JP2008058785A - Lens drive device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device which drives a lens frame by a cam barrel, and which prevents a follower pin from falling away from the cam barrel (its cam groove) by a shock or the like. <P>SOLUTION: The lens drive device is equipped with the lens frames 41 and 51 having the follower pins 42 and 52 and supported to freely move in an optical axis direction L, and the cam barrel 30 applying cam action on the follower pins 42 and 52 in the optical axis direction L by rotation. The cam barrel 30 is formed by assembling an outer barrel 31 demarcating a cylindrical outer wall, and an inner barrel 32 incorporated inside the outer barrel 31 and fixed to rotate integrally therewith, and also having cam holes 32a and 32b formed to penetrate so that they may receive the follower pins 42 and 52 and apply the cam action in the optical axis direction L. Thus, the entire barrel is covered with the outer barrel while achieving the smaller diameter of the cam barrel, and the follower pin of the lens frame is prevented from falling off from the cam hole of the cam barrel when receiving external force such as a shock caused by dropping. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lens driving device that drives a lens in the optical axis direction, and more particularly to a lens driving device that drives a lens frame in the optical axis direction by a cam cylinder that rotates around the optical axis and exerts a cam action in the optical axis direction. .

  As a conventional lens driving device, a cylindrical fixed cylinder fixed to a base and having a cam groove on an inner wall thereof, is rotatably inserted inside the fixed cylinder, and is inserted into an outer wall thereof (inserted into a cam groove of the fixed cylinder). A cylindrical cam cylinder having a follower pin and having a plurality of cam grooves on its inner wall, a lens frame for holding the lens and having a follower pin (inserted into the cam groove of the cam cylinder) on its outer wall, etc. When the cam cylinder rotates relative to the fixed cylinder, the cam groove acts on the follower pin of the lens frame in the optical axis direction to drive the lens frame (lens) in the optical axis direction. It is known (see, for example, Patent Document 1).

However, in this lens driving device, the cam groove formed in the inner wall of the cam cylinder has a narrow groove bottom in the cross section due to manufacturing restrictions (such as a die-cutting gradient) particularly when molded with a resin material. The follower pin of the lens frame which is formed in a tapered shape (having an inclined surface) and is inserted into the tapered cam groove is also formed in a tapered cone shape.
Therefore, when an external force (such as impact force when dropped) is applied to the end of the lens frame when the lens frame is extended, the follower pin of the lens frame falls out of the cam groove of the cam barrel and cannot operate. There was a risk of becoming.
On the other hand, even if the cam groove is deeply formed and the follower pin insertion length is increased to prevent the dropout, a gradient such as die cutting is still necessary, which leads to an increase in the diameter of the cam cylinder and an increase in the size of the device. become.

JP 2003-57705 A

  The present invention has been made in view of the above-mentioned problems of the prior art, and its object is to simplify the structure, ease of manufacturing, reduce the diameter, reduce the size, etc. It is intended to provide a lens driving device that can prevent a follower pin of a lens frame holding a lens from dropping from a cam cylinder even when receiving a lens, and reliably guarantee an expected function.

The lens driving device of the present invention includes a lens frame that holds a lens and has a follower pin protruding radially outward, and is supported so as to be movable in the optical axis direction. The lens frame rotates by rotating with respect to the follower pin of the lens frame. A lens driving device for driving the lens frame in the optical axis direction by rotating the cam cylinder, the cam cylinder including an outer cylinder defining a cylindrical outer wall, and an outer cylinder And an inner cylinder having a cam hole formed so as to penetrate and receive a follower pin and exert a cam action in the optical axis direction. Yes.
According to this configuration, the cam cylinder is formed by the outer cylinder and the inner cylinder, and the cam hole penetrating the inner cylinder is formed, so that it is not necessary to provide a die cutting gradient or the like in the cam hole, and the follower pin For example, a cylindrical follower pin can be inserted into the cam hole. As a result, the overall diameter of the cam cylinder can be reduced while the outer cylinder is covered, and the follower pin of the lens frame can be prevented from falling out of the cam hole of the cam cylinder when an external force such as an impact due to dropping is applied. Can be prevented.

