A core-driven auto-focus camera module

Abstract

The present invention relates to a core-moving autofocus camera module, which solves the problems of the existing core-moving autofocus camera's flexible circuit board being easily offset when moving, occupying a large space, and having poor heat dissipation. The module comprises a housing, a lens arranged on the housing, a circuit board arranged in the housing, an image sensor, a position sensor, and a driving mechanism. When in use, the position sensor is used to detect the displacement of the image sensor to achieve automatic focusing; when the circuit board body moves upward, the deformation support part restores to provide a downward restoring force to the support connection part; when the circuit board body moves downward, the deformation support part restores to provide an upward restoring force to the support connection part at the same time. When the camera module is not working, the restoring force will reset the movable seat to reduce the impact of the movable seat on other parts and abnormal noise caused by external vibration; in addition, the circuit board body is not easy to tilt when moving up and down, the positioning is accurate, and the space occupied is small. Furthermore, the heat dissipation efficiency of the image sensor is improved.

Description

Technical Field

[0001] The invention relates to a core-moving automatic focusing camera module. Background Art

[0002] The core-moving actuator is theoretically more advantageous in terms of power consumption and size, but the actuator technology has many disadvantages, which has prevented this type of technology from becoming mainstream. The actuator (reference patents: CN113325543A, CN214959775U and CN112684565A) and its application camera module require a flexible circuit board to connect the image sensor in the movable structure and the electronic components outside the fixed structure, provide power to the image sensor and send the image signal to the electronic components. The flexible circuit board can adopt a flat deformation design (reference patents: CN113325543A and CN214959775U) or a multiple folding deformation design (reference patent: CN112684565A). Regardless of whether a flat or multiple folding deformation design is adopted, the deformed part of the flexible circuit board also needs to occupy more space, occupying the space outside the camera module, below or beside the image sensor. In addition, the production process of the multiple folding deformation design is complicated, which is not conducive to production cost and yield.

[0003] In addition, some core-moving actuators use a spring-type design (reference patents: CN113325543A and CN214959775U). When the lens is not moving, a large current and electromagnetic force are still required to resist the force caused by the deformation of the spring, resulting in high power consumption. On the other hand, the spring-type design is more sensitive to the size and assembly errors of the flexible circuit board, and it is easy for the image sensor to tilt unnecessarily during the automatic process, affecting the resolution of the image edge. In addition, the magnets in some core-moving actuators (reference patent: CN112684565A) are movable. When there are other magnets near the actuator, it is easy to interfere with the magnets, which may cause serious magnetic interference and affect the normal operation of the actuator.

[0004] Finally, since the image sensor in the actuator needs to move during the autofocus process, the circuit board under the image sensor cannot be close to the housing, affecting the heat dissipation effect. The design of the actuator or camera module does not provide an effective heat dissipation path in a limited space. Poor heat dissipation can cause the image sensor to have a high temperature, and the image sensor may have more image noise or even fail to work properly. Summary of the invention

[0005] The purpose of the present invention is to solve the problems that the flexible circuit board of the existing core-motion auto-focus camera is easy to deviate when moving, occupies a large space and has poor heat dissipation.

[0006] The technical solution adopted to solve the technical problem proposed by the present invention is as follows: the core-moving autofocus camera module of the present invention includes a shell, a lens arranged on the shell, a circuit board arranged in the shell, and an image sensor arranged on the circuit board corresponding to the lens, the circuit board includes a circuit board body, the image sensor is located on the circuit board body, the shell includes an outer shell, and a movable seat, the movable seat is arranged in the outer shell along the axial direction of the lens, the circuit board body is installed on the movable seat, the camera module also includes a driving mechanism for driving the movable seat to move relative to the lens, and a position sensor for detecting the displacement of the image sensor is also provided on the movable seat, the circuit board also includes a supporting connection part connected to the circuit board body and moving up and down with the circuit board body, a flexible deformation support part connected to the supporting connection part, and a mounting seat connected to the deformation support part, a through hole is provided in the middle of the deformation support part corresponding to the image sensor, and the minimum distance from the plane where the deformation support part is located to the image sensor is greater than one tenth of the corresponding lens height; the mounting seat is electrically connected to the circuit board body, and the mounting seat is installed in the outer shell.

[0007] The technical solutions for further limiting the present invention include:

[0008] The shell is provided with more than two lenses, and each lens is respectively provided with a movable seat, a circuit board, an image sensor, a driving mechanism and a position sensor.

[0009] The driving mechanism is a voice coil motor driving mechanism, the first coil of the voice coil motor driving mechanism is installed on the movable seat, and the first magnet of the voice coil motor is installed on the shell.

[0010] One side of the movable seat is connected to the shell by ball rolling, a magnetic seat is provided on the side of the movable seat corresponding to the ball, and a second magnet adsorbed to the magnetic seat is provided on the side of the shell corresponding to the ball.

