WO2021092858A1

WO2021092858A1 - Camera module and mobile terminal

Info

Publication number: WO2021092858A1
Application number: PCT/CN2019/118542
Authority: WO
Inventors: 瞿佳佳; 李勇; 安在煜
Original assignee: 南昌欧菲光电技术有限公司
Priority date: 2019-11-14
Filing date: 2019-11-14
Publication date: 2021-05-20

Abstract

A camera module, wherein a circuit board may slide under the action of a driving force, thereby driving a photosensitive chip to be displaced relative to a lens assembly so as to compensate for the optical axis offset of the lens assembly that is caused by vibration, thus implementing optical anti-shaking. The circuit board is supported by multiple balls and has better stability. In addition, since the circuit board is in point contact with the balls, the balls will roll quickly under the action of a friction force when the circuit board slides. Therefore, the friction force received by the circuit board during sliding is relatively small, therefore response is rapid, sensitivity is higher, and energy consumption is lower. In addition, although the balls roll following the circuit board, the plane defined by the balls remains unchanged, and therefore flatness is better when the circuit board slides. Hence, the described camera module has relatively high reliability while optical anti-shaking is implemented.

Description

Camera module and mobile terminal

Technical field

The present invention relates to the technical field of optical imaging, in particular to a camera module and a mobile terminal.

Background technique

Optical image stabilization is a widely recognized anti-shake technology. It compensates for the vibration of the light path through movable parts, so as to achieve the effect of reducing the blur of the photo. Optical image stabilization technology is mainly divided into two categories, namely, lens movable optical image stabilization, and photosensitive chip movable optical image stabilization.

The lens movable optical image stabilization structure is complex, and is generally not suitable for application to the camera module of a mobile terminal. Therefore, the mobile optical image stabilization of the photosensitive chip has received more and more attention. The core principle of the mobile optical image stabilization of the photosensitive chip is to carry the photosensitive chip by hanging a wire or adding a suspended bracket. Under the action of the driving force, the photosensitive chip can be displaced.

However, the suspension wire is easily broken by force and easily leads to poor flatness during movement. Supporting the photosensitive chip through the bracket will increase friction, which will cause a series of problems such as response lag, stuttering, and high energy consumption. Therefore, when implementing the mobile optical image stabilization of the photosensitive chip, the reliability of the existing camera module is not high.

Summary of the invention

According to various embodiments of the present application, a camera module and a mobile terminal are provided.

A camera module includes:

The base is provided with multiple balls;

A circuit board is provided with a photosensitive chip, the side of the circuit board facing away from the photosensitive chip bears against a side of the plurality of balls facing away from the base, and the balls are in point contact with the circuit board ；

A lens carrier with a lens assembly installed on the base;

Wherein, the circuit board is slidable relative to the plurality of balls along a direction perpendicular to the optical axis of the lens assembly.

A mobile terminal includes the camera module as described in any one of the above embodiments.

The details of one or more embodiments of the present invention are set forth in the following drawings and description. Other features, objects and advantages of the present invention will become apparent from the description, drawings and claims.

Description of the drawings

FIG. 1 is a schematic diagram of the structure of a camera module in a preferred embodiment of the present invention;

Figure 2 is an exploded view of the camera module shown in Figure 1;

Fig. 3 is a cross-sectional view of the camera module shown in Fig. 1;

4 is a partial schematic diagram of the base part of the camera module shown in FIG. 1.

Detailed ways

In order to facilitate the understanding of the present invention, the present invention will be more fully described below with reference to the relevant drawings. The drawings show preferred embodiments of the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or a central element may also be present. When an element is considered to be "connected" to another element, it can be directly connected to the other element or an intermediate element may be present at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field of the present invention. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The term "and/or" as used herein includes any and all combinations of one or more related listed items.