In the above configuration, one of the inner cylinder and the outer cylinder has a first protrusion protruding in the radial direction, and the other of the inner cylinder and the outer cylinder has a first protrusion to restrict relative rotation around the optical axis. A configuration having a first fitting recess to be fitted can be adopted.
According to this configuration, when the inner cylinder having the cam hole is incorporated into the outer cylinder that defines the outer wall to form the cam cylinder that rotates integrally, the first protrusion is fitted into the first fitting recess. It is possible to easily restrict the relative rotation of the two simply by making them.

In the above configuration, one of the inner cylinder and the outer cylinder has a second protrusion that protrudes in the radial direction, and the other of the inner cylinder and the outer cylinder has a second protrusion to restrict relative movement in the optical axis direction. The structure which has the 2nd fitting recessed part which fits can be employ | adopted.
According to this configuration, when the inner cylinder having the cam hole is incorporated into the outer cylinder that defines the outer wall to form the cam cylinder that rotates integrally, the second protrusion is fitted into the second fitting recess. It is possible to easily regulate the relative movement of both in the direction of the optical axis simply by making them.

In the above configuration, one of the inner cylinder and the outer cylinder has a second protrusion that protrudes in the radial direction, and the other of the inner cylinder and the outer cylinder has a second protrusion to restrict relative movement in the optical axis direction. It is possible to adopt a configuration having a second fitting recess for fitting the second projection and a guide groove that slides and receives the second protrusion in the optical axis direction and leads to the second fitting recess by relative rotation of both. .
According to this configuration, when the inner cylinder is inserted into the outer cylinder and incorporated, the second protrusion is moved along the guide groove in the optical axis direction, and then the two are relatively rotated. The second protrusion can be fitted into the second fitting recess.

In the above configuration, the first protrusion is formed so as to restrict relative rotation in a direction in which the second protrusion is detached from the second fitting recess while being fitted in the first fitting recess. Can be adopted.
According to this configuration, when the second protrusion is fitted into the second fitting recess, both (the inner cylinder and the outer cylinder) are positioned in the optical axis direction, and in one direction of both (the inner cylinder and the outer cylinder). When the first protrusion is fitted into the first fitting recess, the relative rotation of the two (inner cylinder and outer cylinder) in the other direction is restricted.
Therefore, it is possible to easily perform the assembly operation of both (inner cylinder and outer cylinder) while positioning both (inner cylinder and outer cylinder) in the optical axis direction and the rotation direction.

The said structure can employ | adopt the structure currently formed so that a 1st protrusion may fit in a 1st fitting recessed part by the elastic deformation of an inner cylinder or an outer cylinder.
According to this configuration, the first projection can be easily fitted to the first fitting recess, and the first projection can be fitted so as to be firmly attached to the first fitting recess. Can do.

In the above configuration, the first protrusion is formed to protrude radially outward from the outer wall of the inner cylinder, the first fitting recess is formed on the inner wall of the outer cylinder, and the second protrusion is formed with a diameter from the inner wall of the outer cylinder. The second fitting recess and the guide groove are formed on the outer wall of the inner cylinder, and at the same time the first projection is fitted into the first fitting recess, the second projection is second fitted. The structure formed so that it may be fitted by the joint recessed part is employable.
According to this configuration, when the inner cylinder is assembled into the outer cylinder, the second protrusion of the outer cylinder is slid in the optical axis direction along the guide groove of the inner cylinder, and then both are rotated relatively. Since the first projection of the inner cylinder is fitted into the first fitting recess of the outer cylinder and the second projection of the outer cylinder is fitted into the second fitting recess of the inner cylinder, both are in the optical axis direction. And positioning around the optical axis (relative rotation restriction) are performed simultaneously. Therefore, the assembly work of the inner cylinder and the outer cylinder can be performed easily and easily.

The said structure WHEREIN: The 1st fitting recessed part can employ | adopt the structure currently formed so that the wall surface of an outer cylinder may be penetrated.
According to this configuration, the first protrusion provided on the outer wall of the inner cylinder is exposed to the outside in a state of being fitted in the first fitting recess (through hole) of the outer cylinder. When separating the inner cylinder from the outer cylinder, the first protrusion can be easily detached from the first fitting recess by pressing the first protrusion inward from the outside through the first fitting recess (through hole). Can do.

  According to the lens driving device having the above-described configuration, the follower pin of the lens frame that holds the lens even when subjected to an external force or the like, while achieving simplification of the structure, ease of manufacture, downsizing, etc. ) Can be prevented, and a lens driving device can be obtained that can reliably ensure the desired function.

