JP2009080248A - Lens driving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To regulate excessive engagement of a half nut with respect to a lead screw in a screw feed structure including the half nut and the lead screw. <P>SOLUTION: In the lens driving device including: a base 10; the lead screw 50; guide shafts 20, 21; a lens frame 40 supported so as to be freely reciprocated with respect to the guide shafts; the half nut 70 moved integrally with the lens frame and screwed with the lead screw; and a torsion spring 80 biasing the half nut toward the lead screw. The base 10 includes an abutment wall 16 for slidable abutment of a part 73 of the half nut to regulate the engagement of the half nut with respect to the lead screw at a prescribed amount. Accordingly, the excessive engagement is regulated to reduce sliding resistance while preventing teeth of the half nut from skipping, and the lens frame (lens) is smoothly and precisely driven in an optical axis direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lens driving device that is applied as a pickup mounted on a recording / reproducing device or the like and drives a lens frame holding a lens in an optical axis direction by a screw feed structure by screwing a lead screw and a half nut.

As a screw feed structure applied to a conventional pickup or the like, a base (chassis), a lead screw provided on the base, a guide shaft provided on the base, an optical pickup supported so as to reciprocate with respect to the guide shaft, A half nut provided swingably with respect to the optical pickup, a torsion spring provided on the optical pickup so as to exert a biasing force in a direction in which the half nut is engaged with the lead screw, and a direction in which the half nut is detached from the lead screw. A device provided with a stopper or the like provided on a base for restricting movement is known (see Patent Document 1).
Other conventional screw feeding structures include a base, a guide shaft provided on the base, a lead screw supported by the base so as to be parallel to the guide shaft, and an optical pickup supported reciprocally by the guide shaft. There are known plate springs fixed to the optical pickup, racks (half nuts) and the like that are fixed to the plate springs and arranged to mesh with the lead screw by the urging force of the plate springs (for example, , See Patent Document 2).

  However, in these screw feed structures, the torsion spring (or plate spring) is configured to maintain the meshing state by simply urging the half nut (or rack) toward the lead screw. (Or leaf spring) assembly error or variation in spring force, etc., the female screw of the half nut (or rack) and the male screw of the lead screw are excessively meshed to increase the sliding resistance. Therefore, the rotation of the lead screw The load increases and smooth driving becomes difficult, and there is a risk of causing sticking.

  Furthermore, as another conventional screw feed structure, a base (chassis), a guide shaft provided on the base, a lead screw supported on the base so as to be parallel to the guide shaft, and a guide shaft are supported so as to be reciprocally movable. A sliding member, a half nut (rack) provided on the sliding member, a coil spring provided on the sliding member to bias the half nut toward the lead screw, and a half nut biased by the coil spring. It is known that a stopper portion or the like provided on the slide member is provided to restrict the half nut so as to restrict excessive engagement of the half nut with the lead screw (for example, see Patent Document 3).

  However, in this screw feed structure, since the stopper portion that regulates the half nut is provided on the slide member together with the half nut and the coil spring, the lead screw and the guide shaft are assembled to the base. Even if it is in a state regulated by the stopper part due to an assembly error when attaching the slide member to the guide shaft, an assembly error when attaching the stopper part to the slide member, etc. The half nut may engage with the lead screw excessively, and it is still impossible to eliminate the increase in sliding resistance. As a result, smooth driving becomes difficult as described above, and biting (sticking) occurs. There is a fear.

Japanese Patent Laid-Open No. 5-198105 JP 2000-156054 A JP 2006-172661 A

  The present invention has been made in view of the above circumstances, and its object is to mesh the half nut (or rack) and the lead screw while simplifying the structure and reducing the size of the apparatus. In relation to the lens drive, the lens nut (lens) can be driven smoothly and accurately in the direction of the optical axis by controlling excessive engagement and reducing sliding resistance while preventing tooth skipping of the half nut. To provide an apparatus.

