Camera module based on split type pre-tightening adjustable ultrasonic motor driving

Abstract

The invention relates to a split type pre-tightening adjustable ultrasonic motor driving-based camera module, which comprises a piezoelectric motor and a lens assembly, and is characterized in that the piezoelectric motor is composed of a pre-pressing magnetic conduction carrier, a magnetic part, a driving unit base, a limiting stepped shaft, a driving unit, a pre-pressing adjusting module, a conductive elastic sheet assembly, a hollow bottom plate, a limiting middle frame and an accommodating cavity. Wherein the driving unit is driven according to the principle of outputting an elliptical orbit through a composite mode, and stable and large-stroke high-speed automatic focusing of the module can be realized; the lens assembly is installed in the installation hole of the pre-pressing magnetic conduction carrier. The pre-pressing adjusting module can adjust the pre-tightening force according to the lens assemblies of different sizes, and the performance output of the electric signal optimization module under the complex working condition is integrated and conducted through the conductive elastic piece assembly. The module can be widely applied to various occasions requiring high-precision automatic focusing, such as the fields of smart phones, digital cameras, security monitoring and the like, and has wide market prospects and application values.

Description

Technical Field

[0001] The present application relates to the field of camera technology, and in particular to a camera module driven by a split-type pre-tightened and adjustable ultrasonic motor. Background Art

[0002] In the camera lens drive system of small devices such as mobile phones, it is often necessary to use lenses with better materials to improve the quality of photos, which leads to the continuous increase in the mass of lens components. In order to achieve the zoom and anti-shake movement of the lens, it is necessary to drive it through a small-sized, high-thrust, high-speed, high-resolution driver. Most mobile phones on the market now use voice coil motors to drive camera lenses. Voice coil motors are electromagnetic motors that use the principle that a powered coil will be driven by a force in a magnetic field. Its outstanding advantage is fast response speed, but it is difficult to output enough force in a small size. Compared with traditional electromagnetic motors, ultrasonic motors have unique advantages such as high power density, fast response speed, high resolution, and anti-electromagnetic interference. Among them, the composite modal ultrasonic motor is most suitable for driving camera lenses due to its large design freedom. The existing camera module driven by ultrasonic motors basically relies on processing and assembly accuracy to achieve the required preload, and the preload is the key factor affecting the stator drive performance. Therefore, it is of great significance to design a camera module based on a composite modal ultrasonic motor that can flexibly adjust the preload. Summary of the invention

[0003] The present application provides a camera module driven by a split-type preloaded and adjustable ultrasonic motor, which can be adapted to lens assemblies of different sizes. By adjusting the preload force, the optimal performance output of the camera module under complex working conditions can be achieved.

[0004] In the first aspect, the present application provides a piezoelectric motor, which may include a drive unit, a drive unit base, a magnetic part, a limit stepped shaft and a pre-stressed magnetic guide carrier. Among them, the drive unit may include an L-shaped hollow drive element and a piezoelectric chip. The piezoelectric chip includes a drive chip and a clamping chip. In addition, the L-shaped hollow drive element is a rectangular plate with a semicircular end, and an L-shaped hollow is designed in the middle of the plate. A driving foot is provided at a corner of the thick part of the drive element away from the limit hole. A circular arc is designed on one side of the driving foot of the thick part of the L-shaped hollow drive element to prevent the original straight edge of the driving foot from interfering with the pre-stressed magnetic guide carrier when it contacts with the pre-stressed magnetic guide carrier. At the same time, the angle between the two drive elements on the same drive unit base can be reduced to save space. The clamping chip can be arranged on the outer side of the thin part of the L-shaped hollow drive element, and the drive chip can be arranged above or below the thick part of the L-shaped hollow drive element.

[0005] By using the driving unit provided by the present application, the L-shaped hollow driving element can be driven to vibrate by applying an electrical signal to the piezoelectric chip, thereby outputting a driving force and a driving displacement at the driving foot. In addition, by continuously applying a regular electrical signal to the piezoelectric chip, the continuous vibration of the stator structure can be achieved, so that it continuously outputs a driving displacement in the same direction, so that the driving unit can drive the pre-stressed magnetic guide carrier to continuously move in the same direction, and by changing the phase difference of the electrical signal, the driving unit can drive the lens assembly to reciprocate, thereby effectively increasing the focus stroke and focus accuracy of the camera module.

[0006] When the piezoelectric chip is specifically set up, the clamping chip can be glued to the outside of the thin part of the L-shaped hollow driving element, and the driving chip can be glued to the top or bottom of the thick part of the stator. The piezoelectric chip is polarized along the thickness direction. When an electric field along the polarization direction is applied to the piezoelectric chip, it can generate a displacement d31 perpendicular to the polarization direction.