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 an exploded perspective view of the device, FIG. 2 is a sectional view of the device, and FIG. 3 is a cam cylinder included in the device. FIG. 4 is a partial view for explaining the assembly of the outer cylinder and the inner cylinder forming the cam cylinder.

  As shown in FIG. 1 and FIG. 2, this apparatus includes a glass filter 11, a base 10 having a substantially rectangular outline to which a CCD 12 as an image sensor is attached, a fixed cylinder 20 fixed to the base 10, and a fixed cylinder. 20 is a cam cylinder 30 that is supported so as to be rotatable and straightly movable inside 20, and a first lens group 40 and a second lens group 50 that are supported so as to be movable in the optical axis direction L inside the cam cylinder 30, and a first lens group. 40 and a guide cylinder 60 that guides in the optical axis direction while restricting rotation of the second lens group 50, a drive mechanism 70 that drives the cam cylinder 30, and the like.

As shown in FIGS. 1 and 2, the fixed cylinder 20 is formed in a cylindrical shape with a resin material so as to have an axis in the optical axis direction L, and is fixed to the base 10. The fixed cylinder 20 has three cam grooves 21 (partially omitted in the drawing) that exert cam action on three follower pins 31b described later on the inner wall thereof.
The three cam grooves 21 are formed so as to form an inclined surface with a narrow groove bottom, as shown in FIG.

  As shown in FIG. 1 to FIG. 4, the cam cylinder 30 includes an outer cylinder 31 molded in a cylindrical shape by a resin material, and an inner cylinder 32 molded in a cylindrical shape by a resin material and fitted inside the outer cylinder 31. In the state where the outer cylinder 31 and the inner cylinder 32 are assembled so as to rotate integrally, they are arranged coaxially in a nested manner inside the fixed cylinder 20.

  As shown in FIG. 3 and FIG. 4, the outer cylinder 31 is arranged at equal intervals (approximately every 120 degrees) in the circumferential direction on the first fitting recess 31 a formed so as to penetrate the wall surface. The first guide has three follower pins 31b, an arc-shaped rack portion 31c to which rotational driving force is transmitted from the outside, and the like, and its inner wall extends in the optical axis direction L and is bent in the circumferential direction. Grooves 31d (see FIG. 4), two second protrusions 31e formed in the optical axis direction L at two equal intervals in the circumferential direction (total 18).

The first fitting recess 31a is formed as a substantially rectangular through-hole, and receives a first projection 32c (described later) of the inner cylinder 32, and positions both (the inner cylinder 32 and the outer cylinder 31) around the optical axis L. It is formed to do.
The three follower pins 31b are formed in a tapered conical shape, are slidably inserted into the cam groove 21 of the fixed cylinder 20, and are subjected to the cam action of the cam groove 21 by the rotation of the outer cylinder 31 itself. It can be moved to L.

  The first guide groove 31d guides a first protrusion 32c (of the inner cylinder 32) to be slidable in the optical axis direction L when the inner cylinder 32 is fitted into the outer cylinder 31, and the inner cylinder 32 When the first protrusion 32c (inner cylinder 32), which will be described later, is fitted into the first fitting recess 31a of the outer cylinder 31 by rotating it by a predetermined angle around the optical axis L with respect to the outer cylinder 31 (inner cylinder) 32, the first protrusion 32c (to be described later) is pressed inward (that is, the wall around the first protrusion 32c is elastically deformed) and is guided to the first fitting recess 31a of the outer cylinder 31. The groove width and the groove depth are formed.

  The second protrusion 31e is slidably guided in the optical axis direction L along a second guide groove 32d (of the inner cylinder 32) (described later) when the inner cylinder 32 is fitted into the outer cylinder 31. The cylinder 32 is rotated by a predetermined angle around the optical axis L with respect to the outer cylinder 31 and fitted into a second fitting recess 32e (of the inner cylinder 32), which will be described later, and both (the inner cylinder 32 and the outer cylinder 31) are lighted. When positioning in the axial direction L, a curved surface having a predetermined curvature and a predetermined chamfer are formed to have a predetermined protrusion height and width so that the second guide groove 32d is smoothly guided to the second fitting recess 32e. It is formed to include.

