Lens driving device

Abstract

The present invention discloses a lens driving device, which includes a carrier, a base, a housing and a piezoelectric mechanism. The carrier and the housing cooperate to form a chamber, and the carrier is installed in the chamber. The four end corners of the base are provided with end corner protrusions, and the inner surfaces of at least two of the end corner protrusions are provided with guiding grooves extending along the optical axis direction. The guiding grooves cooperate with guiding protrusions provided on the carrier. The piezoelectric mechanism is disposed on the base and includes a piezoelectric element and a friction member. The friction member cooperates with a leaf spring provided on the carrier. The piezoelectric element drives the friction member to move and cooperate with the leaf spring to drive the carrier to move along the optical axis direction. The lens driving device of the present invention has the technical effects of stable performance, high reliability and low cost.

Description

Technical Field

[0001] The present invention relates to the field of optical driving, and particularly to a lens driving device. Background Art

[0002] In recent years, it has become common to mount a small camera on a portable device represented by a mobile phone. As a main component of the camera mechanism mounted on the small portable device, a lens driving device is used for automatic focusing for taking still images or moving images, and the required function is to drive a lens body small and with high precision.

[0003] With the popularization of terminals such as smart phones, how to simplify the lens driving structure built in these terminals, make it obtain better driving force, and at the same time simplify its assembly process is what those skilled in the art need to actively consider. Summary of the Invention

[0004] The object of the present invention is to provide a lens driving device to solve the problems existing in the above-mentioned prior art.

[0005] To solve the above problems, according to one aspect of the present invention, a lens driving device is provided. The lens driving device includes a carrier, a base, a housing, and a piezoelectric mechanism. The carrier and the housing cooperate to form a chamber, and the carrier is installed in the chamber, wherein

[0006] End corner protrusions are provided at four end corners of the base, and guiding grooves extending in the optical axis direction are provided on inner surfaces of at least two of the end corner protrusions. The guiding grooves cooperate with guiding protrusions provided on the carrier.

[0007] And the piezoelectric mechanism is provided on the base and includes a piezoelectric element and a friction member. The friction member cooperates with a spring piece provided on the carrier. The piezoelectric element drives the friction member to move and cooperate with the spring piece to drive the carrier to move in the optical axis direction.

[0008] In one embodiment, a ball groove is provided on the guiding protrusion, and balls are provided in the ball groove. When the carrier moves relative to the base, the friction between the guiding protrusion and the guiding groove is reduced by the rolling of the balls.

[0009] In one embodiment, the guiding grooves are provided on inner surfaces of two base protrusions on the same side of the base, and the piezoelectric mechanism is provided between the two base protrusions provided with the guiding grooves.

[0010] In one embodiment, the side of the carrier where the two guiding protrusions are provided extends beyond the driving part at the first instance. The driving part is provided with a shrapnel card slot. The lens driving device further includes a shrapnel. One end of the shrapnel is provided with a bending structure and is clamped in the shrapnel card slot through the bending structure. And the inner wall of the other end of the shrapnel cooperates with the friction part and presses the shrapnel against the friction part through the elastic force of the shrapnel.

[0011] In one embodiment, the piezoelectric element is a piezoelectric block, the friction part is a friction rod, the base is provided with a mounting hole, the piezoelectric block is mounted in the mounting hole and arranged at the bottom of the friction rod. The lower end of the friction rod extends into the mounting hole and contacts the upper surface of the piezoelectric block. After the piezoelectric block is electrified, it deforms to make the friction rod move longitudinally. And the other end of the shrapnel extends to the outside of the friction rod and is in close contact with the friction rod under the action of the elastic force.

[0012] In one embodiment, the piezoelectric mechanism further includes a counterweight block, and the counterweight block is arranged in the mounting groove and below the piezoelectric block.

[0013] In one embodiment, the shrapnel is arranged between the two end protrusions where the guiding protrusions are provided.

[0014] In one embodiment, the base is provided with a built-in circuit of the base, and the built-in circuit of the base is electrically connected to the piezoelectric block.

[0015] In one embodiment, the upper surface of the base is provided with a sensor mounting groove, a sensor is arranged in the sensor mounting groove, and the carrier is provided with an induction magnet. The relative displacement of the carrier relative to the base is detected by the cooperation of the sensor and the induction magnet.

[0016] In one embodiment, each of the guiding protrusions is provided with two ball card slots, and each ball card slot is provided with a ball.