[0007] In the present application, the L-shaped hollow driving element is driven by the composite modal principle, specifically by the clamping mode and the driving mode. The clamping mode refers to the bending vibration parallel to the plane of the driving element produced by the thin part of the driving element when the clamping chip works at the resonant frequency, thereby driving the thick part of the driving element to produce a displacement located in the plane of the driving element, and then realizing the radial clamping action of the pre-stressed magnetic conductive carrier through the driving foot; the driving mode refers to the bending vibration perpendicular to the plane of the driving element produced by the thick part of the driving element when the driving chip works at the resonant frequency, thereby realizing the axial driving action of the pre-stressed magnetic conductive carrier through the driving foot. Optimizing the size of the driving unit, such as adjusting the thickness, length, width of the piezoelectric chip and the driving element, and the size of the L-shaped hollow, can achieve the frequency degeneracy of the clamping and driving modes of the driving unit, that is, the resonant frequencies of the two modes are the same or close, and at this time, the amplitude of the driving foot reaches the peak value in both the clamping and driving directions, and the driving performance of the driving unit is also the best.

[0008] In addition, the driving chip is provided with an electrical signal by excitation one, and the clamping chip is provided with an electrical signal by excitation two, wherein excitation one and excitation two use the same frequency (the frequency here is ultrasonic frequency, that is, the frequency is greater than 20kHz, which can make the piezoelectric motor achieve a silent effect), and the phase difference is π / 2. The vibration generated by the combination of the two modes will cause the driving foot to produce an elliptical trajectory motion with a constant rotation direction, thereby driving the pre-loaded magnetic guide carrier to produce continuous motion in the same direction along the axial direction; keeping the frequency the same and increasing the phase difference between excitation one and excitation two to 3π / 2, the vibration generated by the combination of the two modes will cause the driving foot to produce an elliptical trajectory motion with an opposite rotation direction, thereby driving the pre-loaded magnetic guide carrier to produce reverse continuous motion along the axial direction.

[0009] In addition, in the present application, the two drive units can be arranged symmetrically in the center, so that the two drive feet are in contact with the pre-stressed magnetic permeable carrier respectively, which can make the pre-stress applied by the two drive units to the pre-stressed magnetic permeable carrier at the drive feet a pair of balanced forces, thereby effectively improving the driving stability of the drive unit. In a possible implementation of the present application, four drive units can be arranged symmetrically in the center, which can effectively improve the load capacity and structural reliability of the piezoelectric motor.

[0010] In the present application, in order to adjust the angle between two drive units on the same drive unit base, one side of the L-shaped hollow drive element is designed to be arc-shaped and processed with concentric through holes for limiting, and the limit step shaft is used to limit the movement of the drive unit in its plane while enabling the drive unit to rotate around the limit step shaft. The limit step shaft is an optical axis, the diameter of the small diameter is slightly smaller than the diameter of the through hole of the L-shaped hollow drive element, the assembly gap is used to store lubricating oil, which is conducive to adjusting the angle between the drive units, the small diameter end face is glued to the upper end face of the hollow bottom plate, the transition end face between the large diameter and the small diameter limits the displacement of the drive unit along the axial direction of the limit hole, and the large diameter end face is slightly higher than the base of the drive unit to achieve the positioning of the grounding conductive spring.

[0011] The mounting hole of the pre-stressed magnetic guide carrier is used to carry the lens assembly. In a possible implementation of the present application, in order to achieve flexible contact with the driving foot of the driving unit to improve the driving performance, two arc-shaped springs can be arranged around the central hole, and each arc-shaped spring cantilever end is designed with a limiting arc to prevent the pre-stressed magnetic guide carrier from rotating significantly under extreme working conditions; the number of the cantilever can also be increased to four pieces to improve the structural stability, just like the number of driving feet. In addition, the pre-stressed magnetic guide carrier is provided with a magnetic component installation groove at the gap at the fixed end of the arc-shaped spring for bonding the magnetic component, and a guide groove structure is provided at the gap at the cantilever end of the arc-shaped spring for accommodating the guide component.

[0012] The drive unit base is stepped, with concave sides and through holes for fixing the limit step shaft. The middle protrusion is slightly lower than the installed limit step shaft, which is used to bond the grounding conductive spring. One side is designed with a through groove for bonding the magnetic part, where the magnetic part can be a strong magnet. The distance between the two drive unit bases after bonding the magnetic parts is slightly larger than the pre-loaded magnetic carrier, so that the magnetic part can stably pre-load the magnetic carrier to limit its rotation under frictionless conditions.

