OPTICAL IMAGE STABILIZATION CAMERA MODULE

The present application relates to an optical image stabilization camera module, comprising: a lens; a photosensitive assembly having a photosensitive chip; a first driving part adapted to drive the lens to translate in x-axis and y-axis directions; and a second driving part comprising a second basic portion and a second movable portion, the second driving part having four side surfaces, wherein each side surface is provided with two interlaced SMA wires, and both ends of each SMA line are connected to a fixed end of the second basic portion and a fixed end of the second movable portion, respectively; each of the fixed ends is located at a corner area of the second basic portion or the second movable portion. The photosensitive assembly is fixed to the second movable portion, and the second movable portion is adapted to drive, under the drive of the SMA lines, the photosensitive chip to move in an xoy plane; and the lens and the photosensitive chip are configured to be simultaneously driven and move in opposite directions. According to the present application, the image stabilization stroke and the image stabilization response speed of the camera module can be improved at the cost of a small volume.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the priority of Chinese patent application No. 202011303700.X entitled “OPTICAL IMAGE STABILIZATION CAMERA MODULE” and filed on Nov. 19, 2020, and Chinese patent application No. 202011334144.2 entitled “OPTICAL IMAGE STABILIZATION CAMERA MODULE” and filed on Nov. 25, 2020, the entire disclosure of which is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to the technical field of camera equipment. Specifically, the present disclosure relates to an optical image stabilization camera module.

TECHNICAL BACKGROUND

With the increasing demand of consumers for mobile phone photography, the functions of mobile phone cameras (i.e., camera modules) are becoming more and more diverse, and functions such as portrait photographing, telephoto photographing, optical zoom, and optical image stabilization are integrated into a camera with a limited volume, wherein autofocus, optical image stabilization, optical zoom and other functions often need to rely on optical actuators (which may also sometimes be referred to as motors) to achieve.

FIG.1shows a typical camera module with a motor in the prior art. Referring toFIG.1, the camera module generally comprises a lens1, a motor mechanism2(which may be simply referred to as a motor) and a photosensitive assembly3. In the photographing state of the camera module, light from a photographed object is focused on a photosensitive element3aof the photosensitive assembly3through the lens1. Structurally, the lens1is fixed on a motor carrier of the motor (shown in detail inFIG.1). The motor carrier is a movable component, and it can usually drive, under the action of a driving element of the motor, the lens1to move in the direction of an optical axis, so as to achieve a focus function. As for a camera module with an optical image stabilization (OIS) function, the motor often has a more complicated structure. This is because, in addition to driving the lens to move in the direction of the optical axis, the motor needs to drive the lens1to move in other degrees of freedom (e.g., a direction perpendicular to the optical axis) to compensate for the shake during photographing. Generally, the shake of the camera module comprises translation in a direction perpendicular to the optical axis (translation in x-axis and y-axis directions) and rotation (referring to rotation in an xoy plane, wherein its rotation axis direction may be roughly the same as the optical axis), and tilt shake (referring to rotation around the x and y axes, wherein in the field of camera modules, tilt shake is also called tilt jitter). When a gyroscope (or another position sensing element) in the module detects shake in a certain direction, it can issue an instruction to make the motor drive the lens to move by a distance in the opposite direction, thereby compensating for the shake of the lens. Generally, the lens is only translated and/or rotated in or with respect to the direction perpendicular to the optical axis to compensate for the shake of the camera module. This is due to a fact that if the lens is rotated around the x and y axes, that is, if the tilt adjustment of the lens is used to achieve an image stabilization effect, the imaging quality of the module may be reduced, and even blurring may be caused, which makes it difficult to meet the basic imaging quality requirements.

However, as the imaging quality requirements of mobile phone camera modules are increasingly becoming higher, the volume and weight of the lens are increasingly becoming larger, and the driving force requirements for the motor are also increasingly becoming higher. However, current electronic devices (such as mobile phones) also have great restrictions on the volume of the camera module, and the occupied volume of the motor increases correspondingly with the size increase of the lens. In other words, as the lens develops towards larger volume and heavier weight, it is difficult to increase the driving force provided by the motor accordingly. Insofar as the driving force is limited, the heavier the lens, the shorter the stroke the motor can drive the lens to move, which will affect the image stabilization ability. On the other hand, the heavier the lens, the slower the motor can drive the lens to move, and the longer the time it takes for the lens to reach a predetermined compensation position, which will also affect the image stabilization effect.

Therefore, there is an urgent need for a solution that can improve the image stabilization stroke and image stabilization response speed of the camera module.

SUMMARY

An objective of the present disclosure is to overcome the deficiencies of the prior art and provide a solution that can improve the image stabilization stroke and image stabilization response speed of the camera module.

In order to solve the above technical problem, the present disclosure provides an optical image stabilization camera module, comprising: a lens; a photosensitive assembly having a photosensitive chip; a first driving part adapted to mount the lens and drive the lens to translate in the directions of an x-axis and a y-axis; and a second driving part comprising a second basic portion and a second movable portion, wherein the second basic portion and the second movable portion are movably connected by means of an elastic connecting portion, and the second driving part has four side surfaces; each side surface is provided with two interlaced SMA wires, and two ends of each SMA wire are connected to a fixed end of the second basic portion and a fixed end of the second movable portion, respectively; and each of the fixed ends is located in a corner area of the second basic portion or the second movable portion; wherein the photosensitive assembly is fixed on the second movable portion, and the second movable portion is adapted to drive, under the drive of the SMA wires, the photosensitive chip to move in an xoy plane; and the lens and the photosensitive chip are configured to be simultaneously driven and move in opposite directions; and wherein the x-axis and the y-axis are coordinate axes perpendicular to an optical axis of the camera module, the x-axis and the y-axis are perpendicular to each other, and the xoy plane is a plane formed by the x-axis and the y-axis.

In the optical image stabilization camera module, the second driving part has four corner areas, each corner area is provided with two fixed ends, and the two ends of each SMA wire are fixed and electrically connected to the fixed ends of two adjacent corner areas, respectively.

In the optical image stabilization camera module, in any one of the corner areas, the two fixed ends are arranged along a direction of the optical axis. In this case, the two interlaced SMA wires are approximately in an xoz plane or a yoz plane (the z-axis is a coordinate axis parallel to the optical axis), that is, the two fixed ends of the corner area are arranged vertically (for example, one fixed end is located directly above the other fixed end). The z-axis is a coordinate axis parallel to the optical axis. The interlacing of two SMA lines means that the projections of the two SMA lines in the xoz plane or the yoz plane cross, but the two SMA lines are not in direct contact, to avoid mutual interference when the two SMA lines shrink, resulting in a decrease in the accuracy of position adjustment.

In the optical image stabilization camera module, the four fixed ends of any two adjacent corner areas are all located in a plane parallel to the xoy plane. For example, in any one of the corner areas, one fixed end is located on an outer side of the other fixed end. Here, the outer side refers to a side away from the photosensitive center of the photosensitive chip, and the inner side refers to a side toward the photosensitive center of the photosensitive chip.

In the optical image stabilization camera module, the two fixed ends of each corner area comprise a type-A fixed end and a type-B fixed end, wherein the type-A fixed end and the type-B fixed end are at different heights; the type-A fixed ends located in two diagonal corner areas are at the same height, and the type-B fixed ends located in two diagonal corner areas are also at the same height; each side surface of the second driving part is provided with two SMA wires, wherein the two ends of each SMA wire are connected to one of the type-A fixed ends and one of the type-B fixed ends located in adjacent corner areas, respectively, so that the two SMA wires are interlaced with each other.

In the optical image stabilization camera module, the four type-A fixed ends of the four corner areas are at the same height; and the four type-B fixed ends of the four corner areas are at the same height.

In the optical image stabilization camera module, the four corner areas comprise a first corner, a second corner, a third corner and a fourth corner, wherein the first corner and the third corner are located on one diagonal line of the second driving part, and the second corner and the fourth corner are located on the other diagonal line of the second driving part; the second movable portion extends outward at the first corner and the third corner respectively to form a first extension portion and a third extension portion; and the first extension portion is provided with a first A fixed end and a first B fixed end at different heights, and the third extension portion is provided with a third A fixed end and a third B fixed end at different heights; a second A fixed end and a second B fixed end at different heights are provided at a position of the second corner of the second basic portion; and a fourth A fixed end and a fourth B fixed end at different heights are provided at a position of the fourth corner of the second basic portion; and the first A fixed end, the second A fixed end, the third A fixed end and the fourth A fixed end all belong to the type-A fixed ends; and the first B fixed end, the second B fixed end, the third B fixed end and the fourth B fixed end all belong to the type-B fixed ends.

In the optical image stabilization camera module, the second movable portion further has notches at the second corner and the fourth corner, respectively, to avoid the fixed ends provided on the second basic portion.

In the optical image stabilization camera module, the type-A fixed end and the type-B fixed end located in the same corner area are stacked, and the two are separated by an insulating material.

In the optical image stabilization camera module, the second movable portion is further adapted to drive, under the drive of the SMA wires, the photosensitive chip to move in a direction of rotation around a z-axis; wherein the z-axis is a coordinate axis parallel to the optical axis.

In the optical image stabilization camera module, the second movable portion is further adapted to drive, under the drive of the SMA wires, the photosensitive chip to move in a direction of translation along a z-axis; wherein the z-axis is a coordinate axis parallel to the optical axis.

In the optical image stabilization camera module, the four corner areas comprise a first corner, a second corner, a third corner and a fourth corner, wherein the first corner and the third corner are located on a first diagonal line of the second driving part, and the second corner and the fourth corner are located on a second diagonal line of the second driving part; the second movable portion extends outward at the first corner and the third corner respectively to form a first extension portion and a third extension portion; the two fixed ends of the first corner of the second driving part are provided on the first extension portion, and the two fixed ends of the third corner of the second driving part are provided on the third extension portion; the two fixed ends of the second corner of the second driving part are provided at a second corner of the second basic portion, and the two fixed ends of the fourth corner of the second driving part are provided at a fourth corner of the second basic portion; for each side surface of the second driving part, the two interlaced SMA wires provided on the side surface are fixed and electrically connected to the four fixed ends located in the two corner areas of the side surface; wherein a translational component of the photosensitive chip in a direction of the first diagonal line or in a direction of the second diagonal line is generated by driving two pairs of interlaced SMA wires on two intersecting side surfaces of the second driving part to shrink; and the translational component in the direction of the first diagonal line is combined with the translational component in the direction of the second diagonal line, so that a movement direction of the photosensitive chip in the xoy plane is opposite to a movement direction of the lens.

In the optical image stabilization camera module, rotation of the photosensitive chip in an Rz direction is generated by driving two pairs of interlaced SMA wires on two opposite side surfaces of the second driving part to shrink, wherein the Rz direction is a direction of rotation around a z-axis, and the z-axis is a coordinate axis parallel to the optical axis.

In the optical image stabilization camera module, a rotation component of the photosensitive chip in an Rx or Ry direction is generated by driving a single SMA wire on a single side surface of the second driving part to shrink; wherein the Rx direction is a direction of rotation around the x-axis, and the Ry direction is a direction of rotation around the y-axis.