[0017] In the present invention, by providing guiding protrusions on the outside of the carrier and guiding grooves on the base, the longitudinal movement of the carrier is realized through the cooperation of the guiding protrusions and the guiding grooves, and the driving is realized through the cooperation of the piezoelectric mechanism and the shrapnel. Since the shrapnel itself has elastic force, it can achieve close contact with the friction part of the piezoelectric mechanism, and has the beneficial technical effects of stable performance, high reliability and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is an exploded perspective view of a lens driving device according to an embodiment of the present invention.

[0019] Figure 2 is another exploded perspective view of a lens driving device according to an embodiment of the present invention.

[0020] Figure 3 It is another exploded perspective view of the lens driving device according to an embodiment of the present invention.

[0021] Figure 4 It is another exploded perspective view of the lens driving device according to an embodiment of the present invention.

[0022] Figure 5 It is another exploded perspective view of the lens driving device according to an embodiment of the present invention.

[0023] Figure 6 It is another exploded perspective view of the lens driving device according to an embodiment of the present invention.

[0024] Figure 7 It is another exploded perspective view of the lens driving device according to an embodiment of the present invention. Detailed Embodiments

[0025] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings so as to more clearly understand the objectives, features and advantages of the present invention. It should be understood that the embodiments shown in the drawings are not limitations on the scope of the present invention, but are only for illustrating the essential spirit of the technical solution of the present invention.

[0026] In the following description, for the purpose of illustrating various disclosed embodiments, certain specific details are set forth to provide a thorough understanding of the various disclosed embodiments. However, those skilled in the relevant art will recognize that the embodiments may be practiced without one or more of these specific details. In other instances, well-known devices, structures and techniques associated with the present application may not be shown or described in detail so as to avoid unnecessarily obscuring the description of the embodiments.

[0027] References to "an embodiment" or "one embodiment" in the entire specification mean that the particular features, structures or characteristics described in connection with the embodiment are included in at least one embodiment. Thus, the appearances of "in an embodiment" or "in one embodiment" in various places throughout the specification are not necessarily all referring to the same embodiment. Additionally, the particular features, structures or characteristics may be combined in any manner in one or more embodiments.

[0028] In the following description, in order to clearly show the structure and working manner of the present invention, many directional terms will be used for description. However, words such as "front", "rear", "left", "right", "outer", "inner", "outward", "inward", "up", "down", etc. should be understood as convenient terms and should not be construed as limiting terms.

[0029] The present invention generally relates to a lens driving device, which can be used in terminals such as mobile phones, tablet computers, laptop computers, etc. It is combined with a lens to realize functions such as taking pictures and recording videos. This lens driving device is usually used for front cameras.

[0030] As Figures 1-7 shown, the lens driving device 100 includes a carrier 20, a base 30, a housing 40, and a piezoelectric mechanism 50. The carrier 20 and the housing 40 cooperate to form a chamber. The carrier 20 is installed in the chamber and is used to install a lens. Each of the four end corners of the base 30 is provided with an end corner protrusion 31. The inner surfaces of at least two end corner protrusions 31 are provided with guiding grooves 311 extending along the optical axis direction. The guiding grooves 311 cooperate with guiding protrusions 21 provided on the carrier 20. The piezoelectric mechanism 50 is disposed on the base 30 and includes a piezoelectric element 51 and a friction member 52. The friction member 52 cooperates with a leaf spring 22 provided on the carrier 20. The piezoelectric element 51 drives the friction member 52 to move. The friction member 52 and the leaf spring 22 are in frictional cooperation to drive the carrier 20 to move along the optical axis direction, thereby driving the lens fixedly installed on the carrier 20 to move along the optical axis direction, achieving the zoom effect of the lens.

[0031] In one embodiment, the guiding protrusion 21 is provided with a ball groove 211, and a ball 212 is provided in the ball groove 211. When the carrier 20 moves relative to the base 30, the friction between the guiding protrusion 21 and the guiding groove 311 is reduced by the rolling of the ball 212.

[0032] In one embodiment, each guiding protrusion 21 is provided with two ball grooves 211, and one ball 212 is provided in each ball groove 211.

