JP2021149041A - Lens drive device - Google Patents

Abstract

To provide a lens drive device capable of coping with high function of a camera while suppressing thickness along an optical axis direction so as to be able to be arranged in an electronic apparatus whose thinning is advanced.SOLUTION: A lens drive device includes: a base member; an actuator attached to the base member; a rectilinear frame advancing and retreating in an optical axis direction using the actuator as a power source; and a mounting frame for determining a base position of lens drive by the rectilinear frame. When stored, the rectilinear frame is retreated to a first position close to the base member, and when the lens drive is performed, the rectilinear frame is advanced to a second position separated from the base member.SELECTED DRAWING: Figure 1

Description

The present invention relates to a lens driving device.

The lens driving device elastically supports the lens frame that holds the lens (lens barrel) on the base member directly or via another member, and balances the thrust and the elastic force of the actuator while rotating the lens frame with the optical axis. It moves in the direction or in the direction intersecting the optical axis, and AF (Autofocus) adjustment and OIS (Optical Image Stabilizer: camera shake correction) adjustment are performed by driving the lens with an actuator (see, for example, Patent Document 1). ..

JP-A-2019-28288

In recent years, portable electronic devices and the like that have a camera function have become common. Electronic devices such as portable devices are becoming thinner, and the camera module installed in the housing of the electronic device and the lens drive device mounted on the camera module can be accommodated in the thinner housing. In consideration, it is required to suppress the thickness along the optical axis direction.

On the other hand, the camera module is required to have high functionality for capturing a high-definition image using a large image sensor, and when trying to meet this demand, the distance from the image plane of the image sensor to the lens It is necessary to increase the (back focal length) to increase the variation of lens design. However, as described above, the lens drive device mounted on the camera module mounted in the housing of the thinned electronic device has a limited thickness along the optical axis direction, so that the back focal length can be reduced. There was a problem that it was difficult to meet the demand for large and high-definition images.

The present invention has been proposed to address such problems. That is, it is an object of the present invention to provide a lens driving device that can cope with higher functionality of a camera while suppressing the thickness along the optical axis direction so that it can be deployed in an electronic device that is becoming thinner. ..

In order to solve such a problem, the lens driving device according to the present invention has the following configuration.
It is provided with a base member, an actuator attached to the base member, a straight frame that advances and retreats in the optical axis direction using the actuator as a power source, and a mounting frame that determines the base position of lens drive by the straight frame. A lens driving device characterized in that the straight frame is retracted to a first position close to the base member, and when the lens is driven, the straight frame is advanced to a second position away from the base member.

An exploded perspective view of the lens driving device according to the embodiment of the present invention. The plan view of the lens driving device which concerns on embodiment of this invention. The side view of the lens driving apparatus which concerns on embodiment of this invention. The perspective view which showed the simple substance composition of the base member. The perspective view which showed the simple substance composition of the rotating frame. The perspective view which showed the single structure of the straight frame. The perspective view which showed the simple substance composition of the mounting frame. Explanatory view at the time of storage ((a) is a cross-sectional view of X1-X1 in FIG. 2, and (b) is a cross-sectional view of X2-X2 in FIG. 2). Explanatory drawing at the time of storage (X3-X3 cross-sectional view in FIG. 2). Explanatory drawing at the time of storage (Y1-Y1 cross-sectional view in FIG. 2). Explanatory view when the lens is driven (when used) ((a) is a cross-sectional view of X1-X1 in FIG. 2, and (b) is a cross-sectional view of X2-X2 in FIG. 2). Explanatory drawing (X3-X3 cross-sectional view in FIG. 2) when the lens is driven (when used). Explanatory drawing (Y1-Y1 cross-sectional view in FIG. 2) when the lens is driven (when used). Explanatory drawing of another embodiment ((a) is a cross-sectional view of X1-X1 in FIG. 2, and (b) is a cross-sectional view of X2-X2 in FIG. 2). Explanatory drawing of another embodiment ((a) is a cross-sectional view of X1-X1 in FIG. 2, and (b) is a cross-sectional view of X2-X2 in FIG. 2). Explanatory drawing of another embodiment ((a) is a cross-sectional view of X1-X1 in FIG. 2, and (b) is a cross-sectional view of X2-X2 in FIG. 2). (A) is an image pickup device provided with a lens driving device, and (b) is an explanatory view of an electronic device (portable information terminal) provided with an image pickup device.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same reference numerals in different figures indicate parts having the same function, and duplicate description in each figure will be omitted as appropriate. In the following description, "up" refers to the front (light incident) direction of the lens, and "bottom" refers to the rear (light emission) direction of the lens.