Please refer to FIG. 1, the present invention provides a camera module 100. The present invention also provides a mobile terminal including the camera module 100. With the help of the camera module 100, the mobile terminal can realize the shooting function. The mobile terminal can be an electronic product such as a mobile phone, a PAD, and a camera.

Please refer to FIGS. 2 and 3 together. The camera module 100 in the preferred embodiment of the present invention includes a base 110, a circuit board 120, a lens carrier 140, and a lens assembly 150.

The base 110 plays a bearing role, and is generally integrally formed of a metal material. According to different styling requirements of the camera module 100, the outer contour of the base 110 can be in various shapes such as a circle or a rectangle. The base 110 is provided with a plurality of balls 111. The ball 111 has a spherical shape and can roll relative to the base 110. Moreover, the ball 111 needs to have a relatively high hardness and is not easily deformed. Specifically, the ball 111 may be formed of a material with high hardness such as metal, ceramic, glass, sapphire, and the like.

The diameters of the plurality of balls 111 are generally the same. Therefore, the plurality of balls 111 can jointly define a sliding plane (not shown) that is tangent to the plurality of balls 111. It should be pointed out that the sliding plane is not an actual plane, but a virtual plane. Since three points define a plane. Therefore, the number of balls 111 is at least three.

The circuit board 120 is provided with a photosensitive chip 121, and the circuit board 120 bears on a side of the plurality of balls 111 facing away from the base 110. The circuit board 120 can slide relative to the ball 111. Moreover, the circuit board 120 slides, which can drive the photosensitive chip 121 to move to achieve an anti-shake response. Specifically, when the circuit board 120 bears against the surface of the ball 111, it is located on the above-mentioned sliding plane and can slide along the sliding plane.

A receiving structure such as a groove, a hole, a sleeve, etc. may be formed on the base 110 for accommodating the balls 111 to prevent the balls from being scattered, thereby facilitating assembly and improving the reliability of the camera module 100. Specifically, in this embodiment, the base 110 is provided with a plurality of receiving holes 113 in the same number as the balls 111, and each ball 111 is respectively received in a receiving hole 113, and is partially exposed outside the receiving hole 113 and the circuit. The board 120 is offset. Wherein, the above-mentioned sliding plane is jointly defined by the top ends of the parts of the plurality of balls 111 exposed outside the accommodating hole 113.

The accommodating hole 113 may be a through hole or a blind hole, and its purpose is to limit the position of the ball 111 on the base 110. In this embodiment, the accommodating hole 113 is a through hole and has a funnel shape, and has a large end and a small end that are relatively disposed. Moreover, the diameter of the ball 111 is larger than the inner diameter of the small end of the accommodating hole 113 and smaller than the inner diameter of the large end. Therefore, the ball 111 can be inserted from the large end of the receiving hole 113 first, and then a bottom plate (not shown in the figure) covers the opening of the large end. In this way, the balls 111 can be effectively prevented from being scattered during assembly, which is convenient for assembly.

In addition, a plurality of balls 111 can also be directly scattered on the base 110. Specifically, in another embodiment, a support plane (not shown) is formed on the side of the base 110 facing the circuit board 120, and the edge of the support plane is provided with a limiting protrusion protruding toward the circuit board 120 along the circumferential direction. (Not shown in the figure), a plurality of balls 111 are carried on the supporting plane and clamped between the supporting plane and the circuit board 120.

The ball 111 can roll freely in the support plane, and the limit protrusion forms a boundary to prevent the ball 111 from rolling outside the range of the support plane. The ball 111 is confined to the base 110 by the pressing action of the circuit board 120. Therefore, the ball 111 is restricted only in the direction perpendicular to the sliding plane, and there is no restriction in the direction parallel to the sliding plane. At this time, the resistance received by the ball 111 when rolling is further reduced, so the anti-shake response of the aforementioned camera module 100 is more sensitive.