[0013] In the second aspect, the present application also provides a pre-stress adjustment module, which includes a guide pre-stress adjustment module and a clamping pre-stress adjustment module. The guide pre-stress adjustment module includes a guide mechanism, a reset spring, a pre-tightening wedge, an adjusting wedge and a pre-tightening knob. The guide mechanism includes a guide member and a guide groove, and the guide member is accommodated in the guide groove and the trapezoidal through groove used for guiding the pre-stressed magnetic guide carrier. When the drive unit drives the pre-stressed magnetic guide carrier to drive the lens assembly to move axially, the pre-stressed magnetic guide carrier and the guide member produce relative displacement, thereby providing a guiding effect for its movement, which is beneficial to improve the stability of the movement of the lens assembly. From the above introduction, it can be known that the magnetic parts on the drive unit base and the pre-stressed magnetic guide carrier provide adsorption force to prevent the pre-stressed magnetic guide carrier from generating rotational motion without increasing the friction resistance during the movement. In combination with two symmetrical guide mechanisms, the pre-stressed magnetic guide carrier can be further prevented from overturning during the guiding process, thereby further improving the stability and efficiency of the drive. In the present application, the guide member can be in the form of a needle roller, so that the friction between the guide member and the preloaded magnetic carrier is a sliding friction force, and the friction coefficient can be reduced by applying grease to the needle roller. The preload adjustment knob is designed with a card wing on both sides for embedding into the special-shaped groove on the side of the accommodating cavity, which can realize reciprocating linear movement. The bottom has a square groove that cooperates with the square boss of the adjusting wedge block to achieve adhesive fixation. The preload wedge block is guided by the rectangular through groove on the side of the limiting middle frame and can move in a radial straight line along the lens module. The guide groove and the preload wedge block are connected by a reset spring. Adjusting the position of the preload adjustment knob can make the preload wedge block displace radially, thereby controlling the preload force of the guide groove and the guide member on the preloaded magnetic carrier, and adjusting the driving performance of the camera module. The clamping preload adjustment module includes a clamping preload spring, a reset spring, a preload wedge, an adjustment wedge and a preload adjustment button. The clamping preload spring is against the clamping wafers of the drive units on both sides and is bonded to the preload wedge. By adjusting the preload adjustment button, the clamping preload spring can be moved in a radial straight line, thereby adjusting the angle between the drive units. The reset spring is connected to the drive unit base and the preload wedge to play a resetting role.

[0014] In the third aspect, the present application provides a conductive spring assembly, including a grounding conductive spring, a clamping conductive spring, a driving conductive spring, a driving pre-stressed spring, and a clamping connection spring. In order to avoid a series of problems caused by wiring harness routing, the present application uniformly adopts a self-designed metal spring conductive method, wherein the grounding conductive spring is designed with a positioning hole to be positioned through a limit step shaft and glued to the drive unit base, the clamping conductive spring is positioned through a U-shaped groove on the side of the accommodating cavity and glued to the clamping connection spring, ensuring that the signals of the clamping wafers of the drive units on both sides are homologous, and the driving conductive spring is positioned through a U-shaped groove on the upper surface of the hollow bottom plate and glued to the driving pre-stressed spring through conductive glue, ensuring that the signals of the driving wafers of the drive units on both sides are homologous, and the above metal springs finally lead out three contacts at the two corners of the same side of the hollow bottom plate, a total of six contacts, providing space for circuit design. The design of the overall metal spring cleverly utilizes the remaining space in the accommodating cavity, improves the utilization rate of the space, and avoids the complexity of wire connection.

[0015] In the fourth aspect, the present application also provides a camera module, which may include a lens assembly, a piezoelectric motor of the first aspect, a preload adjustment module of the second aspect, a conductive spring assembly of the third aspect, a hollow bottom plate, a receiving cavity, and a limiting middle frame. The lens assembly can be installed in the mounting hole of the preloaded magnetic guide carrier, and the piezoelectric motor can drive the lens assembly to reciprocate along its optical axis direction to achieve stable, large-stroke, high-speed automatic focusing of the camera module. The upper surface of the hollow bottom plate is designed with a U-shaped groove for driving the conductive spring to position, a circular through hole is arranged in the center to ensure the optical path of the lens module, rectangular through holes are arranged on all four sides of the limiting middle frame for guiding the preload wedge, and special-shaped grooves are designed on the four sides of the receiving cavity to cooperate with the preload adjustment knob, and a stepped through hole is designed on the inner side, which increases the working stroke of the preloaded magnetic guide carrier and plays a certain shielding role, thereby improving the aesthetics of the camera module, and a U-shaped groove is designed on the inner side of the receiving cavity for clamping the conductive spring to position. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the structure of an electronic device provided in one embodiment of the present application;

[0017] Figure 2 This is a diagram showing the appearance of a camera module provided in one embodiment of the present application;

[0018] Figure 3 An exploded diagram of a camera module provided in one embodiment of the present application;

[0019] Figure 4 A schematic structural diagram of a receiving cavity provided in an embodiment of the present application from another perspective;

[0020] Figure 5A schematic diagram of the detailed structure of the inner and outer sides of the accommodating cavity adjustment groove provided in one embodiment of the present application;

[0021] Figure 6 A top view of a hollow bottom plate provided in one embodiment of the present application;

[0022] Figure 7 A top view of the assembled drive unit base, the drive unit, and the pre-compressed magnetic guide carrier with the lens assembly provided in one embodiment of the present application;

[0023] Figure 8 An exploded schematic diagram of a drive unit base, a drive unit, a pre-loaded magnetic guide carrier, and a lens assembly provided in one embodiment of the present application;

[0024] Fig. 9 An axonometric diagram of a drive unit provided in one embodiment of the present application;

