A lens motor module and a camera with piezoelectric autofocus

Abstract

The present invention discloses a lens motor module and a camera with piezoelectric autofocus, which include a housing, a base, a lens fixedly arranged on the housing, a carrier located inside the housing, as well as a guiding mechanism, a guiding power module and a control circuit. An image sensor is mounted on the carrier. The guiding mechanism is used to limit the degrees of freedom of the carrier, so that the carrier can only move linearly along the optical axis direction. The piezoelectric power module moves the carrier under the control of the control circuit, driving the carrier and the component module thereon to perform reciprocating translation along the optical axis direction. Compared with the conventional voice coil motor module, the present invention drives the image sensor to hover and focus at different focusing positions by changing the current parameters of the piezoelectric power module. The present invention can complete focusing without configuring components such as upper and lower elastic sheets and magnet coil groups, the part design is simpler, the winding process is more concise, and the lens motor module tends to be lightweight and even miniaturized.

Description

Technical Field

[0001] The present invention relates to the technical field of voice coil motors, and more specifically, to a piezoelectric autofocus lens motor module and a camera. Background Art

[0002] Currently, common voice coil motor modules mainly include a housing, an upper spring piece, a lens carrier, a coil wound around the lens carrier, a lower spring piece, and a base. A magnet group is arranged on the periphery of the lens carrier to generate a magnetic field. The lens carrier is suspended between the housing and the base by the upper spring piece and the lower spring piece. When the coil is energized, an electromagnetic force is generated to drive the lens carrier and the lens thereon to move back and forth along the optical axis direction to achieve the focusing function. The structure of this kind of voice coil motor module is relatively complex, requiring a large number of parts, and the structure is delicate, with relatively high requirements for the production process. Therefore, there are certain difficulties in terms of processing and assembly, which is also one of the reasons why the production cost of the voice coil motor is difficult to control. Summary of the Invention

[0003] The primary object of the present invention is to provide a piezoelectric autofocus lens motor module for the problems existing in the prior art, so as to overcome the technical problems of complex structure and unfavorable processing of the voice coil motor in the prior art.

[0004] The technical effects to be achieved by the present invention are realized through the following technical solutions:

[0005] A piezoelectric autofocus lens motor module, comprising

[0006] A housing and a base;

[0007] A lens fixedly arranged on the housing;

[0008] A carrier located inside the housing, and the carrier is equipped with a component module;

[0009] A guiding mechanism for limiting the degree of freedom of the carrier, such that the carrier can only move linearly along the optical axis direction;

[0010] A piezoelectric power module, one end of which is fixedly connected to the base, and the other end is connected to the carrier;

[0011] A control circuit for controlling the piezoelectric power module to move the carrier, driving the carrier and the component module thereon to perform reciprocating translation along the optical axis direction.

[0012] Preferably, the guiding mechanism includes a guide post hole fixedly arranged on the carrier and a guide post fixed on the base. The position and size of the guide post hole correspond to those of the guide post, and the guide post hole is sleeved on the guide post.

[0013] Preferably, the axes of the guide pillar and the guide pillar hole are parallel to the optical axis direction of the lens.

[0014] Preferably, a connecting rod is provided on the carrier, the connecting rod is connected to the piezoelectric power module, and the piezoelectric power module transmits the electric frequency vibration to the carrier through the connecting rod.

[0015] Preferably, the piezoelectric power module comprises an open clamping jaw and a piezoelectric device mounted on the clamping jaw, the clamping jaw is used to clamp the connecting rod, and the piezoelectric device is electrically connected to the control circuit.

[0016] Preferably, the bottom of the connecting rod is fixedly arranged on the base, the connecting rod is in the form of a screw rod, and the clamping claw is used to clamp the rod body of the screw rod.

[0017] Preferably, the connecting rod is parallel to the guide column, and the connecting rod and the guide column are respectively located at diagonal positions of the carrier.

[0018] Preferably, the component module includes an image sensor.

[0019] Preferably, the piezoelectric power module is spaced from the component module and the carrier.