The circuit board 120 is generally a PCB board on which many electronic components are integrated. For example, as described above, the circuit board 120 is provided with a photosensitive chip 121. The photosensitive chip 121 is used to convert light into electrical signals to achieve imaging. In addition, in order to sense the jitter of the camera module 100 and achieve anti-shake, the circuit board 120 may also integrate a gyroscope (not shown), a driving chip (not shown), a driving mechanism (not shown), etc. The gyroscope detects the jitter and quantifies the degree of jitter, the drive chip generates a drive current according to the amount of jitter, and the drive mechanism performs jitter compensation under the action of the drive current.

In order to improve the imaging effect of the photosensitive chip 121, in this embodiment, the camera module 100 further includes a filter 160 that can filter out invisible light, and the filter 160 is covered on the surface of the photosensitive chip 121. Specifically, the filter 160 may be blue glass, which will filter out invisible light and avoid interference, thereby preventing noise from being generated on the image.

In this embodiment, the camera module 100 further includes a position limiting member 130. The position limiting member 130 provides a force directed to the ball 111 on the circuit board 120. The force restricts the circuit board 120 in a direction perpendicular to the sliding plane, so that the circuit board 120 always keeps contact with the ball 111. Otherwise, a stable support cannot be formed between the circuit board 120 and the ball 111, and the circuit board 120 will be separated from the ball 111 when shaking or turning over.

The limiting member 130 can press the circuit board 120 on the plurality of balls 111. In other words, the circuit board 120 and the base 110 are supported by a plurality of balls 111. Specifically, in this embodiment, the ball 111 is an insulated ball. Therefore, while playing a supporting role, insulation can also be formed between the circuit board 120 and the base 110. When the driving mechanism performs jitter compensation, the driving circuit board 120 is slid along the sliding plane, thereby driving the photosensitive chip 121 on the circuit board 120 to move, so as to realize the movable optical anti-shake of the photosensitive chip.

Since the ball 111 is not easily deformed, the stability of the support for the circuit board 120 is better. Moreover, since the circuit board 120 and the ball 111 are in point contact, when the circuit board 120 slides, the ball 111 will also roll relative to the base 110 under the action of friction. Therefore, the friction force received by the circuit board 120 during the sliding process is relatively small rolling friction. Therefore, only a small driving force is required to drive the circuit board 120 to slide, so the anti-shake response is fast, the sensitivity is higher, and the energy consumption is lower.

In addition, the ball 111 may roll with the sliding of the circuit board 120. However, the surface of the ball 111 is a spherical surface, and its rolling does not cause fluctuations in the height of the sliding plane. Therefore, the circuit board 120 will always remain on the same plane when sliding, that is, the flatness is better.

Please also refer to FIG. 4. In this embodiment, there are three accommodating holes 113, and they are triangularly distributed on the base 110, and each ball 111 is accommodated in one accommodating hole 113. A triangle can form a stable support. Therefore, the minimum number of balls 111 can be used to support the circuit board 120, thereby significantly reducing the number of balls 111. On the one hand, it can further reduce the friction of the circuit board 120; on the other hand, it can reduce the difficulty of assembly while reducing the cost.

The force provided by the limiting member 130 to the circuit board 120 may be pressure or pulling force; the limiting member 130 may directly apply force to the circuit board 120 in contact or non-contact force. The limiting effect member 130 can have various forms, as long as it does not interfere with the sliding of the circuit board 120 along the sliding plane.

In this embodiment, the position-limiting member 130 is a magnet provided on the base 110, and the circuit board 120 is provided with a ferromagnetic member 123 that can be attracted by the magnet.

The ferromagnetic member may be a member formed of iron, nickel, or cobalt, and is attracted to the ferromagnetic member 123 by a magnet, thereby generating a pulling force directed to the ball 111 on the circuit board 120. Moreover, through the attraction of the magnet, the position-limiting member 130 exerts a force on the circuit board 120 in a non-contact manner. Therefore, the circuit board 120 does not receive the friction force from the limiting member 130, so the sliding resistance of the circuit board 120 is smaller, and the anti-shake response speed and sensitivity are further improved.

