A driving device for realizing automatic focusing of camera

Abstract

The present invention relates to a driving device for realizing automatic focusing of a camera, which has a supporting module and a moving part suitable for lens installation assembly, the moving part is assembled on the supporting module through a suspension system, and realizes the movement of the moving part along the optical axis of the lens; and also includes a pair of driving modules, the driving modules are symmetrically arranged on opposite sides of the moving part, the driving modules are driven based on the principle of SMA wire contraction under heat and have a driving arm to push the moving part to move along the optical axis of the lens, the two driving modules drive the moving part to move along the optical axis of the lens in the same direction, and the tilt angle adjustment of the lens in one direction is realized by separate control of the two driving modules. The present invention utilizes the characteristic of SMA wire contraction under heat to drive the automatic focusing of the lens, and utilizes the resistance of the SMA wire as feedback to realize closed-loop control of the movement of the lens, the product structure is lightweight and miniaturized, and the control is simple and accurate.

Description

Technical Field

[0001] The present invention relates to the field of camera technology, and in particular to the field of camera focusing technology applied to portable electronic devices such as mobile phones or tablet computers. Background Art

[0002] With the development and popularization of portable electronic devices such as mobile phones and tablet computers, the requirements for the accompanying camera functions have also increased. In order to achieve camera focus and zoom, it is necessary to arrange a driving device in the small space of the camera to drive the lens to move along the optical axis. Due to the small space, the types of driving device structures that can be used are limited. The cameras in the prior art mainly use magnets and coil structures to achieve drive, but the structure is still relatively complex, the volume is difficult to reduce, and it cannot meet the requirements of product miniaturization. Summary of the invention

[0003] The object of the present invention is to provide a driving device for realizing automatic focusing of a camera, so as to meet the requirements of product miniaturization and obtain better performance of driving the lens to move along the optical axis.

[0004] In order to achieve the above object, the present invention adopts the following technical scheme:

[0005] A driving device for realizing automatic focusing of a camera comprises a supporting module and a moving part suitable for lens mounting assembly, wherein the moving part is assembled on the supporting module through a suspension system, and the suspension system guides the moving part to move along the optical axis of the lens; and further comprises a pair of driving modules, wherein the driving modules are symmetrically arranged on opposite sides of the moving part, the driving modules are driven based on the principle of thermal contraction of an SMA wire and have a driving arm to push the moving part to move along the optical axis of the lens, the two driving modules drive the moving part to move in the same direction along the optical axis of the lens, and the tilt angle adjustment of the lens in one direction is realized by separately controlling the two driving modules.

[0006] The above scheme is further that the driving module includes two driving arms, an SMA wire and two conductive supports, the conductive supports are fixed on the supporting module and electrically connected to the control system of the camera, the conductive supports are provided with expandable and contractible elastic arms, the two driving arms and the SMA wire form a movable triangular relationship, the two ends of the SMA wire are respectively connected to the elastic arms on the two conductive supports, one end of the driving arm is connected to the elastic arm of the corresponding conductive support, and the other end of the driving arm is hingedly connected to the moving part.

[0007] The above scheme is further that the suspension system includes an upper spring and a lower spring, and the upper spring and the lower spring are respectively connected between the upper and lower ends of the moving part and the support module; the upper spring includes an upper inner ring and a first flexible portion led out from the outer periphery of the upper inner ring, the upper inner ring is fixedly connected to the upper end of the moving part, and the end of the first flexible portion is fixedly connected to the support module; the lower spring includes a lower inner ring and a second flexible portion led out from the outer periphery of the lower inner ring, the lower inner ring is fixedly connected to the lower end of the moving part, and the end of the second flexible portion is fixedly connected to the support module.

[0008] The above scheme is further that the support module is composed of a stacked base plate and an upper seat, and an upwardly protruding column is provided on the upper side of the upper seat away from the base plate, and the column is adapted for the installation of the suspension system and the drive module; a hinged part is provided on the peripheral side of the moving part, and the hinged part is hinged to the drive arm of the drive module.

[0009] The above solution is further that the control system of the camera uses the resistance of the SMA wire as feedback to achieve closed-loop control of the movement of the lens.

[0010] A further aspect of the above scheme is that the two driving arms and the SMA wire form an isosceles triangle relationship, the SMA wire is the base, and the SMA wire is arranged horizontally.