[0020] The second object of the present invention is to provide a camera, which uses the above-mentioned lens motor module. This is because the lens motor module is mainly used to realize the automatic focus of the lens, and has become a key component of the camera of digital products such as mobile phones and cameras. Therefore, any camera that uses the lens motor module provided by the present invention to achieve the effect of strengthening the strength of the carrier impact platform and optimizing the thickness and space of the motor also belongs to the protection scope of the technical solution of the present invention.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention sets the lens to be relatively stationary, and utilizes the frequency vibration generated by the piezoelectric power module after being energized to drive the carrier and the image sensor thereon to move back and forth. During this process, the carrier is able to move along the optical axis with the help of a guide mechanism, thereby changing the focal length to achieve an ideal focusing effect.

[0023] Compared with conventional voice coil motor modules, the present invention drives image sensor and other component modules to hover and focus at different focus positions by changing the current parameters of the piezoelectric power module. With this arrangement, the lens motor module provided by the present invention can complete focusing without the need to configure upper and lower springs, magnet coil groups and other components. The parts design is simpler and the winding process is simpler, so the lens motor module tends to be lightweight or even miniaturized. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings.

[0025] Figure 1 It is an assembly schematic diagram of the lens motor module provided in this embodiment;

[0026] Figure 2 It is a disassembly schematic diagram of the lens motor module provided in this embodiment;

[0027] Figure 3 It is a structural schematic diagram of the piezoelectric power module provided in this embodiment;

[0028] In the figure, 1 - housing; 2 - base; 3 - lens; 4 - component module; 41 - image sensor; 5 - carrier; 6 - guiding mechanism; 61 - guide post hole; 62 - guide post; 7 - piezoelectric power module; 71 - clamping jaw; 711 - grasping part; 712 - placing plane; 72 - piezoelectric device; 8 - connecting rod. Specific embodiments

[0029] The following will further illustrate the specific embodiments of the present invention in conjunction with the drawings. It should be noted here that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation to the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0030] Please refer to Figure 1 and Figure 2 , this embodiment provides a lens motor module with piezoelectric autofocus. The lens motor module includes a housing 1 and a base 2. A lens 3 is fixedly arranged at the top of the housing 1. A carrier 5 carrying a component module 4 is placed inside the housing 1. One end of the carrier 5 is connected with a guiding mechanism 6. The carrier 5 is installed on the base 2 through the guiding mechanism 6 and the moving direction is determined by means of the guiding mechanism 6. A piezoelectric power module 7 is arranged between the carrier 5 and the base 2. The piezoelectric power module 7 is connected with a control circuit. After being powered on, the piezoelectric power module 7 vibrates at a certain frequency and conducts this kinetic energy to the carrier 5, so that the carrier 5 and the component module 4 thereon vibrate synchronously.

[0031] Specifically, a connecting rod 8 is connected to the carrier 5. The connecting rod 8 is connected to the piezoelectric power module 7. The piezoelectric power module 7 conducts the electric frequency vibration to the carrier 5 via the connecting rod 8.

[0032] Please refer to Figure 3 , the piezoelectric power module 7 includes a jaw 71 with an opening and a piezoelectric device 72 mounted on the jaw 71. In this embodiment, the jaw 71 is arranged as a flat plate, one end of which is open to form a grasping part 711, and the other end is closed to form a placing plane 712. The piezoelectric device 72 is mounted on the placing plane 712. The jaw 71 clamps the connecting rod 8 through the grasping part 711 to form a fixed contact, and then introduces the electric frequency vibration through the electrical connection between the piezoelectric device 72 and the control circuit. Using the working principle of the piezoelectric power module 7, the jaw 71 is driven to vibrate in multiple directions relative to the piezoelectric device 72, and the jaw 71 thus rubs the connecting rod 8 to rotate forward or backward.