In the optical image stabilization camera module, translation of the photosensitive chip in a direction of a z-axis is generated by driving a first group of SMA wires and a second group of SMA wires of the second driving part to shrink; and a translation direction of the photosensitive chip in the z-axis direction is opposite to a translation direction of the lens in the z-axis direction, wherein the z-axis is a coordinate axis parallel to the optical axis; wherein the first group of SMA wires are two SMA wires with a first common fixed end, and the two SMA wires are located on two intersecting side surfaces of the second driving part, respectively; the second group of SMA wires are the other two SMA wires with a second common fixed end, and the other two SMA wires are located on the other two intersecting sides of the second driving part; and each of the first common fixed end and the second common fixed end is one of eight fixed ends of the second driving part, and the first common fixed end and the second common fixed end are located at the same height.

In the optical image stabilization camera module, the first driving part comprises a first basic portion and a first movable portion, and the second basic portion is fixed on the first basic portion.

In the optical image stabilization camera module, the first basic portion is located on the periphery of the first movable portion; the second basic portion comprises a basic portion side wall and a base, a bottom surface of the basic portion side wall is connected to the base, and a top surface of the basic portion side wall is connected to the first basic portion.

In the optical image stabilization camera module, an edge area of the bottom surface of the first basic portion forms a step-shaped notch, and the basic portion side wall can extend upward and into the step-shaped notch and be connected to the first basic portion.

In the optical image stabilization camera module, the second movable portion comprises a movable portion main body, the movable portion main body is of a flat plate shape, and has a light-passing hole in its center; and an outer edge area of the bottom surface of the movable portion main body extends downward to form the movable portion side wall.

In the optical image stabilization camera module, the photosensitive assembly comprises the photosensitive chip, a circuit board, a lens holder and a filter; the photosensitive chip is mounted on an upper surface of the circuit board, the lens holder is mounted on the upper surface of the circuit board and surrounds the photosensitive chip, and the filter is mounted on the lens holder; a bottom surface of the movable portion side wall is bonded to the upper surface of the circuit board of the photosensitive assembly; and an inner side surface of the movable portion side wall, a bottom surface of the movable portion main body, and the upper surface of the circuit board and an outer side surface of the lens holder form an accommodating cavity among them, and electronic elements are arranged in the accommodating cavity.

In the optical image stabilization camera module, an inner edge area of the movable portion main body has a step-shaped notch facing an object side to avoid part of a structure of the optical lens.

In the optical image stabilization camera module, the second basic portion is fixed to the first driving part, the second basic portion comprises a basic portion side wall, the basic portion side wall surrounds the second movable portion, and there is a gap between the basic portion side wall and the second movable portion for accommodating the SMA wires.

In the optical image stabilization camera module, the photosensitive assembly comprises a suspended circuit board, and the suspended circuit board comprises a rigid circuit board main body and a flexible connecting band; the connecting band is led out from a first side surface and a second side surface of the circuit board main body and bent upwards to form a bent portion; a top part of the bent portion extends along the periphery of the photosensitive assembly in a horizontal direction, so that the connecting band surrounds the periphery of a first side surface, a second side surface and a third side surface of the photosensitive assembly; and the connecting band has at least one suspension portion on each of the first side surface and the second side surface, and the suspension portion is fixed to the second basic portion of the second driving part or fixed to the second basic portion through an intermediate object; wherein the photosensitive assembly has a first side surface and a second side surface which are at the same positions as those of the circuit board main body, the first side surface and the second side surface are arranged oppositely, and the third side surface intersects both the first side surface and the second side surface.

In the optical image stabilization camera module, the suspension portion has a suspension hole, the second basic portion or the intermediate object has a hook, and the hook is hooked to the suspension hole.

In the optical image stabilization camera module, a part of sections of the connecting band are attached to a rigid substrate for reinforcement to form the suspension portion.

In the optical image stabilization camera module, the suspended circuit board is made of a rigid-flex board, wherein the circuit board main body and the suspension portion are formed by a rigid board part of the rigid-flex board, and the bent portion and a connecting band section connected between a plurality of suspension portions are formed by a flexible board part of the rigid-flex board.

In the optical image stabilization camera module, the connecting band comprises a third connecting band and a fourth connecting band, and the third connecting band is led out from the first side surface of the circuit board main body and bent upward to form a bent portion, then extends along the first side surface of the photosensitive assembly, is bent in a horizontal direction at a corner and continues to extend along the third side surface; the fourth connecting band is led out from the second side surface of the circuit board main body and bent upward to form another bent portion, then extends along the second side surface of the photosensitive assembly, and is horizontally bent at a corner and continues to extend along the third side surface; and the third connecting band and the fourth connecting band are joined and electrically conducted with each other at the third side surface.

In the optical image stabilization camera module, the camera module further comprises a first connecting band electrically connected to the first driving part, and the first connecting band is led out from a top area of the first driving part, then bent downward and jointed and electrically conducted with the third connecting band or the fourth connecting band on the third side surface.

In the optical image stabilization camera module, the camera module further comprises a housing, and an inner side surface of the housing has an accommodating groove for accommodating a joint portion of the third side surface; wherein the joint portion represents a joint portion where the first connecting band, the third connecting band and the fourth connecting band are joined to each other; and the accommodating groove is filled with a glue material to fix the first connecting band, the third connecting band and the fourth connecting band to the housing.

In the optical image stabilization camera module, the connecting band located on the third side surface is further connected to a fifth connecting band, and the fifth connecting band has a connector for external connection; and the suspended circuit board further has a fixing portion for fixing the fifth connecting band.

In the optical image stabilization camera module, a lens movement distance b by which the first driving module drives the lens to move, and a photosensitive chip movement distance c by which the second driving module drives the photosensitive chip to move, are determined according to a detected tilt-shake angle a of the camera module; wherein the lens movement distance b, the photosensitive chip movement distance c and an image-side focal length f of the camera module satisfy: a=arctan(b/f)+arctan(c/f).

In the optical image stabilization camera module, the driving structure further comprises a driving logic module, which is used/configured to maintain a ratio between the lens movement distance b and the photosensitive chip movement distance c at a preset fixed ratio.

In the optical image stabilization camera module, the driving structure further comprises a driving logic module having an image stabilization threshold K; the driving logic module is used/configured to: when the tilt-shake angle a is less than or equal to the image stabilization threshold K, cause a ratio of the lens movement distance b and the photosensitive chip movement distance c to maintain at a preset fixed ratio, and when the tilt-shake angle a is greater than the image stabilization threshold K, cause the photosensitive chip movement distance c to reach a maximum value cmaxof its moving stroke; and the lens movement distance b is calculated according to a relational formula b=tan(a/f)−cmax.

In the optical image stabilization camera module, the preset fixed ratio of the lens movement distance to the photosensitive chip movement distance is set according to weight of the lens, driving force of the first driving part, weight of the photosensitive chip or the photosensitive assembly, and driving force of the second driving part, so that the lens and the photosensitive chip move to their respective image stabilization target positions in the same time.

Compared with the prior art, the present application has at least one of the following technical effects:1. The present application can improve the image stabilization stroke of the camera module, so that a larger shake of the camera module may be compensated for.2. The present application can improve the image stabilization response speed of the camera module.3. The optical image stabilization camera module of the present application has the advantage of compact structure, which is especially suitable for miniaturized camera modules.4. In some embodiments of the present application, settings may be made according to factors such as the weight of the lens, the driving force of the first driving part, the weight of the photosensitive chip (or photosensitive assembly), the driving force of the second driving part, etc., so that the lens and the photosensitive chip move to their respective image stabilization target positions in the same time, thereby obtaining a better image stabilization effect.5. In some embodiments of the present application, by arranging interlaced SMA wires on the four sides of the second driving part, the photosensitive chip may be adjusted on multiple degrees of freedom in a small space.6. In some embodiments of the present application, the translational component of the photosensitive chip in the direction of the first diagonal line or in the direction of the second diagonal line may be generated by driving two pairs of interlaced SMA wires on two intersecting side surfaces of the second driving part to shrink; and the translational component in the direction of the first diagonal line is combined with the translational component in the direction of the second diagonal line, so that the movement direction of the photosensitive chip in the xoy plane is opposite to the movement direction of the lens. According to this design, the image stabilization stroke and the image stabilization response speed of the camera module may be improved at the cost of a small volume.7. In some embodiments of the present application, in the second driving part, in any one of the corner areas, the two fixed ends are arranged along the optical axis direction. According to this arrangement, the space of the photosensitive assembly in the height direction (z-axis direction) may be effectively used, which will thus not increase the height of the camera module. At the same time, the space in the x-axis and y-axis directions of the camera module can be saved, thereby reducing the lateral dimension of the camera module.8. In some embodiments of the present application, the glue material for bonding the first basic portion and the second basic portion is arranged between the step-shaped notch of the first basic portion and the top surface of the basic portion side wall extending into the notch, so as to prevent the problem of camera module photo stains caused by the overflow of AA glue material.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In order to better understand the present application, various aspects of the present application will be described in more detail with reference to the drawings. It should be understood that the detailed description is merely description of exemplary implementations of the present application, and does not limit the scope of the present application in any way. Throughout the description, the same reference numerals refer to the same elements. The expression “and/or” includes any and all combinations of one or more of the associated listed items.

It should be noted that in the present description, the expressions of “first”, “second”, etc. are only used to distinguish one feature from another feature, and do not indicate any limitation on the feature. Therefore, without departing from the teachings of the present application, a first main body discussed below may also be referred to as a second main body.

In the drawings, for convenience of explanation, the thickness, size, and shape of the object have been slightly exaggerated. The drawings are only examples and are not drawn strictly to scale.

It should also be understood that the terms “comprising”, “comprise”, “having”, “including” and/or “include” when used in the present description, indicate the existence of stated features, integers, steps, operations, elements and/or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or combinations thereof. Furthermore, when an expression such as “at least one of” appears after a list of listed features, it modifies the entire list of features, rather than individual elements in the list. In addition, when describing an implementation of the present application, “may”/“can” is used to denote “one or more implementations of the present application”. Also, the term “exemplary” is intended to refer to an example or illustration.

As used herein, the terms “substantially”, “approximately” and similar terms are used as a term expressing an approximation and not as a term expressing an extent, and are intended to indicate an inherent deviation in a measurement value or calculated value, which will be recognized by those of ordinary skill in the art.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meanings as commonly understood by those of ordinary skill in the art to which the present application belongs. It should also be understood that the terms (such as those defined in commonly used dictionaries) should be interpreted to have meanings consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless it is clearly defined herein.

It needs to be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments may be combined with each other.

The present disclosure will be further described below in conjunction with the drawing and specific embodiments.