[0011] The above solution is further characterized in that the two driving arms are respectively integrally formed with the two conductive supports.

[0012] The above scheme is further that the circuit is integrally manufactured on the base plate or an FPC circuit board is attached. When integrally manufactured, the base plate is provided with terminals or pads for realizing circuit connection with other components, and a shell for anti-collision and protection is assembled on the supporting module.

[0013] The present invention utilizes the characteristic of SMA (Shape Memory Alloys) wire shrinking when heated, and is used to manufacture a driving device for a camera module of a mobile phone or tablet computer, which can drive the lens to move up and down to realize the automatic focusing function of the lens, and can use the resistance of the SMA wire as feedback to realize closed-loop control of the movement of the lens, and can adjust the inclination angle of the lens around the X-axis or Y-axis to improve the performance of the camera. The SMA wire is small in size and effectively simplifies the driving structure, so that the product miniaturization requirements are met, the product structure is lightweight and miniaturized, and the manufacturing cost is reduced. At the same time, the control is simple and accurate, and it is suitable for promotion and utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Attached Figure 1 It is a structural schematic diagram of a preferred embodiment of the present invention;

[0015] Attached Figure 2 for Figure 1 A schematic diagram of the drive module structure of an embodiment;

[0016] Attached Figure 3 for Figure 1 A schematic diagram of the structure of the moving parts of the embodiment;

[0017] Attached Figure 4 for Figure 1 A schematic diagram of the support module structure of an embodiment;

[0018] Attached Figure 5 for Figure 1 A schematic diagram of the upper spring structure of an embodiment;

[0019] Attached Figure 6 for Figure 1 Schematic diagram of the lower spring structure of an embodiment. DETAILED DESCRIPTION

[0020] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present invention.

[0021] It should be noted that in the description of the present invention, the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third" and "fourth" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0022] See also Figures 1 to 6The figure is a schematic diagram of a preferred embodiment of the present invention. The present invention is related to a driving device for realizing automatic focusing of a camera, which has a supporting module 1 and a moving part 2 suitable for lens installation and assembly, and of course also includes a control system inherent to the camera device and a corresponding housing (not shown in the figure). The housing covers the moving part 2 and the corresponding parts, and has anti-collision and protection effects. The supporting module 1 is adapted to be installed on a portable electronic device such as a mobile phone or a tablet computer. The moving part 2 is assembled on the supporting module 1 through a suspension system 3. The suspension system 3 guides the moving part 2 to move along the optical axis of the lens. An assembly hole is left in the middle of the moving part 2 to meet the lens element assembly, so that the moving part 2 and the lens element move together. And it also includes a pair of driving modules 4, which are symmetrically arranged on opposite sides of the moving part 2. The driving module 4 is driven based on the principle of SMA wire shrinkage due to heat and has a driving arm 41 to push the moving part 2 to move along the optical axis of the lens. The two driving modules 4 drive the moving part 2 to move along the optical axis of the lens in the same direction. In this way, the SMA wire shrinks due to heat and drives the driving arm 41, thereby causing the driving arm 41 to push the moving component 2 to move along the optical axis of the lens and overcome the reverse force of the suspension system 3 to achieve automatic focusing. At the same time, the suspension system 3 obtains corresponding stored force to reset the movement.

[0023] See also Figure 1 , 2As shown, in this embodiment, the driving module 4 includes two driving arms 41, SMA wires 42 and two conductive supports 43. The conductive supports 43 are fixed on the support module 1 and electrically connected to the control system of the camera. The conductive supports 43 are provided with elastic arms 431 that can be opened and closed. The two driving arms 41 and the SMA wires 42 form a movable triangle relationship. The two ends of the SMA wires 42 are respectively connected to the elastic arms 431 on the two conductive supports 43. One end of the driving arm 41 is connected to the elastic arm 431 of the corresponding conductive support 43, and the other end of the driving arm 41 is hingedly connected to the moving part 2. The SMA wire (such as nickel-titanium memory alloy wire) is a martensitic structure at room temperature. When the temperature rises, the SMA wire will undergo a phase change from martensite to austenite, the length will become shorter, and the resistance will become smaller; when the temperature drops, the SMA wire will undergo a phase change from austenite to martensite, the length will become longer, and the resistance will become larger. These two processes can be repeated. During the phase change, the linearity between the temperature and strain of the SMA wire is not very good, but within a certain temperature range, its resistance and strain show linear characteristics. Therefore, by controlling the resistance of the SMA wire, its length can be accurately controlled, and the position and movement distance of the driving device can be calculated based on the resistance of the SMA wire. Thus, by energizing and heating the SMA wire 42 through the control system, the SMA wire 42 will shrink, changing the triangle relationship formed by the two driving arms 41 and the SMA wire 42, so that the two driving arms 41 push the moving part 2 to move along the optical axis of the lens, realizing the focus and zoom of the camera, and using the relative stability of the triangle, the moving part 2 can be stably and accurately driven to move with the lens focusing. In this embodiment, the two driving modules 4 are symmetrically arranged on opposite sides of the moving part 2, and the two driving modules 4 are powered on at the same time through the control system of the camera (the same power-on conditions). At this time, the two driving modules 4 synchronously drive the moving part 2 to move along the optical axis of the lens; when the two driving modules 4 are driven and controlled separately and independently (when the two currents are of different sizes), the two driving modules 4 are driven asynchronously, thereby adjusting the inclination angle of the lens around the X-axis or Y-axis, thereby improving the performance of the camera.