Moreover, because the magnet is always fixed in the magnetic field. Therefore, when the ferromagnetic member 123 deviates from the initial position due to sliding with the circuit board 120, the magnet's attraction force to the ferromagnetic member 123 will cause the ferromagnetic member 123 to have a tendency to reset. In other words, when the jitter is eliminated and the driving force acting on the circuit board 120 disappears, the circuit board 120 can also be automatically reset under the drive of the ferromagnetic component 123.

Furthermore, in this embodiment, the ferromagnetic member 123 is an iron sheet covering the side of the circuit board 120 facing the base 110.

Specifically, the sheet structure is beneficial to reduce the thickness of the camera module 100. Moreover, since the iron sheet is covered on the side of the circuit board 120 facing the base 110, the balls 111 directly contact the surface of the iron sheet when supporting the circuit board 120. The surface of the iron sheet is smooth and the friction coefficient is small. Therefore, the frictional force between the circuit board 120 and the balls 111 can be further reduced.

Furthermore, in this embodiment, the base 110 is provided with a receiving groove 115 on the side facing the circuit board 120, and the magnet is received and fixed in the receiving groove 115. The accommodating groove 115 allows the magnet to be buried in the base 110 without protruding from the surface of the base 110, thereby reducing the risk of the magnet contacting the surface of the circuit board 120. At the same time, embedding magnets in the base 110 can also help reduce the thickness of the camera module 100 described above.

It should be pointed out that in other embodiments, the position-limiting member 130 may also be in other forms. for example:

The position-limiting member 130 may be a stretched elastic cord, one end of which is fixed to the base 110 and the other end to the circuit board 120. Through the pulling force of the elastic cord, a force directed to the ball 111 can also be applied to the circuit board 120. Moreover, when the jitter is eliminated and the driving force acting on the circuit board 120 disappears, the elastic cord can also pull the circuit board 120 to automatically reset. Another example:

The limiting effect member 130 may also be a structure composed of a sleeve, a spring, and a rolling ball (the structure may be the same as that of the rolling ball 111). Among them, the spring and the rolling ball are contained in the sleeve, and the compression of the spring generates a force on the rolling ball. The sleeve points to the surface of the circuit board 120 facing away from the ball 111 (that is, the upper surface shown in the figure), and the ball abuts against the upper surface. Under the action of the elastic force of the spring, the rolling ball exerts a force directed toward the rolling ball 111 on the circuit board 120. At this time, the upper and lower surfaces of the circuit board 120 are supported by rolling, so it does not affect its sliding along the sliding plane.

The lens carrier 140 is used to install the lens assembly 150, and the lens carrier 140 is disposed on the base 110. The optical axis of the lens assembly 150 generally points to the circuit board 120. The light enters the photosensitive chip 121 through the lens assembly 150 to realize imaging. The lens assembly 150 is generally formed by stacking a plurality of lenses with different focal lengths. The optical axis generally coincides with the central axis of the lens assembly 150 and is perpendicular to the sliding plane. That is, the circuit board 120 can slide along a plane perpendicular to the optical axis of the lens assembly 150. For circular lenses, the optical axis passes through the center of the circle.

In this embodiment, the lens carrier 140 is a voice coil motor, and includes a housing 141 and a movable carrier 143 installed in the housing 141 and retractable relative to the housing 141 along the optical axis direction of the lens assembly 150. The lens assembly 150 is installed On the movable carrier 143, the housing 141 is installed on the base 110.

Specifically, a coil and a magnet are generally integrated in the housing 141. After the coil is energized, an electromagnetic force will be generated between the coil and the magnet. The electromagnetic force drives the movable carrier 143 to expand and contract, thereby realizing the automatic zooming of the camera module 100.