[0011] The first coil is arranged on the other side of the movable seat adjacent to the magnetic conductive seat, and the first magnet is arranged corresponding to the first coil. The first magnet adopts single-sided bipolar magnetization, the upper surface of the first magnet facing the coil is the north pole, and the lower surface of the first magnet facing the coil is the south pole.

[0012] The first coil is arranged on the other side of the movable seat adjacent to the magnetic conductive seat, the first magnet is arranged corresponding to the first coil, and the first magnet includes a third magnet and a fourth magnet arranged opposite to each other up and down, and the third magnet and the fourth magnet have opposite magnetic poles facing the first coil; a second coil is arranged on the other side of the movable seat opposite to the first coil, and a fifth magnet and a sixth magnet are arranged opposite to each other up and down on the outer shell corresponding to the second coil, and the fifth magnet and the sixth magnet have opposite magnetic poles facing the second coil.

[0013] The angle between the plane where the deformation support part is located and the image sensor is less than 20 degrees.

[0014] The deformation support portion is composed of more than two layers of deformation support portion monomers, and gaps are provided between adjacent deformation support portion monomers.

[0015] The vertical angle between at least one connecting surface included in the supporting connecting portion and the axis of the lens is less than 30 degrees.

[0016] The total area of ​​at least one connection surface included in the supporting connection portion is larger than one half of the image sensor.

[0017] Through the above technical scheme, the beneficial effects of the present invention are as follows: the core-moving autofocus camera module of the present invention realizes electrical connection of the circuit board through the mounting seat. When in use, the driving mechanism drives the movable seat to drive the image sensor to move relative to the lens. The position sensor is used to detect the displacement of the image sensor to realize automatic focus. The image sensor corresponds to the through hole in the middle of the deformation support part. The support connection part of the circuit board is located in the space around the image sensor, so that the overall structure is compact and occupies a small space. When the circuit board body moves up, the support connection part moves up with the circuit board body, and the deformation support part deforms upward. At the same time, the deformation support part restores to provide a downward restoring force for the support connection part; when the circuit board body moves down, the support connection part moves down with the circuit board body, and at the same time, the deformation support part restores to provide an upward restoring force for the support connection part; when the camera module is not working, the restoring force will reset the movable seat to reduce the impact of the movable seat on other components and abnormal noise caused by external vibration. In addition, when the circuit board body moves up and down, because the torque of the deformation support part on the center position of the circuit board body is small, the circuit board body is not easy to tilt and the positioning is accurate. Furthermore, the supporting connection part and the deformable supporting part in the circuit board effectively increase the effective heat dissipation area of ​​the image sensor, improve the heat dissipation efficiency, and reduce the temperature and noise of the image sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The present invention is a schematic diagram of the three-dimensional structure of a core-driven auto-focus camera module.

[0019] Figure 2The figure is a schematic diagram of the three-dimensional structure of a first embodiment of a core-driven auto-focus camera module of the present invention.

[0020] Figure 3 The figure is a schematic structural diagram of a driving mechanism of a first embodiment of a core-driven auto-focus camera module of the present invention.

[0021] Figure 4 The figure is a schematic cross-sectional structure diagram of a first embodiment of a core-driven auto-focus camera module of the present invention.

[0022] Figure 5 The figure is a schematic cross-sectional structure diagram of a first embodiment of a core-driven auto-focus camera module of the present invention.

[0023] Figure 6 The figure is a schematic structural diagram of a driving mechanism of a second embodiment of a core-driven auto-focus camera module of the present invention.

[0024] Figure 7 The present invention is a schematic structural diagram of a circuit board of a core-activated auto-focus camera module.

[0025] Figure 8 The present invention is a schematic structural diagram of a circuit board of a core-activated autofocus camera module when the deformation support portion is two-layered.

[0026] Fig. 9 for Figure 8 The enlarged structure at A in DETAILED DESCRIPTION

[0027] The structure of the present invention is further described below in conjunction with the accompanying drawings.

