JP4699126B2 - Lens drive device - Google Patents

Description

  The present invention relates to a lens driving device mounted on a digital camera, a silver salt film camera, and the like, and more particularly, to a lens driving device that extends a plurality of lens groups capable of zooming from a retracted position during shooting.

  As a lens driving device for a camera capable of zooming shooting, a plurality of lens groups arranged in the optical axis direction, a plurality of driving mechanisms for moving the respective lens groups in the optical axis direction, at least during non-shooting retraction Equipped with a swing mechanism that swings one lens group within a plane perpendicular to the optical axis (rotates about an axis arranged parallel to the optical axis) and retracts it to a retracted position off the optical axis It has been known.

In this lens driving device, at the time of shooting, the lens group that is swung is made to face the shooting position on the optical axis from the retracted position, and then the plurality of lens groups are relatively moved in the optical axis direction to perform zooming and On the other hand, when the lens group that is swung is retracted to a retracted position that is out of the optical axis in advance, the front lens group or the retracted lens group is moved backward in the optical axis direction. (See, for example, Patent Document 1 and Patent Document 2).
JP 2003-315861 A JP 2003-149723 A

  By the way, in the above lens driving device, at the time of retraction, at least one lens group is swung around an axis parallel to the optical axis and retracted to a retracted position off the optical axis. Because it is retracted, the size in the optical axis direction when retracted can be shortened and the device can be thinned, but the retracting method is a method of swinging the lens group around the axis parallel to the optical axis. In order to be able to accommodate the outer contour of the lens group in the retracted state, the case of the device becomes large in the direction perpendicular to the optical axis, which leads to an increase in the size of the device as a whole.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a lens driving device capable of simplifying the structure, reducing the size, reducing the thickness at the time of retraction, and reducing the size. It is in.

The lens driving device according to the present invention holds a lens and includes a plurality of lens frames including a foremost lens frame and a rearmost lens frame arranged on the optical axis, and extends and retracts the plurality of lens frames in the optical axis direction. Positioned at the retracted position, the drive mechanism, the retracting mechanism that retracts the rearmost lens frame from the position on the optical axis facing the optical axis when retracted to the retracted position bent in a direction substantially perpendicular to the optical axis direction And a locking mechanism that locks the rearmost lens frame so that the rearmost lens frame cannot swing . The frontmost lens frame defines an inner space that receives the rearmost lens frame positioned at the retracted position when retracted. The locking mechanism is characterized in that it also serves as the foremost lens frame that receives the rearmost lens frame and engages a part thereof .
According to this configuration, the plurality of lens frames are appropriately moved in the position on the optical axis by the driving mechanism during shooting to perform zooming and focusing, and retracted by the driving mechanism during non-shooting, and the rearmost lens frame is bent. The retracting mechanism retracts from a position on the optical axis to a retracted position bent in a direction substantially perpendicular to the optical axis direction. As a result, the other lens frames can be further retracted toward the space after the rearmost lens frame is retracted, and the apparatus can be thinned when retracted. Further, the rearmost lens frame, because it is received inside the space of the forwardmost lens frame with positioned angular transformation to the retracted positions Tsu line so as to face the direction substantially perpendicular from the optical axis position, perpendicular to the optical axis Thus, it is possible to suppress the protrusion in the radial direction, and it is possible to achieve a reduction in size in the radial direction perpendicular to the optical axis at the same time as making the device thinner.
In addition, when the rearmost lens frame is retracted to the retracted position, the locking mechanism operates to lock the rearmost lens frame so that it cannot swing. The frame is held in the retracted position without causing rattling or collision noise. In particular, since the locking mechanism serves as the foremost lens frame that receives the rearmost lens frame and engages a part thereof, the locking mechanism can be simplified, contributing to the downsizing and thinning of the apparatus.