[0033] Please supplement and refer to Figure 2 , the bottom of the connecting rod 8 is fixedly arranged on the base 2. Therefore, no matter how the jaw 71 moves, the connecting rod 8 will not rotate around its own axis. According to the energy conduction principle, the connecting rod 8 will conduct the received vibration to the carrier 5 in contact therewith, so that the carrier 5 makes synchronous vibration or even rotation relative to the connecting rod 8.

[0034] The carrier 5 is further connected with the guiding mechanism 6. The guiding mechanism 6 can restrict the rotation of the carrier 5 and only allow the carrier 5 to slide up and down. Specifically, the guiding mechanism 6 includes a guide post hole 61 and a guide post 62. The guide post hole 61 is fixedly arranged on the carrier 5, and the guide post 62 is fixedly arranged on the base 2. The shape and size of the guide post hole 61 correspond to those of the guide post 62. The sleeved connection between the guide post hole 61 and the guide post 62 restricts the circumferential movement of the carrier 5. Therefore, the vibrating carrier 5 can only move back and forth along the axis direction of the guide post 62. In this embodiment, the axes of the guide post 62 and the guide post hole 61 are parallel to the optical axis direction of the lens. That is to say, after being driven by the piezoelectric power module 7, the carrier 5 will only move up and down along the optical axis direction. The component module 4 includes an image sensor 41. During the up and down movement of the carrier 5, the distance between the image sensor 41 and the lens 3 changes accordingly, that is, the focal length changes accordingly, so as to obtain different focusing effects.

[0035] The present invention adjusts the displacement of the image sensor 41 in the optical axis direction by setting a piezoelectric power module 7 and utilizing the frequency vibration generated after it is powered on. Compared with the conventional method of driving the lens to move to change the focal length by using electromagnetic phenomena, by virtue of the working characteristics of the piezoelectric power module, on the one hand, an architecture opposite to that of the conventional voice coil motor module is realized, forming a movement relationship in which the image sensor 41 moves while the lens 3 is stationary. According to such a design, the component composition of the motor module of the present invention is simpler. Without configuring components such as a magnet group and a coil, focusing can be completed, enabling the overall size of the module to be significantly reduced, and the thickness can also be further thinned, greatly promoting the miniaturization and light weight of the product. On the other hand, the piezoelectric power module 7 can drive the image sensor 41 to hover and focus at different focusing positions by changing the current parameters, directly exciting and controlling the movement of the image sensing device 41 through power transmission, greatly improving the focusing speed and focusing accuracy. Moreover, the lens 3 that does not need to move can also be hermetically installed with the housing 1, playing a complete dust-proof role.

[0036] In some embodiments, the connecting rod 8 is specifically in the form of a screw, and corresponding screw holes are provided on the carrier 5. Thus, one end of the carrier 5 is slidably connected to the guide post 62, and the other end is screwed to the screw. As a moving element of a precision product, the surface quality and position accuracy of the carrier 5 have strict technical requirements. The screwed connection can make the actual installation of the carrier 5 more convenient and can also avoid the impact on the carrier 5 caused by hard connections such as riveting or pressing, which is beneficial to protecting the movement accuracy of the carrier 5. On the other hand, in this solution, the clamping jaw 71 clamps the rod body of the screw, and the grasping portion 711 contacts the threads on the circumferential surface of the screw. Compared with contact with other smooth rod bodies, the threaded setting can significantly increase the friction force of the contact surface, reduce slipping, and significantly improve the conduction efficiency of vibration energy.

[0037] Please refer to Figure 3 , in addition, the clamping jaw 71 is preferably made of a plastic material. In this embodiment, the clamping jaw 71 is preferably a structure similar to a plastic shrapnel, enabling it to have a certain flexible rebound effect and be able to withstand small-amplitude and high-frequency vibration conduction for a long time. More importantly, plastic products have excellent insulation performance, which can prevent the piezoelectric device 72 placed on it from generating electrical radiation to the carrier 5 and the component module 4, affecting the working performance of the component module 4.