[0025] Fig.10 An exploded diagram of a drive unit provided in one embodiment of the present application;

[0026] Fig.11 A schematic diagram of a vibration mode of a driving unit in a driving direction provided by an embodiment of the present application;

[0027] Fig.12 A schematic diagram of a vibration mode of a driving unit in a clamping direction provided by an embodiment of the present application;

[0028] Fig.13 A schematic diagram of an excitation signal provided in an embodiment of the present application;

[0029] Fig.14 A schematic diagram of the driving principle of a driving unit provided in an embodiment of the present application;

[0030] Fig.15 An exploded schematic diagram of a clamping preload adjustment module provided in one embodiment of the present application;

[0031] Fig.16 An exploded schematic diagram of a guide preload adjustment module (partial middle frame is shown) provided in an embodiment of the present application;

[0032] Fig.17 Three views and an axonometric view of a preload adjustment knob provided in one embodiment of the present application;

[0033] Fig.18 Schematic diagram of the explosion of conductive springs with different functions provided in one embodiment of the present application.

[0034] Reference numerals:

[0035] 1- camera module; 2- processor; 3- housing;

[0036] 101- lens assembly; 102- piezoelectric motor;

[0037] 1021-driving unit; 10211-L-shaped hollow driving element; 102112-thick part; 102111-thin part; 102113-end; 102114-L-shaped hollow area; 102115-limiting hole; 10213-clamping chip; 10212-driving chip;

[0038] 102117-driving foot; 102116-arc;

[0039] 1021111- first surface of thin part; 1021112- second surface of thin part; 1021121- first surface of thick part; 1021122- second surface of thick part;

[0040] 1022-accommodating cavity; 1023-limiting middle frame; 1024-hollow bottom plate;

[0041] 10221- rectangular groove; 10222- key groove; 10223- clamping spring positioning groove; 10224- accommodating cavity special-shaped groove;

[0042] 10241-hollow bottom plate special-shaped groove; 10242-driving spring piece positioning groove; 10243-short groove; 102511-trapezoidal through groove; 102512-limiting arc; 102513-arc spring piece; 102514-carrier rectangular through groove;

[0043] 10251-pre-pressed magnetic guide carrier; 10252-drive unit base; 10253-limiting stepped shaft; 10254-base magnetic part; 10255-carrier magnetic part;

[0044] 10261-guide piece; 10262-guide groove; 10263-return spring; 10264-preload wedge; 10265-adjustment wedge; 10266-preload adjustment knob;

[0045] 102521- rectangular through groove of base; 102522- cylindrical boss of base; 102713- clamping preload spring; 102641- cylindrical boss of wedge block; 102651- square boss;

[0046] 102661- rectangular boss; 102662- square groove; 102663- card wing;

[0047] 102711- clamping conductive spring; 102712- clamping connecting spring; 102721- driving conductive spring; 102722- driving pre-compression spring; 10273- grounding conductive spring. DETAILED DESCRIPTION

[0048] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings.

[0049] Piezoelectric motors use the deformation of piezoelectric ceramics operating at ultrasonic frequencies to drive the lens assembly through friction. They have the characteristics of self-locking when power is off, fast response speed, large stroke and strong load capacity. Compared with the common voice coil motors on the market, they have broader development prospects and have become a hot research topic in the field of imaging.

[0050] Figure 1 A schematic diagram of a mobile phone device provided in this application may mainly include a camera module 1, a processor 2 and a housing 3, and other components are not shown in the figure. A camera hole is opened on one side of the housing 3 for the camera module 1 to collect light for shooting, and the camera module 1 transmits data to the processor 2 for analysis.

[0051] The camera module 1 may include a lens assembly 101 and a piezoelectric motor 102, which may be referred to Figure 2 , Figure 2 This is a schematic diagram of the structure of a camera module provided by the present application, wherein the piezoelectric motor 102 can drive the lens assembly 101 to reciprocate along the optical axis direction to achieve the focus of the camera module.

[0052] The driving efficiency of the piezoelectric motor 102 on the lens assembly 101 and the movement stroke have a significant impact on the focusing performance of the camera module 1, and the preload is a key factor affecting the driving performance of the piezoelectric motor 102. Existing piezoelectric motors 102 generally optimize the assembly design and improve the processing accuracy to meet the preload required for driving the lens assembly 101, but it is difficult to adjust the size of the preload, which often leads to inconsistent performance of the lens assembly 101 during movement, and only providing preload through assembly means that the piezoelectric motor 102 and the lens assembly 101 must correspond one to one. As people's requirements for camera quality continue to increase, a mobile phone usually has multiple lens assemblies 101 of different sizes and functions, which makes it difficult to unify their specifications. If the traditional solution is adopted, it is necessary to design and produce piezoelectric motors 102 with matching sizes for each different lens assembly 101, resulting in high production costs.

