WO2023092385A1

WO2023092385A1 - Optical member driving device and imaging device

Info

Publication number: WO2023092385A1
Application number: PCT/CN2021/133128
Authority: WO
Inventors: Tatsuya Nakatsuji; Yoji Okazaki; Takashi Hashimoto
Original assignee: Guangdong Oppo Mobile Telecommunications Corp., Ltd.
Priority date: 2021-11-25
Filing date: 2021-11-25
Publication date: 2023-06-01

Abstract

An optical member driving device (100) includes a lens driving member (13) and a mirror driving member (14). The lens driving member (13) drives a lens group (31), which is held in a barrel (33). The mirror driving member (14) drives a mirror (32) which is rotatable about a first rotation axis (32a). The mirror driving member (14) includes an elastic member (141) which applies an elastic force to the mirror (32) in a direction from a mirror retracted position, where the mirror (32) is substantially perpendicular to the optical axis (OA), toward a mirror tilted position, where the mirror (32) is tilted with respect to an optical axis (OA) and rotation of the mirror (32) is restricted. The mirror driving member (14) further includes a roller (143) which is disposed on the mirror (32) so as to be rotatable about a second rotation axis (144) and which is in contact with the barrel (33) from a side of a lens retracted position by using the elastic force of the elastic member (141).

Description

OPTICAL MEMBER DRIVING DEVICE AND IMAGING DEVICE

TECHNICAL FIELD

The present disclosure relates to an optical member driving device and an imaging device, and more specifically, to an optical member driving device and an imaging device with a collapsible lens.

BACKGROUND

In recent years, portable imaging devices such as mobile phones and digital cameras are being widely used. A technique proposed in response to the recent trend of slimming (miniaturizing) imaging devices reduces a thickness of the imaging device by collapsing the lens mounted on the imaging device.

However, in a conventional collapsible imaging device, switching from a collapsed state to a shooting state is far from swift.

SUMMARY

The present disclosure aims to solve at least one of the technical problems mentioned above. Accordingly, the present disclosure needs to provide an imaging lens, a camera module and an imaging device.

In accordance with the present disclosure, an optical member driving device includes:

a lens driving member which drives a lens along an optical axis of the lens, the lens being held in a barrel, the lens driving member driving the lens between at least a lens retracted position where the lens is retracted into a holder which accommodates the lens, and a lens protruding position where the lens protrudes out of the holder; and

a mirror driving member which drives a mirror which is disposed on the optical axis on a side of the lens retracted position with respect to the lens and which is rotatable about a first rotation axis, the mirror driving member including:

an elastic member which applies an elastic force to the mirror in a direction from a mirror retracted position, where the mirror is substantially perpendicular to the optical axis, toward a mirror tilted position where the mirror is tilted with respect to the optical axis and rotation of the mirror is restricted; and

a roller which is disposed on the mirror so as to be rotatable about a second rotation axis and which is in contact with the barrel from a side of the lens retracted position by using the elastic force of the elastic member.

In accordance with the present disclosure, an imaging device includes:

the optical member driving device;

the lens;

the barrel;

the mirror; and

the holder which accommodates the lens, the barrel, the mirror, and the optical member driving device.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of embodiments of the present disclosure will become apparent and more readily appreciated from the following descriptions made with reference to the drawings, in which:

Fig. 1 is a perspective view of the imaging device according to the present disclosure;

Fig. 2 is a plane view of the imaging device according to the present disclosure;

Fig. 3A is a cross-sectional view of the imaging device in a stored lens state according to the present disclosure;

Fig. 3B is a cross-sectional view of the imaging device in a shooting state according to the present disclosure;

Fig. 4 is a side view illustrating a lens driving member of an optical member driving device according to the present disclosure;

Fig. 5A is a side view illustrating the imaging device in the stored lens state as an example of an operation of the imaging device according to the present disclosure;

Fig. 5B is a perspective view illustrating the imaging device in the stored lens state as an example of an operation of the imaging device according to the present disclosure;

Fig. 6A is a side view illustrating the imaging device during switching from the stored lens state to a protruding lens state as an example of an operation of the imaging device according to the present disclosure;

Fig. 6B is a perspective view illustrating the imaging device during switching from the stored lens state to the protruding lens state as an example of an operation of the imaging device according to the present disclosure;

Fig. 7A is a side view illustrating the imaging device in the protruding lens state as an example of an operation of the imaging device according to the present disclosure;

Fig. 7B is a perspective view illustrating the imaging device in the protruding lens state as an example of an operation of the imaging device according to the present disclosure;

Fig. 8A is a cross-sectional view of the imaging device in the stored lens state according to a first modification of the present disclosure;

Fig. 8B is a cross-sectional view of the imaging device in the protruding lens state according to the first modification of the present disclosure, and

Fig. 9 is a cross-sectional view of the imaging device according to a second modification of the present disclosure.

DETAILED DESCRIPTION

Embodiments of the present disclosure will be described in detail and examples of the embodiments will be illustrated in the accompanying drawings. The same or similar elements and the elements having same or similar functions are denoted by like reference numerals throughout the descriptions. The embodiments described herein with reference to the drawings are explanatory and aim to illustrate the present disclosure but shall not be construed to limit the present disclosure.

Fig. 1 is a perspective view of an imaging device 1 according to the present disclosure. Fig. 2 is a plane view of the imaging device 1. As shown in Fig. 1, the imaging device 1 to which the present disclosure applies includes a camera module 11, an optical member driving device 100, a holder 121, and a housing 12. The holder 121 accommodates the optical member driving device 100 and a part of the camera module 11. The holder 121 has an upper wall portion 121a, a bottom wall portion 121b, and a side wall portion 121c connecting the upper wall portion 121a and the bottom wall portion 121b. The housing 12 accommodates the optical member driving device 100, the holder 121, and the entire camera module 11. The size of the housing 12 may differ from the size shown in Fig. 1.

The camera module 11 includes an imaging lens assembly 21 (see Figs. 3A and 3B) and an image sensor 23 having an imaging surface S. The imaging lens assembly 21 includes a lens group 31 and a mirror 32. An aperture stop may be arranged on an object side of the lens group 31.