As shown in FIGS. 1 to 3, the lens driving device 1 includes at least a base member 2, an actuator 3, a straight-ahead frame 4, and a mounting frame 5. In FIG. 1, the Z direction indicates the optical axis direction, and the XY direction indicates a direction orthogonal to it.

The base member 2 supports the actuator 3, the straight frame 4, and the mounting frame 5. As shown in FIG. 4, the base member 2 has an opening 2P in the center, and an opening edge 2D is formed around the opening 2P. A plurality of elastic body support portions 2A extending in the optical axis direction and erected are provided around the base member 2. An engaged portion 2A1 with which the upper engaging portion 24a of the connecting elastic body 24, which will be described later, is engaged is provided above the elastic body supporting portion 2A.

Further, a gear support portion 2B is provided around the base member 2, and a gear 23, which is a transmission member, is rotatably supported by the gear support portion 2B. A guide shaft support portion 2C is provided on the bottom surface of the base member 2 around the opening 2P.

A rotating frame 6 is supported on the bottom surface of the base member 2. As shown in FIG. 5, the rotary frame 6 is a cylindrical member provided with a meshing portion 6A around which the gear 23 meshes, and a cam 6B is provided on the cylindrical side wall. In the illustrated example, the cam 6B has a cam surface formed downward, and the first position 6B1 which is a horizontal cam surface closer to the base member 2 and the second position 6B2 which is a horizontal cam surface away from the base member 2 It is formed, and an inclined cam surface extending from the first position 6B1 to the second position 6B2 is formed. Further, on the side surface of the rotating frame 6, an engaging projection 6C is provided so as to project outward so as to prevent the rotating frame 6 from coming off in the thrust direction.

The actuator 3 is attached to the base member 2 by a coupling member 7 via a mounting flange 3A, transmits a driving force to the gear 23, and rotationally drives the rotary frame 6 via the gear 23. The gear 23 decelerates the rotation of the actuator 3 to rotate the rotary frame 6. The mounting flange 3A covers the gear 23 and also serves as a thrust position regulation for the gear 23. As the actuator 3, for example, a stepping motor can be used, but the actuator 3 is not limited to this, and a piezo actuator or the like may be used.

The straight frame 4 is arranged inside the rotating frame 6, and moves back and forth in the optical axis direction using the actuator 3 as a power source. The cam 6B of the rotating frame 6 functions for advancing and retreating the straight frame 4. The cam contact portion 4B provided on the side surface of the straight frame 4 comes into contact with the cam surface of the cam 6B. The straight frame 4 is urged upward by the connecting elastic body (spring) 24 so that the cam contact portion 4B comes into contact with the cam surface of the cam 6B.

More specifically, the lower engaging portion 24b of the connecting elastic body 24 is engaged with the engaged portion 4A provided on the outside of the cam contact portion 4B in the straight frame 4, and the upper engaging portion of the connecting elastic body 24 is engaged. The joint portion 24a is engaged with the engaged portion 2A1 of the elastic body support portion 2A in the base member 2 located above the rotating frame 6. As a result, the straight frame 4 is urged upward by the elastic force of the connecting elastic body 24, and the cam contact portion 4B of the straight frame 4 comes into contact with the downward cam surface of the cam 6B.

Further, as shown in FIG. 6, the straight frame 4 is provided with a guide hole 4C inside. The guide shaft 26 is inserted into the guide hole 4C. The lower end of the guide shaft 26 is supported by the guide shaft support 2C of the base member 2, and the upper end is supported by the support member 8 attached to the base member 2 and extending upward.

A mounting frame 5 is provided inside the straight frame 4. The lens driving unit 10 is housed inside the mounting frame 5. As shown in FIG. 7, a support surface 5B for supporting the lens driving unit 10 is provided inside the mounting frame 5, and an opening 5A for passing light passing through the lens driving unit 10 is provided on the support surface 5B. Has been done. A pair of upper and lower guided portions 5C are provided on the outside of the side surface of the mounting frame 5 corresponding to the two guide shafts 26, and a guide hole of the straight frame 4 is provided between the pair of upper and lower guided portions 5C. 4C is sandwiched.