[0053] The piezoelectric motor 102 provided in the present application is intended to solve the above-mentioned problems. It adopts a split drive unit 1021 and designs a preload adjustment mechanism, so that the piezoelectric motor 102 can adjust the angle between the drive units 1021 to adapt to lens assemblies 101 of different sizes, which can greatly improve the versatility of the piezoelectric motor 102 and significantly reduce the cost of producing camera modules with lens assemblies of different specifications. It can also fine-tune the preload force for lens assemblies 101 of the same specification to optimize the driving performance, which is beneficial to improving the camera effect of mobile phone devices using the piezoelectric motor 102. To facilitate the understanding of the drive unit 1021 provided in the embodiment of the present application, its specific structure is described in detail below in conjunction with the accompanying drawings.

[0054] Figure 3 The exploded view of the camera module 1 provided in one embodiment of the present application, the limiting middle frame 1023 is glued to the upper end surface of the hollow bottom plate 1024, and the four sides thereof have rectangular through holes that can play a guiding role. The appearance of the accommodating cavity 1022 is as follows Figure 3 shown.

[0055] Figure 4 This is a structural diagram of another perspective of the accommodating cavity 1022 provided in one embodiment of the present application. The accommodating cavity 1022 is designed with through holes on all four sides, a key groove 10222 is designed on the outer side, and a rectangular groove 10221 is designed on the inner side. The structural diagram of the details of the inner and outer sides of the adjusting groove of the accommodating cavity 1022 is shown in FIG. Figure 5 As shown, the width of the rectangular groove 10221 is slightly wider than the width of the key groove 10222, and wider than the width of the wings 102663 on both sides of the preload adjustment button 10266, and the length is only half the length of the key groove 10222, so that the preload adjustment button 10266 can be supported on both sides within the working stroke, and the sum of the depths of the key groove 10222 and the rectangular groove 10221 is equal to the wall thickness of the accommodating cavity 1022, so that the planar ends of the wings 102663 on both sides of the preload adjustment button 10266 can just rest on the two sides of the rectangular groove 10221 that are wider than the key groove 10222, thereby providing assembly conditions for the reciprocating linear motion of the preload adjustment button 10266 along the key groove 10222.

[0056] Figure 6A top view of a hollow base plate 1024 is provided for one embodiment of the present application. A circular through hole with the same outer diameter and size as the lens assembly 101 is provided in the center of the hollow base plate 1024 and the accommodating cavity 1022, which can meet the lighting conditions for video recording and shield the internal structure of the piezoelectric motor 102 to achieve an aesthetic effect. At the same time, the upper end surface of the hollow base plate 1024 and the inner surface of the accommodating cavity 1022 are respectively provided with a hollow base plate shaped groove 10241 and an accommodating cavity shaped groove 10224 on the periphery of the circular through hole according to the contour of the pre-stressed magnetic guide carrier 10251, which can reduce the portion of the hollow base plate 1024 and the accommodating cavity 1022 interfering with the pre-stressed magnetic guide carrier 10251, thereby effectively increasing the stroke of the lens assembly 101.

[0057] Figure 7 The top view of the assembled drive unit base 10252, drive unit 1021 and pre-stressed magnetic guide carrier 10251 equipped with lens assembly 101 provided in one embodiment of the present application, four arc-shaped spring pieces 102513 are distributed on the circumference of the pre-stressed magnetic guide carrier 10251 in a centrally symmetrical manner, and the fixed end thereof extends radially outward to reserve sufficient deformation space, and the essence of clamping preload force adjustment is to change the positive pressure of the drive foot 102117 on the arc-shaped spring piece 102513 by adjusting the preload adjustment knob 10266, so as to cause the arc-shaped spring piece 102513 to produce different degrees of deformation. The free end of each arc-shaped spring piece 102513 is also designed with an outwardly turned limiting arc 102512, which can play a limiting role to prevent the pre-stressed magnetic guide carrier 10251 from rotating too much in an emergency condition, causing the drive unit 1021 and the corresponding arc-shaped spring piece 102513 to be misaligned. The boss between the free ends of the two arc-shaped spring pieces 102513 is designed with a trapezoidal through groove 102511 for cooperating with the guide member 10261 , and the boss between the fixed ends of the two arc-shaped spring pieces 102513 is designed with a carrier rectangular through groove 102514 for positioning and gluing the carrier magnetic member 10255 .

[0058] Figure 8 The exploded schematic diagram of the drive unit base 10252, the drive unit 1021, the pre-stressed magnetic guide carrier 10251 and the lens assembly 101 provided in one embodiment of the present application, the small diameter end face of the limit step shaft 10253 is glued to the upper end face of the hollow bottom plate 1024, and the large and small diameter transition end face thereof has a certain gap with the end 102113 of the L-shaped hollow drive element 10211, so that the L-shaped hollow drive element 10211 can rotate around the limit step shaft 10253. The magnetic force between the carrier magnetic part 10255 glued to the carrier rectangular through groove 102514 of the pre-stressed magnetic guide carrier 10251 and the base magnetic part 10254 glued to the base rectangular through groove 102521 of the drive unit base 10252 can prevent the pre-stressed magnetic guide carrier 10251 and the drive unit base 10252 from rotating relative to each other, and play a guiding role.