FIG.2shows a schematic sectional view of a camera module with an image stabilization function according to an embodiment of the present application. Referring toFIG.2, in this embodiment, the camera module comprises a lens10, a photosensitive assembly20, a first driving part30and a second driving part40. The photosensitive assembly20comprises a photosensitive chip21. The first driving part30is configured to drive the lens10to move in x and y directions, and the second driving part40is configured to drive the photosensitive chip21to move in the x and y directions. In this embodiment, the x and y directions are perpendicular to each other, and both are parallel to a photosensitive surface of the photosensitive element20. A z direction is parallel to the normal direction of the photosensitive surface. For ease of understanding,FIG.2also shows a three-dimensional Cartesian coordinate system constructed based on the x, y and z directions. In this embodiment, the optical image stabilization of the camera module is realized by controlling the module to simultaneously drive the lens10and the photosensitive chip21to move in opposite directions. Specifically, the lens1and the photosensitive chip21are configured to be simultaneously driven and move in opposite directions. For example, when the lens10is driven to move in the positive direction of the x-axis, and the photosensitive chip21is driven to move in the negative direction of the x-axis. If the lens10is driven to move in the positive direction of the y-axis, the photosensitive chip21is driven to move in the negative direction of the y-axis; or the lens10is driven to move in the x-axis and y-axis, and at the same time, the photosensitive chip21is driven to move toward the direction opposite to the movement direction of the lens10in the x-axis and the y-axis. In other words, when it is necessary to move on the x-axis and the y-axis at the same time, the directions of the displacement vector of the lens10and the displacement vector of the photosensitive chip21in the xoy plane are opposite. The camera module usually comprises a position sensor, and the position sensor is used to detect the shake of the camera module or a terminal device (i.e., an electronic device equipped with the camera module, such as a mobile phone). When shake is detected, the position sensor sends a signal to the camera module, and the lens10and the photosensitive chip21are driven to move accordingly to compensate for the shake, so as to achieve the purpose of optical image stabilization. In this embodiment, the lens10and the photosensitive chip21are configured to move simultaneously, and the lens10and the photosensitive chip21move in opposite directions, which can achieve faster response and a better image stabilization effect. In addition, the image stabilization angle range of the camera module is usually limited by a suspension system and a driving system, and a relatively large compensation angle range cannot be achieved. In this embodiment, the lens10and the photosensitive chip21are simultaneously driven to move in opposite directions so as to achieve large-angle shake compensation. In addition, in this embodiment, by simultaneously driving the lens10or the photosensitive chip21to move in opposite directions, compared with the solution of only driving the lens10to move, there is a larger relative movement stroke between the lens10and the photosensitive chip21(for ease of description, this relative movement stroke may be simply referred to as an image stabilization stroke), which can have a better compensation effect. In particular, due to the increase of the image stabilization stroke, this embodiment also has a better compensation effect for the tilt shake of the camera module. Further, the moving direction of the image stabilization movement in this embodiment may be limited in the xoy plane, and it is not necessary to tilt the optical axis of the lens10or the photosensitive chip21, thereby avoiding the problem of image blur caused by the image stabilization movement.

Further, in another embodiment of the present application, the photosensitive chip21may also be driven by the second driving part40to rotate in the xoy plane, so as to compensate for the shake in the rotation direction of the camera module.

Further, still referring toFIG.2, in an embodiment of the present application, the camera module comprises a first driving part30, a lens10, a second driving part40and a photosensitive assembly20. The lens10is mounted on the first driving part30. The first driving part30may have a first motor carrier of a cylindrical shape, the first motor carrier may be used as a movable portion of the first driving part, and the lens is mounted on an inner side surface of the first motor carrier. The first driving part further has a stationary portion, which may also be referred to as a basic portion. In this embodiment, the basic portion may be implemented as a motor casing. The motor casing may comprise a base and a cover. The base has a light-passing hole. The movable portion is movably connected to the basic portion. The driving element may be a coil magnet combination, which may be mounted between the movable portion and the basic portion. For example, it may be mounted between the first motor carrier and the motor casing. In practice, the first driving part in this embodiment may directly adopt a common structure of an optical image stabilization motor in the prior art. Further, in this embodiment, the second driving part40may be borne against and fixed on the bottom surface of the first driving part30. The second driving part40may also comprise a basic portion and a movable portion. The basic portion is directly connected to the first driving part. The movable portion is located below the basic portion and is movably connected to the basic portion. The photosensitive assembly20comprises a circuit board23, a photosensitive chip21mounted on the surface of the circuit board, and a lens holder22surrounding the photosensitive chip21. The bottom of the lens holder22may be mounted on the surface of the circuit board23, and the top surface of the lens holder22may be fixed on the movable portion of the second driving part40. The center of the lens holder22has a light-passing hole, and a filter24is mounted on the lens holder22(the filter24may also be regarded as an integral part of the photosensitive assembly20). Under the drive of the movable portion of the second driving part40, the photosensitive assembly20can translate relative to the basic portion in the x and y directions or rotate in the xoy plane. For ease of description, herein, the basic portion of the first driving part30is sometimes referred to as a first basic portion, the basic portion of the second driving part40is sometimes referred to as a second basic portion, the movable portion of the first driving part30is sometimes referred to as a first movable portion, and the movable portion of the second driving part40is sometimes referred to as a second movable portion.

FIG.3shows a schematic sectional view of a camera module with an image stabilization function according to another embodiment of the present application. In this embodiment, the camera module comprises a first driving part30, a lens10, a second driving part40and a photosensitive assembly20. The lens10is mounted on the first driving part30. The structures and assembling methods of the first driving part30and the lens10may be the same as those of the previous embodiment shown inFIG.2, and will not be repeated here. This embodiment is different from the previous embodiment in that the second driving part40is located inside the photosensitive assembly20. In this embodiment, the photosensitive assembly20comprises a circuit board23, a lens holder22, a filter24, and a photosensitive chip21. The bottom of the lens holder22may be mounted on the surface of the circuit board23, and the top surface of the lens holder22may be fixed on the basic portion of the first driving part30. The center of the lens holder22has a light-passing hole, and a filter24is mounted on the lens holder22. The lens holder22, the filter24and the circuit board23can form a cavity, and the photosensitive chip21is located in the cavity25. In this embodiment, the second driving part40may also be located in the cavity25. Specifically, the basic portion of the second driving part40may be mounted on the surface of the circuit board23, and the movable portion of the second driving part40is movably connected to the basic portion. The photosensitive chip21is mounted on the surface of the movable portion. In this way, under the drive of the movable portion of the second driving part40, the photosensitive chip21can translate relative to the basic portion in the x and y directions or rotate in the xoy plane.

Different structural implementations of the second driving part of the camera module of the present application have been described above with reference to the two embodiments. A method for compensating for the tilt shake of the camera module based on the design idea of the present application will be further described below.

FIG.4shows schematic diagrams of the relationships between movement distances of the lens and the photosensitive chip and a tilt angle of the module in four different situations in the present application. Position A in the figure represents a combination of movement distances of the lens and the photosensitive chip for compensating the shake angle a of the camera module. As shown inFIG.4, in the figure, the movement distance of the lens is b, the movement distance of the photosensitive chip (hereinafter sometimes simply referred to as the chip) is c, and the movement distance of the lens or chip can be equivalent to an angle of an image plane deviating from an optical axis during optical imaging. Specifically, when the translation distance of the lens in the xoy plane is b, it causes an arithmetic relationship between an image plane offset angle α1and an image distance. The image distance is different under different photographing distances. For the convenience of calculation and expression, the image distance is replaced by an image side focal length here. Specifically, it causes the relationship between the image plane shift angle α1and the image side focal length f of the lens to be: tan(α1)=b/f, and when the photosensitive chip moves by a distance c in the xoy plane, it causes the relationship between the image plane shift angle α2 and the image side focal length f of the lens to be: tan(α2)=c/f. In this embodiment, the moving directions of the lens and the photosensitive chip are opposite, so the comprehensive compensation angle a of the camera module is calculated as: a=α1+α2=arctan(b/f)+arctan(c/f). In one embodiment, the movement distances of the lens and the photosensitive chip may be set to be the same, that is, b=c. In another embodiment, the movement distances of the lens and the photosensitive chip may be set to be unequal. For example, the movement distance of the lens may be greater than the movement distance of the photosensitive chip, that is, b>c. In this embodiment, the second driving part can select a driver with a smaller size (e.g., a mems driver, etc., wherein the movable stroke of such a driver is usually relatively small), so as to facilitate the overall miniaturization of the camera module.

Further, in an embodiment of the present application, a ratio of the movement distance of the lens to the movement distance of the photosensitive chip is optionally set to maintain a fixed ratio, such as b/c=6:4, or b/c=7:3, or b/c=5:5. No matter what the compensation value of the camera module shake (such as the comprehensive compensation angle a) is, the movement distances of the lens and the photosensitive chip are maintained at the preset ratio, which is advantageous for the uniform compensation effect of the camera module within a compensable range, and is also advantageous to reduce the design difficulty of the driving logic module of the image stabilization system of the camera module.

Further, in the configuration in which the movement distance of the lens and the movement distance of the photosensitive chip are based on a fixed ratio for image stabilization movement, because the movable range of the photosensitive chip is small, sometimes the shake of the camera module may exceed the maximum moving stroke of the photosensitive chip. Therefore, in an embodiment of the present application, an image stabilization threshold may be set. For example, for the shake angle a that needs to be compensated, a threshold K may be set. When the actually calculated shake angle a is less than or equal to the image stabilization threshold K, the movement distance b of the lens and the movement distance c of the photosensitive chip are maintained at a fixed ratio, and the fixed ratio may be preset, for example, b/c=6:4, or b/c=7:3, or b/c=5:5. When the actually calculated shake angle a is greater than the image stabilization threshold K, the movement distance c of the photosensitive chip takes the maximum value of its movement stroke, i.e. the photosensitive chip maximum stroke cmax, and the movement distance of the lens is b=tan(a/f)−cmax. In other words, when the shake angle of the camera module that needs to be compensated is above the image stabilization threshold K, based on the preset fixed ratio, the lens moves to a position corresponding to the maximum movement distance of the photosensitive chip (i.e., the photosensitive chip maximum stroke cmax), and then the first driving part may drive the lens to continue to move until the lens moves by a distance b=tan(a/f)−cmax. At the same time, the photosensitive chip synchronously moves by the maximum movement distance cmaxof the photosensitive chip in the opposite direction, and then remains stationary.

Further, in another embodiment of the present application, in the xoy plane, an image stabilization angle corresponding to the maximum stroke borax of the lens movement (the image stabilization angle refers to an angle at which the camera module tilts and shakes) may be less than an image stabilization angle corresponding to the photosensitive chip maximum stroke cmax. Under this design, the image stabilization system of the camera module can have a faster response speed. In a high-end lens, the lens often has a large number of lens elements. For example, at present, the number of lens elements in a rear main camera lens of a smart phone can reach 8, and in order to further improve the image quality, some lenses also use glass lens elements, all of which result in the heavier weight of the lenses. When the driving force does not increase significantly, the speed at which a driving device drives the lens to move will decrease. However, the photosensitive chip or photosensitive assembly is relatively light in weight, and can reach a preset position with a small driving force. Therefore, in the solution of this embodiment, the advantages of the photosensitive chip or photosensitive assembly being relatively close in weight and relatively fast moving can be better utilized to effectively improve the response speed of the image stabilization system of the camera module.

Further, in another embodiment of the present application, the fixed ratio of the movement distance of the lens to the movement distance of the photosensitive chip may be set according to the weight of the lens, the driving force of the first driving part, the weight of the photosensitive chip (or the photosensitive assembly), the driving force of the second driving part and other factors are set. An appropriate fixed ratio is set, so that the lens and the photosensitive chip move to their respective image stabilization target positions substantially in the same time, so as to obtain a better image stabilization effect. Specifically, the weight of the lens and the driving force of the first driving part can substantially determine the moving speed of the lens, and the weight of the photosensitive chip (or the photosensitive assembly) and the driving force of the second driving part can substantially determine the moving speed of the photosensitive chip. When the moving speed of the photosensitive chip is lower than the moving speed of the photosensitive chip (for example, when the weight of the lens is large), the movement distance of the photosensitive chip can occupy a larger proportion during setting of the fixed ratio. In this way, the characteristics of the fast moving speed of the photosensitive chip can be utilized, so that the photosensitive chip moves by a longer distance, and the lens and the photosensitive chip move to their respective image stabilization target positions substantially in the same time.