The lens group 31 includes at least a most object side disposed lens and a most imaging surface S side disposed lens. The number of lenses included in the lens group 31 may be between 4 or more and 7 or less. By setting the number of lenses included in the lens group 31 to between 4 or more and 7 or less, it is possible to obtain good optical performance while suppressing the thickness of the imaging device 1 (i.e., the housing 12) .

Fig. 3A is a cross-sectional view of the imaging device 1 in a stored lens state according to the present disclosure. Fig. 3B is a cross-sectional view of the imaging device 1 in a shooting state according to the present disclosure. Figs. 3A and 3B correspond to III-III cross-sectional views of Fig. 2.

The lens group 31 is configured to be integrally movable along the optical axis OA of the lens group 31. Specifically, in the examples shown in Figs. 1 to 3B, the lens group 31 is held or fixed in a single cylindrical barrel 33. Therefore, the relative positional relationship between the lenses included in the lens group 31 does not change.

A position of the lens group 31 in an optical axis direction when the imaging device 1 is in a stored lens state where the lens group 31 is housed in the holder 121 (i.e., the housing 12. ) differs from a position of the lens group 31 in an optical axis direction when the imaging device 1 is in a shooting state where a subject (object) is shot (recorded as an image) . When the imaging device 1 is in the stored lens state, the lens group 31 is in a lens retracted position close to the bottom wall portion 121b of the holder 121. When the imaging device 1 is in the shooting state, the lens group 31 is in an in-focus position where the subject is in focus. In the in-focus position, the lens group 31 protrudes out of the holder 121 through an opening 121d which is provided in the upper wall portion 121a of the holder 121 along an outer circumference of the barrel 33. Further, in the in-focus position, the lens group 31 also protrudes out of the housing 12 through an opening (not shown) which is provided in the housing 12.

The mirror 32 is disposed between the lens group 31 and the imaging surface S. As shown in Fig. 3A, the mirror 32 is substantially perpendicular (i.e., 90°) to the optical axis OA of the lens group 31 when the imaging device 1 is in the stored lens state. That is, in the stored lens state of the imaging device 1, the mirror 32 is in a mirror retracted position. The mirror 32 secures a storage space for the lens group 31 in the holder 121 by being substantially perpendicular to the optical axis OA of the lens group 31. Specifically, in the examples shown in Figs. 3A and 3B, the mirror 32 is rotatable about a first rotation shaft 32a (i.e., a first rotation axis) which is disposed on one end side of the mirror 32 on the imaging surface S side. More specifically, the mirror 32 is held by a plate-shaped mirror holder 320 which is rotatably supported by the first rotation shaft 32a. The first rotation shaft 32a can also be said to be a support shaft that rotatably supports the mirror 32. By the mirror 32 being rotated about the first rotation shaft 32a, an angle of the mirror 32 with respect to the optical axis OA of the lens group 31 can be changed.

On the other hand, as shown in Fig. 3B, the mirror 32 is tilted with respect to the optical axis OA of the lens group 31 when the imaging device 1 is in the shooting state. That is, in the shooting state of the imaging device 1, the mirror 32 is in a mirror tilted position. By being tilted with respect to the optical axis OA of the lens group 31, the mirror 32 reflects an incident light from the lens group 31 toward the imaging surface S. In the example shown in Fig. 3B, the imaging surface S is substantially parallel to the optical axis OA of the lens group 31 (i.e., substantially perpendicular to a reflection direction of the incident light on the mirror 32) .

In the shooting state, the tilt angle θ of the mirror 32 with respect to the optical axis OA of the lens group 31 may be between 42° or more and 48° or less, for example, 45°. By having the tilt angle θ in such a range, the mirror 32 can reflect an incident light, incident from the lens group 31, in a direction substantially perpendicular to the optical axis OA of the lens group 31 (i.e., a thickness direction of the imaging device 1) in the shooting state. That is, an optical path can be bent substantially 90°. As a result, a thickness of the imaging device 1 can be effectively suppressed.

The mirror 32 can be easily manufactured, for example, by coating a substrate containing at least one of two materials, i.e., glass and plastic, with a reflective film containing a metal such as aluminum.

The image sensor 23 is, for example, a solid-state image sensor such as a CMOS (Complementary Metal Oxide Semiconductor) or a CCD (Charge Coupled Device) . The image sensor 23 has the imaging surface S which is an imaging plane of the imaging lens assembly 21. The image sensor 23 receives incident light from the subject (object side) via the imaging lens assembly 21, photoelectrically converts the light, and outputs an image data, obtained by photoelectric conversion of the light, to a subsequent stage.

The image sensor 23 is disposed outside the holder 121. The side wall portion 121c between the mirror 32 and the image sensor 23 is transparent or provided with an opening so as not to hinder the progress of light from the mirror 32 to the image sensor 23.

An optical filter may be disposed between the mirror 32 and the image sensor 23. The optical filter may be, for example, an IR filter. Alternatively, the optical filter may be disposed between the lens group 31 and the mirror 32 and may be movable together with the lens group 31.

Such a collapsible imaging device 1, in which the lens group 31 protrudes from the holder 121 during the shooting state, has excellent storability and portability when shooting is not performed. Further, by disposing the mirror 32 between the lens group 31 and the imaging surface S, the mirror 32 being rotatable and reflecting the incident light from the lens group 31 toward the imaging surface S side, a focal length of the imaging lens assembly 21 in the shooting state can be increased despite the restricted thickness of the imaging device 1. Further, by holding the lens group 31 in the barrel 33 so as to be integrally movable, it is possible to suppress a deterioration of optical performance due to eccentricity of the lens group 31.

The optical member driving device 100 is a device that drives optical members mounted on the imaging device 1. Specifically, the optical member driving device 100 is a device that drives the lens group 31 and the mirror 32 in conjunction with each other. The optical member driving device 100 includes a lens driving member 13 and a mirror driving member 14.

First, the lens driving member 13 will be described.