[0033] In one embodiment, the guiding grooves 311 are provided on the inner surfaces of two base end corner protrusions 31 on the same side of the base 30, and the piezoelectric mechanism 50 is disposed between the two base end corner protrusions 31 provided with the guiding grooves 311. With this arrangement, when the piezoelectric mechanism drives the carrier to move, the movement of the carrier is more stable. However, those skilled in the art can understand that in other embodiments, the guiding grooves can also be provided on the inner surfaces of three base end corner protrusions, and guiding protrusions are provided at corresponding positions on the carrier to cooperate with the guiding grooves, or the guiding grooves are provided on the inner surfaces of four base end corner protrusions, and four guiding protrusions are provided at corresponding positions on the carrier to cooperate with the four guiding grooves. The base end corner protrusions 31 can be of any shape, and the shapes of the four base end corner protrusions 31 can be the same or different.

[0034] Optionally, the shapes of the two base corner protrusions provided with guiding grooves are different from those of the two base corner protrusions without guiding grooves. For example, as shown in the figure, the cross-sectional shape of the base corner protrusion without a guiding groove is triangular, and the cross-sectional shape of the base corner protrusion provided with a guiding groove is rectangular. Optionally, the shapes of the base protrusions provided with guiding grooves can also be different.

[0035] In one embodiment, as Figures 1-7 shown, the length of one base corner protrusion provided with a guiding groove is greater than that of the other base corner protrusion provided with a guiding groove, and a guiding groove is provided on the inner surface (i.e., the surface close to the lens), and a friction member avoidance groove 312 is provided on the outer surface for avoiding the friction member.

[0036] In one embodiment, the side of the carrier 20 provided with two guiding protrusions 21 integrally extends out the driving part 23. The driving part 23 is provided with a spring piece clamping groove 231. One end of the spring piece 22 is provided with a bending structure and is clamped in the spring piece clamping groove 231 through the bending structure. The inner wall of the other end of the spring piece 22 cooperates with the friction member 52, and the spring piece 22 is pressed against the friction member 52 by the elastic force of the spring piece 22.

[0037] Optionally, the outer side surface of the driving part 23 is further provided with a spring piece limiting groove 232. The root of the other end of the spring piece 22 is arranged in the spring piece limiting groove 232, and the end of the other end of the spring piece 22 extends beyond the spring piece limiting groove 232 and reaches the outside of the base corner protrusion provided with the friction member avoidance groove to be in contact and cooperation with the friction member. The spring piece has a certain elastic structure. Under the elastic action of the spring piece, the carrier abuts against one side of the base where the piezoelectric mechanism is installed. Under this elastic action, both the ball clamping groove 211 and the inner wall of the guiding groove are in contact with the ball to prevent the ball from disengaging from the ball clamping groove; at the same time, under the action of the spring piece, one end of the spring piece will abut against the side wall of the friction rod, and the friction rod performs high-frequency telescopic movements to drive the spring piece and the carrier to perform longitudinal movements.

[0038] In one embodiment, the spring piece 22 is arranged between the two corner protrusions 31 provided with guiding protrusions 21. When the device drops, the corner protrusions are stressed and transmit the force to the balls, and the collision force will not affect the spring piece and will not cause any influence on the force received by the spring piece, ensuring the stability of the longitudinal movement of the carrier.

[0039] In one embodiment, the piezoelectric element 51 is a piezoelectric block, the friction member 52 is a friction rod, the base is provided with a mounting hole 32, the piezoelectric block 51 is installed in the mounting hole 32 and arranged at the bottom of the friction rod 52. The lower end of the friction rod 52 extends into the mounting hole 32 and contacts the upper surface of the piezoelectric block 51. After the piezoelectric block 51 is energized, it deforms to make the friction rod 52 move longitudinally, and the other end of the spring piece 22 extends to the outside of the friction rod 52 and is in close contact with the friction rod 52 under the action of the elastic force.

[0040] Optionally, an opening is formed on the outer side of the base end corner protrusion of the friction member avoidance groove, the inner wall of the opening forms the friction member avoidance groove, and the bottom of the opening forms a mounting hole 32. The mounting hole 32 is located below the friction member avoidance groove. The piezoelectric block is disposed in the mounting hole 32, and the friction member is disposed above the piezoelectric block and contacts the piezoelectric block at the lower end.