In the above structure, the bending retracting mechanism includes a support shaft for supporting the rearmost lens frame swingably about the axis of the optical axis direction perpendicular to the retraction position from the optical axis position rearmost lens frame when collapsed A configuration including a guide member for guiding may be employed.
According to this configuration, when retracted, the rearmost lens frame swings around the support shaft while being guided by the guide member, and the direction of the lens is converted between the position on the optical axis and the retracted position. In this way, the bending and retracting mechanism is formed by a simple configuration of a support shaft that supports the rearmost lens frame in a swingable manner and a guide member that guides the rearmost lens frame when retracted, thereby simplifying the device. Contributes to downsizing and thinning of the device.

In the above configuration, the guide member includes a cam portion that is provided at a predetermined position and exerts a cam action when the rearmost lens frame is retracted, and a spring that biases the rearmost lens frame toward the position on the optical axis. Including configurations can be employed.
According to this configuration, with the collapsed operation of the rearmost lens frame to move the rearmost lens frame to the retracted position from the optical axis position exerts camming the cam portion to the rearmost lens frame. At this time, since the rearmost lens frame is urged toward the position on the optical axis by the spring, the cam portion can surely exert a cam action on the rearmost lens frame.

In the above-described configuration, it is possible to adopt a configuration in which the rearmost lens frame retracted by the bending retracting mechanism is supported so as to be swingable with respect to the support frame supported to be movable in the optical axis direction.
According to this configuration, when the rearmost lens frame is at the position on the optical axis, it is supported by the support frame and guided in the optical axis direction, and when retracted to the retracted position, the rearmost lens frame is in a direction substantially perpendicular to the support frame. The direction is changed. As described above, since the rearmost lens frame is supported so as to be swingable with respect to the support frame, it is possible to prevent the positional deviation at the position on the optical axis as much as possible, and to move stably with high accuracy.

In the above configuration, the plurality of lens frames includes a first lens frame as the foremost lens frame, a second lens frame, and a third lens frame as the rearmost lens frame arranged in order from the front in the optical axis direction. The bending retraction mechanism can adopt a configuration in which the third lens frame is moved between the position on the optical axis and the retraction position.
According to this configuration, at the time of non-photographing, the first lens frame to the third lens frame are retracted, and the third lens frame located at the rearmost side is bent by the bending retracting mechanism and retracted to the retracting position. Thereby, the length in the optical axis direction (conjugate length) can be set longer during shooting, while the apparatus can be thinned by reducing the dimension in the optical axis direction during non-shooting.

  According to the lens driving device having the above configuration, it is possible to obtain a lens driving device that can achieve the simplification of the structure, the miniaturization, the thinning and the miniaturization when retracted, and the like.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. 1 to 7 show an embodiment of a lens driving device according to the present invention. FIGS. 1 and 2 are sectional views of the device, and FIGS. 3 and 4 are sectional views and a front view showing a bending and retracting mechanism. 5 to 7 are operation diagrams for explaining the operation of the lens frame being bent and retracted.

  As shown in FIGS. 1 to 4, this lens driving device is fixed to a base 10 and a base 10 to which a contour is formed in a substantially rectangular contour and a glass filter 11 and an image sensor (CCD etc.) 12 are attached. The fixed barrel 20, a cylindrical cam barrel 30 that is supported so as to be rotatable and rectilinearly movable inside the fixed barrel 20, and a variable magnification lens optical system that is supported movably in the optical axis direction L inside the cam barrel 30. A focusing lens optical system supported by the first lens group 40, the second lens group 50, and the base 10 so as to be movable in the optical axis direction L and to be bent in a direction substantially perpendicular to the optical axis direction L. The third lens group 60, the first drive mechanism 70 for driving the variable lens optical system, the second drive mechanism 80 for driving the focusing lens optical system, and the third lens group 60 are bent and retracted to the retracted position. bent And a avoid mechanism 90 or the like.