  As shown in FIGS. 3 and 4, the inner cylinder 32 is formed so as to penetrate the wall surface, and has three cam holes 32 a and second cams that have a cam action in the optical axis direction L with respect to the first lens group 40. Three cam holes 32b having a cam action in the optical axis direction L with respect to the lens group 50, first protrusions 32c projecting radially outward on the outer wall, and extending in the optical axis direction L at equal intervals in the circumferential direction Nine second guide grooves 32d formed so as to be connected, second fitting recesses 32e connected to the respective second guide grooves 32d and arranged side by side in the optical axis direction L (18 in total), etc. Have

The cam holes 32a and 32b are all formed as through-holes penetrating the wall surface, and the inner edge (wall surface defining the hole) is formed not as an inclined surface but as a vertical surface. Therefore, the cam holes 32a and 32b can slidably receive follower pins 42 and 52, which will be described later, formed in a columnar shape instead of a conical shape.
Thus, by forming the cam holes 32a and 32b penetrating the inner cylinder 32, it is not necessary to provide a die-cutting gradient or the like at the inner edge thereof, and the cylindrical follower pins 42 and 52 are not provided in the conical shape. Since it can be inserted into 32a, 32b, it is possible to prevent follower pins 42, 52, which will be described later, from falling out of the cam holes 32a, 32b when receiving external force such as impact due to dropping.

  The first protrusion 32c is slidably guided in the optical axis direction L along the first guide groove 31d of the outer cylinder 31 when the inner cylinder 32 is fitted into the outer cylinder 31, and the inner cylinder 32 is When positioning the both (inner cylinder 32 and outer cylinder 31) around the optical axis L by rotating the cylinder 31 around the optical axis L by a predetermined angle and fitting it into the first fitting recess 31a of the outer cylinder 31. , Forming a predetermined inclined surface so as to be smoothly guided to the first fitting recess 31a while being pressed inward (that is, the wall portion around the first protrusion 32c is elastically deformed), and the first fitting At the same time as fitting into the mating recess 31a, it is in contact with the inner edge thereof to restrict reverse rotation.

  The second guide groove 32 d guides the second protrusion 31 e so as to be slidable in the optical axis direction L when the inner cylinder 32 is fitted into the outer cylinder 31, and the inner cylinder 32 is optically guided with respect to the outer cylinder 31. When the second protrusion 31e is rotated around the axis L by a predetermined angle so that the second protrusion 31e is fitted in the second fitting recess 32e of the inner cylinder 32, and both of them (the inner cylinder 32 and the outer cylinder 31) are positioned in the optical axis direction L, The second protrusion 31e is formed to have a predetermined groove width and groove depth so as to smoothly guide the second protrusion 31e to the second fitting recess 32e of the inner cylinder 32.

The outer cylinder 31 and the inner cylinder 32 having the above-described configuration are assembled by positioning the first protrusion 32c of the inner cylinder 32 in the first guide groove 31d of the outer cylinder 31, and the second protrusion 31e of the outer cylinder 31 as the inner. Positioning in the second guide groove 32d of the cylinder 32, as shown in FIG. 4A, the inner cylinder 32 is fitted into the outer cylinder 31 (inserted in the optical axis direction L).
Then, the first protrusion 32c is guided in the optical axis direction L by the first guide groove 31d, and the second protrusion 31e is guided in the optical axis direction L by the second guide groove 32d, as shown in FIG. Until the predetermined fitting allowance is reached (until the second protrusion 31e near the rear end contacts the end of the second guide groove 32d).

Subsequently, as shown in FIG. 4B, when the inner cylinder 32 is rotated by a predetermined angle with respect to the outer cylinder 31, the second protrusion 31e is fitted into the second fitting recess 32e, and at the same time, After the one protrusion 32c is pressed, it is elastically restored and fitted into the first fitting recess 31a.
Thereby, both (the inner cylinder 32 and the outer cylinder 31) are fixed so as not to move relatively in the optical axis direction L by fitting the second protrusion 31e into the second fitting recess 32e, By fitting the first protrusion 32c into the first fitting recess 31a, the second protrusion 31e is fixed so as not to rotate relatively around the optical axis L in cooperation with the fitting of the second protrusion 31e into the second fitting recess 32e. Is done.