Please refer to FIG. 2 again. In this embodiment, the camera module 100 further includes a suspension wire 170 connected to the lens carrier 140 at one end and connected to the circuit board 120 at the other end, and the suspension wire 170 is elastically stretchable along its extension direction.

Specifically, there are generally multiple suspension wires 170, and one end is generally connected to the edge of the circuit board 120. For the rectangular circuit board 120, the four suspension wires 170 are respectively connected to the four top corners of the circuit board 120. The suspension wire 170 can be a common elastic rope, so it can be elastically stretched and deformed. In the initial state, the suspension wire 170 may be in a natural state or a stretched state.

When the circuit board 120 deviates from the initial position, the suspension wire 170 will be elastically stretched, so a certain pulling force can be provided to the circuit board 120. Therefore, when the anti-shake response does not occur, the suspension wire 170 can prevent the circuit board 120 from moving randomly along the sliding plane. When an anti-shake response occurs, the suspension wire 170 can also play a traction effect on the circuit board 120.

In the above-mentioned camera module 100, the circuit board 120 is slidable under the action of driving force, thereby driving the photosensitive chip 121 to shift relative to the lens assembly 150 to compensate for the deviation of the optical axis of the lens assembly 150 caused by jitter, and realize optical protection. shake. The circuit board 120 is supported by a plurality of balls 111, and the stability is better. Moreover, since the circuit board 120 and the ball 111 are in point contact, when the circuit board 120 slides, the ball 111 will roll quickly under the action of friction. Therefore, the friction force received by the circuit board 120 during the sliding process is small, so the response is fast, the sensitivity is higher, and the energy consumption is low. In addition, although the ball 111 will roll with the circuit board 120, the plane defined by the ball 111 will always remain unchanged, so the flatness of the circuit board 120 when sliding is also better. It can be seen that the aforementioned camera module 100 has high reliability while realizing optical anti-shake.

The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the various technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, All should be considered as the scope of this specification.

The above-mentioned embodiments only express several embodiments of the present invention, and the descriptions are relatively specific and detailed, but they should not be understood as limiting the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can be made, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims

A camera module is characterized in that it comprises:

The base is provided with multiple balls;

A circuit board on which a photosensitive chip is arranged, a side of the circuit board facing away from the photosensitive chip bears against a side of a plurality of balls facing away from the base, and the balls are in point contact with the circuit board ; The lens carrier with the lens assembly installed on the base;

Wherein, the circuit board is slidable relative to the plurality of balls along a direction perpendicular to the optical axis of the lens assembly.
The camera module of claim 1, wherein the base is provided with a plurality of accommodating holes having the same number as the balls, and each of the balls is accommodated in one of the accommodating holes, and Part of it is exposed outside the accommodating hole to abut against the circuit board.
The camera module according to claim 2, wherein the number of the accommodating holes is three, and the accommodating holes are triangularly distributed on the base, and each of the balls is accommodated in one of the accommodating holes.
The camera module according to claim 1, wherein a support plane is formed on the side of the base facing the circuit board, and an edge of the support plane is provided with a side convex toward the circuit board along the circumferential direction. The plurality of balls are carried on the supporting plane and clamped between the circuit board and the supporting plane.
The camera module according to claim 1, further comprising a position-limiting member, the position-limiting member is a magnet provided on the base, and the circuit board is provided with a magnet for the magnet Adsorbed ferromagnetic pieces.
The camera module according to claim 5, wherein the ferromagnetic member is an iron sheet covering a side of the circuit board facing the base.
The camera module of claim 5, wherein the base is provided with a receiving groove on a side facing the circuit board, and the magnet is received and fixed in the receiving groove.
The camera module of claim 1, wherein the ball is an insulated ball.
The camera module according to claim 1, further comprising a suspension wire connected to the lens carrier at one end and connected to the circuit board at the other end, and the suspension wire is elastically stretchable along its extension direction .
A mobile terminal, characterized by comprising the camera module according to any one of claims 1 to 9.