  As shown in FIGS. 1 and 2, the cam cylinder 30 includes three follower pins 31 that protrude radially outward from the outer peripheral surface, and arc-shaped teeth formed on the outer peripheral surface of the rear region in the optical axis direction L. Part 32, three cam grooves 33, 34 formed on the inner peripheral surface and camming the first lens group 40 and the second lens group 50, respectively, and rotatable relative to the inner peripheral surface and the fixed cylinder 20 And a guide tube 35 that guides in the optical axis direction L while restricting rotation of the first lens group 40 and the second lens group 50. The follower pin 31 is inserted into a cam groove 21 formed on the inner peripheral surface of the fixed cylinder 20, and the cam cylinder 30 reciprocates in the optical axis direction L when rotated. .

As shown in FIGS. 1 and 2, the first lens group 40 includes a first lens frame 41 as a cylindrical frontmost lens frame that holds the lens G <b> 1, and radially outward from the outer peripheral surface of the first lens frame 41. There are provided three follower pins 42, a barrier mechanism 43, and the like that protrude and are provided at equiangular intervals in the outer circumferential direction. The three follower pins 42 are inserted into the cam grooves 33 of the cam cylinder 30, and when the cam cylinder 30 rotates, the first lens group 40 is controlled by the guide cylinder 35 while rotating in the optical axis direction. In L, it moves forward and retracts backward.

Here, as shown in FIG. 1, the first lens frame 41 of the first lens group 40 is an engaging member that engages with the third lens frame 61 positioned at the retracted position by a bending retracting mechanism 90 described later, that is, The third lens frame 61 also serves as a lock mechanism that locks the third lens frame 61 in the retracted position so as not to swing.
According to this, even if the apparatus receives an impact or vibration from the outside, the rattling or collision noise of the third lens frame 61 is prevented, and the first lens frame 41 also serves as a locking mechanism, so that a dedicated member is provided. This is unnecessary, and the device can be further reduced in size and thickness by reducing the number of parts and simplifying the structure.

  As shown in FIGS. 1 and 2, the second lens group 50 is disposed behind the first lens group 40, and is radially outward from the second lens frame 51 that holds the lens G <b> 2 and the second lens frame 51. 3 follower pins 52 provided at equiangular intervals in the outer peripheral direction, and a shutter mechanism 53 that is held by the second lens frame 51 to open and close the opening for exposure and adjust the amount of light. Yes. The three follower pins 52 are inserted into the cam groove 34 of the cam cylinder 30, and when the cam cylinder 30 rotates, the rotation of the second lens group 50 is restricted by the guide cylinder 35, while in the optical axis direction. In L, it moves forward and retracts backward.

  The first drive mechanism 70 moves the first lens group 40 and the second lens group 50 in the optical axis direction L to perform zooming (magnification operation), and rotates the cam cylinder 30. Therefore, as shown in FIGS. 1 and 2, a spur gear that is rotatably supported by the base 10 and meshes with the teeth 32 of the cam cylinder 30, a gear train that meshes with the spur gear, and a DC motor (not shown). Etc.

  That is, when the first drive mechanism 70 is driven, the cam cylinder 30 is rotated forward in one direction and is advanced forward in the optical axis direction L, and the first lens group 40 and the second lens group 50 are operated by the cam grooves 33 and 34. The lens is extended from the retracted position toward the front in the optical axis direction L and the distance between them is adjusted as appropriate to perform zooming from wide angle to telephoto. On the other hand, the cam barrel 30 rotates backward to the rear in the optical axis direction L. The first lens group 40 and the second lens group 50 are retracted from the extended position toward the rear in the optical axis direction L by the action of the cam grooves 33 and 34.

As shown in FIGS. 1 to 4, the third lens group 60 is disposed behind the second lens group 50, and includes a third lens frame 61 and a third lens as the rearmost lens frame that holds the lens G <b> 3. A support frame 62 that supports the frame 61 in a swingable manner, a guide hole that is integrally formed with the support frame 62 and fixed to the guide shafts 13 and 14 fixed to the base 10, and a connection having a U-shaped notch The parts 63, 64, a nut holding part 65 for holding a nut 85 described later in a non-rotatable manner, a latching piece 66 for latching one end of a coil spring 86 described later, and the like are provided.
Here, the third lens frame 61 is integrally provided with a hemispherical protrusion 61a that engages with a cam portion 93 to be described later when retracted.