  When disassembling the inner cylinder 32 and the outer cylinder 31, the first protrusion 32 c of the inner cylinder 32 is exposed to the outside in a state where the first protrusion 32 c is fitted in the first fitting recess 31 a (through hole) of the outer cylinder 31. Therefore, the first protrusion 32c is pressed from the outside to the inside through the first fitting recess 31a (through hole) to be detached from the first fitting recess 31a, and both are rotated in the reverse direction and extracted. Therefore, it can be easily separated.

That is, the cam cylinder 30 is completed by assembling both separately formed (inner cylinder 32 and outer cylinder 31) so as to rotate integrally.
In the cam cylinder 30, as shown in FIG. 2, an annular groove 30 a is defined between the distal end wall of the inner cylinder 32 and the distal end wall of the outer cylinder 31.

  As described above, when the inner cylinder 32 having the cam holes 32a and 32b is incorporated into the outer cylinder 31 that defines the outer wall to form the cam cylinder 30 that rotates integrally, the first protrusion 32c is inserted into the first fitting 32c. By simply fitting the mating recess 31a and fitting the second protrusion 31e to the second fitting recess 32e, the relative rotation of both can be easily controlled and both in the optical axis direction L. Relative movement can be easily controlled.

As shown in FIGS. 1 and 2, the first lens group 40 has a lens frame 41 formed in a substantially cylindrical shape by a resin material, projects radially outward on the outside of the lens frame 41, and is equally spaced in the circumferential direction. Three follower pins 42 that are arranged (at every 120 ° angle) and slidably engage with the cam hole 32a, are supported movably in the optical axis direction L inside the lens frame 41, and hold the lens G1. And a drive mechanism 44 for driving the holding cylinder 43 in the optical axis direction L.
As shown in FIG. 2, the follower pin 42 is formed in a cylindrical shape and is slidably inserted into the cam hole 32a.
In the first lens group 40, the cam cylinder 30 rotates and the cam hole 32 a exerts a cam action on the follower pin 42, whereby the lens frame 41 moves forward and backward in the optical axis direction L, and is driven by the drive mechanism 44. The holding cylinder 43 moves forward and backward in the optical axis direction L with respect to the lens frame 41.

As shown in FIGS. 1 and 2, the second lens group 50 is formed in a substantially cylindrical shape by a resin material, and protrudes radially outward from the lens frame 51 that holds the lens G2, the lens frame 51, and the periphery. It is provided with three follower pins 52, a shutter mechanism 53, and the like that are arranged at equal intervals in the direction (every 120 degrees) and slidably engage with the cam holes 32b.
As shown in FIG. 2, the follower pin 52 is formed in a cylindrical shape and is slidably inserted into the cam hole 32b.
The second lens group 50 moves forward and backward in the optical axis direction L when the cam barrel 30 rotates and the cam hole 32 b exerts a cam action on the follower pin 52.

As shown in FIGS. 1 and 2, the guide cylinder 60 is disposed between the first lens group 40 and the second lens group 50 and the cam cylinder 30 (inner cylinder 32), and the first lens group 40 and the first lens group 40. The two lens group 50 is guided so as to reciprocate in the optical axis direction L while restricting rotation around the optical axis L.
That is, the guide tube 60 receives the follower pin 42 of the first lens group 40 and guides it in the optical axis direction L, and receives the guide pin 52 of the second lens group 50 and guides it in the optical axis direction 3. One guide groove 62, three engagement pieces 63 engaged with an annular groove 30a defined on the inner peripheral surface of the cam cylinder 30, and non-rotatable with respect to the fixed cylinder 20 and movable in the optical axis direction L A projection 64 and the like are provided.
Here, the guide groove 61 and the guide groove 62 are arranged at equal intervals in the circumferential direction (at an angle of 120 degrees), and are slit-shaped (long holes) that are notched and extend in the optical axis direction L. The groove shape is defined in cooperation with the inner peripheral surface of the cam cylinder 30 (inner cylinder 32).

The guide cylinder 60 is fitted to the inner peripheral surface of the cam cylinder 30, and the engagement piece 63 is engaged with the annular groove 30a so that it does not move relatively in the optical axis direction L. The protrusion 64 is hooked on the fixed cylinder 20 so as not to rotate around the optical axis L.
Therefore, when the cam cylinder 30 rotates, the guide groove 61 of the guide cylinder 60 guides the follower pin 42, which is cammed by the cam hole 32a, so that it can reciprocate only in the optical axis direction L. 62 guides the follower pin 52, which is cammed by the cam hole 32b, so as to be reciprocally movable only in the optical axis direction L.