[0059] Fig. 9 This is a schematic diagram of the structure of a driving unit 1021 provided in an embodiment of the present application. The driving unit 1021 may include an L-shaped hollow driving element 10211 and a piezoelectric chip.

[0060] Fig.10 An exploded view of a driving unit 1021 provided in one embodiment of the present application. The piezoelectric chip may include a clamping chip 10213 and a driving chip 10212. The L-shaped hollow driving element 10211 may include a thick portion 102112, a thin portion 102111 and an end portion 102113, and the closed area surrounded by the three portions is an L-shaped hollow area 102114, wherein the end portion 102113 is also designed with a limiting hole 102115, and a driving foot 102117 is designed at a corner of the thick portion 102112 away from the end portion 102113 and the L-shaped hollow area 102114, and a concave arc is provided between the driving foot 102117 and the end portion 102113, i.e., on the side of the thick portion 102112 away from the L-shaped hollow area 102114. 102116. In the present application, the curvature of the arc 102116 is not specifically limited. By way of example, the curvature of the arc 102116 may be the same as the curvature of the arc-shaped spring piece 102513 of the pre-stressed magnetic guide carrier 10251. Properly increasing the curvature may increase the maximum angle between the two drive units 1021 on the same drive unit base 10252 under the condition that the drive foot 102117 is in contact with the arc-shaped spring piece 102513 of the pre-stressed magnetic guide carrier 10251, thereby reducing the distance between the drive unit bases 10252 on both sides and saving space in the camera module 1. The piezoelectric chip can be used to drive the L-shaped hollow driving element 10211, the clamping chip 10213 can be glued to the first surface 1021111 of the thin part or the second surface 1021112 of the thin part, and the driving chip 10212 can be glued to the first surface 1021121 of the thick part or the second surface 1021122 of the thick part according to the installation position of the driving unit 1021.

[0061] The driving chip 10212 drives the thick portion 102112 to excite the driving unit 1021 to generate a driving mode along the axial direction of the pre-compressed magnetic guide carrier 10251, such as Fig.11 As shown, the clamping wafer 10213 drives the thin portion 102111 to excite the driving unit 1021 to generate a clamping mode along the radial direction of the pre-pressed magnetic guide carrier 10251, such as Fig.12 shown.

[0062] Fig.13A schematic diagram of an excitation signal is provided for an embodiment of the present application, wherein excitation one provides an electrical signal for the driving chip 10212, and excitation two provides an electrical signal for the clamping chip 10213. By controlling the excitation signals of the driving chip 10212 and the clamping chip 10213, the driving unit 1021 can generate coupled vibration under the condition that excitation one and excitation two have a certain phase difference (such as π / 2 or 3π / 2). At this time, the motion trajectory of the driving foot 102117 is elliptical. Further changing the phase difference of the excitation signal can achieve the reverse motion trajectory of the driving foot, so that the driving unit 1021 can output positive and negative driving forces and driving displacements.

[0063] The specific driving principle of the driving unit 1021 is as follows Fig.14 As shown, for the driving unit 1021 driven along the negative direction of the z-axis (i.e., the axial downward direction of the pre-stressed magnetic guide carrier 10251), its vibration within one cycle can be divided into four nodes. The first point: when t=T1, a pair of driving chips 10212 are stimulated to apply an electrical signal with a voltage of +A. At this time, the driving unit 1021 generates a bending motion along the negative direction of the z-axis, and the driving foot 102117 drives the pre-stressed magnetic guide carrier 10251 to move along the negative direction of the z-axis while clamping it; the second point: when t=T2, two pairs of clamping chips 10213 are stimulated to apply an electrical signal with a voltage of -A. At this time, the driving unit 1021 generates a bending motion along the negative direction of the x-axis (i.e., the radial outward direction of the pre-stressed magnetic guide carrier 10251), and the driving foot 102117 is temporarily separated from the pre-stressed magnetic guide carrier 10251; the third point: when t=T3, a pair of driving chips 10212 are stimulated to apply an electrical signal with a voltage of -A. At this time, the driving unit 1021 generates bending motion along the positive direction of the z-axis (i.e., the axial upward direction of the pre-stressed magnetic guide carrier 10251), and the driving foot 102117 moves rapidly along the positive direction of the z-axis while being away from the pre-stressed magnetic guide carrier 10251; Fourth point: When t=T4, the second excitation applies an electrical signal with a voltage of +A to the clamping wafer 10213, and at this time, the driving unit 1021 generates bending motion along the positive direction of the x-axis (i.e., the radial inward direction of the pre-stressed magnetic guide carrier 10251), and the driving foot 102117 clamps the pre-stressed magnetic guide carrier 10251 again. The driving force of this process is provided by the friction between the driving foot 102117 and the pre-stressed magnetic guide carrier 10251, so the pre-stressed magnetic guide carrier 10251 moves axially downward under the drive of this excitation source. Similarly, if the phase difference between the first excitation and the second excitation is increased to 3π / 2, the pre-stressed magnetic guide carrier 10251 can be moved axially upward. In the present application, the material of the L-shaped hollow driving element 10211 is not specifically limited. For example, the material of the L-shaped hollow driving element 10211 can be a metal material with lower rigidity such as Al6061 or Al7075, which is beneficial to increase the amplitude generated by the driving unit 1021 when the piezoelectric chip is excited.