  The second drive mechanism 80 extends the third lens group 60 in the optical axis direction L and retracts it rearward so as to perform a focusing operation on the first lens group 40 and the second lens group 50. FIG. As shown in FIG. 4, the step motor 81 fixed to the base 10, the gear 82 directly connected to the step motor 81, the gear 83 that is rotatably supported by the base 10 and meshes with the gear 82, and the gear 83 are integrated. The lead screw 84 is formed so as to rotate in the direction of the optical axis L and extends in the optical axis direction L, the nut 85 screwed into the lead screw 84, the base 10 and the latch piece 66 of the support frame 62. A coil spring 86 or the like is provided that urges the lens 62 (third lens group 60) toward the retracted direction (backward in the optical axis direction L).

  That is, when the gears 82 and 83 are rotated by the step motor 81 and the lead screw 84 rotates in one direction, the third lens group 60 together with the nut 85 opposes the urging force of the coil spring 86 in the optical axis direction L. On the other hand, when the lead screw 84 rotates in the reverse direction, the third lens group 60 is retracted together with the urging force of the coil spring 86 toward the rear in the optical axis direction L together with the nut 85 (retraction). ) Thereby, focusing is performed to position the third lens group 60 at the in-focus position corresponding to the zoom position of the first lens group 40 and the second lens group 50.

  As shown in FIGS. 1 to 4, the bending / retracting mechanism 90 supports the third lens frame 61 with respect to the support frame 62 so as to be swingable about an axis S in a direction perpendicular to the optical axis direction L. A predetermined position of the torsion-type spring 92 and the base 10 arranged around the support shaft 91 to urge the third lens frame 61 toward the position on the optical axis facing the support frame 62 and facing the optical axis. And a cam portion 93 and the like that are provided integrally with the third lens group 60 and exert a cam action when the third lens group 60 (third lens frame 61) is retracted. That is, a guide that guides the third lens frame 61 from a position on the optical axis facing the optical axis to a retracted position bent in a direction substantially perpendicular to the optical axis direction L by the spring 92, the cam portion 93, etc. A member is configured.

The bending and retracting mechanism 90 is configured so that the first lens group 40, the second lens group 50, and the third lens group 60 are retracted by the first drive mechanism 70 and the second drive mechanism 80 during non-photographing. The 60 third lens frame 61 is retracted from a position on the optical axis that contacts the support frame 62 to a retracted position bent in a direction substantially perpendicular to the optical axis direction L.
Accordingly, the first lens group 40 and the second lens group 50 can be further retracted toward the space after the third lens frame 61 is retracted, and the apparatus can be thinned during the retracting. In addition, the retracted position of the third lens frame 61 is a position where angle conversion is performed so as to face the direction substantially perpendicular to the position on the optical axis, so that the protrusion in the radial direction perpendicular to the optical axis L is suppressed. Simultaneously with the thinning of the device, the size reduction in the radial direction perpendicular to the optical axis L is achieved.
Further, since the third lens frame 61 is swingably supported with respect to the support frame 62 supported so as to be movable in the optical axis direction L, the third lens frame 61 is supported by the support frame 62 when in the position on the optical axis. Guided with high accuracy in the optical axis direction L, it is possible to prevent positional displacement at the position on the optical axis as much as possible, and high-accuracy and stable movement becomes possible.

  Further, the bending / retracting mechanism 90 includes a support shaft 91 that supports the third lens frame 61 so as to be swingable about an axis S in a direction perpendicular to the optical axis direction L, and the third lens frame 61 from the position on the optical axis when retracted. Since the cam portion 93 that guides to the retracted position and the protrusions 61a of the third lens frame 61 are formed by a simple configuration of a spring 92 that exerts an urging force so as to come into contact with the cam portion 93, the device is simplified. Contributes to downsizing and thinning. In particular, since the biasing force of the spring 92 acts, it is possible to restrict the protrusion 61 a from being separated from the cam portion 93, and the cam portion 93 can reliably exert a cam action on the third lens frame 61.