The lens driving member 13 is a member that drives the lens group 31 held in the barrel 33 together with the barrel 33 along the optical axis OA of the lens group 31. The lens driving member 13 is configured to drive the lens group 31 between at least a lens retracted position where the lens group 31 is retracted into the holder 121 (i.e., the housing 12) and a lens protruding position where the lens group 31 protrudes out of the holder 121.

In the example shown in Figs. 1 to 3B, the lens driving member 13 is configured to drive the lens group 31 between the lens retracted position and the in-focus position (i.e., a shooting position) which is on a side of the object with respect to the lens protruding position. By driving the lens group 31 between the lens retracted position and the in-focus position, the lens driving member 13 can function both as a collapse mechanism and an autofocus mechanism.

On the other hand, if the drive section of the lens group 31 defined by the lens driving member 13 is between the lens retracted position and the lens protruding position, an autofocus mechanism for driving the lens group 31 from the lens protruding position to the in-focus position may be provided separately. In this case, the autofocus mechanism may include an actuator such as a voice coil motor, for example.

The lens driving member 13 includes a motor 131, which is an example of a drive source, and a driving force transmission member 132 that transmits a driving force (rotational force) of the motor 131 to the barrel 33. The lens driving member 13 further includes a main shaft 133A, a sub shaft 133B, a second spring 134 which is an example of the second elastic member, a first sliding member 135A, and a second sliding member 135B.

The motor 131 has a motor output shaft 131a that is substantially parallel to the optical axis OA of the lens group 31. The motor 131 is, for example, a stepping motor. By adopting a stepping motor, the lens group 31 can be appropriately driven with a sufficient driving force.

The driving force transmission member 132 includes, in the order of transmitting the driving force, a first gear 1321, a second gear 1322, a cylindrical cam 1323 which is an example of a three-dimensional cam, and a cam pin 1324.

The first gear 1321 is disposed above the motor 131 in Fig. 1. The first gear 1321 is disposed or fixed on the motor output shaft 131a. The first gear 1321 is, for example, a spur gear.

The second gear 1322 is disposed in a direction perpendicular to the optical axis OA of the lens group 31 with respect to the first gear 1321 and the barrel 33. The second gear 1322 meshes with the first gear 1321. The second gear 1322 is, for example, a spur gear.

The cylindrical cam 1323 is disposed below the second gear 1322 in Fig. 1. The cylindrical cam 1323 is disposed concentrically with, i.e., is fixed relative to, the second gear 1322.

Fig. 4 is a side view illustrating the lens driving member 13. As shown in Fig. 4, the cylindrical cam 1323 has an outer peripheral surface 1323a concentric with the second gear 1322. The outer peripheral surface 1323a is provided with a spiral cam groove 1323b which is tilted with respect to a direction perpendicular to the optical axis OA of the lens group 31. The cylindrical cam 1323 is rotatable about a rotation axis substantially parallel to the optical axis OA of the lens group 31 (i.e., the cylindrical cam 1323 is concentric with the second gear 1322) .

The cam pin 1324 is provided on the barrel 33. The cam pin 1324 extends in a direction substantially perpendicular to the optical axis OA of the lens group 31 toward the cylindrical cam 1323. The tip of the cam pin 1324 is inserted into the cam groove 1323b.

In the lens driving member 13 having such a configuration, as the rotation of the motor 131 is transmitted to the cylindrical cam 1323 via the first gear 1321 and the second gear 1322, the cylindrical cam 1323 rotates. Then, the rotation of the cam groove 1323b, following the rotation of the cylindrical cam 1323, causes the cam pin 1324 inserted in the cam groove 1323b to move along the optical axis OA of the lens group 31 following the cam groove 1323b. As a result, as the rotational motion of the motor 131 is converted into the linear motion of the barrel 33, the lens group 31 is driven together with the barrel 33 along the optical axis OA. In this way, the lens driving member 13 can drive the lens group 31 along the optical axis OA between the lens retracted position and the in-focus position.

The lens driving member 13 is configured to drive the lens group 31 from the lens retracted position to the in-focus position at a reduced driving speed at least in a drive section from the lens protruding position to the in-focus position. As a result, the lens driving member 13 can perform a focusing operation for driving the lens group 31 from the lens protruding position to the in-focus position with high accuracy.

More specifically, the lens driving member 13 is configured to drive the lens group 31 at high speed in a high-speed drive section which is between the lens retracted position and a speed switching position, the speed switching position being on a side of the lens retracted position with respect to the lens protruding position. Further, the lens driving member 13 is configured to drive the lens group 31 at low speed in a low-speed drive section which is between the speed switching position and the in-focus position, the in-focus position being on a side of the lens protruding position with respect to the speed switching position. The speed switching position is a position closer to the lens protruding position than the lens retracted position. The speed switching position may be a position slightly closer to the lens retracted position than the lens protruding position.

By driving the lens group 31 at high speed in the high-speed drive section and driving the lens group 31 at low speed in the low-speed drive section, the movement time of the lens group 31 from the lens retracted position to the lens protruding position can be decreased and the focus operation can be performed with high accuracy. Further, since the speed switching position is on a side of the lens retracted position with respect to the lens protruding position, an impact, which is applied to the mirror 32 by a rotation restriction part 145 provided on the holder 121, can be suppressed when the lens group 31 is moved to the lens protruding position and the rotation of the mirror 32 is restricted by the rotation restriction part 145 as described later.

In order to change the driving speed of the lens group 31, a tilt angle of the cam groove 1323b on a side of the lens protruding position is smaller than a tilt angle of the cam groove 1323b on a side of the lens retracted position. More specifically, as shown in Fig. 4, a tilt angle θ1 of the cam groove 1323b in a range R1 corresponding to the low-speed drive section is smaller than a tilt angle θ2 of the cam groove 1323b in a range R2 corresponding to the high- speed drive section. The tilt angle θ1 may be constant or may change within the range R1. The tilt angle θ2 may be constant or may change within the range R2. The cylindrical cam 1323 transmits the driving force of the motor 131 to the barrel 33 so that the lens group 31 is driven at high speed in the high-speed drive section by using the cam groove 1323b, which has a large tilt angle θ2, in the range R2. The cylindrical cam 1323 transmits the driving force of the motor 131 to the barrel 33 so that the lens group 31 is driven at low speed in the low-speed drive section by using the cam groove 1323b, which has a large tilt angle θ1, in the range R1.