[0024] See also Figure 1 , 2As shown, the present embodiment further has two driving arms 41 and SMA wire 42 forming an isosceles triangle relationship, SMA wire 42 being the bottom side, and SMA wire 42 being arranged horizontally, and the structure has more stable movement and more accurate control. Furthermore, the two driving arms 41 are respectively formed in one piece with two conductive supports 43, and the driving arms 41 are connected by elastic arms 431 of the conductive supports 43, which optimizes the structure and facilitates manufacturing and assembly. The two conductive supports 43 are connected to the control system circuit of the camera by welding, and the control system also uses the resistance of the SMA wire 42 as feedback to realize closed-loop control of the movement of the lens. By comparing the deviation between the real-time resistance value and the target value, the movement deviation of the moving component 2 can be corrected, thereby forming a closed-loop control system with the resistance of the SMA wire 42 as the feedback variable, and obtaining precise control.

[0025] Figures 1 to 6 As shown, in this embodiment, the support module 1 is composed of a bottom plate 11 and an upper seat 12 stacked together, and an upwardly protruding column 121 is provided on the upper side of the upper seat 12 away from the bottom plate 11, and the column 121 is adapted to be installed in the suspension system 3 and the drive module 4. A hinge part 21 is provided on the peripheral side of the moving part 2, and the hinge part 21 is hinged to the driving arm 41 of the drive module 4 to obtain a driven kinematic pair. The suspension system 3 includes an upper spring 31 and a lower spring 32, and the upper spring 31 and the lower spring 32 are respectively connected between the upper and lower ends of the moving part 2 and the support module 1. The upper spring 31 includes an upper inner ring 311 and a first flexible portion 312 drawn from the outer periphery of the upper inner ring 311, the upper inner ring 311 is fixedly connected to the upper end of the moving component 2, and the end of the first flexible portion 312 is fixedly connected to the support module 1; the lower spring 32 includes a lower inner ring 321 and a second flexible portion 322 drawn from the outer periphery of the lower inner ring 321, the lower inner ring 321 is fixedly connected to the lower end of the moving component 2, and the end of the second flexible portion 322 is fixedly connected to the support module 1. The suspension system 3 has a simple structure, is easy to manufacture and assemble, has a small size, and effectively supports the moving component 2 to be suspended on the support module 1 and meets the movement of the moving component 2 along the optical axis of the lens; cooperates with the driving module 4 to realize the automatic focusing of the lens. In this embodiment, the circuit is integrally made on the bottom plate 11, and the bottom plate 11 is used as a circuit substrate. At this time, the bottom plate 11 is provided with terminals or pads for realizing circuit connection with other components; of course, in order to increase the function and facilitate the circuit wiring, an FPC circuit board can also be attached to the bottom plate 11, and the specific situation is determined according to actual needs.

[0026] The present invention utilizes the characteristic of SMA (Shape Memory Alloys) wire shrinking when heated, and is used to manufacture a driving device for a camera module of a mobile phone or tablet computer, which can drive the lens to move up and down to realize the automatic focusing function of the lens, and can use the resistance of the SMA wire as feedback to realize closed-loop control of the up and down movement of the lens, and can adjust the inclination angle of the lens around the X-axis or Y-axis to improve the performance of the camera. The SMA wire is small in size and effectively simplifies the driving structure, so that the product miniaturization requirements are met, the product structure is lightweight and miniaturized, and the manufacturing cost is reduced. At the same time, the control is simple and accurate, and it is suitable for promotion and utilization.