Next, the bending and retracting operation of the lens driving device will be described with reference to FIGS. 1, 2, 5 to 7. First, at the time of photographing, as shown in FIGS. 2 and 5A, the first lens group 40 to the third lens group 60 are located on the optical axis and extended forward in the optical axis direction L. .
Here, when the photographing power switch or the like is turned off, the first drive mechanism 70 and the second drive mechanism 80 are operated so as to shift to the non-shooting state, and the first lens group 40 to the third lens group 60 are It begins to retract toward the rear of the optical axis direction L.

  Then, as shown in FIG. 5B, the third lens group 60 is retracted, the projection 61 a of the third lens frame 61 is in contact with the cam portion 93, and the third lens group 60 is further retracted, As shown in FIG. 5C and FIG. 6D to FIG. 6F, the bending and retracting mechanism 90 (support shaft 91, coil spring 92, cam portion 93) is provided on the third lens frame 61 (projection 61a). Due to the cam action, the third lens frame 61 starts to bend from the position on the optical axis facing the optical axis and reaches the retracted position in a direction substantially perpendicular to the optical axis direction L.

Thereafter, as shown in FIG. 7G, a part of the second lens group 50 (second lens frame 51) is retracted into the space where the third lens frame 61 is retracted and vacated.
Subsequently, as shown in FIG. 7 (h), the first lens group 40 is retracted, and a part of the first lens frame 41 is engaged with a part of the third lens frame 61 in the retracted position. The third lens frame 61 is locked. As a result, the third lens frame 61 is held at the retracted position so as not to swing, and is firmly held without rattling or vibration even when the apparatus receives an impact or the like from the outside.

  As described above, at the time of non-photographing, the second lens group 50 is retracted so as to enter the empty space after the third lens frame 61 moves to the retracted position, and the first lens group 50 is adjacent to the second lens group 50. Since the lens group 40 is retracted, the apparatus can be thinned in the optical axis direction L. Further, since the third lens frame 61 is bent and retracted so as to enter the inner space of the first lens group 40, the apparatus can be miniaturized in the radial direction perpendicular to the optical axis direction L.

On the other hand, at the time of photographing, the reverse path is basically followed. First, the first drive mechanism 70 is activated, and the first lens group 40 and the second lens group 50 are slightly closer to the telephoto position than the wide-angle end position. After the movement, the second drive mechanism 80 is actuated so that the support frame 62 is extended forward in the optical axis direction L, and the projection 61a is detached from the cam portion 93, and the third lens is biased by the biasing force of the spring 92. The frame 61 returns to a position on the optical axis that is supported by being in contact with the support frame 62.
Thereby, smooth operation is performed without causing mutual interference of the first lens group 40 to the third lens group 60.
In the above embodiment, the bending and retracting mechanism 90 includes the first lens frame 41, the second lens frame 51, and the third lens frame 61 arranged in order from the front in the optical axis direction L. Since the position is moved between the position on the optical axis and the retracted position, the length in the optical axis direction L (conjugate length) can be set longer during shooting, while the dimension in the optical axis direction L can be set during non-shooting. It can be shortened to achieve a thinner device.

  8 and 9 show another embodiment of the lens driving device according to the present invention. As an engaging member for locking the third lens frame 61 in the retracted position, instead of the first lens frame 41, FIG. The engaging member 51a forming a part of the second lens frame 51 of the second lens group 50 is employed. Therefore, the same reference numerals are given to the same components as those of the above-described embodiment, and the description thereof is omitted.

In this apparatus, as shown in FIGS. 8A to 9D, the engaging member 51a provided as a part of the second lens frame 51 of the second lens group 50 is a support shaft when retracted. 91 has a rotation axis parallel to 91, and is urged by a spring (not shown) so as to be swingable around the rotation axis, and engages with the third lens frame 61 located at the retracted position to lock the rotation. It is supposed to be.
Similarly, in this case, it is possible to reduce the thickness and size of the apparatus when retracted, and to reliably prevent rattling or vibration of the third lens frame 61.