As a result, the movement time of the lens group 31 from the lens retracted position to the lens protruding position can be decreased by a simple configuration, and the focusing operation can be performed with high accuracy.

The main shaft 133A and the sub shaft 133B are disposed in a direction perpendicular to the optical axis OA of the lens group 31 with respect to the mirror 32. The main shaft 133A and the sub shaft 133B are substantially parallel to the optical axis OA of the lens group 31. In the example shown in Fig. 1, the main shaft 133A and the sub-shaft 133B extend upward from the inner bottom surface 121e of the holder 121 (i.e., an upper surface of the bottom wall portion 121b) along the optical axis OA of the lens group 31. In the example shown in Fig. 1, the main shaft 133A and the sub shaft 133B are disposed on opposite sides of the lens group 31.

The first sliding member 135A is provided on an outer periphery of the barrel 33 at a position corresponding to the main shaft 133A. The first sliding member 135A is slidable along the main shaft 133A. By sliding the first sliding member 135A along the main shaft 133A, the drive of the lens group 31 is guided by the main shaft 133A.

In the example shown in Fig. 2, the first sliding member 135A has a V-groove surface 1352, which is an example of a groove surface, and a leaf spring 1353, which is an example of a third elastic member. The V-groove surface 1352 is an inner surface of the V-groove 1354 having a V-shape when viewed in a plan view. The main shaft 133A comes into contact with the V-groove surface 1352 from a direction substantially perpendicular to the optical axis OA of the lens group 31. The contact of the main shaft 133A with the V-groove surface 1352 may be a point. In this case, it is possible to suppress a frictional resistance between the main shaft 133A and the first sliding member 135A and facilitate the driving of the lens group 31 along the optical axis OA.

The leaf spring 1353 is disposed so as to sandwich the main shaft 133A between the leaf spring 1353 and the V-groove surface 1352. The contact of the leaf spring 1353 with the main shaft 133A may be a point. In this case, a frictional resistance between the main shaft 133A and the first sliding member 135A is further suppressed, and the driving of the lens group 31 along the optical axis OA is further facilitated.

The leaf spring 1353 applies to the main shaft 133A an elastic force in a direction toward the V-groove surface 1352. By sandwiching the main shaft 133A between the V-groove surface 1352 and the leaf spring 1353 using the elastic force of the leaf spring 1353, the first sliding member 135A can be steadily held on the outer periphery of the main shaft 133A. As a result, the lens group 31 can be driven along the optical axis OA while effectively suppressing an eccentricity and tilt of the lens group 31.

The second spring 134 is provided on the outer circumference of the main shaft 133A. The second spring 134 has an expansion /contraction direction along the optical axis OA of the lens group 31. The second spring 134 is, for example, a compression spring. The lower end of the second spring 134 is fixed to the inner bottom surface 121e of the holder 121. The upper end of the second spring 134 is fixed to the first sliding member 135A. The second spring 134 applies to the barrel 33 an elastic force in the direction from the lens retracted position to the lens protruding position. The elastic force of the second spring 134 allows the cam pin 1324, provided on the barrel 33, to slide along the top surface of the cam groove 1323b of the cylindrical cam 1323. As a result, the lens group 31 can be driven with precision.

The second sliding member 135B is provided on the outer periphery of the barrel 33 at a position corresponding to the sub shaft 133B. The second sliding member 135B is slidable along the sub shaft 133B. By sliding the second sliding member 135B along the sub shaft 133B, the drive of the lens group 31 is also guided by the sub shaft 133B. By guiding the drive of the lens group 31 along the sub shaft 133B, the rotation of the lens group 31 with the main shaft 133A as the rotation axis can be suppressed. The contact of the sub shaft 133B with the second sliding member 135B may be a point. In this case, a frictional resistance between the sub shaft 133B and the second sliding member 135B is suppressed, and the driving of the lens group 31 along the optical axis OA can be further facilitated.

Further, while the first sliding member 135A steadily holds the main shaft 133A, the second sliding member 135B is disposed with play with respect to the sub shaft 133B so that it can be displaced with respect to the sub shaft 133B in a direction perpendicular to the optical axis OA of the lens group 31. Specifically, as shown in Fig. 2, the second sliding member 135B is provided with a U-shaped notch 1351 toward the optical axis OA of the lens group 31, the U-shaped notch 1351 being perpendicular to the optical axis OA. The sub shaft 133B is inserted in the notch 1351. As a result, even if at least one of the main shaft 133A and the sub shaft 133B is tilted with respect to the optical axis OA of the lens group 31, the lens group 31 can be appropriately driven along the optical axis OA of the lens group 31.

Next, the mirror driving member 14 will be described.

The mirror driving member 14 is a member that drives the mirror 32 which is disposed on the optical axis OA of the lens group 31 on a side of the lens retracted position (that is, the imaging surface S side) with respect to the lens group 31 and which is rotatable about the first rotation shaft 32a.

The mirror drive member 14 includes a first spring 141 which is an example of an elastic member, a roller 143, a second rotation shaft 144 (i.e., a second rotation axis) , and a rotation restriction part 145.

The first spring 141 applies to the mirror 32 an elastic force in a direction from the mirror retracted position, where the mirror 32 is substantially perpendicular to the optical axis OA, toward the mirror tilted position where the mirror 32 is tilted with respect to the optical axis OA and rotation of the mirror 32 is restricted. In the mirror tilted position, the rotation of the mirror 32 is restricted by the rotation restriction part 145. The first spring 141 is provided on the outer circumference of the first rotation shaft 32a. The first spring 141 is, for example, a torsion coil spring. One end of the first spring 141 is fixed to the inner bottom surface 121e of the holder 121. Another end of the first spring 141 is fixed to a lower surface of the mirror holder 320.

