120 spring 121 one end 122 other end 130 first center SA 140 Second sensor L Optical axis direction

Claims (7)

A lens frame for holding a lens, a guide shaft for guiding the lens frame in the optical axis direction, a rotation stop shaft for restricting the rotation of the lens frame, a lead screw for moving the lens frame in the optical axis direction, and the lead screw A nut that is screwed onto the lens frame, a holding portion that is provided on the lens frame to hold the nut in a non-rotatable manner, and a spring that biases the nut and the holding portion in close contact with each other in the optical axis direction. A lens driving device,
The nut has a cam surface that exerts a cam action on the holding portion in a direction substantially perpendicular to the guide shaft and not intersecting the holding shaft.
A lens driving device. The holding portion has a holding surface that is inclined so as to come into surface contact with the cam surface of the nut.
The lens driving device according to claim 1. The lens frame includes a first lens frame and a second lens frame arranged in the optical axis direction,
The lead screw includes a first lead screw and a second lead screw that move the first lens frame and the second lens frame in the optical axis direction, respectively.
The nut includes a first nut held in a first holding part provided in the first lens frame and a second nut held in a second holding part provided in the second lens frame,
The spring is stretched so as to exert a biasing force in a direction in which the first lens frame and the second lens frame are brought closer to each other.
The lens driving device according to claim 1 or 2, wherein The first nut and the second nut each have a cam surface that exerts a cam action so as to rotate the first lens frame and the second lens frame in the same direction with the guide shaft as a rotation center.
The lens driving device according to claim 3. The first nut has a cam surface that exerts a cam action so as to rotate the first lens frame in one direction around the guide shaft as a rotation center;
The second nut has a cam surface that exerts a cam action so as to rotate the second lens frame in the other direction with the guide shaft as a rotation center.
The lens driving device according to claim 3. The cam surface of the nut is formed so as to exert a cam action in a direction substantially perpendicular to a straight line passing through the optical axis and guide shaft of the lens.
The lens driving device according to claim 1, wherein the lens driving device is a lens driving device. The guide shaft and the rotation stop shaft are disposed at positions separated by approximately 180 ° in the circumferential direction of the lens frame.
The lens driving device according to claim 6.

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