The lens driving device according to the present invention includes a base, a lead screw that is rotatably supported with respect to the base, a guide shaft that is disposed in parallel with the lead screw and fixed to the base, and is reciprocally supported with respect to the guide shaft. A lens driving device comprising: a lens frame, a half nut that moves integrally with the lens frame and meshes with the lead screw, and a first urging member that urges the half nut toward the lead screw. Has a contact wall that slidably contacts a part of the half nut so as to restrict the engagement of the half nut with the lead screw to a predetermined amount.
According to this configuration, when the lead screw rotates, the lens frame moves in the screw feed direction (in the optical axis direction of the lens) along the guide shaft together with the half nut. Here, the half nut is urged toward the lead screw by the first urging member, and a part of the half nut is slidably brought into contact with the abutting wall of the base. Since the engagement of the half nut (female screw) with respect to is restricted to a predetermined amount, excessive engagement is restricted and sliding resistance is reduced while preventing tooth skipping of the half nut, and the lens frame (lens) It is driven smoothly and with high accuracy in the optical axis direction.
In particular, since the lead screw and guide shaft are positioned and assembled with reference to the base, and the half nut abuts against the abutting wall of the base serving as a positioning reference, the meshing is restricted to a predetermined amount. Assembling errors are not accumulated, and excessive screwing (meshing) between the lead screw and the half nut can be regulated to reliably reduce sliding resistance.

In the above configuration, the guide shaft includes a main guide shaft that slidably guides the lens frame, and a detent guide shaft that restricts the lens frame from rotating around the main guide shaft, and the first biasing member includes: A configuration may be employed in which the torsion spring is disposed around the main guide shaft, and has one end hooked to the lens frame and the other end hooked to the half nut.
According to this configuration, the lens frame is slidably guided by the main guide shaft (in the optical axis direction of the lens) while its rotation is restricted by the non-rotating guide shaft. Here, since one end of the torsion spring is hooked on the lens frame and the other end of the torsion spring is hooked on the half nut, the torsion spring urges the half nut toward the lead screw and its reaction force. Thus, the lens frame is urged so as to be loosely moved against the non-rotating guide shaft.
That is, with a single torsion spring, the half nut can be urged and the lens frame can be moved at the same time. Therefore, the structure can be simplified and the cost can be reduced, and in a plane perpendicular to the optical axis. It is possible to prevent the lens frame from rattling and to smoothly move the lens frame in the optical axis direction.

The said structure WHEREIN: The half nut can employ | adopt the structure supported so that rocking | fluctuation is possible with respect to the spindle formed on the lens frame.
According to this configuration, since the half nut is swingably supported on the lens frame, the number of parts can be reduced and the structure can be simplified.

The said structure WHEREIN: The structure containing the 2nd biasing member which urges | biases a lens frame with respect to a half nut in the screw feed direction of a lead screw is employable.
According to this configuration, the backlash between the half nut and the lead screw is eliminated by the urging force of the second urging member exerted through the lens frame, and rattling of the lens frame in the screw feed direction can be prevented. It is possible to prevent or reduce the occurrence of drive hysteresis due to reversal of the lens, and to move the lens frame integrally with the half nut.

In the above configuration, the auxiliary shaft arranged to extend parallel to the main guide shaft and the non-rotating guide shaft and fixed to the base, and the lens frame is urged against the half nut in the screw feed direction of the lead screw. The structure which is a compression type coil spring arrange | positioned around the auxiliary | assistant shaft can be employ | adopted including 2 urging | biasing members.
According to this configuration, the backlash between the half nut and the lead screw is eliminated by the biasing force of the coil spring (second biasing member) exerted through the lens frame, and the lens frame can be prevented from rattling in the screw feed direction. The occurrence of drive hysteresis due to reversal of the lead screw can be prevented or reduced, and the lens frame can be moved integrally with the half nut. In addition, since the coil spring is arranged around the auxiliary shaft, not around the main guide shaft, the guided portion (cylindrical fitting portion) of the lens frame guided by the main guide shaft should be set longer. Can do. As a result, the lens frame can be guided with high accuracy in the screw feed direction (the optical axis direction of the lens) while preventing the tilt of the lens frame.

The said structure WHEREIN: The half nut can employ | adopt the structure currently supported so that rocking | fluctuation is possible with respect to the auxiliary shaft.
According to this configuration, the outline of the lens frame can be simplified or smoothed by supporting the half nut so as to be swingable on the auxiliary shaft instead of the lens frame.

  According to the lens driving device having the above-described configuration, the simplification of the structure, the miniaturization of the device, and the like are achieved, while the half nut (or rack) and the lead screw are prevented from skipping teeth in the meshing relationship. Further, it is possible to reduce excessive sliding and reduce sliding resistance, and to drive the lens frame (lens) smoothly and with high accuracy in the optical axis direction.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, exemplary embodiments of the invention will be described with reference to the accompanying drawings.
1 to 4 show an embodiment of a lens driving device according to the present invention. FIG. 1 is a perspective view of the device, FIGS. 2 and 3 are exploded perspective views, and FIG. 4 is an internal view of the device. FIG.