[0027] Although the preferred specific embodiments of the present invention are described above in conjunction with the accompanying drawings, the present invention should not be limited to the structures and operations that are exactly the same as the above descriptions and drawings. For those skilled in the art, many equivalent improvements and changes can be made to the above embodiments through logical analysis, reasoning or limited experiments without exceeding the concept and scope of the present invention, but these improvements and changes should all fall within the scope of protection required by the present invention.

Claims

1. A driving device for realizing automatic focusing of a camera, characterized in that: The invention comprises a support module (1) and a moving component (2) suitable for lens installation, wherein the moving component (2) is assembled on the support module (1) via a suspension system (3), and the suspension system (3) guides the moving component (2) to move along the optical axis of the lens; and further comprises a pair of drive modules (4), wherein the drive modules (4) are symmetrically arranged on opposite sides of the moving component (2), and the drive modules (4) drive the drive arms (41) provided therein based on the principle of SMA wire contraction under heat to push the moving component (2) to move along the optical axis of the lens, and the directions in which the two drive modules (4) drive the moving components (2) to move along the optical axis of the lens are consistent, and the tilt angle adjustment of the lens in a single direction is realized by separately controlling the two drive modules; The suspension system (3) comprises an upper spring (31) and a lower spring (32), the upper spring (31) and the lower spring (32) are respectively connected between the upper and lower ends of the moving component (2) and the support module (1); the driving module (4) comprises two driving arms (41), an SMA wire (42) and two conductive supports (43), the conductive supports (43) are fixed on the support module (1) and electrically connected to the control system of the camera, and an elastic arm (431) that can be opened and closed is provided on the conductive support (43), the two driving arms (41) and the SMA wire ( The two driving arms (41) and the SMA wire (42) form an active triangle relationship, so as to stably and accurately drive the moving part (2) to drive the lens focusing movement, the two ends of the SMA wire (42) are respectively connected to the elastic arms (431) on the two conductive supports (43), one end of the driving arm (41) is connected to the elastic arm (431) of the corresponding conductive support (43), and the other end of the driving arm (41) is hingedly connected to the moving part (2); the two driving arms (41) and the SMA wire (42) form an isosceles triangle relationship, the SMA wire (42) is the bottom side, and the SMA wire (42) is arranged horizontally.

2. A driving device for realizing automatic focusing of a camera according to claim 1, characterized in that: The upper spring (31) comprises an upper inner ring (311) and a first flexible portion (312) extending from the outer periphery of the upper inner ring (311), the upper inner ring (311) being fixedly connected to the upper end of the moving component (2), and the end of the first flexible portion (312) being fixedly connected to the support module (1); the lower spring (32) comprises a lower inner ring (321) and a second flexible portion (322) extending from the outer periphery of the lower inner ring (321), the lower inner ring (321) being fixedly connected to the lower end of the moving component (2), and the end of the second flexible portion (322) being fixedly connected to the support module (1).

3. A driving device for realizing automatic focusing of a camera according to claim 1 or 2, characterized in that: The support module (1) is composed of a base plate (11) and an upper seat (12) stacked together. The upper side of the upper seat (12) facing away from the base plate (11) is provided with an upwardly protruding column (121), and the column (121) is adapted to be installed on the suspension system (3) and the drive module (4). A hinged portion (21) is provided on the peripheral side of the moving component (2), and the hinged portion (21) is hinged to a drive arm (41) of the drive module (4).

4. The driving device for realizing automatic focusing of a camera according to claim 1, characterized in that: The control system of the camera uses the resistance of the SMA wire (42) as feedback to achieve closed-loop control of the movement of the lens.

5. The driving device for realizing automatic focusing of a camera according to claim 1, characterized in that: The two driving arms (41) are respectively integrally formed with the two conductive supports (43).

6. The driving device for realizing automatic focusing of a camera according to claim 3, characterized in that: The bottom plate (11) is integrally manufactured with a circuit or an additional FPC circuit board. When integrally manufactured, the bottom plate (11) is provided with terminals or pads for realizing circuit connection with other components, and a shell for anti-collision and protection is assembled on the support module (1).

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