The lens drive unit 10 housed inside the mounting frame 5 is an actuator or the like that drives a lens frame (lens) (not shown) on the drive base unit 11 in one or both of the optical axis direction and the direction intersecting the optical axis. Is provided. The drive base portion 11 of the lens drive portion 10 is provided with a connection terminal 12 for energizing its own actuator, and one end side of the connection circuit board 13 is connected to the connection terminal 12. The connection circuit board 13 is pulled out from the slit hole 5D of the mounting frame 5 and is supported by the connection circuit board support portion 2E in the base member 2.

A protective plate 27 is provided at the upper end of the straight frame 4, and a light transmitting plate 28 is provided at the opening of the protective plate 27. The light transmitted through the light transmitting plate 28 passes through the lens of the lens drive unit 10, passes through the opening 5A of the mounting frame 5, passes through the opening 2P of the base member 2, and reaches the circuit board 20 attached to the base member 2. It is incident (imaged) on the imaging surface of the mounted image pickup device 21. An IR cut filter 22 or the like can be provided on the front surface of the image sensor 21 as needed. By integrally attaching the image sensor 21 to the base member 2 via the circuit board 20, a camera module including the lens driving device 1 can be configured.

By driving the actuator 3, the lens driving device 1 rotates the rotating frame 6 around the rotating axis along the optical axis within a predetermined angle range on the base member 2. In the rotating frame 6, an engaging protrusion 6C projects outward from the side surface, and the engaging protrusion 6C engages with the thrust receiver 2F of the base member 2 to prevent the rotating frame 6 from coming off in the thrust direction. ..

When the rotary frame 6 rotates, the straight frame 4 moves back and forth along the guide shaft 26 in the optical axis direction due to the cam surface of the cam 6B that abuts on the cam contact portion 4B of the straight frame 4. The actuator 3 rotates the rotary frame 6 as described above, but the straight frame 4 in the rotary frame 6 and the mounting frame 5 in the straight frame 4 are both engaged with the guide shaft 26 supported by the base member 2. Therefore, the movement in the rotation direction is stopped by the guide shaft 26, and only the movement in the optical axis direction along the guide shaft 26 is possible.

FIG. 8 shows a stored state of the lens driving unit 10. At this time, the cam contact portion 4B of the straight frame 4 is in contact with the first position 6B1 of the cam 6B in the rotating frame 6. The straight frame 4 is urged upward by the elastic force of the connecting elastic body 24, but its movement to the upper side is restricted by the first position 6B1 of the cam 6B, and the straight frame 4 is held in the stored state.

In this stored state, as shown in FIG. 9, the upper surface of the guide shaft support portion 2C in the base member 2 comes into contact with the lower surface of the guided portion 5C of the mounting frame 5, and the mounting frame 5 moves further downward. It is not possible. As a result, the mounting frame 5 is retracted to a position where contact with the base member 2 is avoided at the first position 6B1 of the straight frame 4.

At this time, the mounting frame 5 is connected to the straight frame 4 via the connecting elastic body 25, and the upper engaging portion 25a of the connecting elastic body 25 engages with the engaged portion 5E of the mounting frame 5 and is connected. The lower engaging portion 25b of the elastic body 25 is engaged with the engaged portion 4E of the straight frame 4. Therefore, when the guided portion 5C of the mounting frame 5 comes into contact with the upper surface of the guide shaft supporting portion 2C, the connecting elastic body 25 contracts and the mounting frame 5 moves relative to the straight frame 4.

FIG. 11 shows a state of the lens driving unit 10 when the lens is driven (during use). At this time, the cam contact portion 4B of the straight frame 4 is in contact with the second position 6B2 of the cam 6B in the rotating frame 6. The straight frame 4 is urged upward by the elastic force of the connecting elastic body 24, but the upward movement is restricted by the second position 6B2 of the cam 6, and the straight frame 4 is kept in the used state.

In this used state, as shown in FIGS. 12 and 13, the lower surface of the guided portion 5C of the mounting frame 5 is separated from the upper surface of the guide shaft support portion 2C of the base member 2, and the pair of guided portions 5C The guide hole 4C of the straight frame 4 sandwiched between the guide holes 4C is urged by the connecting elastic body 25 on the upper side of the pair of guided portions 5C. As a result, after the lower surface of the guided portion 5C of the mounting frame 5 is separated from the upper surface of the guide shaft supporting portion 2C, the mounting frame 5 and the straight frame 4 move together along the guide shaft 26.

In this used state, the straight frame 4 protrudes upward with respect to the rotating frame 6, and the lens drive unit 10 housed in the mounting frame 5 held by the straight frame 4 is mounted on the base member 2. It is possible to secure a sufficient distance from the image pickup surface of the image pickup element 21 mounted on the circuit board 20.