Further, in another embodiment of the present application, the first driving part may adopt a driving element with a large driving force and a suspension system with a large stroke. For example, the first driving part may be driven by an SMA (shape memory alloy) element. Compared with the traditional coil-magnet combination, the SMA element can provide a larger driving force with a smaller occupied space, so the first driving part can be designed to be more compact, facilitating the miniaturization of the camera module.

Further,FIG.5shows a schematic sectional view of a camera module in an embodiment of the present application. Referring toFIG.5, in this embodiment, the basic portion of the second driving part40is fixed with the basic portion (not shown inFIG.5) of the first driving part30. The lens10may be mounted on a movable portion (e.g., a first motor carrier, which is not specifically shown inFIG.5) of the first driving part30. The photosensitive assembly20comprises a circuit board23, a photosensitive chip21, a lens holder22, a filter24, etc. The photosensitive assembly20may be mounted on a movable portion42of the second driving part40. Specifically, the bottom surface of the movable portion42can be borne against the top surface of the lens holder22of the photosensitive assembly20. In the second driving part40, the second basic portion41and the second movable portion42can be elastically connected by means of a suspension system. In this embodiment, the suspension system allows the second movable portion42to translate relative to the second basic portion41in the xoy plane. Optionally, the suspension system may be a ball bearing system, the advantage of which is that in the z direction, the second movable portion42and the second basic portion41are in contact with each other through ball(s), the second movable portion42only moves in the xoy plane, and the movement in the optical axis direction can be blocked by the ball(s) between the second movable portion42and the second basic portion41, so as to avoid affecting focusing of the camera module.

Optionally, in another embodiment, the suspension system may include an elastic element (such as a spring) through which the fixed portion and the movable portion are connected, which allows the movable portion to translate relative to the basic portion in the xoy plane, but prevents movement of the movable portion relative to the basic portion outside the xoy plane. Compared with the ball bearing system, the advantage of providing the elastic element is that the elastic element can provide an initial force between the basic portion and the movable portion, and the initial force can control the movement distance of the movable portion or maintain its position in cooperation with the driving force of the driving element, without additionally providing a driving element to provide a conjugate driving force so as to control the position of the movable portion. If the ball bearing system is used, the movable portion can move freely relative to the basic portion in the xoy direction without the driving force provided by the driving element, so it is often necessary to provide at least a pair of mutually opposite driving forces so that the movable portion can be controlled to remain in its initial position.

Further, still referring toFIG.5, in one embodiment of the present application, image stabilization can be achieved by driving the entire photosensitive assembly20to move. At the same time, the circuit board23, the photosensitive chip21, the lens holder22, and the optical filter24are packaged as a whole. The circuit board23, the lens holder22, and the optical filter24form a closed space. The photosensitive chip21is accommodated in the closed space, which improves the closure property of the photosensitive assembly20, and ensures that the imaging of the photosensitive chip21is not affected by dust during the production or use of the camera module.

In this embodiment, still referring toFIG.5, in an embodiment of the present application, the back of the circuit board can be directly borne against a terminal device (i.e., an electronic device equipped with the camera module, such as a mobile phone). Specifically, the back of the circuit board23can be borne against the main board of the terminal device or other bearing members90. Although the second movable portion42is connected to the photosensitive assembly20and the second basic portion41is connected to the first driving part30in this embodiment, it should be understood that the movements of the second movable portion42and the second basic portion41are relative. In the image stabilization movement, the opposite movement directions mean that the movement direction of the movable portion of the first driving part relative to its basic portion is opposite to the movement direction of the movable portion of the second driving part relative to its basic portion.

Further,FIG.6shows a schematic sectional view of a camera module according to another embodiment of the present application. Referring toFIG.6, in this embodiment, a rear shell49is added below the second driving part40, and the rear shell49is connected to the second basic portion41of the second driving part40to form an accommodating cavity. Both the second movable portion42of the second driving part40and the photosensitive assembly20are accommodated in the accommodating cavity. As shown inFIG.6, there may be a gap49abetween the photosensitive assembly20and the bottom of the rear shell49. That is, the photosensitive member20is suspended, and the photosensitive member20is only connected to the second movable portion42of the second driving part40. In this embodiment, the rear shell49is directly supported on the terminal device. Since the rear shell49is connected to the terminal device, the second driving part40and the basic portion of the first driving part30, during the image stabilization process, with the terminal device as a reference, the movable portions of the first driving part30and the second driving part40simultaneously drive the lens10and the photosensitive assembly20to move in opposite directions, respectively. Further, in this embodiment, the second movable portion42of the second driving part40is directly bonded to the upper end surface of the photosensitive assembly20, so that the filter24can be separated from the external space, thereby preventing debris generated by friction or collision of the second movable portion42from falling directly on the surface of the color filter24when the second movable portion42moves relative to the second basic portion41.

FIG.7shows a schematic sectional view of a camera module in still another embodiment of the present application. Referring toFIG.7, in this embodiment, the first driving part30is implemented to be adapted to drive the lens10to move in the optical axis direction to realize the focusing function, and also adapted to drive the lens10to move in the xoy plane to realize the image stabilization function. Optionally, the first driving part30comprises at least two carriers, which are a first carrier31and a second carrier32, respectively. The lens10is borne against the first carrier31, a suspension system is provided between the first carrier31and the second carrier32, and a suspension system is provided between the second carrier32and a housing33of the first driving part30. In this embodiment, the suspension system (i.e., a first suspension system) between the first carrier31and the second carrier32is set as a ball bearing system, and the suspension system (i.e., a second suspension system) between the second carrier32and the housing33is a suspension system based on an elastic element (such as a leaf spring). In this embodiment, the second suspension system is provided outside the first suspension system, the first suspension system allows the lens10and the first carrier31to translate in the xoy plane to realize the image stabilization function, and the second suspension system allows the lens10, the first carrier31and the second carrier32to integrally move in the optical axis direction to realize the focusing function. Optionally, in another embodiment, the second suspension system may also be provided inside the first suspension system. In another modified embodiment, the second suspension system may also be provided below the first suspension system. In this embodiment, the suspension system refers to a system in which two components are movably connected, and the degrees of freedom (i.e., movement directions) of the relative movement of two components are limited to a certain extent. The two movably connected components may be referred to as a basic portion and a movable portion, respectively. Typically, a suspension system is used in cooperation with a driving element (such as an SMA element or a coil-magnet combination). A driving force is provided by the driving element, and under the action of the driving force, the movable portion moves relative to the basic portion in a movement direction defined by the suspension system.

Further,FIG.8shows a schematic sectional view of a camera module in yet another embodiment of the present application. Referring toFIG.8, the movable portion of the second driving part40in this embodiment may be provided with an extension arm42aextending downward, and the extension arm42ais bonded to the circuit board23of the photosensitive assembly20. The extension arm42amay be provided with an FPC board42b, and the FPC board42bmay be directly welded to the circuit board23, so that the driving element mounted on the movable portion and the circuit board23are electrically conducted. This embodiment can prevent the glue from flowing onto the filter when the photosensitive assembly20is bonded to the movable portion, thereby affecting the imaging. In addition, in this embodiment, there is a gap between the upper end surface (i.e., the top end) of the photosensitive element20and the second driving part40, which can prevent the color filter from being scratched or broken.

Further, in some embodiments of the present application, an SMA element may be used to provide the second driving part with a driving force, so as to realize the controlled movement of the second movable portion relative to the second basic portion. Generally, the SMA element can provide a large driving force in a small occupied space. The second driving part of the SMA drive will be described below with reference to the drawings and an embodiment based on eight SMA wires.

FIG.9ashows a schematic perspective view of a camera module in an embodiment of the present application after being cut away. Referring toFIG.9a, in this embodiment, the center of the first driving part has an accommodating hole30aadapted to the outer side surface of the optical lens10, so that the optical lens10is mounted in the accommodating hole30a. The second driving part40is located below the first driving part30. The second driving part40comprises a second basic portion41and a second movable portion42. In this embodiment, the second basic portion41may be an annular frame structure. Specifically, the frame structure may be formed by an annular basic portion side wall41a, and the basic portion side wall41amay surround the second movable portion42. The top surface of the basic portion side wall41amay be bonded to the first driving part30by means of a second glue material23b, so as to fix the second driving part40together with the first driving part30. It should be noted that only the overall shape of the first driving part30is shown inFIG.9a, and the first basic portion and the first movable portion are not shown separately. Generally, the first basic portion is located on the periphery of the first movable portion. In this embodiment, an edge area of the bottom surface of the first driving part (i.e., an edge area of the bottom surface of the first basic portion) may form a step-shaped notch33, and the basic portion side wall41aof the second basic portion41may extend upward and into the step-shaped notch33. This design can enhance the structural strength of the second basic portion41so as to more reliably mount the SMA wire and the second movable portion42and the photosensitive assembly20suspended thereon. Further, this design also improves the rigidity of the connection between the second basic portion41and the first driving part30, so that the movement of the second movable portion42is more stable and more accurate. Further,FIG.9bshows a schematic sectional view of a camera module in an embodiment of the present application. Referring toFIGS.9aand9bin combination, in this embodiment, the bottom surface of the second movable portion42may be bonded to the circuit board23of the photosensitive assembly20through a first glue material23a, so as to fix the photosensitive assembly20together with the second movable portion42. There is a gap between the outer side surface of the second movable portion42and the inner side surface of the second basic portion41(i.e., the inner side of the basic portion side wall41a), and the gap can be used for accommodating the SMA wire48and for accommodating a leaf spring47which supports the second movable portion41. Specifically, the second basic portion41and the second movable portion42can be movably connected by means of a leaf spring47(the leaf spring may also be replaced with other elastic connecting portions). The SMA wire may also be connected between the second basic portion41and the second movable portion42to provide a driving force for the movement of the second movable portion42.

Further, still referring toFIG.9b, in an embodiment of the present application, the second movable portion42may comprise a movable portion main body42a, the movable portion main body42ais generally of a flat plate shape, and the center of the movable portion main body42ahas a through hole (i.e., a light-passing hole) to allow the light used for imaging to pass through. The outer edge area of the bottom surface of the movable portion main body42aextends downward to form a movable portion side wall42b, and the bottom surface of the movable portion side wall42bis bonded to the upper surface of the circuit board23. An accommodating cavity is formed between the inner side surface of the movable portion side wall42b, the bottom surface of the movable portion main body42a, the upper surface of the circuit board23and the outer side surface of the lens holder22, and the accommodating cavity can be used for arranging electronic elements29. The electronic elements29comprise a resistor, a capacitor, etc. These electronic elements29may form circuits of the circuit board together with the wiring in the circuit board23.

Further, still referring toFIG.9b, in an embodiment of the present application, the inner side edge of the movable portion main body has a step-shaped notch43, so as to avoid the optical lens10, so that the optical lens10can have a greater movement range (i.e., having a larger focusing stroke or image stabilization stroke).