[0064] Fig.15 The schematic diagram of the clamping preload adjustment module provided in one embodiment of the present application is exploded. A circular hole is designed in the center of the cross beam of the clamping preload spring 102713. The spring is positioned and glued to the plane of the preload wedge 10264 through the wedge cylindrical boss 102641 of the preload wedge 10264. The reset spring 10263 abuts against the inner side of the clamping preload spring 102713. The arc-shaped end of the clamping preload spring 102713 abuts against the clamping wafer 10213. When the position of the clamping preload spring 102713 is adjusted, the angle of the driving unit 1021 can be indirectly changed, and at the same time, it can play the role of conducting electricity for the clamping wafer 10213. The drive unit base 10252 is designed with a base rectangular through groove 102521 on the side close to the lens assembly 101 for positioning and gluing the base magnetic part 10254, and is designed with a base cylindrical boss 10252 on the side away from the lens assembly 101 for positioning the reset spring 1026. The bottom surface of the drive unit base 10252 is glued to the upper end surface of the hollow bottom plate 1024.

[0065] Fig.16 The exploded schematic diagram of the guide preload adjustment module provided in one embodiment of the present application, the guide groove 10262 and the trapezoidal through groove of the preload magnetic guide carrier 10251 are respectively matched with the guide member 10261 to achieve guidance. The two end faces of the guide groove 10262 are clearance matched with the inner side of the accommodating cavity 1022 and the upper end face of the hollow bottom plate 1024, and the clearance is used to store lubricating oil to reduce the sliding friction generated when the guide groove 10262 moves linearly along the axial direction of the reset spring 10263. The reset spring 10263 is positioned by the guide groove 10262 and the wedge cylindrical boss 102641 designed on the preload wedge 10264. The wedge surface of the adjustment wedge 10265 and the preload wedge 10264 fit each other, and the linear movement of the adjustment wedge 10265 along the side of the limiting middle frame 1023 can be converted into the linear movement of the preload wedge 10264 along the radial direction of the preload magnetic guide carrier 10251 through the wedge surface. A square boss 102651 is designed in the center of the plane opposite to the wedge surface in the adjusting wedge block 10265, which can be embedded in the square groove 102662 on the side of the clamping wing 102663 of the pre-tightening knob 10266. Such a split design can simplify the structural design of the parts to reduce the processing cost. The angle between the two driving units 1021 on the same driving unit base 110252 can be adjusted by adjusting the distance between the clamping pre-stressing spring piece 102713 and the axis of the lens assembly 101 by the pre-tightening knob 10266, so as to change the size of the pre-stressing force generated by the driving foot 102117 of the L-shaped hollow driving element 10211 and the arc spring piece 102513 of the pre-stressing magnetic guide carrier 10251.

[0066] The three-view and axonometric drawing of the preload knob 10266 are as follows: Fig.17The upper end surface is designed with rectangular bosses 102661 with equal spacing to increase friction for easy adjustment, the lower end surface is designed with a square groove 102662 for positioning the adjustment wedge 10265, and the two sides are designed with locking wings 102663, which have inclined surfaces that can be easily inserted into the accommodating cavity 1022 so that the preload knob 10266 can be embedded in the keyway 10222 on the outer side of the accommodating cavity 1022 and the rectangular groove 10221 on the inner side.

[0067] Fig.18 An explosion schematic diagram of conductive springs with different functions provided in an embodiment of the present application, wherein the arc-shaped end of the clamping connection spring 102712 contacts the clamping pre-stressing spring 102713, and its crossbeam is glued to the clamping conductive spring 102711 by conductive glue. At this time, the signal sources of the four clamping chips 10213 are unified, and the clamping conductive spring 102711 is positioned and fixed by the clamping spring positioning groove 10223 on the inner side of the accommodating cavity 1022. The conductive current of the clamping chip 10213 is guided to the clamping conductive spring 102711 on the inner side of the accommodating cavity 1022 through the clamping connection spring 102712, and extends along the inner side of the limiting middle frame 1023 to the short groove 10243 on the upper end face of the hollow bottom plate 1024 and is exposed to facilitate power supply by the power supply in the mobile phone device. The grounding conductive spring 10273 is positioned by the large end of the limiting stepped shaft 10253, and is glued to the upper end surface of the driving unit base 10252, and extends along the inner side of the limiting middle frame 1023 to the short slot 10243 of the hollow bottom plate 1024. In order to avoid interference with the clamping connection spring 102712 and improve the overall space utilization of the camera module 1, the driving conductive spring 102721 is glued to the upper end surface of the hollow bottom plate 1024 through the positioning of the driving spring positioning slot 10242 on the hollow bottom plate 1024, and extends to the short slot 10243. At this time, three conductive spring pins are arranged at the same interval on both sides of one side of the upper end surface of the hollow bottom plate 1024 for power supply. The arc-shaped end of the driving pre-stressing spring 102722 contacts the driving chip 10212, and the crossbeam is glued to the driving conductive spring 102721 by conductive glue. At this time, the signal sources of the four driving chips 10212 are unified.