[0038] Please refer to Figure 2, Further, the guiding mechanism 6 and the piezoelectric power module 7 should be located at the diagonal positions of the carrier 5 respectively. With such a structure, the carrier 5 can be completely suspended by the guiding mechanism 6 and the piezoelectric power module 7 together, without the need to configure additional supports or even mounting bodies. On the one hand, it can minimize the movement constraints on the carrier 5 as much as possible, and on the other hand, it can avoid unnecessary loss of kinetic energy caused by the conduction of kinetic energy to other places. This setting not only simplifies the structural materials but also helps to maintain the vibration intensity of the carrier 5.

[0039] In some other embodiments, there is a space between the piezoelectric power module 7 and the component module 4 and the carrier 5. One end of the piezoelectric power module 7 is connected to the base 2, and one end is indirectly connected to the connecting rod 8 through the clamping jaw 71. In addition, the piezoelectric power module 7 does not come into contact with other components. In particular, the piezoelectric power module 7 does not contact the component module 4. Thus, the carrier 5 only receives the vibration action through the connecting rod 8, and the connecting rod 8 does not contact any workpiece carried on the carrier 5. Therefore, other parts of the carrier 5 will not be driven by the piezoelectric power module 7, thereby preventing resonance and avoiding unnecessary interference with the focusing operation.

[0040] Furthermore, this embodiment also provides a camera that adopts the above-mentioned lens motor module. This is because the lens motor module is mainly used to achieve automatic focusing of the lens and has now become a key component of the cameras of digital products such as mobile phones and cameras. Therefore, any camera that applies the lens motor module provided by the present invention to enhance the strength of the carrier hitting the table and optimize the thickness space of the motor also falls within the protection scope of the technical solution of the present invention.

[0041] The present invention provides a camera motor module with a simple design, easy to manufacture and produce. It uses the piezoelectric motion principle to promote the movement of the image sensor 41 relative to the lens 3 to achieve optimal focusing, eliminating the use of components such as spring sheets, coils, and magnet groups. The part design is simpler and the winding process is correspondingly simplified. On this basis, it can still provide an equal or even more accurate focusing function. Accordingly, the present invention has made significant and effective improvements in terms of light weight and miniaturization, has a considerable market advantage, and is very worthy of popularization and use in the focusing function of the voice coil motor module.

[0042] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, without departing from the principle and spirit of the present invention, various changes, modifications, substitutions, and variations made to these embodiments still fall within the protection scope of the present invention.

Claims

1. A lens motor module with piezoelectric autofocus, characterized in that, Comprising a housing and a base; a lens fixedly arranged on the housing; a carrier located inside the housing, and the carrier is equipped with a component module; a guiding mechanism for limiting the degrees of freedom of the carrier so that the carrier can only move linearly along the optical axis direction; the guiding mechanism includes a guide post hole fixedly arranged on the carrier and a guide post fixed on the base, the position dimension of the guide post hole corresponds to that of the guide post, and the guide post hole is sleeved on the guide post; a piezoelectric power module, one end of which is fixedly connected to the base and the other end is connected to the carrier; a connecting rod is arranged on the carrier and is connected to the piezoelectric power module, and the piezoelectric power module conducts electrical vibration to the carrier through the connecting rod; a control circuit for controlling the piezoelectric power module to move the carrier, driving the carrier and the component module thereon to translate back and forth along the optical axis direction, the piezoelectric power module includes an open jaw and a piezoelectric device installed on the jaw, the bottom of the connecting rod is fixedly arranged on the base, the connecting rod is in the form of a screw, the jaw is used for clamping the rod body of the screw, the connecting rod is parallel to the guide post, and the connecting rod and the guide post are respectively located at the diagonal positions of the carrier, the jaw is arranged as a flat plate, one end of which is open to form a grasping part, and the other end is closed to form a placing plane, and the piezoelectric device is installed on the placing plane.

2. The lens motor module with piezoelectric autofocus according to claim 1, characterized in that, The component module includes an image sensor.

3. The lens motor module with piezoelectric autofocus according to claim 1, characterized in that, The piezoelectric power module is arranged in an air gap with both the component module and the carrier.

4. A camera, characterized in that, Adopt the lens motor module according to any one of claims 1-3.

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