In the above embodiment, as a plurality of lens frames, showed three lens frame 41, 51, 61 of the first lens group 40 to the third lens group 60 is not limited thereto, 2 Zur Alternatively, the present invention may be employed in a configuration including lens frames included in four or more lens groups.

  As described above, the lens driving device of the present invention can achieve simplification of the structure, downsizing, thinning and downsizing at the time of retracting, etc. In addition to being applicable to cameras and the like, it is also useful in fixed cameras or other lens optical systems.

It is sectional drawing which shows one Embodiment of the lens drive device which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a lens driving device according to an embodiment of the present invention, and is a cross-sectional view of a telephoto state that is extended. It is a partial expanded sectional view which shows the bending retraction mechanism of the lens drive device which concerns on this invention. It is a partial enlarged front view which shows the bending retraction mechanism of the lens drive device which concerns on this invention. (A), (b), (c) is a state diagram which shows the bending retraction operation | movement of the lens drive device based on this invention. (D), (e), (f) is a state diagram which shows the bending retraction operation | movement of the lens drive device based on this invention. (G), (h) is a state diagram which shows the bending retraction operation | movement of the lens drive device based on this invention. (A), (b) is a state figure which shows the bending operation | movement of the lens drive device which concerns on other embodiment of this invention. (C), (d) is a state diagram which shows the bending operation | movement of the lens drive device which concerns on other embodiment of this invention.

Explanation of symbols

10 Base 12 CCD
20 fixed cylinder 30 cam cylinder 40 first lens group 41 first lens frame (engagement member, lock mechanism)
50 Second lens group 51 Second lens frame 51a Engaging member (locking mechanism)
60 Third lens group 61 Third lens frame 61a Protrusion 62 Support frame 70 First drive mechanism 80 Second drive mechanism 90 Bending and retracting mechanism 91 Support shaft 92 Spring (guide member)
93 Cam part (guide member)
L Optical axis (optical axis direction)
S Axis G1, G2, G3 in the direction perpendicular to the optical axis direction Lens

Claims (5)

A drive mechanism for feeding and retracting in the optical axis direction and a plurality of lens frames, the plurality of lens frames comprising frontmost lens frame and rearmost lens frame arranged on the optical axis while holding the lens, the rearmost A bending / retracting mechanism for retracting the lens frame from a position on the optical axis facing the optical axis when retracted to a retracted position bent in a direction substantially perpendicular to the optical axis direction; and a rearmost lens frame positioned at the retracted position. A lens driving device including a locking mechanism that locks in a non-oscillating manner,
The foremost lens frame is formed to define an inner space for receiving the rearmost lens frame positioned at the retracted position when retracted;
The locking mechanism also serves as the foremost lens frame that receives the rearmost lens frame and engages a part thereof.
A lens driving device. The bending retraction mechanism, the retracted position of the rearmost lens frame and shaft for swingably supported around an axis in the optical axis direction and a direction perpendicular to the rearmost lens frame when collapsed from the upper optical axis position A guide member for guiding to,
The lens driving device according to claim 1. The guide member is provided at a predetermined position and has a cam portion that exerts a cam action as the rearmost lens frame is retracted, and a spring that biases the rearmost lens frame toward the position on the optical axis. Including,
The lens driving device according to claim 2. The rearmost lens frame that is retracted by the bending retracting mechanism is swingably supported with respect to a support frame that is supported movably in the optical axis direction.
Claims 1, wherein the lens driving apparatus according to 3 any one. The plurality of lens frames include a first lens frame as the foremost lens frame, a second lens frame, and a third lens frame as the rearmost lens frame, which are arranged in order from the front in the optical axis direction.
The bending retraction mechanism moves the third lens frame between the position on the optical axis and the retraction position;
Claims 1, wherein the lens driving device according to 4 or.

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