Further,FIG.10ashows a schematic perspective view of a camera module in another embodiment of the present application after being cut away.FIG.10bshows a schematic sectional view of a camera module in another embodiment of the present application. Referring toFIGS.10aand10bin combination, in this embodiment, the second basic portion comprises a basic portion side wall41aand a base41b. The base41bis generally of a flat plate shape, and the center of the flat plate-like base41bhas a through hole to avoid the imaging light path. In this embodiment, the base41bmay be located above the second movable portion42. The base41band the basic portion side wall41amay be integrally molded. The basic portion side wall41amay surround the second movable portion42. The top surface of the basic portion side wall41amay be bonded to the first basic portion to fix the second driving part40together with the first driving part30.

Further,FIG.11ashows a schematic view of the three-dimensional structure of a second driving part shown inFIGS.10aand10b.FIG.11is a schematic view after being turned upside down. The second movable portion42is placed above the base41b, so that the detailed structure of the second movable portion can be more easily observed. InFIGS.10aand10b, the second movable portion42is located below the base41b.FIG.11bshows an exploded perspective view ofFIG.11a.FIG.12shows a schematic view of the connection of the SMA wire of the second driving part in an embodiment of the present application. Referring toFIGS.11a,11band12, in an embodiment of the present application, the second driving part40comprises eight SMA wires48, and the eight SMA wires48may be fixed on eight fixed ends located at the second basic portion41and the second moving portion42, respectively. Specifically, the second driving part40has a generally rectangular outer contour in a plan view, and four corner areas of the rectangular outer contour may be denoted as a first corner51, a second corner52, a third corner53and a fourth corner54, respectively. The first corner51and the third corner53are located on one diagonal line AX1, and the second corner52and the fourth corner53are located on the other diagonal line AX2(refer toFIG.12in combination). In this embodiment, the movable portion main body42aof the second movable portion42may extend outward at the positions of the first corner51and the third corner53, respectively, to form a first extension portion51aand a third extension portion53a. The first extension portion51amay be provided at a first A fixed end1aand a first B fixed end1b, wherein the first B fixed end1bmay be mounted or formed on the upper surface of the first extension portion51a(here, it may be formed in an integral molding manner, which will not be described in detail below), the first A fixed end1amay be located above the first B fixed end1b, and the first A fixed end1aand the first B fixed end1bmay be isolated by an insulating material, so as to prevent short circuit of the circuit for driving the SMA wires to work. Similarly, the third extension portion53amay be provided at a third A fixed end3aand a third B fixed end3b, wherein the third B fixed end3bmay be mounted or formed on the upper surface of the third extension portion53a, the third A fixed end3amay be located above the third B fixed end3b, and the third A fixed end3aand the third B fixed end3bmay be isolated by an insulating material, so as to prevent short circuit of the circuit for driving the SMA wires to work. Further, the movable portion main body42amay also be designed with a gap at each of the positions of the second corner52and the fourth corner54, so as to avoid the functional structure of the second basic portion41at the second corner52and the fourth corner54. Here, the functional structures of the second basic portion41at the second corner52and the fourth corner54refer to a second A fixed end2a, a second B fixed end2b, a fourth A fixed end4aand a fourth B fixed end4blocated on the second basic portion41. Specifically, the second A fixed end2aand the second B fixed end2bmay be provided at the position of the second corner52of the second basic portion41, wherein the second B fixed end2bmay be mounted or formed on the upper surface of the second corner52area of the base41b, the second A fixed end2amay be located above the second B fixed end2b, and the second A fixed end2aand the second B fixed end2bmay be isolated by an insulating material. A fourth A fixed end4aand a fourth B fixed end4bmay be provided at the position of the fourth corner54of the second basic portion41, wherein the fourth B fixed end4bmay be mounted or formed on the upper surface of the fourth corner54area of the base41b, the fourth A fixed end4amay be located above the fourth B fixed end4b, and the fourth A fixed end4aand the fourth B fixed end4bmay be isolated by an insulating material. It should be noted that in this paragraph, the above and below are based onFIGS.11a,11band12, and these figures are inverted, that is, the below is an object side. InFIGS.10aand10b, the above and below need to be interchanged, that is, inFIGS.10aand10b, the above is the object side. Further, in this embodiment, eight SMA wires are fixed between the above eight fixed ends, respectively. The first A fixed end is connected to the fourth B fixed end through an SMA wire, and for ease of description, the SMA wire is denoted as wire1a-4b; the first B fixed end is connected to the fourth A fixed end through an SMA wire, and for ease of description, the SMA wire is denoted as wire1b-4a; the first A fixed end is connected to the second B fixed end through an SMA wire, and for ease of description, the SMA wire is denoted as wire1a-2b, the B fixed end is connected to the second A fixed end through an SMA wire, and for ease of description, the SMA wire is denoted as wire1b-2a, the second A fixed end is connected to the third B fixed end through an SMA wire, and for ease of description, the SMA wire is denoted as wire2a-3b; the second B fixed end is connected to the third A fixed end through an SMA wire, and for ease of description, the SMA wire is denoted as wire2b-3a; the third A fixed end is connected to the fourth fixed end B through an SMA wire, and for ease of description, the SMA wire is denoted as wire3a-4b; and the third fixed end B is connected to the fourth fixed end A through an SMA wire, and for ease of description, the SMA wire is denoted as wire3b-4a. InFIGS.11a,11band12, in order to avoid occlusion, only two SMA wires are shown, namely, wire1a-4band wire1b-4a. All eight SMA wires are shown inFIG.12. Referring toFIGS.11and12, in this embodiment, two interlaced SMA wires are arranged on each of the four side surfaces of the second driving part, and an electric current is selectively applied to all or part of the SMA wires, so that all or part of the SMA wires can shrink, thereby driving the second movable portion to move in a set degree of freedom.

Specifically, the manner of driving the second movable portion to move may comprise translational driving in the xoy plane, Rz-degree-of-freedom driving, tilting driving (i.e., Rx and Ry-degree-of-freedom driving), and z-axis translational driving. In this embodiment, each of the above fixed ends located at the positions of four corners is not only a fixed end of the mechanical connection of the SMA wire, but also a connection terminal of the electrical connection of the SMA wire. SMA is the English abbreviation of shape memory alloy. After the electric current is applied to the SMA wire, the SMA wire can shrink under the effect of the shape memory alloy, thereby playing the effect of driving the second movable portion to move. The greater the amount of electric current applied, the greater the shrinkage of the SMA wire. The electric current applied to the SMA wire may also be referred to as the driving current of the SMA wire. Based on the above driving principles, the four types of driving manners will be described individually below.

Translation driving in the xoy plane: when the wire1a-2band wire1b-2ashrink synchronously (the two can shrink by the same amount) and wire1a-4band wire1b-4ashrink synchronously (the two can shrink by the same amount), the second movable portion42can be driven to translate along the first diagonal line AX1in the xoy plane; and when wire1a-2band wire1b-2ashrink synchronously (the two can shrink by the same amount), and wire2a-3band wire2b-3ashrink synchronously (the two can shrink by the same amount), the second movable portion42can be driven to translate along the second diagonal line AX2in the xoy plane. In this embodiment, the translation of the first diagonal line AX1and the second diagonal line AX2may be perpendicular to each other, so that the direction of the first diagonal line AX1and the direction of the second diagonal line AX2form two components of a displacement vector in the xoy plane. By controlling the magnitudes of the two components, the displacement vector in any direction in the xoy plane can be constructed. When the first driving part drives the lens to translate in the x-axis and y-axis directions, the x-axis and y-axis components of the translation motion determine the movement direction of the lens in the xoy plane, which is referred to as a first direction for the ease of description. By controlling the magnitudes of the components of the photosensitive chip in the direction of the first diagonal line AX1and the direction of the second diagonal line AX2, a displacement vector in a second direction opposite to the first direction can be constructed, so that the photosensitive chip can move in the xoy plane in the direction (i.e., the second direction) opposite to the translation direction of the lens.

It should be noted that, in the present application, the combined driving of the SMA wires for realizing the translational driving of the photosensitive chip in the xoy plane is not limited to the above driving manner. For example, the translation in the direction of the first diagonal line AX1may also be realized by driving wire2a-3band wire2b-3ato synchronously shrink (the two can shrink by the same amount) and driving wire3a-4band wire4a-3bto synchronously shrink (the two can shrink by the same amount); and the translation in the direction of the second diagonal line AX2may also be realized by driving wire1a-4band wire1b-4ato synchronously shrink (the two can shrink by the same amount) and driving wire3a-4band wire4a-3bto synchronously shrink (the two can shrink by the same amount). In a nutshell, when the four SMA wires on the two adjacent sides of the second driving part synchronously shrink, the translation on the direction of one diagonal line can be realized. The translation in the directions of two diagonal lines is simultaneously driven, and the displacement vector in any direction in the xoy plane can be constructed by different linear combinations of the translation amounts in the directions of two diagonal lines, so that the movement direction of the photosensitive chip in the xoy plane is opposite to the movement direction of the lens in the xoy plane.

Rz-degree-of-freedom driving: wire1a-2band wire1b-2asynchronously shrink (the two can shrink by the same amount), and wire3a-4band wire3b-4asynchronously shrink (the two can shrink by the same amount), so that the second movable portion can be driven to rotate in the xoy plane relative to the second basic portion, that is, to rotate around the z-axis; and when the other four wires are driven, that is, wire2a-3band wire2b-3asynchronously shrink (the two can shrink by the same amount), and wire1a-4band wire1b-4asynchronously shrink (the two can shrink by the same amount), so that the movable portion can be driven to rotate around the z-axis in the opposite direction relative to the second basic portion. For example, it is assumed that the second movable portion rotates clockwise around the z-axis relative to the second basic portion when a former set of SMA wires is powered on, and the second movable portion rotates counterclockwise around the z-axis relative to the second basic portion when a latter set of SMA wires is powered on. The former set of SMA wires refers to wires1a-2b,1b-2a,3a-4band3b-4a, and the latter set of SMA wires refers to wires1a-4b,1b-4a,2a-3band2b-3a.

Tilt driving: Tilt driving may also be referred to as tilt driving, i.e., driving on the two rotational degrees of freedom, Rx and Ry. When wire1a-2bis applied with an electric current and shrinks, the second movable portion can rotate in the Ry direction relative to the second basic portion, that is, rotate around the y-axis. When wire1a-4bis applied with an electric current and shrinks, the second movable portion can rotate in the Rx direction relative to the second basic portion, that is, rotate around the x-axis. Wires1a-2band1a-4bline can be simultaneously applied with electric currents and shrink, and the shrinkage amounts of the two may be the same or different. By applying electric currents of different magnitudes, the shrinkage amounts of wires1a-2band1a-4bcan be changed, so that the displacement vector of the second movable portion (i.e., the displacement vector of the photosensitive chip) has different magnitudes of Rx and Ry components. In this embodiment, the tilt drive of the second driving part can be driven by the SMA wire combination to adjust the tilt angle (i.e., tilt) of the photosensitive chip, thereby compensating for the tilt of the image plane of the camera module, and further improving the imaging quality.