  As shown in FIGS. 1 to 4, the apparatus includes a base 10, a main guide shaft 20 as a guide shaft fixed to the base 10 and extending in the optical axis direction L, a non-rotating guide shaft 21, a main guide shaft 20, and a rotating shaft. A lens arranged parallel to the stop guide shaft 21 and fixed to the base 10 and holding the lens G and supported by the main guide shaft 20 and the rotation stop guide shaft 21 so as to be movable only in the optical axis direction L. A lead screw 50 disposed in parallel with the frame 40, the main guide shaft 20 and the non-rotating guide shaft 21 and supported by the base 10, a motor 60 for rotationally driving the lead screw 50, and the lens frame 40 are moved together with the lead. Half nut 70 and half nut 70 to be screwed into screw 50 are removed. A torsion spring 80 as a first urging member that urges toward the screw 50, and a coil spring as a second urging member that urges the lens frame 40 toward the front F in the optical axis direction L toward the half nut 70. 90, a detection sensor 100 for detecting the initial position of the lens frame 40, and the like.

  As shown in FIGS. 1 to 4, the base 10 is formed using a resin material, a metal material, or the like, and fits the fixing portion 11 that fixes the motor 60 through the lead screw 50 and the leading end portion of the lead screw 50. Fitting hole 13 for fitting and fixing the main guide shaft 20, fitting hole 14 for fitting and fixing the anti-rotation guide shaft 21, and fitting for fixing and fixing the auxiliary shaft 30 A hole 15, a contact wall 16 formed to extend in the optical axis direction L so that a part of the half nut 60 is slidably contacted, a spring receiving portion 17 that receives one end of a coil spring 90, and the like are provided. .

  As shown in FIGS. 1 to 4, the contact wall 16 extends in the optical axis direction L (screw feed direction of the lead screw 50) and is formed on a flat surface. The abutting wall 16 is configured so that the abutting portion 73 of the half nut 70 is slidable in the optical axis direction L and is urged to rotate in a plane perpendicular to the optical axis L. As shown in FIG. 4, the meshing of the half nut 70 (the female screw 71) with the lead screw 50 (the male screw 51) is restricted to a predetermined amount as shown in FIG.

As shown in FIGS. 1 to 4, the main guide shaft 20 is formed to extend in the optical axis direction L by a metal material having a circular cross section, and both ends thereof are fitted in the fitting holes 13 of the base 10. Are combined.
As shown in FIGS. 1 to 4, the non-rotating guide shaft 21 is formed to extend in the optical axis direction L by a metal material having a circular cross section, and both ends thereof are formed in the fitting holes 14 of the base 10. It is mated.
The main guide shaft 20 guides the lens frame 40 in the optical axis direction L, the anti-rotation guide shaft 21 guides the lens frame 40 in the optical axis direction L, and the lens frame 40 rotates around the main guide shaft 20. Is regulated.

As shown in FIGS. 1 to 4, the auxiliary shaft 30 is formed to extend in the optical axis direction L by a metal material having a circular cross section, and both ends thereof are fitted in the fitting holes 15 of the base 10. Has been.
The auxiliary shaft 30 is passed through a through hole or a U-shaped notch (not shown) of the lens frame 40 in a non-contact manner, and as shown in FIG. 2 and FIG. The arranged coil spring 90 is held in a compressible manner so as not to tilt, and the half nut 70 arranged on the front surface (receiving surface 44) of the lens frame 40 is supported in a swingable manner.

  The lens frame 40 is formed of a resin material, and as shown in FIGS. 1 to 4, the main guide shaft 20 extends rearward from the holding portion 41 that holds the lens G by fitting, and extends rearward. A cylindrical guided portion 42 that is slidably fitted, a U-shaped cutout portion 43 through which the detent guide shaft 21 is passed, a receiving surface 44 that swingably receives the half nut 70, and a torsion spring 80 A hooking protrusion 45 for hooking one end 81 of the head, and a detected piece 46 that extends from the holding portion 41 and is detected by the detection sensor 100 are provided.

As shown in FIGS. 1 to 4, the lead screw 50 is formed by a metal material so as to extend in the optical axis direction L, one end thereof is directly connected to the motor 60, and the tip thereof is the bearing hole 12 of the base 10. The male screw 51 is disposed so as to mesh with the female screw 71 of the half nut 70.
The lead screw 50 rotates in one direction to move the half nut 70 toward the front F in the optical axis direction L, and rotates in the other direction, thereby moving the half nut 70 in the rear in the optical axis direction L. It moves to R.