Claims

1. A camera module based on a split preloaded and adjustable ultrasonic motor drive, characterized in that: The invention comprises a piezoelectric motor (102) and a lens assembly (101), wherein the piezoelectric motor (102) is composed of a pre-stressed magnetic guide carrier (10251), a magnetic part, a drive unit base (10252), a position-limiting stepped shaft (10253), a drive unit (1021), a pre-stressing adjustment module, a conductive spring assembly, a hollow bottom plate (1024), a position-limiting middle frame (1023) and a receiving cavity (1022); the lens assembly (101) is installed on the mounting plate of the pre-stressed magnetic guide carrier (10251). The drive unit base (10252) is glued to the hollow bottom plate (1024), the drive unit (1021) is installed on the drive unit base (10252) through a limiting stepped shaft (10253), the preload adjustment module can change the preload force between the drive unit (1021) and the preload magnetic guide carrier (10251) through the limiting and guiding provided by the limiting middle frame (1023) and the accommodating cavity (1022), and the conductive spring sheet assembly can unify the signal sources of various parts of the drive unit (1021).

2. According to claim 1, a camera module based on split preloaded adjustable ultrasonic motor drive, characterized in that: The driving unit (1021) is composed of an L-shaped hollow driving element (10211) and a piezoelectric chip, wherein the L-shaped hollow driving element (10211) has a thick portion (102112), a thin portion (102111) and an end portion (102113), which are connected end to end to form an L-shaped hollow area (102114), a limiting hole (102115) is arranged in the center of the end portion (102113) to cooperate with a limiting stepped shaft (10253), a driving foot (102117) is arranged at a corner of the thick portion (102112) away from the end portion (102113), and a concave arc (102117) is arranged between the driving foot (102117) and the end portion (102113). 02116); the piezoelectric chip comprises a clamping chip (10213) and a driving chip (10212); the clamping chip (10213) is glued to the thin part (102111) of the L-shaped hollow driving element (10211), and the driving chip (10212) is glued to the thick part (102112) of the L-shaped hollow driving element (10211); by applying an excitation signal with a certain phase difference to the clamping chip (10213) and the driving chip (10212), the driving unit (1021) generates coupled vibration, and forms two elliptical trajectories in two rotation directions at the driving foot (102117), thereby outputting positive and negative motion displacements.

3. According to claim 1, a camera module based on split preloaded adjustable ultrasonic motor drive, characterized in that: The magnetic part comprises a carrier magnetic part (10255) and a base magnetic part (10254); the preload adjustment module comprises a guide preload adjustment module and a clamping preload adjustment module, which are used to adjust the angle between the drive units (1021) and the preload of the drive foot (102117) on the preload magnetic guide carrier (10251); the conductive spring sheet assembly comprises a grounding conductive spring sheet (10273), a clamping conductive spring sheet (102711), a driving conductive spring sheet (102721), a driving preload spring sheet (102722) and a clamping connection spring sheet (102712) , through a specific positioning and gluing method, the signal sources of the clamping chip (10213) and the driving chip (10212) are unified, and the power supply is convenient; the driving unit base (10252) is designed with a base rectangular through groove (102521) on the side close to the lens assembly (101) for positioning the base magnetic part (10254), and the side away from the lens assembly (101) is designed with a base cylindrical boss (102522); the small diameter end face of the limiting stepped shaft (10253) is glued to the upper end face of the hollow bottom plate (1024), and the large and small diameter transition end face is connected to the L The end (102113) of the L-shaped hollow driving element (10211) has a certain gap, so that the L-shaped hollow driving element (10211) can rotate around the limiting stepped shaft (10253); four arc-shaped spring pieces (102513) are distributed on the circumference of the pre-loaded magnetic guide carrier (10251) in a centrally symmetrical manner, and the free end of each arc-shaped spring piece (102513) is designed with a limiting circular arc (102512) turned outward, and the boss between the free ends of the two arc-shaped spring pieces (102513) is designed with a trapezoidal through groove (102511), and the two arc-shaped spring pieces The boss between the fixed ends (102513) is designed with a carrier rectangular through groove (102514) for positioning the carrier magnetic part (10255); a circular through hole with the same outer diameter and size as the lens assembly (101) is arranged in the center of the hollow bottom plate (1024) and the accommodating cavity (1022); at the same time, the upper end surface of the hollow bottom plate (1024) and the inner side surface of the accommodating cavity (1022) are also provided with a hollow bottom plate shaped groove (10241) and an accommodating cavity shaped groove (10224) on the periphery of the circular through hole, respectively, which can reduce interference and increase the working stroke of the lens assembly (101).

Images