According to such a lens driving device 1, the mounting frame 5 uses an actuator 3 mounted on the base member 2 as a power source to move the straight frame 4 forward and backward in the optical axis direction, and the straight frame 4 determines the base position for driving the lens. It has. As a result, when not in use, the mounting frame 5 can be retracted with respect to the optical axis to reduce the total thickness of the lens driving device 1 when stored.

Then, when the lens is driven, the straight frame 4 is advanced in the optical axis direction to increase the distance between the lens driving unit 10 and the image sensor 21 supported by the base member 2 to increase the back focal length of the lens. be able to. As a result, it is possible to increase the variation of the lens design in the lens driving unit 10 and take a high-definition image.

A lens driving unit 10 for driving the lens in one or both of the optical axis direction and the direction intersecting the optical axis is provided in the mounting frame 5, and the lens driving unit 10 is located at a predetermined position of the mounting frame 5. Since the lens can be driven, the lens position can be driven in the optical axis direction by the operation of adding the movement of the mounting frame 5 to the fine movement of the lens of the lens driving unit 10 alone.

Further, the mounting frame 5 is connected to the straight frame 4 via the connecting elastic body 25, and the straight frame 4 is connected to the rotating frame 6 via the connecting elastic body 24, so that the backlash between the members can be removed. It is formed by the connecting elastic members 24 and 25, and further, when the straight frame 4 and the mounting frame 5 are separated from the base member 2, when an external pressure directed at the base member 2 acts on the straight frame 4 and the mounting frame 5. The straight frame 4 and the mounting frame 5 are elastically retracted with respect to this external pressure, and damage to the lens driving unit 10 and the like with respect to the external pressure can be suppressed.

At that time, when the mounting frame 5 connected to the straight frame 4 approaches the base member 2, it hits the upper surface of the guide shaft support portion 2C which is a protrusion of the base member 2 and stops, so that the mounting frame 5 is directed toward the base member 2. Even when an external pressure is applied to the straight-ahead frame 4 or the mounting frame 5, a collision with the image sensor 21 can be avoided.

14 to 16 show other embodiments of the present invention. In the lens driving device 1 of this embodiment, the straight frame 4 can advance to the third position 6B3 further away from the base member 2 with respect to the second position 6B2, and the lens driving base position is determined by the straight frame 4. The mounting frame 5 is provided with a lens driving unit 10 that drives at least the lens so as to be movable along the optical axis direction. Then, the lens position is adjusted by the movement of the straight frame 4 in the optical axis direction by the actuator 3 and the lens drive in the optical axis direction by the lens driving unit 10.

The adjustment of the lens position at this time can proceed from the storage position shown in FIG. 14 to the first use position shown in FIG. 15, and further to the third use position shown in FIG. It becomes possible to proceed. The lens adjustment here can be one or both of focus adjustment and zoom adjustment.

Further, in the third use position, the lens position adjustment range by the lens driving unit 10 is narrowed with respect to the lens position adjustment range by the actuator 3, and the mounting frame 5 is most separated from the base member 2 by the actuator 3. In this state, the lens can be driven for macro (close-up / close-up) photography by setting the infinity focus position to be outside the lens operable range in the lens driving unit 10.

When adjusting the lens position in this way, the lens drive unit 10 housed in the mounting frame 5 is provided with a detection unit for detecting the lens position, and the lens drive unit is provided with respect to the amount of movement of the straight frame 4 by the actuator 3. The lens position can be adjusted by adding the detection result of the lens position in 10. Alternatively, a detection unit for detecting the position of the mounting frame 5 in the optical axis direction is provided, and the lens position adjustment is performed by matching the detection result of the lens position in the lens driving unit 10 with the detection result of the position of the mounting frame 5 in the optical axis direction. You may try to do.

A voice coil motor (VCM) or the like can be used for adjusting the lens in the lens driving unit 10. Further, in the lens adjustment of the lens driving unit 10, a lens driving mechanism for camera shake correction may be provided in addition to the focus adjustment in the optical axis direction.

In the examples shown in FIGS. 14 to 16, horizontal surfaces are provided at the second position 6B2 and the third position 6B3 of the cam 6B, and at these two positions, the optical axis direction of the mounting frame 5 during use. The position is stopped. Then, the lens position adjustment in the lens driving unit 10 can be performed at these two positions. Here, the position of the mounting frame 5 in the optical axis direction is stopped at two places during use, but three or more stop positions may be provided.