  The motor 60 is a stepping motor that can rotate step by step with a predetermined angle. As shown in FIGS. 1 to 4, the motor 60 is fixed to the fixing portion 11 of the base 10 with screws or the like. The motor 60 applies a rotational driving force while positioning and positioning the directly connected lead screw 50 parallel to the optical axis direction L.

The half nut 70 is formed of a metal material in a substantially flat plate shape, and as shown in FIGS. 1 and 4, the half nut 70 is a female formed over an arc-shaped predetermined length so as to mesh with the male screw 51 of the lead screw 50. A screw 71, a circular hole 72 that is slidably fitted to the auxiliary shaft 30, a contact portion 73 that slidably contacts the contact wall 16 of the base 10, and the other end 82 of the torsion spring 80 are latched. The latch part 74 grade | etc., Is provided.
The half nut 70 is supported so as to be swingable around the auxiliary shaft 30 while being in contact with the receiving surface 44 of the lens frame 40. The urging force of the torsion spring 80 causes the female screw 71 to become the male screw 51 of the lead screw 50. As shown in FIG. 4, the abutment portion 73 abuts against the abutment wall 16 of the base 10, so that the amount of meshing is regulated to a predetermined amount. As the lead screw 50 rotates, the optical axis direction L Can be moved to.
Here, the engagement is restricted to a predetermined amount, while the tooth skipping of the half nut 70 is prevented, and as shown in FIG. 4, excessive engagement (for example, the top of the thread and the bottom of the thread valley contact each other). Or a state where both sides of the screw thread come into contact with both sides of the screw valley).
In this embodiment, since the half nut 70 is swingably supported with respect to the auxiliary shaft 30, the lens frame 40 is simply slidably contacted in the optical axis direction L. The lens frame 40 can be simplified and smoothed by forming a flat contour.

That is, the half nut 70 is urged toward the lead screw 50 by the torsion spring 80, and the contact portion 73 (a part) is slidably contacted with the contact wall 16 of the base 10, so that the lead screw Since the engagement of the female screw 71 with respect to the 50 male screws 51 is regulated to a predetermined amount, excessive meshing is restricted and sliding resistance is reduced while preventing tooth skipping of the half nut 70, and the lens frame 40 ( The lens G) is smoothly and accurately driven in the optical axis direction L.
In particular, with the base 10 as a reference, the lead screw 50 and the main guide shaft 20 (and the non-rotating guide shaft 21) are positioned and assembled, and the half nut 70 is attached to the abutting wall 16 of the base 10 serving as a positioning reference. Since the amount of engagement with the lead screw 50 is restricted to a predetermined amount, the assembly error is not accumulated as a whole, and the lead screw 50 and the half nut 70 are excessively engaged (engaged). Regulated, the sliding resistance is reliably reduced.

As shown in FIGS. 1, 2, and 4, the torsion spring 80 is disposed around the main guide shaft 20 on the front surface of the lens frame 40, and one end 81 of the torsion spring 80 is latched on the latching protrusion 45 of the lens frame 40. The other end 82 is hooked on the hooking portion 74 of the half nut 70.
Then, as shown in FIG. 4, the torsion spring 80 urges the half nut 70 toward the lead screw 50 with a clockwise urging force F1 so that the female screw 71 meshes with the male screw 51, and counteracts the torsion spring 80. The lens frame 40 is urged by a counterclockwise urging force F <b> 2 so that the notch 43 is loosely moved against the rotation-preventing guide shaft 21 by the force.
Here, since the biasing of the half nut 70 and the backlash of the lens frame 40 can be performed simultaneously with one torsion spring 80, the structure is simplified and the cost is reduced, while being perpendicular to the optical axis L. It is possible to prevent the lens frame 40 from rattling in the plane and to smoothly move the lens frame 40 in the optical axis direction L.

As shown in FIGS. 1 to 3, the coil spring 90 is a compression type coil spring, and is arranged around the auxiliary shaft 30 behind the lens frame 40, and one end of the coil spring 90 is the spring receiving portion 17 of the base 10. The other end is in contact with the back surface of the holding portion 41 of the lens frame 40 and is attached in a compressed state with a predetermined compression allowance.
The coil spring 90 biases the lens frame 40 toward the front F in the optical axis direction L so that the lens frame 40 moves in the optical axis direction L integrally with the half nut 70. Thereby, the backlash between the half nut 70 and the lead screw 50 is eliminated, the rattling of the lens frame 40 in the screw feeding direction can be prevented, and the generation of driving hysteresis due to the reversal of the lead screw 50 can be prevented or reduced. Furthermore, the lens frame 40 can be moved integrally with the half nut 70.
Further, since the coil spring 90 is disposed around the auxiliary shaft 30, the guided portion 42 of the lens frame 40 guided by the main guide shaft 20 can be set longer. As a result, the lens frame 40 can be guided with high accuracy in the optical axis direction L (screw feeding direction) while preventing the tilt of the lens frame 40.