Z-axis translational driving: when four SMA wires1a-2b,1a-4b,2b-3aand3a-4bsimultaneously shrink and their shrinkage amounts are the same, the second movable portion can be driven to translate in a z-axis direction relative to the second basic portion, and the translation of the second movable portion in the z-axis direction can be used in combination with the translation degree of freedom in the z-axis direction of the first driving part, thereby helping to improve the focusing speed of the camera module and increase the focusing range of the camera module. Specifically, during the focusing process, the first driving part can drive the optical lens to move along the z-axis, and the second driving part can drive the photosensitive assembly to move in the opposite direction (opposite to the movement direction of the lens) along the z-axis, thus improving the focusing speed. On the other hand, the movement stroke of the relative movement of the optical lens and the photosensitive chip in the z-axis direction can also be increased, thereby increasing the focusing range of the camera module.

The implementations of translational driving, Rz-degree-of-freedom driving, tilt driving (i.e., Rx and Ry-degree-of-freedom driving) and z-axis translational driving in the xoy plane are described above with reference to a specific embodiment. However, it should be noted that the implementations of the present application are not limited to the above embodiments. More generally, in some embodiments of the present application, the external shape of the second driving part is generally rectangular, and its four corner areas comprise a first corner, a second corner, a third corner and a fourth corner, wherein the first corner and the third corner are located on the first diagonal line of the second driving part, and the second corner and the fourth corner are located on the second diagonal line of the second driving part. The second movable portion extends outward at each of the positions of the first corner and the third corner to form a first extension portion and a third extension portion. The two fixed ends of the first corner of the second driving part are provided on the first extension portion, and the two fixed ends of the third corner of the second driving part are provided on the third extension portion. The two fixed ends of the second corner of the second driving part are provided at the second corner of the second basic portion, and the two fixed ends of the fourth corner of the second driving part are provided at the fourth corner of the second basic portion. For each side surface of the second driving part, the two interlaced SMA wires provided on the side surface are fixed and electrically connected to the four fixed ends located in the two corner areas of the side surface.

In some embodiments of the present application, for the movement degrees of freedom of the movement in the xoy plane, the translational component of the photosensitive chip in the direction of the first diagonal line or in the direction of the second diagonal line may be generated by driving two pairs of interlaced SMA wires on two intersecting side surfaces of the second driving part to shrink; and the translational component in the direction of the first diagonal line is combined with the translational component in the direction of the second diagonal line, so that the movement direction of the photosensitive chip in the xoy plane is opposite to the movement direction of the lens. Two intersecting side surfaces are grouped into one group, so that four groups can be summarized. Two pairs of interlaced SMA wires (four in total) of any group of side surfaces shrink, so that either a translational component of the photosensitive chip in the direction of the first diagonal line or a translational component of the photosensitive chip in the direction of the second diagonal line can be generated. All the interlaced SMA wires on at least two groups of side surfaces that generate translation components in different diagonal directions shrink (the shrinkage amounts corresponding to different translational components may be different), so that the translational component in the direction of the first diagonal line or the translational component in the direction of the second diagonal line are combined into a translation direction of the photosensitive chip at any angle in the xoy plane.

Further, in some embodiments, for the Rz-degree-of-freedom driving, the rotation of the photosensitive chip in an Rz direction is generated by driving two pairs of interlaced SMA wires on two opposite side surfaces of the second driving part to shrink, wherein the Rz direction is a direction of rotation around a z-axis, and the z-axis is a coordinate axis parallel to the optical axis.

Further, in some embodiments, for the tilt driving, the rotation component of the photosensitive chip in an Rx or Ry direction is generated by driving a single SMA wire on a single side surface of the second driving part to shrink; wherein the Rx direction is a direction of rotation around the x-axis, and the Ry direction is a direction of rotation around the y-axis.

Further, in some embodiments, for the translational driving on the z-axis direction, the translation of the photosensitive chip in the z-axis direction is generated by driving a first group of SMA wires and a second group of SMA wires of the second driving part to shrink; and the translation direction of the photosensitive chip in the z-axis direction is opposite to the translation direction of the lens in the z-axis direction, wherein the z-axis is a coordinate axis parallel to the optical axis; wherein the first group of SMA wires are two SMA wires with a first common fixed end, and the two SMA wires are located on two intersecting side surfaces of the second driving part, respectively; the second group of SMA wires are the other two SMA wires with a second common fixed end, and the other two SMA wires are located on the other two intersecting sides of the second driving part; and each of the first common fixed end and the second common fixed end is one of eight fixed ends of the second driving part, and the first common fixed end and the second common fixed end are located at the same height.

It should be noted that when tilt adjustment is not required, the four type-A fixed ends described previously may be at different heights, and the four type-B fixed ends may be at different heights. For example, when the second driving part only needs to achieve translation in the xoy plane, it is only required that the two type-A fixed ends on the same diagonal line are at the same height, and the two type-B fixed ends on the same diagonal line are at the same height. Specifically, the type-A fixed ends of the first corner and the third corner are at the same height, and the type-A fixed ends of the second corner and the fourth corner are at the same height. Two type-A fixed ends of adjacent corner areas (i.e., two corner areas that are not on the same diagonal line) may not be at the same height, and two type-B fixed ends of adjacent corner areas (i.e., two corner areas that are not on the same diagonal line) may not be at the same height.

It should be noted that, in the above embodiment, the eight fixed ends are provided as follows: in any one of the corner areas, the two fixed ends are arranged along the optical axis direction. In this case, the two interlaced SMA wires are approximately in an xoz plane or a yoz plane (the z-axis is a coordinate axis parallel to the optical axis), that is, the two fixed ends of the corner area are arranged vertically (for example, one fixed end is located directly above the other fixed end). Herein, the interlacing of two SMA wires means that the projections of the two SMA lines in the xoz plane or the yoz plane cross, but the two SMA wires are not in direct contact during actual production (the two are slightly staggered to avoid direct contact) to avoid mutual interference when the two SMA wires shrink, resulting in a decrease in the accuracy of position adjustment.

The four fixed ends of any two adjacent corner areas are all located in a plane parallel to the xoy plane. For example, in any one of the corner areas, one fixed end is located on an outer side of the other fixed end. Here, the outer side refers to a side away from the photosensitive center of the photosensitive chip, and the inner side refers to a side toward the photosensitive center of the photosensitive chip. This arrangement can effectively utilize the space of the photosensitive assembly in the height direction (z-axis direction), so the height of the camera module will not be increased. At the same time, the space in the x-axis and y-axis directions of the camera module can be saved, thereby reducing the lateral dimension of the camera module. That is, the photosensitive chip can be adjusted in multiple degrees of freedom of movement at a small volume cost. However, it should be noted that the arrangement of the eight fixed ends in the present application is not limited to this. In some embodiments of the present application, the eight fixed ends may also be arranged so that the four fixed ends of any two adjacent corner areas are all located in a plane parallel to the xoy plane.

In some embodiments of the present application, the lens and the first driving part may be assembled into a first combined body, the photosensitive assembly and the second driving part may be assembled into a second combined body, and then the first combined body and the second combined body are bonded based on an active alignment process (AA process).

Further, in an embodiment of the present application, the glue material for bonding in the AA process may be arranged between the second basic portion and the first basic portion. Specifically, referring toFIGS.9aand9bin combination, in this embodiment, the edge area of the bottom surface of the first driving part (i.e., the edge area of the bottom surface of the first basic portion) may form a step-shaped notch33, and the basic portion side wall41aof the second basic portion41may extend upward and into the step-shaped notch33. The glue material for bonding the first combined body and the second combined body may be arranged between the step-shaped notch33and the top surface of the basic portion side wall41a. This design helps to prevent the AA glue material from overflowing and contaminating the imaging optical path (AA process bonding may require a large amount of glue material, so there may be a risk of overflowing at the position of the applied glue), thereby preventing the problem of photo stains on the camera module.

Further, in an embodiment of the present application, the second basic portion may comprise a base41band a basic portion side wall41a, and the second movable portion42may be located below the base (refer toFIGS.10aand10b). Under this design solution, when the first combined body and the second combined body are bonded using the AA process, the photosensitive assembly20mounted on the second movable portion42can be protected by the base41b, which thus helps to prevent the AA glue material from overflowing and contaminating the imaging optical path, thereby preventing the problem of photo stains on the camera module. In addition, in this embodiment, the glue material for bonding the first combined body (the first basic portion) and the second combined body (the second basic portion) may also be arranged between the step-shaped notch33and the top surface of the basic portion side wall41a, so as to further prevent the problem of photo stains on the camera module caused by the overflow of AA glue material.

Further, in some embodiments of the present application, the eight fixed ends for mounting the eight SMA wires may be mounted on the surface of the base, or may be mounted on the inner side surface of the basic portion side wall.

Further, in the camera module, the circuit board of the photosensitive assembly usually comprises a rigid circuit board main body and a flexible connecting band, one end of the flexible connecting band is connected to the circuit board main body, and the other end is connected and electrically conducted with a motherboard or other components of an electronic device through a connector. In the prior art, the flexible connecting band of the photosensitive assembly is usually led out from the side surface of the circuit board main body, and the flexible connecting band is roughly parallel to the surface of the circuit board main body. In this arrangement, the flexible connecting band will have a greater resistance to the movement of the circuit board main body, which may increase the force required to drive the movement of the circuit board main body, resulting in insufficient stroke for image stabilization compensation and reduced response speed. In addition, the resistance caused by the connecting band is irregular, so that it is difficult for the second driving part to compensate for the resistance, which may result in a decrease in the accuracy of the image stabilization compensation. Therefore, in this embodiment, a suspended circuit board is provided as a circuit board of a photosensitive assembly adapted to the second driving part, and this design manner will help to overcome the above defects caused by the connecting band.

FIG.13shows a schematic perspective view of a second driving part and a photosensitive assembly in an embodiment of the present application after being assembled.FIG.14shows an exploded schematic view of a second driving part and a photosensitive assembly in an embodiment of the present application.FIG.15shows a schematic perspective view of a photosensitive assembly and a suspended circuit board used by the same in an embodiment of the present application. Referring toFIGS.13,14and15, in the camera module of the embodiment, the photosensitive assembly20is connected to the second movable portion42of the second driving part40, so the circuit board main body71can move in the xoy plane under the drive of the second movable portion42. The circuit board23of this embodiment is designed to be a suspended structure. Specifically, the circuit board23comprises a rigid circuit board main body71and a flexible connecting band72, and the connecting band72may comprise a third connecting band72aand a fourth connecting band72b. The third connecting band72aand the fourth connecting band72bmay be led out from two opposite side surfaces of the circuit board main body71(for ease of description, the two opposite side surfaces may be referred to as a first side surface74aand a second side surface74b), respectively, and may be bent upward. The bent third connecting band72aand the fourth connecting band72bcan form suspension portions75, respectively. The suspension portion75may be connected to the basic portion of the second driving part40(or the first driving part30) to form a suspension structure. The suspending structure allows the basic portion to suspend the circuit board main body71and various components mounted on the surface thereof through the bent portion73of the flexible connecting band72(i.e., suspending the photosensitive assembly20). Specifically, in one example, the suspension portion75may have a through hole (a suspension hole75a), the second basic portion41of the second driving part40may have a corresponding hook75b, and the hook75bis hooked to the through hole of the suspension portion75to connect the suspension portion75. In the prior art, the connecting band and the circuit board main body are usually in the same plane, and at this time, the deflection of the connecting band relative to the circuit board main body in the same plane will generate a greater resistance. In this embodiment, the connecting position of the connecting band72and the circuit board main body71is provided with a bent portion73formed by bending upward. At this time, the resistance produced by the connecting band72relative to the circuit board main body71in the xoy plane (which may be regarded as a horizontal plane) is relatively small.