In this case, the lens position adjustment is performed, for example, by moving the mounting frame 5 by the actuator 3 to roughly adjust the lens position, and after the mounting frame 5 stops at the second position 6B2 or the third position 6B3, the lens driving unit 10 Make fine adjustments with. At that time, a locking portion such as a recess into which the cam contact portion 4B is fitted is provided at the horizontal position of the second position 6B2 and the third position 6B3, and the cam contact is provided in a state where the actuator 3 can escape. When the portion 4B is locked, the cam contact portion 4B is locked to the locking portion described above, so that the mounting frame 5 can be stopped while the actuator 3 is de-energized, and the lens drive is saved. It can be converted to electricity.

In the above description, an example of stopping the mounting frame 5 at the horizontal position of the cam 6B has been described. However, by making it possible to stop the mounting frame 5 at an arbitrary tilted position of the cam 6B, a function of adjusting the lens position further Can be enhanced. At this time, if the straight frame 4 can be held at an arbitrary position by the non-energized holding torque of the actuator 3, the mounting frame 5 can be held in the non-energized state, and power saving drive becomes possible. The position of the mounting frame 5 may be held by the energization holding torque of the actuator 3.

FIG. 17 shows an image pickup device (camera unit) 100 (see FIG. 17 (a)) equipped with the lens driving device 1 described above, and an electronic device 200 (see FIG. 17 (b)) equipped with the image pickup device 100. Indicates an information terminal. Such an imaging device 100 or an electronic device 200 can mount a camera unit provided with a high-performance lens driving device 1 on a thin body.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and the design changes, etc. within the range not deviating from the gist of the present invention, etc. Even if there is, it is included in the present invention. Further, each of the above-described embodiments can be combined by diverting the technologies of each other as long as there is no particular contradiction or problem in the purpose and configuration thereof.

1: Lens drive device,
2: Base member, 2A: Elastic body support part, 2A1: Engagement part,
2B: Gear support, 2C: Guide shaft support, 2D: Open edge,
2E: Connection circuit board support, 2F: Thrust receiver, 2P: Aperture,
3: Actuator, 3A: Mounting flange,
4: Straight frame, 4A: Engaged part,
4B: cam contact part, 4C: guide hole, 4E: engaged part,
5: Mounting frame, 5A: Aperture, 5B: Support surface, 5C: Guided part,
5D: Slit hole, 5E: Engaged part,
6: Rotating frame, 6A: Engagement part,
6B: Cam, 6B1: 1st position, 6B2: 2nd position, 6B3: 3rd position,
6C: Engagement protrusion, 7: Coupling member, 8: Support member,
10: Lens drive unit, 11: Drive base unit, 12: Connection terminal,
13: Connection circuit board, 20: Circuit board,
21: Image sensor, 22: IR cut filter,
23: Gear, 24, 25: Connected elastic body,
24a, 25a: upper engaging part, 24b, 25b: lower engaging part,
26: Guide shaft, 27: Protective plate, 28: Translucent plate,
100: Imaging device, 200: Electronic device (portable information terminal)

Claims (6)

With the base member
The actuator attached to the base member and
A straight frame that advances and retreats in the optical axis direction using the actuator as a power source,
It is equipped with a mounting frame that determines the base position of the lens drive by the straight frame.
A lens driving device characterized in that when retracted, the straight frame is retracted to a first position close to the base member, and when the lens is driven, the straight frame is advanced to a second position away from the base member. The lens driving device according to claim 1, wherein the mounting frame retracts to a position where contact with the base member is avoided at the first position of the straight frame. The base member supports a rotating frame that is rotationally driven around a rotating axis along the optical axis by the actuator.
The lens driving device according to claim 1 or 2, wherein the straight frame advances and retreats in the optical axis direction by a cam provided on the rotating frame. The straight frame can advance to a third position further away from the base member with respect to the second position.
A lens driving unit that drives the lens so as to be movable along the optical axis direction is provided in the mounting frame in which the base position for driving the lens is determined by the straight frame.
The lens driving device according to claim 1, wherein the lens position is adjusted by the movement of the straight frame in the optical axis direction by the actuator and the lens driving in the optical axis direction in the lens driving unit. The lens driving device according to claim 4, wherein the infinity focus position is out of the lens movable range in the lens driving unit when the mounting frame is most separated from the base member by the actuator. An imaging device including the lens driving device according to any one of claims 1 to 5.

Images