  The detection sensor 100 is a transmissive optical sensor having a light emitting element and a light receiving element, and is fixed to the base 10 as shown in FIGS. 1, 2, and 4. The detection sensor 100 detects the initial position (home position) of the lens frame 40 based on the presence or absence of the detected piece 46 of the lens frame 40.

Next, the operation of this apparatus will be described.
First, when the lens frame 40 is located at one side (initial position) in the optical axis direction L, the detection sensor 100 detects the detected piece 46.
When the motor 60 rotates in the forward direction, the lead screw 50 rotates in one direction, and the half nut 70 starts to move toward the other side in the optical axis direction L by a screw feeding action. At this time, since the lens frame 40 is urged so as to move integrally with the half nut 70 by the coil spring 90, the lens frame 40 moves integrally with the half nut 70 toward the other side in the optical axis direction L. Moving.
Then, the number of steps from the start of the motor 60 is counted, the driving amount of the lens frame 40 is appropriately controlled, and the lens frame 40 is positioned at a desired position in the optical axis direction L.

  On the other hand, when the motor 60 rotates in the reverse direction, the lead screw 50 rotates in the other direction, and the half nut 70 starts to move toward one side in the optical axis direction L due to the screw feeding action. At this time, the lens frame 40 moves toward one side in the optical axis direction L integrally with the half nut 70 while receiving the urging force of the coil spring 90, and is positioned at a desired position by appropriately controlling the driving amount. It further moves to one side and returns to the initial position.

  In this driving operation, the lead screw 50, the guide shafts 20, 21 and the auxiliary shaft 30 are all assembled with the base 10 as a reference, and the abutting wall 16 for regulating the meshing amount of the half nut 70 is also provided on the base 10. Therefore, assembling errors are not accumulated as a whole, excessive meshing between the lead screw 50 and the half nut 70 is restricted, sliding resistance is reliably reduced, and a smooth driving operation is obtained.

  5 to 7 show another embodiment of the lens driving device according to the present invention. FIG. 5 is a perspective view of the device, and FIGS. 6 and 7 are exploded perspective views of the device. In this embodiment, the auxiliary shaft 30 is eliminated, the half nut 70 is supported on the lens frame, and the arrangement location of the coil spring 90 is changed. Are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIGS. 5 to 7, the lens driving device in this embodiment includes a base 10 ′, a main guide shaft 20, a non-rotating guide shaft 21, a lens frame 40 ′, a lead screw 50, a motor 60, a half nut 70, A torsion spring 80, a coil spring 90, a detection sensor 100, and the like are provided.

As shown in FIGS. 5 to 7, the base 10 ′ includes a fixing portion 11, a bearing hole 12, a fitting hole 13, a fitting hole 14, a contact wall 16, a spring receiving portion 17 ′, and the like.
As shown in FIGS. 5 to 7, the lens frame 40 ′ includes a holding part 41, a guided part 42, a notch part 43, a receiving surface 44, a latching protrusion 45, a detected piece 46, and a circular hole in the half nut 70. A support shaft 47 ′ and the like that are fitted to 72 and support the half nut 70 in a swingable manner are provided.

That is, the half nut 70 is supported so as to be swingable with respect to a support shaft 47 ′ formed on the lens frame 40 ′. Thus, since the half nut 70 is swingably supported on the lens frame 40 ′, the number of parts can be reduced and the structure can be simplified as compared with the case where the auxiliary shaft 30 is used.
Further, as shown in FIGS. 5 to 7, the coil spring 90 is arranged around the main guide shaft 20 behind the lens frame 40 ′. Therefore, as described above, the number of parts can be reduced and the structure can be simplified and consolidated as compared with the case where the auxiliary shaft 30 is disposed around.

  Also in this embodiment, as described above, the lead screw 50 and the guide shafts 20 and 21 are all assembled with the base 10 as a reference, and the abutting wall 16 for restricting the meshing amount of the half nut 70 is also provided on the base 10. Therefore, assembling errors are not accumulated as a whole, excessive engagement between the lead screw 50 and the half nut 70 is restricted, sliding resistance is reliably reduced, and a smooth driving operation is obtained.