Further, in an embodiment of the present application, the third connecting band72aand the fourth connecting band72bmay extend along the periphery of the circuit board main body71and the photosensitive assembly20, so that the connecting band72surrounds the photosensitive assembly on at least three side surfaces. Moreover, the third connecting band72aand the fourth connecting band72bare connected and electrically conducted with each other. The photosensitive assembly20has a first side surface74aand a second side surface74bwhich are at the same positions as those of the circuit board main body71. The first side surface74aand the second side surface74bare arranged opposite to each other (that is, they do not intersect with each other), and the third side surface74cof the photosensitive assembly20intersects both the first side surface74aand the second side surface74b. The connecting band72may surround the first side surface74a, the second side surface74band the third side surface74cof the photosensitive assembly20. The third connecting band72ais led out from the first side surface74aof the circuit board main body71and bent upward to form the bent portion73, then extends along the first side surface74aof the photosensitive assembly20, is bent in the horizontal direction at a corner and continues to extend along the third side surface74c. The fourth connecting band72bis led out from the second side surface74bof the circuit board main body71and bent upward to form another bent portion73, then extends along the second side surface74bof the photosensitive assembly20, is bent horizontally at a corner and continues to extend along the third side surface74c. The third connecting band72aand the fourth connecting band72bcan be joined at the third side surface74cand electrically conducted with each other, so as to form a complete connecting band72. Three connecting band sections located on the first side surface74a, the second side surface74band the third side surface74cmay each have at least one suspension portion75. Each suspension portion has at least one through hole for facilitating the connection with the basic portion of the second driving part40(or the first driving part30). In this embodiment, the suspension portion75can suspend the circuit board main body71through the bent portions73located on opposite sides of the circuit board main body71, so that when the circuit board main body71is driven by the second driving part40to move, the bent portion73and the connecting band72can be bent and deformed to meet the movement stroke of the circuit board main body71.

Further, in an embodiment of the present application, the suspension portions73of the three connecting band sections located on the first side surface74a, the second side surface74band the third side surface74cmay all be made of rigid substrates for reinforcement. For example, a rigid substrate may be attached to a partial area of the flexible connecting band to form the suspension portion73. However, other areas of the flexible connecting band are still in a flexible state so as to be able to be bent and deformed, so as to meet the movement stroke of the circuit board main body71.

Further, in an embodiment of the present application, the connecting band section located on the third side surface74cmay have a rigid suspension portion75c, and the suspension portion75cmay lead out a fifth connecting band76. The fifth connecting band76can be used to connect to a motherboard of an electronic device (e.g., a mobile phone).

Further, in another embodiment of the present application, the suspension portion may also be connected to an outer bracket (not shown in the figure), and the outer bracket is directly or indirectly fixed with the basic portion of the second driving part together. In the present application, the suspension portion may be fixed together with the basic portion of the second driving part through other intermediate objects. The intermediate object may be directly or indirectly fixed to the basic portion of the second driving part. The intermediate object has a hook to be hooked to the suspension portion, or the intermediate object is bonded to the suspension portion. The intermediate object may be an outer bracket, the basic portion of the first driving part, or other intermediate objects.

Further, in another embodiment of the present application, the suspension portion may not have the through hole. In this embodiment, the suspension portion may be fixed together with the basic portion of the second driving part (or with the basic portion of the first driving part or the outer bracket) by means of bonding. Further, in another embodiment of the present application, the third connecting band and the fourth connecting band may be rigid-flex boards, wherein a part forming the suspension portion may adopt a rigid board, and both a part of connecting the suspension portion and a bent portion formed by bending upward can adopt flexible boards. Since the suspension portion is directly formed by a rigid board, in this embodiment, the suspension portion can no longer be attached to a rigid substrate for reinforcement.

Further, in an embodiment of the present application, the circuit board main body, the third connecting band, and the fourth connecting band may be composed of a complete rigid-flex board.

Further, still referring toFIGS.13,14and15, in an embodiment of the present application, the circuit board may further have a fixing portion76afor fixing the fifth connecting band76. This design can prevent the circuit board main body71, the third connecting band72aand the fourth connecting band72bfrom being affected by external factors.

Further,FIG.16ashows a schematic front view of a suspended circuit board in an embodiment of the present application after being unfolded, andFIG.16bshows a schematic rear view of a suspended circuit board in an embodiment of the present application after being unfolded. Referring toFIGS.16aand16b, in this embodiment, the circuit board23may be composed of a rigid-flex board. Sections of the third connecting band72aand the fourth connecting band72blocated on the third side surface74ccan be fastened to each other through connectors78and79(refer toFIG.15in combination), so that the third connecting band72aand the fourth connecting band72bare connected and fixed, and further electrically connected. The third connecting band72aand the fourth connecting band72bare both provided with circuits, so as to lead out a circuit in the circuit board main body71and connect to external circuits through the fifth connecting band76and its connector77. Since the third connecting band72aand the fourth connecting band72bcan each lead out a part of the circuit through corresponding bent portions73formed by bending upward, the circuit required to be led out from each bent portion73can be reduced. In this way, the width of each bent portion73can be reduced, so as to further reduce the resistance formed by the flexible connecting band72to the movement of the circuit board main body71, thereby reducing the driving force required to be provided by the second driving part40. It should be noted that, in other embodiments of the present application, the circuit of the circuit board main body may also be led out through only one of the bent portions (for example, the upwardly bent bent portion of the third connecting band or the upwardly bent bent portion of the fourth connecting band).

Further,FIG.17ashows a schematic front view of a suspended circuit board in another embodiment of the present application after being unfolded, andFIG.17bshows a schematic rear view of a suspended circuit board in an embodiment of the present application after being unfolded. Referring toFIGS.17aand17b, the photosensitive assembly20comprises a suspended circuit board, and the suspended circuit board comprises a rigid circuit board main body71and a flexible connecting band72. The connecting band72is led out from the first side surface74aand the second side surface74bof the circuit board main body71and bent upward to form a bent portion, and the top of the bent portion extends along the periphery of the photosensitive assembly20in the horizontal direction, so that the connecting band72surrounds the periphery of the first side surface74a, the second side surface74band the third side surface74cof the photosensitive assembly20. Moreover, the connecting bands located on the first side surface74aand the second side surface74beach have at least one suspension portion75. The suspension portion75is fixed to the second basic portion41of the second driving part40or fixed to the second basic portion41through an intermediate object. The photosensitive assembly20has a first side surface74aand a second side surface74bthat are at the same positions as those of the circuit board main body71, the first side surface74aand the second side surface74bare arranged oppositely, and the third side surface74cintersection with both the first side surface74aand the second side surface74b. The suspension portion75has a suspension hole75a, the second basic portion41or the intermediate object has a hook, and the hook is hooked to the suspension hole75a. A part of sections of the connecting band are attached to a rigid substrate for reinforcement to form the suspension portion (in a modified embodiment, the suspended circuit board may also adopt a rigid-flex board, wherein the circuit board main body and the suspension portion are formed by a rigid board part of the flex-rigid board, and the bent portion and connecting band sections connected between a plurality of suspension portion are formed by a flexible board part of the flex-rigid board). Different from the previous embodiment, in this embodiment, the third side surface74cis not provided with a suspension portion, that is, the suspension portion75and the suspending hole75aare only provided on the first side surface74aand the second side surface74b. Alternatively, in this embodiment, the connecting band of the third side surface74cis fixed to the second basic portion41through an glue material (or fixed to the second basic portion41through an intermediate object). Specifically, in this embodiment, the connecting band may comprise a third connecting band72aand a fourth connecting band72b. The third connecting band72ais led out from the first side surface74aof the circuit board main body71and bent upward to form a bent portion73, then extends along the first side surface74aof the photosensitive assembly20, is bent in the horizontal direction at the corner and continues to extend along the third side surface74c. The fourth connecting band72bis led out from the second side surface74bof the circuit board main body71and bent upward to form another bent portion, then extends along the second side surface74bof the photosensitive assembly20, is bent horizontally at the corner and continues to extend along the third side surface74c. The third connecting band72aand the fourth connecting band72bare joined and electrically conducted with each other at the third side surface74c(which may be joined and electrically conducted by fastening of male and female connectors or by welding). Further,FIG.18shows a schematic exploded perspective view of a camera module based on a suspended circuit board in an embodiment of the present application.FIG.19shows a schematic perspective view of a camera module based on a suspended circuit board with a housing according to an embodiment of the present application. Referring toFIGS.17a,17b,18and19in combination, in this embodiment, the camera module further comprises a first connecting band84electrically connected to the first driving part. The first connecting band84is led out from the top area of the first driving part, then bent downward, and is jointed and electrically conducted with the third connecting band72aor the fourth connecting band72bat the third side surface74c. The camera module further comprises a housing81and a module base80, and the inner side surface of the housing81has an accommodating groove82for accommodating a joint portion of the third side surface74c; wherein the joint portion is a join portion83where the first connecting band, the third connecting band72aand the fourth connecting band72bare joined with each other; and a glue material is filled into the accommodating groove82to fix the first connecting band, the third connecting band72aand the fourth connecting band72bto the housing81. The module base80and the housing81can be fastened together, so that a first optical driving assembly85and a second optical driving assembly86are packaged inside the base80and the housing81(refer toFIGS.18and19). Further, the connecting band located on the third side surface74cis also connected to a fifth connecting band76, and the fifth connecting band76has a connector77for external connection. The suspended circuit board may further have a fixing portion76afor fixing the fifth connecting band76. The first optical driving assembly85comprises a first driving part and an optical lens, and the optical lens is mounted in the first movable portion of the first driving part. The second optical driving assembly86comprises a second driving part and a photosensitive assembly, and the photosensitive assembly is fixed to the second movable portion of the second driving part.

When assembling, the first driving part and the optical lens may be assembled to form the first optical driving assembly85, and the second driving part and the photosensitive assembly may be assembled to form the second optical driving assembly86. Then, the relative positions of the optical lens and the photosensitive chip are adjusted through an active calibration process, and then the first driving part (the first basic portion) and the second driving part (the second basic portion) are bonded by glue. Next, the bonded first optical driving assembly85and the second optical driving assembly86are assembled in the through hole of the module housing81from bottom to top, and then the module base80is attached to the module housing81. Finally, glue is filled into the accommodating groove82of the housing to fix the first optical driving assembly85and the second optical driving assembly86to the module housing81. At the same time, glue is filled into the accommodating groove82, and the joint portion of the first connecting band84, the third connecting band72aand the fourth connecting band72bmay also be fixed to the module housing81, the first basic portion or the second basic portion.

In the above embodiment, each side surface of the second driving part is configured with a pair of SMA wires arranged in an interlaced manner to realize multi-axis driving, but this is not the only arrangement (i.e., SMA mounting manner) of SMA wires in the present application. Another SMA arrangement will be described below with reference toFIGS.9aand20-23.