The roller 143 is disposed on the mirror 32 so as to be rotatable about the second rotation shaft 144. The roller 143 comes into contact with the barrel 33 from a side of the lens retracted position (i.e., imaging surface S side) by using the elastic force of the first spring 141. In the example shown in Fig. 1, the roller 143 comes into contact with the barrel 33 by coming into contact with the second sliding member 135B provided on the barrel 33. The second rotation shaft 144 is fixed to the mirror holder 320. The second rotation axis 144 is substantially perpendicular to the optical axis OA of the lens group 31 and substantially parallel to the first rotation shaft 32a. The roller 143 is rotatably disposed on the outer circumference of the second rotation shaft 144. The second rotation shaft 144 can also be said to be a support shaft that rotatably supports the roller 143. The second rotation shaft 144 extends laterally from the roller 143 to enable the second rotation shaft 144 to come into contact with the rotation restriction part 145.

The rotation restriction part 145 is disposed in the holder 121 on a side of the mirror tilted position (i.e., the object side) with respect to the mirror 32. The rotation restriction part 145 restricts the rotation of the mirror 22 in the mirror tilted position. That is, the rotation restriction part 145 stops the rotation of the mirror 32 when the mirror 32 is rotated from the mirror retracted position to the mirror tilted position. By restricting the rotation of the mirror 32 in the mirror tilted position, the rotation restriction part 145 performs a positioning of the mirror 32. In the example shown in Fig. 1, the rotation restriction part 145 is a side wall structure of the holder 121, which has a plane (positioning surface) 145a facing the second rotation shaft 144. The plane 145a of the rotation restriction part 145 is substantially parallel to the second rotation shaft 144. The rotation restriction part 145 restricts the rotation of the mirror 32 by coming into contact with the second rotation shaft 144.

The mirror driving member 14 brings the roller 143 into contact with the barrel 33 and drives the mirror 32 from the mirror retracted position to the mirror tilted position by using the elastic force of the first spring 141, while the lens driving member 13 drives the lens group 31 from the lens retracted position to the lens protruding position. Then, in the mirror tilted position, the rotation of the mirror 32 is restricted (i.e., stopped) by the rotation restriction part 145. On the other hand, the mirror driving member 14 drives the mirror 32 from the mirror tilted position to the mirror retracted position against the elastic force of the first spring 141 by using a pressing force, which is applied by the barrel 33 to the roller 143 (i.e., the second sliding member 135B) , while the lens driving member 13 drives the lens group 31 from the lens protruding position to the lens retracted position. The roller 143 contacts the barrel 33 (i.e., the second sliding member 135B) in a rotatable state in a drive section of the mirror 32 between the mirror retracted position and the mirror tilted position.

According to such a configuration, by bringing the rotatable roller 143 provided on the mirror 32 into contact with the barrel 33 (i.e., the second sliding member 135B) , an impact applied to the mirror 32, whose rotation is restricted in the mirror tilted position, by the barrel 33 can be suppressed. By suppressing the impact applied to the mirror 32, it is possible to suppress a bounce of the mirror 32 due to the impact. By suppressing the bounce of the mirror 32, it is possible to quickly switch from the stored lens state (that is, collapsed state) to the shooting state. In addition, damage to the mirror 32 due to the impact can be prevented.

The lens driving member 13 drives the lens group 31 so that a driving speed of the lens group 31 decreases before the second rotation shaft 144 comes into contact with the rotation restriction part 145 during driving the lens group 31 from the lens retracted position to the in-focus position (i.e., a side of the lens protruding position) . Such a driving of the lens group 31 can be realized by the above-mentioned cam groove 1323b whose tilt angle is designed so that the driving speed of the lens group 31 decreases at the speed switching position which is on a side of the lens retracted position side with respect to the lens protruding position.

According to such a configuration, the rotation speed of the mirror 32 can be decreased before the second rotation shaft 144 comes into contact with the rotation restriction part 145. By decreasing the rotation speed of the mirror 32, it is possible to suppress the impact applied to the mirror 32 by the rotation restriction part 145 in the mirror tilted position. As a result, the bounce of the mirror 32 due to the impact can be suppressed more effectively, and the switching from the stored lens state to the shooting state can be performed more quickly.

The lens driving member 13 drives the lens group 31 so that the barrel 33 is separated from the roller 143 and the lens group 31 reaches the in-focus position after the second rotation shaft 144 comes into contact with the rotation restriction part 145 during driving the lens group 31 from the lens retracted position to the in-focus position. Such a driving of the lens group 31 can be realized by the cam groove 1323b in the low-speed drive section described above.

According to such a configuration, after the rotation of the mirror 32 is restricted in the mirror tilted position, the focus operation can be performed independently of the drive of the mirror 32.

Such an imaging device 1 can be applied to a small digital device such as a mobile phone, a wearable camera, or a surveillance camera.

Next, an example of an operation of the imaging device 1 configured as described above will be described.

Fig. 5A is a side view illustrating the imaging device 1 in the stored lens state. Fig. 5B is a perspective view illustrating the imaging device 1 in the stored lens state.

First, as shown in Figs. 5A and 5B, in the stored lens state, the lens group 31 is in the lens retracted position where the cam pin 1324 provided on the barrel 33 is located at the lower end side of the cam groove 1323b. In the stored lens state, the lens group 31 is stored in the holder 121 together with the barrel 33. Further, in the stored lens state, the mirror 32 is in the mirror retracted position as a result of the pressing force applied to the roller 143, provided on the mirror 32, from the second sliding member 135B, provided on the barrel 33.

Then, in the stored lens state, the imaging device 1 switches from the stored lens state to the shooting state when, for example, a predetermined user operation or an automatic operation by an algorithm for starting shooting mode is performed.

During switching from the stored lens state to the shooting state, the lens driving member 13 drives the lens group 31 from the lens retracted position to the in-focus position. In conjunction with this, the mirror driving member 14 drives the mirror 32 from the mirror retracted position to the mirror tilted position. Driving the lens group 31 and the mirror 32 is described in more detail below.

Fig. 6A is a side view illustrating the imaging device 1 during switching from the stored lens state to the protruding lens state. Fig. 6B is a perspective view illustrating the imaging device 1 during switching from the stored lens state to the protruding lens state. Fig. 7A is a side view illustrating the imaging device 1 in the protruding lens state. Fig. 7B is a perspective view illustrating the imaging device 1 in the protruding lens state.