In the above embodiment, one lens frame 40, 40 'is shown as a lens frame that moves in the optical axis direction L, but the present invention is not limited to this, and the present invention is applied to a configuration including a plurality of lens frames. can do.
In the above embodiment, the lens frames 40 and 40 ′ holding the lens G, that is, the optical pickups are shown as the objects driven by the screw feeding structure, but the present invention is not limited to this, and other screw feeding operations are performed. It may be a movable body driven by.
In the above embodiment, the torsion spring 80 is shown as the first urging member for urging the half nut 70. However, the torsion spring 80 is not limited to this, but a flexible leaf spring, a compression type coil spring, and the like. It may be an elastic body.
In the above embodiment, the half nut 70 is a rack other than a nut that is formed in a completely annular shape and screwed with the lead screw 50, regardless of the length of the arc-shaped portion on which the female screw 71 is formed. It is a concept that also includes.

  As described above, the lens driving device of the present invention achieves simplification of the structure, downsizing of the device, and the like, and the half nut tooth skipping in the screwed relationship between the half nut (or rack) and the lead screw. It can be mounted on a recording / reproducing apparatus or the like because it can control excessive engagement and reduce sliding resistance and can drive the lens frame (lens) smoothly and with high accuracy in the optical axis direction. Of course, it can be applied to optical pickups, etc., as long as it includes a lead screw and half-nut (or rack) feed screw structure, it is also useful for camera lens drive devices, other optical equipment and electronic equipment, etc. It is.

It is a perspective view which shows one Embodiment of the lens drive device which concerns on this invention. It is a disassembled perspective view of the lens drive device shown in FIG. It is a disassembled perspective view of the lens drive device shown in FIG. It is a top view which shows the inside of the lens drive device shown in FIG. It is a perspective view which shows other embodiment of the lens drive device which concerns on this invention. It is a disassembled perspective view of the lens drive device shown in FIG. FIG. 6 is an exploded perspective view of the lens driving device shown in FIG. 5.

Explanation of symbols

L Optical axis direction (screw feed direction)
10, 10 'Base 11 Fixing portion 12 Fitting holes 13, 14, 15 Fitting hole 16 Abutting walls 17, 17' Spring receiving portion 20 Main guide shaft 21 Non-rotating guide shaft 30 Auxiliary shaft 40, 40 'Lens frame 41 Holding portion 42 Guided portion 43 Notch portion 44 Receiving surface 45 Latching protrusion 46 Detected piece 47 ′ Support shaft 50 Lead screw 51 Male screw 60 Motor 70 Half nut 71 Female screw 72 Circular hole 73 Contact portion 74 Hooking portion (Part of half nut)
80 Torsion spring (first biasing member)
81 One end 82 Other end 90 Coil spring (second biasing member)
100 detection sensor

Claims (6)

A base, a lead screw rotatably supported with respect to the base, a guide shaft disposed in parallel with the lead screw and fixed to the base, and a lens frame supported reciprocally with respect to the guide shaft A lens driving device comprising: a half nut that moves integrally with the lens frame and meshes with the lead screw; and a first biasing member that biases the half nut toward the lead screw,
The base has a contact wall that slidably contacts a part of the half nut so as to restrict the engagement of the half nut with the lead screw to a predetermined amount.
A lens driving device. The guide shaft includes a main guide shaft that slidably guides the lens frame, and a detent guide shaft that restricts the lens frame from rotating around the main guide shaft,
The first biasing member is a torsion spring disposed around the main guide shaft, one end hooked to the lens frame, and the other end hooked to the half nut.
The lens driving device according to claim 1. The half nut is swingably supported with respect to a support shaft formed on the lens frame.
The lens driving device according to claim 1 or 2, wherein A second biasing member that biases the lens frame against the half nut in the screw feed direction of the lead screw;
The lens driving device according to claim 1, wherein the lens driving device is a lens driving device. An auxiliary shaft arranged to extend parallel to the main guide shaft and the non-rotating guide shaft and fixed to the base, and urges the lens frame against the half nut in the screw feed direction of the lead screw. Including a second biasing member;
The second urging member is a compression type coil spring disposed around the auxiliary shaft.
The lens driving device according to claim 2. The half nut is swingably supported with respect to the auxiliary shaft.
The lens driving device according to claim 5.

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