As shown in FIG. 1, the drive mechanism 70 includes a DC motor 71 fixed to the base 10, a gear train (not shown) that meshes with the rack portion 31 c of the cam cylinder 30, and the like. Is transmitted to the cam cylinder 30.
That is, when the DC motor 71 rotates in one direction, the cam cylinder 30 rotates in one direction relative to the fixed cylinder 20 via the gear train, and passes through the wide-angle end position from the retracted position to the first lens group 40. When the second lens group 50 moves forward in the optical axis direction L and moves to the telephoto end position, while the DC motor 71 rotates in the reverse direction, the cam cylinder 30 is moved relative to the fixed cylinder 20 via the gear train. Thus, the first lens group 40 and the second lens group 50 move rearward in the optical axis direction L, pass through the wide-angle end position, and then move to the retracted position.

  According to the apparatus having the above configuration, the cam cylinder 30 is formed by the outer cylinder 31 and the inner cylinder 32, and the cam holes 32a and 32b penetrating the inner cylinder 32 are formed. It is not necessary to provide a draft angle, and the follower pins 42 and 52 formed in a columnar shape instead of a conical shape can be inserted into the cam holes 32a and 32b. Accordingly, the follower pins 42 and 52 of the lens frames 41 and 51 are prevented from falling out of the cam holes 32a and 32b of the cam cylinder 30 when an external force such as an impact due to dropping is received while achieving a reduction in the diameter of the cam cylinder 30. Can be prevented.

Next, a general operation when the above lens driving device is mounted on a digital camera will be described. First, at the time of non-shooting, the first lens group 40 and the second lens group 50 are rearward in the optical axis direction L. It is in the retracted position retracted toward.
When the cam cylinder 30 is rotated by the drive mechanism 70 from the retracted position, the follower pin 31b is guided and moved by the cam groove 21, and the cam cylinder 30 is advanced forward in the optical axis direction L. Further, the rotation of the cam cylinder 30 causes the follower pin 42 to be guided only in the optical axis direction L by the guide groove 61 while receiving the cam action by the cam hole 32a, and the follower pin 52 is guided only in the optical axis direction L by the guide groove 62. In response to the cam action by the cam hole 32b, the first lens group 40 and the second lens group 50 are relatively relative to the front F and the rear R in the optical axis direction L while being restricted from rotating with respect to the cam barrel 30. It moves and reaches the wide-angle end position and further the telephoto end position.
On the other hand, when the driving mechanism 70 exerts a driving force in the reverse direction, the first lens group 40 and the second lens group 50 follow the reverse path and return from the telephoto end position to the retracted position.

In the first lens group 40, in addition to the movement of the cam cylinder 30 through the cam hole 32 a, the holding cylinder 43 moves relative to the lens frame 41 in the optical axis direction L by driving the drive mechanism 44. Thus, a focusing operation corresponding to zooming is performed.
In this focusing operation, when the lead screw is rotated by the driving force of the stepping motor, the nut is screwed and the holding cylinder 43 is appropriately driven in the optical axis direction L together with the nut.

In the state where the first lens group 40 is extended, the follower pin 42 of the lens frame 41 can be removed from the cam hole 32a of the cam barrel 30 even if an external force that pushes the lens frame 41 toward the rear R due to dropping or the like acts. It can be prevented from falling off.
Further, even when an impact force (inertial force) is applied due to dropping or the like, the follower pin 52 of the lens frame 51 can be prevented from coming off from the cam hole 32b of the cam barrel 30.

In the above embodiment, the case where the present invention is applied is shown in the configuration including the first lens group 40 and the second lens group 50 driven in the optical axis direction L by the cam cylinder 30, but the present invention is limited to this. The present invention may be employed in a configuration including one or three or more lens groups.
In the above embodiment, the first protrusion 32 c, the second guide groove 32 d and the second fitting recess 32 e are provided on the outer wall of the inner cylinder 32, and the second protrusion 31 e and the outer cylinder 31 are formed on the inner wall of the outer cylinder 31. Although the case where the first fitting recess 31 a is provided so as to penetrate the outer cylinder 31 is not limited thereto, the second protrusion or the first protrusion is provided on the outer wall of the inner cylinder 32, and the outer cylinder 31 is provided. You may employ | adopt the structure which provides a 2nd fitting recessed part and a 2nd guide groove or a 1st fitting recessed part, and a 1st guide groove with respect to the inner wall.
In the said embodiment, although the case where the 1st fitting recessed part 31a was formed so that it might penetrate the wall surface of the outer cylinder 31 (as a through-hole) was shown, it is not limited to this, The outer cylinder 31 It may be formed so as not to penetrate through the inner wall.