As shown in Figs. 6A to 7B, the driving of the lens group 31 from the lens retracted position to the lens protruding position is performed together with the driving of the mirror 32 in a state where the roller 143 is in contact with the second sliding member 135B. The driving of the lens group 31 from the lens protruding position to the in-focus position is performed independently of the mirror 32 whose rotation is restricted in the mirror tilted position.

More specifically, in driving the lens group 31 from the lens retracted position to the lens protruding position, the motor 131 is rotated clockwise as shown by the arrow A1 in Fig. 5B, for example. When the motor 131 is rotated, the rotational force of the motor 131 is transmitted to the cylindrical cam 1323 via the first gear 1321 and the second gear 1322. By being transmitted the rotational force of the motor 131, the cylindrical cam 1323 rotates in a direction which results in raising the cam pin 1324. Then, according to the rotation of the cam groove 1323b following the rotation of the cylindrical cam 1323, the cam pin 1324 inserted in the cam groove 1323b rises following the cam groove 1323b.

As a result, the rotational motion of the motor 131 is converted into the linear motion of the barrel 33 and, as shown by the arrow A2 in Fig. 6A, the lens group 31 is driven together with the barrel 33 from the lens retracted position to the lens protruding position. At this time, since the cam pin 1324 rises following the cam groove 1323b which has a large tilt angle θ2 (see Fig. 4) , the lens group 31 can be driven close to the lens protruding position at high speed. When the lens group 31 rises close to the lens protruding position, the cam pin 1324 begins to rise following the cam groove 1323b which has a small tilt angle θ1 (see Fig. 4) . As a result, the lens group 31 is driven at low speed when the lens is close to the lens protruding position.

When the lens group 31 is driven from the lens retracted position toward the lens protruding position, the second sliding member 135B pressing the roller 143 rises together with the barrel 33. As the second sliding member 135B rises, the roller 143 pressed by the second sliding member 135B rotates clockwise together with the mirror 32 by using the elastic force of the first spring 141 as shown by the arrow A3 in Fig. 6A. By rotating clockwise, the mirror 32 moves from the mirror retracted position to the mirror tilted position.

The driving speed (i.e., the rotational speed) of the mirror 33 depends on the driving speed of the barrel 33 (i.e., the lens group 31) with which the roller 143 is in elastic contact. The mirror 32 is also driven at high speed according to the high driving speed of the lens group 31 up to the vicinity of the mirror tilted position. When the mirror 32 is near the mirror tilted position, the driving speed of the lens group 31 becomes low, so that the mirror 32 is also driven at low speed. Therefore, the driving speed of the mirror 32 is decreased before the mirror 32 reaches the mirror tilted position.

As shown in Figs. 7A and 7B, when the lens group 31 reaches the lens protruding position, the mirror 32 reaches the mirror tilted position. In the mirror tilted position, the rotation of the mirror 32 is restricted (stopped) as the second rotation shaft 144 comes into contact with the rotation restriction part 145. At this time, since the roller 143 is rotatably in contact with the second sliding member 135B, the impact applied to the mirror 32 by the barrel 33 can be suppressed. Further, the damage imparted by the barrel 33 to the mirror 32 can be prevented in comparison with the case where the mirror 32 comes into direct contact with the barrel 33.

Further, since the driving speed of the mirror 32 is decreased, it is possible to suppress the impact applied to the mirror 32 by the rotation restriction part 145. By suppressing the impact applied to the mirror 32, the bounce of the mirror 32 in the mirror tilted position can be effectively suppressed. By suppressing the bounce of the mirror 32, it is possible to quickly position the mirror 32 which in turn causes the mirror 32 to be still in the mirror tilted position. By quickly positioning the mirror 32, it is possible to quickly switch from the stored lens state to the shooting state.

After the lens group 31 reaches the lens protruding position, the lens group 31 moves to the in-focus position independently of the mirror 32 whose rotation is restricted. At this time, since the driving speed of the lens group 31 is low, the focusing operation can be performed with precision.

Therefore, according to the present disclosure, it is possible to suppress the bounce of the mirror 32 in the mirror tilted position by suppressing the impact applied to the mirror 32 whose rotation is restricted in the mirror tilted position. By suppressing the bounce of the mirror 32, the imaging device 1 in the collapsed state (i.e., the stored lens state) can be quickly switched to the shooting state.

Fig. 8A is a cross-sectional view of the imaging device 1 in the stored lens state according to a first modification. Fig. 8B is a cross-sectional view of the imaging device 1 in the lens protruding state according to the first modification.

As shown in Figs. 8A and 8B, the imaging device 1 may include an annular seal member 5 arranged in the opening 121d of the holder 121. The seal member 5 is, for example, an O-ring arranged inside the opening 121d so as to be in contact with the inner peripheral surface of the opening 121d over the entire circumference.

By providing the seal member 5, the imaging device 1 can prevent foreign matter (liquid or dust) from entering the holder 121.

Fig. 9 is a cross-sectional view of the imaging device 1 according to the second modification. So far, an example of the imaging device 1 that guides the driving of the lens group 31 along the optical axis OA by the main shaft 133A and the sub shaft 133B has been described. On the other hand, as shown in Fig. 9, the drive of the lens group 31 may be guided by a fixed cylinder 6 and a moving cylinder 7. The fixed cylinder 6 is fixed to the holder 121. The moving cylinder 7 holds the lens group 31 and is movable in the optical axis direction along the fixed cylinder 6. The mechanism for driving the moving cylinder 7 is not particularly limited. For example, a spiral cam groove may be provided on the outer peripheral surface of the moving cylinder 7, and a rotatable rotor provided with a cam pin to be inserted into the cam groove may be provided on the inner circumference of the fixed cylinder 6. The rotor may be driven by a gear or the like (mechanical rotation) , or may be driven by an energized coil that generates an electromagnetic force (electrical rotation) .