[0041] In one embodiment, the piezoelectric mechanism further includes a counterweight 53. The counterweight 53 is disposed in the mounting hole 32 and arranged below the piezoelectric block 51. The friction member is a friction rod. The lower end of the friction rod contacts the upper surface of the piezoelectric block 51 and is located in the mounting hole 32, and the main body portion of the friction rod is located in the friction member avoidance groove. The counterweight is an optional structure. In this technical solution, the mounting hole sinks all the way to form a through hole. The counterweight is installed at the bottom end of the base and is flush with the bottom end of the base. The upper end of the counterweight is connected to the piezoelectric block, the piezoelectric block is connected to the friction rod, and the friction rod extends from the mounting hole into the friction rod avoidance groove.

[0042] Optionally, the base 30 is provided with a base built-in circuit 33, and the base built-in circuit 33 is electrically connected to the piezoelectric block 51. The base built-in circuit supplies power to the piezoelectric block. After the piezoelectric block is energized, it deforms to make the friction rod move longitudinally. After the piezoelectric block is powered off, it returns to its original state. By controlling the energization state of the piezoelectric block, the high-frequency telescopic movement of the friction rod is realized.

[0043] Optionally, a sensor mounting groove 34 is provided between the two base end corner protrusions 31 provided with guiding grooves. A position sensor 35 is provided in the sensor mounting groove 34. The carrier 20 is provided with an induction magnet 36. The relative displacement of the carrier 20 relative to the base 30 is detected by the cooperation of the sensor 35 and the induction magnet 36. The position sensor is connected to the base built-in circuit for power supply. After the position sensor and the induction magnet cooperate, the longitudinal movement position of the carrier is monitored.

[0044] The preferred embodiments of the present invention have been described in detail above. However, it should be understood that after reading the above teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention. These equivalent forms also fall within the scope defined by the appended claims of the present application.

Claims

1. A lens driving device, characterized in that, The lens driving device includes a carrier, a base, a housing, and a piezoelectric mechanism. The carrier and the housing cooperate to form a chamber, and the carrier is installed in the chamber, wherein end corner protrusions are provided at four end corners of the base, and guiding grooves extending in the optical axis direction are provided on the inner surfaces of at least two of the end corner protrusions. The guiding grooves cooperate with guiding protrusions provided on the carrier, and the piezoelectric mechanism is provided on the base and includes a piezoelectric element and a friction member. The friction member cooperates with a spring piece provided on the carrier. The piezoelectric element drives the friction member to move and cooperate with the spring piece to drive the carrier to move in the optical axis direction; the guiding grooves are provided on the inner surfaces of two base protrusions on the same side of the base, and the piezoelectric mechanism is provided between the two base protrusions where the guiding grooves are provided; the lens driving device further includes a spring piece. The spring piece is arranged between two end corner protrusions provided with the guiding protrusions. The other end of the spring piece extends to the outside of a friction rod. The inner wall of the other end of the spring piece cooperates with the friction member and presses the spring piece against the friction member through the elastic force of the spring piece, so as to achieve close contact between the spring piece and the friction rod.

2. The lens driving device according to claim 1, wherein The guiding protrusions are provided with ball grooves, and balls are provided in the ball grooves. When the carrier moves relative to the base, the friction between the guiding protrusions and the guiding grooves is reduced by the rolling of the balls.

3. The lens driving device according to claim 1, wherein On the side of the carrier where the two guiding protrusions are provided, a driving portion protrudes. The driving portion is provided with a spring piece slot, and one end of the spring piece is provided with a bending structure and is clamped in the spring piece slot through the bending structure.

4. The lens driving device according to claim 1, wherein The piezoelectric element is a piezoelectric block, and the friction member is a friction rod. The base is provided with a mounting hole. The piezoelectric block is installed in the mounting hole and arranged at the bottom of the friction rod. The lower end of the friction rod extends into the mounting hole and contacts the upper surface of the piezoelectric block. After the piezoelectric block is energized, it deforms to make the friction rod move longitudinally.

5. The lens driving device according to claim 4, wherein The piezoelectric mechanism further includes a counterweight block, and the counterweight block is arranged in a mounting groove and below the piezoelectric block.

6. The lens driving device according to claim 4, wherein The base is provided with a built-in circuit of the base, and the built-in circuit of the base is electrically connected to the piezoelectric block.

7. The lens driving device according to claim 1, wherein A sensor mounting groove is provided on the upper surface of the base, and a sensor is provided in the sensor mounting groove. The carrier is provided with an induction magnet, and the relative displacement of the carrier relative to the base is detected by the cooperation of the sensor and the induction magnet.

8. The lens driving device according to claim 2, wherein Each of the guiding protrusions is provided with two ball grooves, and one ball is provided in each ball groove.

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