Referring toFIG.9a, in another embodiment of the present application, the center of the first driving part has an accommodating hole30aadapted to the outer surface of the optical lens10, so that the optical lens10is mounted in the accommodating hole30a. The second driving part40is located below the first driving part30. The second driving part40comprises a second basic portion41and a second movable portion42. In this embodiment, the second basic portion41may be an annular frame structure. Specifically, the frame structure may be formed by an annular basic portion side wall41a, and the basic portion side wall41amay surround the second movable portion42. The top surface of the basic portion side wall41amay be bonded to the first driving part30by means of a second glue material23b, so as to fix the second driving part40together with the first driving part30. It should be noted that only the overall shape of the first driving part30is shown inFIG.9a, and the first basic portion and the first movable portion are not shown separately. Generally, the first basic portion is located on the periphery of the first movable portion. In this embodiment, an edge area of the bottom surface of the first driving part (i.e., an edge area of the bottom surface of the first basic portion) may form a step-shaped notch33, and the basic portion side wall41aof the second basic portion41may extend upward and into the step-shaped notch33. This design can enhance the structural strength of the second basic portion41so as to more reliably mount the SMA wire and the second movable portion42and the photosensitive assembly20suspended thereon. Further, this design also improves the rigidity of the connection between the second basic portion41and the first driving part so that the movement of the second movable portion42is more stable and more accurate. Further,FIG.20shows a schematic sectional view of a camera module in an embodiment of the present application. Referring toFIGS.9aand20in combination, in this embodiment, the bottom surface of the second movable portion42may be bonded to the circuit board23of the photosensitive assembly20through a first glue material23a, so as to fix the photosensitive assembly20together with the second movable portion42. There is a gap between the outer side surface of the second movable portion42and the inner side surface of the second basic portion41(i.e., the inner side of the basic portion side wall41a), and the gap can be used for accommodating the SMA wire48and for accommodating a leaf spring47which supports the second movable portion41. Specifically, the second basic portion41and the second movable portion42can be movably connected by means of a leaf spring47(the leaf spring may also be replaced with other elastic connecting portions). The SMA wire may also be connected between the second basic portion41and the second movable portion42to provide a driving force for the movement of the second movable portion42.

Further, still referring toFIG.20, in an embodiment of the present application, the second movable portion42may comprise a movable portion main body42a, the movable portion main body42ais generally of a flat plate shape, and the center of the movable portion main body42ahas a through hole (i.e., a light-passing hole) to allow the light used for imaging to pass through. The outer edge area of the bottom surface of the movable portion main body42aextends downward to form a movable portion side wall42b, and the bottom surface of the movable portion side wall42bis bonded to the upper surface of the circuit board23. An accommodating cavity is formed between the inner side surface of the movable portion side wall42b, the bottom surface of the movable portion main body42a, the upper surface of the circuit board23and the outer side surface of the lens holder22, and the accommodating cavity can be used for arranging electronic elements29. The electronic elements29comprise a resistor, a capacitor, etc. These electronic elements29may form circuits (i.e., functional circuits required by the camera module) of the circuit board together with the wiring in the circuit board23.

Further, still referring toFIG.20, in an embodiment of the present application, the inner side edge of the movable portion main body has a step-shaped notch43, so as to avoid the optical lens10, so that the optical lens10can have a greater movement range (i.e., having a larger focusing stroke or image stabilization stroke).

Further,FIG.21shows a schematic top view of a second driving part in an embodiment of the present application. Referring toFIG.21, in this embodiment, the second basic portion41may comprise a basic portion base41band a basic portion sidewall41amounted on the basic portion base41b(refer toFIG.22in combination). An end surface of the basic portion side wall41amay be connected to the edge area of the basic portion base41b, or the basic portion side wall41aand the basic portion base41bmay be integrally molded. The photosensitive assembly can be fixed on the second movable portion42, the second basic portion41and the second movable portion42are movably connected by an elastic connecting portion (e.g., a leaf spring47), and the second driving part40has four side surfaces, wherein at least one SMA wire48is arranged on at least one side surface of the second driving part40. Each SMA wire48is located in the gap between the outer side surface of the second movable portion42and the inner side surface of the second basic portion41, two ends of each SMA wire48are fixed and electrically connected to two fixed ends located on the second basic portion41(for example, a first fixed end A and a second fixed end B, or a third fixed end C and a fourth fixed end D), respectively, and the two fixed ends are located in two adjacent corner areas (for example, a first corner and a second corner, or a second corner and a third corner; wherein the first corner and the third corner are diagonal to each other, and the second fixed end B and the third fixed end C may both be located at the second corner, that is, the second corner is a common corner), respectively. The outer side surface of the second movable portion42has an extension portion44, the extension portion44is in contact with a waist part48aof the SMA wire48, and the extension portion44presses, under the action of the elasticity of the elastic connecting portion (e.g., a leaf spring47), against the SMA wire48along the x-axis or y-axis direction at the waist part48aof the SMA wire48to make it bend. The second driving part40causes the SMA wire48to shrink by applying an electric current to the SMA wire48, so as to move the photosensitive chip in the x-axis or y-axis direction. On the other hand, in this embodiment, the first driving part is adapted to drive the lens to translate in the x-axis and y-axis directions. The lens and the photosensitive chip are configured to be simultaneously driven and move in opposite directions; wherein the x-axis and the y-axis are coordinate axes perpendicular to an optical axis of the camera module, and the x-axis and the y-axis are perpendicular to each other. Further, in this embodiment, the SMA wire48comprises an x-axis driving SMA wire and a y-axis driving SMA wire; at least one x-axis driving SMA wire48ais arranged on at least one side surface45aof the second driving part that is perpendicular to the x-axis, and the second driving part causes the x-axis driving SMA wire48ato shrink by applying an electric current to the x-axis driving SMA wire48a, so as to move the second movable portion42in the x-axis direction, thereby driving the photosensitive chip to move in the x-axis direction. In addition, at least one y-axis driving SMA wire48bis arranged on at least one side surface45bof the second driving part40that is perpendicular to the y-axis, and the second driving part40causes the y-axis driving SMA wire48bto shrink by applying an electric current to the y-axis driving SMA wire48b, so as to move the second movable portion42in the x-axis direction, thereby driving the photosensitive chip to move in the y-axis direction.

In some embodiments of the present application, the extension portion may be configured as a hook, a roller or an arc track.

Still referring toFIG.21, in some embodiments of the present application, the second basic portion40has four corner areas, wherein three corner areas have the fixed ends, and the fixed end of one corner area is fixed to both the x-axis driving SMA wire48aand the y-axis driving SMA wire portion48b. The second driving part40has a first side46a, a second side46bintersecting with the first side46a, a third side46copposite to the first side46a, and a fourth side46dopposite to the second side46b. The x-axis driving SMA wire45ais only provided on the first side46a, and the y-axis driving SMA wire45bis only provided on the second side portion46b. Further, in an embodiment of the present application, the second driving part may be provided with only one x-axis driving SMA wire and one y-axis driving SMA wire. This design can reduce the number of SMA wires, which helps to reduce the lateral dimension of the camera module. Here, the lateral dimension may also be referred to as a radial dimension, i.e., the dimension in a direction perpendicular to the optical axis of the camera module.

Further, in some embodiments of the present application, in the second driving part, a gap between an inner side surface of the second basic portion located on the first side and an outer side surface of the second movable portion (i.e., a gap between the basic portion side wall41alocated on the first side and the second movable portion42) is larger than a gap between an inner side surface of the second basic portion located on the third side and the outer side surface of the second movable portion (i.e., a gap between the basic portion side wall41alocated on the third side and the second movable portion42). A gap between an inner side surface of the second basic portion located on the second side and the second movable portion is larger than a gap between an inner side surface of the second basic portion located on the fourth side and the second movable portion. Further,FIG.22shows a schematic sectional view of a camera module in an embodiment of the present application. Referring toFIG.22, in this embodiment, the photosensitive assembly20may comprise a photosensitive chip, a circuit board and electronic elements26mounted on the surface of the circuit board26. The photosensitive chip21is mounted in a central area of the circuit board23, the electronic elements26are located on an outer side of the photosensitive chip21, and the electronic elements26are all located on the first side46aand/or the second side46b(i.e., a side provided with the x-axis driving SMA wire and/or the y-axis driving SMA wire). Further,FIG.23shows a schematic sectional view with marking a part of edge areas of a circuit board based on the camera module ofFIG.22. Referring toFIG.23, in this embodiment, in the photosensitive assembly, the circuit board23has four edge areas, which are a first edge area46a′ located on the first side46a, a second edge area located on the second side46b, a third edge area46c′ located on the third side46c, and a fourth edge area located on the fourth side46d, respectively; a width of the third edge area is smaller than that of the first edge area; and a width of the fourth edge area is smaller than that of the first edge area, wherein the respective width of a respective edge area represents a distance from an edge of the photosensitive chip to an edge of the circuit board. In this embodiment, the electronic elements may be concentrated on the first side and the second side of the circuit board, so as to effectively utilize the lateral space for arranging the SMA wires, and reduce the lateral space occupied by the circuit board and the second driving part on the third side and the fourth side, thereby helping to reduce the lateral dimension of the camera module. Here, the lateral dimension may also be referred to as a radial dimension, i.e., the dimension in a direction perpendicular to the optical axis of the camera module.

Further, in an embodiment of the present application, in the second driving part, the extension portion and the fixed end are at different heights, the height represents a position in a direction of a z-axis, and the z-axis is a coordinate axis perpendicular to the x-axis and the y-axis. In this embodiment, optionally, the extension portion may be higher than the fixed end (meaning that the position of the contact point between the extension portion and the SMA wire is higher than the position of the contact point between the fixed end and the SMA wire), so that an acting force the SMA wire can apply to the extension portion has a downward (downward along the z-axis) component. This downward component cooperates with the leaf spring (or referred to as a flexure member), so that the movement of the second movable portion in the z-axis direction can be better limited, that is, the image stabilization movement of the second movable portion can be more reliably limited within the xoy plane. In contrast, if only the leaf spring is used to limit the movement of the second movable portion in the z-axis direction, sometimes the shift of the second movable portion in the z-axis direction cannot be prevented.

Further, in the camera module, the circuit board of the photosensitive assembly usually comprises a rigid circuit board main body and a flexible connecting band, one end of the flexible connecting band is connected to the circuit board main body, and the other end is connected and electrically conducted with a motherboard or other components of an electronic device through a connector. In the prior art, the flexible connecting band of the photosensitive assembly is usually led out from the side surface of the circuit board main body, and the flexible connecting band is roughly parallel to the surface of the circuit board main body. In this arrangement, the flexible connecting band will have a greater resistance to the movement of the circuit board main body, which may increase the force required to drive the movement of the circuit board main body, resulting in insufficient stroke for image stabilization compensation and reduced response speed. In addition, the resistance caused by the connecting band is irregular, so that it is difficult for the second driving part to compensate for the resistance, which may result in a decrease in the accuracy of the image stabilization compensation. Therefore, in the present application, a suspended circuit board is provided as a circuit board of a photosensitive assembly adapted to the second driving part, and this design manner will help to overcome the above defects caused by the connecting band. Such a suspended circuit board can be applied to the embodiments of the SMA mounting manner shown inFIGS.20-23. Various technical details of the suspended circuit board have been described above in combination withFIGS.13-19, and are not repeated here.

Only preferred implementations of the present application and an explanation of the applied technical principle are described above. It should be understood by those skilled in the art that the scope of disclosure involved in the present application is not limited to technical solutions formed by specific combinations of the above technical features, and at the same time, should also cover other technical solutions formed by any combination of the above technical features or equivalent features thereof without departing from the concept of the disclosure. For example, the above features and (but not limited to) the technical features with similar functions disclosed in the present application are replaced with each other to form technical solutions.