In the description of embodiments of the present disclosure, it is to be understood that terms such as "central" , "longitudinal" , "transverse" , "length" , "width" , "thickness" , "upper" , "lower" , "front" , "rear" , "left" , "right" , "vertical" , "horizontal" , "top" , "bottom" , "inner" , "outer" , "clockwise" and "counterclockwise" should be construed to refer to the orientation or the position as described or as shown in the drawings under discussion. These relative terms are only used to simplify description of the present disclosure, and do not indicate or imply that the device or element referred to must have a particular orientation, or constructed or operated in a particular orientation. Thus, these terms cannot be constructed to limit the present disclosure.

In addition, terms such as "first" and "second" are used herein for purposes of description and are not intended to indicate or imply relative importance or significance or to imply the number of indicated technical features. Thus, the feature defined with "first" and "second" may comprise one or more of this feature. In the description of the present disclosure, "a plurality of" means two or more than two, unless specified otherwise.

In the description of embodiments of the present disclosure, unless specified or limited otherwise, the terms "mounted" , "connected" , "coupled" and the like are used broadly, and may be, for example, fixed connections, detachable connections, or integral connections; may also be mechanical or electrical connections; may also be direct connections or indirect connections via intervening structures; may also be inner communications of two elements, which can be understood by those skilled in the art according to specific situations.

In the embodiments of the present disclosure, unless specified or limited otherwise, a structure in which a first feature is "on" or "below" a second feature may include an embodiment in which the first feature is in direct contact with the second feature, and may also include an embodiment in which the first feature and the second feature are not in direct contact with each other, but are contacted via an additional feature formed therebetween. Furthermore, a first feature "on" , "above" or "on top of" a second feature may include an embodiment in which the first feature is right or obliquely "on" , "above" or "on top of" the second feature, or just means that the first feature is at a height higher than that of the second feature; while a first feature "below" , "under" or "on bottom of" a second feature may include an embodiment in which the first feature is right or obliquely "below" , "under" or "on bottom of" the second feature, or just means that the first feature is at a height lower than that of the second feature.

Various embodiments and examples are provided in the above description to implement different structures of the present disclosure. In order to simplify the present disclosure, certain elements and settings are described in the above. However, these elements and settings are only by way of example and are not intended to limit the present disclosure. In addition, reference numbers and/or reference letters may be repeated in different examples in the present disclosure. This repetition is for the purpose of simplification and clarity and does not refer to relations between different embodiments and/or settings. Furthermore, examples of different processes and materials are provided in the present disclosure. However, it would be appreciated by those skilled in the art that other processes and/or materials may be also applied.

Reference throughout this specification to "an embodiment" , "some embodiments" , "an exemplary embodiment" , "an example" , "a specific example" or "some examples" means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. Thus, the appearances of the above phrases throughout this specification are not necessarily referring to the same embodiment or example of the present disclosure. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

Any process or method described in a flow chart or described herein in other ways may be understood to include one or more modules, segments or portions of codes of executable instructions for achieving specific logical functions or steps in the process, and the scope of a preferred embodiment of the present disclosure includes other implementations, in which it should be understood by those skilled in the art that functions may be implemented in a sequence other than the sequences shown or discussed, including in a substantially identical sequence or in an opposite sequence.

The logic and/or step described in other manners herein or shown in the flow chart, for example, a particular sequence table of executable instructions for realizing the logical function, may be specifically achieved in any computer readable medium to be used by the instruction execution system, device or equipment (such as the system based on computers, the system comprising processors or other systems capable of obtaining the instruction from the instruction execution system, device and equipment and executing the instruction) , or to be used in combination with the instruction execution system, device and equipment. As to the specification, "the computer readable medium" may be any device adaptive for including, storing, communicating, propagating or transferring programs to be used by or in combination with the instruction execution system, device or equipment. More specific examples of the computer readable medium comprise but are not limited to: an electronic connection (an electronic device) with one or more wires, a portable computer enclosure (a magnetic device) , a random access memory (RAM) , a read only memory (ROM) , an erasable programmable read-only memory (EPROM or a flash memory) , an optical fiber device and a portable compact disk read-only memory (CDROM) . In addition, the computer readable medium may even be a paper or other appropriate medium capable of printing programs thereon, this is because, for example, the paper or other appropriate medium may be optically scanned and then edited, decrypted or processed with other appropriate methods when necessary to obtain the programs in an electric manner, and then the programs may be stored in the computer memories.

It should be understood that each part of the present disclosure may be realized by the hardware, software, firmware or their combination. In the above embodiments, a plurality of steps or methods may be realized by the software or firmware stored in the memory and executed by the appropriate instruction execution system. For example, if it is realized by the hardware, likewise in another embodiment, the steps or methods may be realized by one or a combination of the following techniques known in the art: a discrete logic circuit having a logic gate circuit for realizing a logic function of a data signal, an application-specific integrated circuit having an appropriate combination logic gate circuit, a programmable gate array (PGA) , a field programmable gate array (FPGA) , etc.

Those skilled in the art shall understand that all or parts of the steps in the above exemplifying method of the present disclosure may be achieved by commanding the related hardware with programs. The programs may be stored in a computer readable storage medium, and the programs comprise one or a combination of the steps in the method embodiments of the present disclosure when run on a computer.

In addition, each function cell of the embodiments of the present disclosure may be integrated in a processing module, or these cells may be separate physical existence, or two or more cells are integrated in a processing module. The integrated module may be realized in a form of hardware or in a form of software function modules. When the integrated module is realized in a form of software function module and is sold or used as a standalone product, the integrated module may be stored in a computer readable storage medium.

The storage medium mentioned above may be read-only memories, magnetic disks, CD, etc.

Although embodiments of the present disclosure have been shown and described, it would be appreciated by those skilled in the art that the embodiments are explanatory and cannot be construed to limit the present disclosure, and changes, modifications, alternatives and variations can be made in the embodiments without departing from the scope of the present disclosure.