  As described above, the lens driving device of the present invention achieves the simplification of the structure, the ease of manufacture, the miniaturization, etc., and the follower pin of the lens frame that holds the lens even when subjected to an external force or the like is the cam cylinder. The lens can be applied to a lens driving device mounted on a portable camera or the like where there is a concern about dropping or the like. It is also useful in an optical system other than a camera equipped with a driving device.

It is a disassembled perspective view which shows one Embodiment of the lens drive device which concerns on this invention. It is sectional drawing of the lens drive device shown in FIG. It is a disassembled perspective view which shows the cam cylinder contained in the lens drive device shown in FIG. (A), (b) is a fragmentary figure which shows the assembly | attachment procedure of the cam cylinder contained in the lens drive device shown in FIG.

Explanation of symbols

L Optical axis direction F Optical axis direction forward R Optical axis direction rear G1, G2 Lens 10 Base 11 Glass filter 12 CCD
20 fixed cylinder 21 cam groove 30 cam cylinder 30a annular groove 31 outer cylinder 31a first fitting recess 31b follower pin 31c rack part 31d first guide groove 31e second protrusion 32 inner cylinder 32a, 32b cam hole 32c first protrusion 32d second Guide groove 32e Second fitting recess 40 First lens group 41 Lens frame 42 Follower pin 43 Holding cylinder 44 Drive mechanism 50 Second lens group 51 Lens frame 52 Follower pin 53 Shutter mechanism 60 Guide cylinder 61, 62 Guide groove 63 Engagement piece 64 Protrusion 70 Drive mechanism 71 DC motor

Claims (8)

A lens frame that holds a lens and has a follower pin that protrudes radially outward and is supported so as to be movable in the optical axis direction, and a cam cylinder that exerts a cam action in the optical axis direction by rotation with respect to the follower pin of the lens frame A lens driving device for rotating the cam cylinder to drive the lens frame in the optical axis direction,
The cam cylinder is fixed to the outer cylinder defining the cylindrical outer wall and the inner cylinder so as to rotate integrally, and to receive the follower pin to exert a cam action in the optical axis direction. An inner cylinder having a cam hole formed therethrough,
A lens driving device. One of the inner cylinder and the outer cylinder has a first protrusion protruding in the radial direction,
The other of the inner cylinder and the outer cylinder has a first fitting recess for fitting the first protrusion to restrict relative rotation around the optical axis.
The lens driving device according to claim 1. One of the inner cylinder and the outer cylinder has a second protrusion protruding in the radial direction,
The other of the inner cylinder and the outer cylinder has a second fitting recess for fitting the second protrusion to restrict relative movement in the optical axis direction.
The lens driving device according to claim 2. One of the inner cylinder and the outer cylinder has a second protrusion protruding in the radial direction,
The other of the inner cylinder and the outer cylinder includes a second fitting recess for fitting the second protrusion to restrict relative movement in the optical axis direction, and sliding the second protrusion in the optical axis direction. A guide groove that receives and guides to the second fitting recess by relative rotation of the two;
The lens driving device according to claim 2. The first protrusion is formed so as to restrict relative rotation in a direction in which the second protrusion is detached from the second fitting recess while being fitted in the first fitting recess.
The lens driving device according to claim 4. The first protrusion is formed to fit into the first fitting recess by elastic deformation of the inner cylinder or the outer cylinder.
The lens driving device according to claim 5. The first protrusion is formed to protrude radially outward from the outer wall of the inner cylinder,
The first fitting recess is formed on the inner wall of the outer cylinder,
The second protrusion is formed to protrude radially inward from the inner wall of the outer cylinder,
The second fitting recess and the guide groove are formed on the outer wall of the inner cylinder,
The second protrusion is formed so as to be fitted into the second fitting recess at the same time as the first protrusion is fitted into the first fitting recess.
The lens driving device according to claim 4, wherein the lens driving device is a lens driving device. The first fitting recess is formed so as to penetrate the wall surface of the outer cylinder.
The lens driving device according to claim 7.

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