Claims

An optical member driving device, comprising:

a lens driving member which drives a lens along an optical axis of the lens, the lens being held in a barrel, the lens driving member driving the lens between at least a lens retracted position where the lens is retracted into a holder which accommodates the lens, and a lens protruding position where the lens protrudes out of the holder; and

a mirror driving member which drives a mirror, which is disposed on the optical axis on a side of the lens retracted position with respect to the lens and which is rotatable about a first rotation axis, the mirror driving member comprising:

an elastic member which applies an elastic force to the mirror in a direction from a mirror retracted position, where the mirror is substantially perpendicular to the optical axis, toward a mirror tilted position where the mirror is tilted with respect to the optical axis and rotation of the mirror is restricted; and

a roller which is disposed on the mirror so as to be rotatable about a second rotation axis and which is in contact with the barrel from a side of the lens retracted position by using the elastic force of the elastic member.
The optical member driving device according to claim 1, wherein

the mirror driving member brings the roller into contact with the barrel and drives the mirror from the mirror retracted position to the mirror tilted position by using the elastic force of the elastic member, while the lens driving member drives the lens from the lens retracted position to the lens protruding position, and

the mirror driving member drives the mirror from the mirror tilted position to the mirror retracted position, against the elastic force by using a pressing force, which is applied by the barrel to the roller, while the lens driving member drives the lens from the lens protruding position to the lens retracted position.
The optical member driving device according to claim 1, further comprising a rotation restriction part which is disposed inside the holder on a side of the mirror tilted position with respect to the mirror and restricts a rotation of the mirror in the mirror tilted position.
The optical member driving device according to claim 3, wherein

the rotation restriction part restricts the rotation of the mirror when coming into contact with the second rotation axis.
The optical member driving device according to claim 4, wherein

the lens driving member drives the lens so that the barrel is separated from the roller and the lens reaches an in-focus position, which is on a side of an object with respect to the lens protruding position, after the second rotation axis comes into contact with the rotation restriction part during a driving of the lens from the lens retracted position to a side of the lens protruding position.
The optical member driving device according to claim 4, wherein

the lens driving member drives the lens so that a driving speed of the lens decreases before the second rotation axis comes into contact with the rotation restriction part during driving the lens from the lens retracted position to a side of the lens protruding position.
The optical member driving device according to claim 6, wherein

the lens driving member drives the lens at a reduced driving speed until the lens reaches an in-focus position, which is on a side of an object with respect to the lens protruding position, after the driving speed of the lens is decreased during the driving of the lens from the lens retracted position to the side of the lens protruding position.
The optical member driving device according to claim 1, wherein

the lens driving member drives the lens at high speed in a high-speed drive section between the lens retracted position and a speed switching position which is on a side of the lens retracted position with respect to the lens protruding position, and drives the lens at low speed in a low-speed drive section between the speed switching position and a lens position which is on a side of the lens protruding position with respect to the speed switching position.
The optical member driving device according to claim 8, wherein

the lens position which is on a side of the lens protruding position with respect to the speed switching position is the lens protruding position.
The optical member driving device according to claim 8, wherein

the lens position which is on a side of the lens protruding position with respect to the speed switching position is an in-focus position.
The optical member driving device according to claim 1, wherein the lens driving member further comprises

a drive source, and

a driving force transmission member which transmits a driving force of the drive source to the barrel.
The optical member driving device according to claim 11, wherein

the driving force transmission member comprises

a three-dimensional cam which is provided with a spiral cam groove which is tilted with respect to a direction perpendicular to the optical axis, the three-dimensional cam being rotatable around a rotation axis which is substantially parallel to the optical axis, and

a cam pin which is provided on the barrel and which is inserted into the cam groove.
The optical member driving device according to claim 12, wherein

a tilt angle of the cam groove on a side of the lens protruding position is smaller than a tilt angle of the cam groove on a side of the lens retracted position.
The optical member driving device according to claim 13, wherein

the driving force transmission member transmits the driving force of the drive source to the barrel so that the lens is driven at high speed in a high-speed drive section between the lens retracted position and a speed switching position which is on a side of the lens retracted position with respect to the lens protruding position, and which is driven at low speed in a low-speed drive section between the speed switching position and a lens position which is on a side of the lens protruding position with respect to the speed switching position, and

a tilt angle of the cam groove corresponding to the low-speed drive section is smaller than a tilt angle of the cam groove corresponding to the high-speed drive section.
The optical member driving device according to claim 12, wherein the three-dimensional cam is a cylindrical cam.
The optical member driving device according to claim 1, wherein the lens driving member further comprises

a main shaft which is substantially parallel to the optical axis,

a first sliding member which is provided on the barrel and which is slidable along the main shaft, and

a second elastic member which is provided on an outer circumference of the main shaft with one end of the second elastic member fixed to an inner bottom surface of the holder and with another end of the second elastic member fixed to the first sliding member, the second elastic member applying, in a direction from the lens retracted position toward the lens protruding position, an elastic force to the barrel.
The optical member driving device according to claim 16, wherein the first sliding member comprises

a groove surface which is in contact with the main shaft from a direction substantially perpendicular to the optical axis, and

a third elastic member which is disposed so as to sandwich the main shaft between the third elastic member and the groove surface and which applies, in a direction toward the groove surface, an elastic force to the main shaft.
The optical member driving device according to claim 16, wherein the lens driving member further comprises

a sub shaft which is substantially parallel to the optical axis, and

a second sliding member which is provided on the barrel and which is slidable along the sub shaft.
The optical member driving device according to claim 18, wherein the roller is in contact with the barrel by being in contact with the second sliding member.
The optical member driving device according to claim 1, wherein the first rotation axis and the second rotation axis are substantially parallel to each other and substantially perpendicular to the optical axis.
The optical member driving device according to claim 12, wherein the drive source is a motor, and the driving force transmission member further comprises

a first gear which is disposed on an output shaft of the motor, and

a second gear which is disposed concentrically with the three-dimensional cam and which is meshed with the first gear.
An imaging device, comprising:

the optical member driving device according to any one of claims 1 to 21;

the lens;

the barrel;

the mirror; and

the holder which accommodates the lens, the barrel, the mirror, and the optical member driving device.
The imaging device according to claim 22, wherein

the barrel has a cylindrical shape,

the holder is provided with an opening along an outer circumference of the barrel for the lens to protrude out of the holder, and

the imaging device comprises a sealing member which is disposed at the opening.