[0028] In the description of the present application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or component must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0029] Reference Figures 1 to 9A core-actuated auto-focus camera module includes a housing 10, a lens 11 disposed on the housing, a circuit board 20 disposed in the housing, and an image sensor 30 disposed on the circuit board corresponding to the lens. The circuit board 20 includes a circuit board body 21, and the image sensor is located on the circuit board body. The housing 10 includes a shell 101 and a movable seat 102, and the movable seat is disposed in the shell along the axial direction of the lens. The circuit board body is mounted on the movable seat. The camera module also includes a driving mechanism 40 for driving the movable seat to move relative to the lens. The movable seat is also provided with a position sensor 50 for detecting the displacement of the image sensor. The circuit board 20 also includes a support connection part 22 connected to the circuit board body and moving up and down with the circuit board body, a flexible deformation support part 23 connected to the support connection part, and a mounting seat 24 connected to the deformation support part. A through hole 231 is provided in the middle of the deformation support part 23 corresponding to the image sensor. The minimum distance from the plane where the deformation support part is located to the image sensor is greater than one tenth of the corresponding lens height. If the distance is too small, the deformed part will avoid the image sensor and surrounding electronic parts, and space cannot be saved. The mounting seat is electrically connected to the circuit board body, and the mounting seat is installed in the housing. The circuit board is electrically connected through the mounting seat. When in use, the driving mechanism drives the movable seat to drive the image sensor to move relative to the lens. The position sensor is used to detect the displacement of the image sensor to achieve automatic focus. The image sensor corresponds to the through hole in the middle of the deformation support part. The support connection part of the circuit board is located in the space around the image sensor, so that the overall structure is compact and occupies a small space. When the circuit board body moves up, the support connection part moves up with the circuit board body, and the deformation support part deforms upward, and the deformation support part restores to provide a downward restoring force for the support connection part; when the circuit board body moves down, the support connection part moves down with the circuit board body, and the deformation support part restores to provide an upward restoring force for the support connection part; when the camera module is not working, the restoring force will reset the movable seat to reduce the impact of the movable seat on other components and abnormal noise caused by external vibration. In addition, when the circuit board body moves up and down, because the torque of the deformation support part on the center position of the circuit board body is small, the circuit board body is not easy to tilt and the positioning is accurate. Furthermore, the supporting connection part and the deformable supporting part in the circuit board effectively increase the effective heat dissipation area of ​​the image sensor, improve the heat dissipation efficiency, and reduce the temperature and noise of the image sensor.

[0030] In this embodiment, the housing is coated with a dark color to improve the efficiency of absorbing heat radiation and further reduce the temperature and noise of the image sensor.

[0031] In this embodiment, a lens, a circuit board, an image sensor, a driving mechanism and a position sensor are arranged on the housing. In specific implementation, more than two lenses may be arranged on the housing, and each lens is respectively provided with a movable seat, a circuit board, an image sensor, a driving mechanism and a position sensor. Thus, multi-lens autofocus is realized.

[0032] In this embodiment, the driving mechanism 40 is a voice coil motor driving mechanism, the first coil 41 of the voice coil motor driving mechanism is installed on the movable seat, and the first magnet 42 of the voice coil motor is installed on the shell. By changing the current of the first coil, the electromagnetic force and direction of the first coil can be changed, and the movable seat can be driven to drive the image sensor to move relative to the lens to achieve an autofocus effect. In specific implementation, other types of driving mechanisms can be used, such as a spring-type voice coil motor, a memory metal motor, and a piezoelectric motor, to replace the ball-type voice coil motor; the use of other numbers of magnets, coils, and shell designs is also within the scope of protection of the present invention.

[0033] In this embodiment, one side of the movable seat is connected to the housing by rolling through a ball 60, a magnetic seat 70 is provided on the side of the movable seat corresponding to the ball, and a second magnet 80 adsorbed to the magnetic seat is provided on the side of the housing corresponding to the ball. The second magnet and the magnetic seat are adsorbed to each other, and the movable seat and the housing can be pressed on the ball, limiting the movable seat from moving along the axial direction of the lens, and not easily deviating. The magnetic seat is made of magnetic material and can be attracted by a magnet.

[0034] In the first embodiment, the first coil is arranged on the other side of the movable seat adjacent to the magnetic seat, the first magnet is arranged corresponding to the first coil, the first magnet 42 is magnetized by single-sided bipolar, the upper surface of the first magnet facing the coil is the north pole, and the lower surface of the first magnet facing the coil is the south pole. When the first wire is energized, an electromagnetic force roughly parallel to the optical axis can be generated, pushing the movable seat to drive the image sensor to move relative to the lens, achieving the effect of autofocus.

[0035] In the second embodiment, the first coil is arranged on the other side of the movable seat adjacent to the magnetic conductive seat, the first magnet is arranged corresponding to the first coil, the first magnet 42 includes a third magnet 421 and a fourth magnet 422 arranged opposite to each other up and down, and the third magnet and the fourth magnet have opposite magnetic poles facing the first coil; the second coil 43 is arranged on the other side of the movable seat relative to the first coil, and the fifth magnet 44 and the sixth magnet 45 are arranged opposite to each other up and down on the shell corresponding to the second coil, and the fifth magnet and the sixth magnet have opposite magnetic poles facing the second coil. When the first coil and the second coil are energized, an electromagnetic force roughly parallel to the optical axis can be generated, which pushes the movable seat to drive the image sensor to move relative to the lens to achieve the effect of autofocus. The position sensor 50 can measure the position of the first coil relative to the third magnet and the fourth magnet, adjust the current of the first coil and the second coil, and achieve the effect of closed-loop control. The position sensor is integrated in the driver chip and the driver chip is integrated in the position sensor, both of which are within the protection range.

[0036] In this embodiment, the angle between the plane where the deformation support part is located and the image sensor is 0 degrees, at which time the upper and lower spring constants are the smallest and the power consumption is the smallest. In a specific implementation, the angle between the plane where the deformation support part is located and the image sensor is less than 20 degrees. If the angle is too large, the upper and lower spring constants will be too large and the power consumption will be too high.

[0037] In this embodiment, the support connection part 22 includes at least one connection surface parallel to the lens axis. In a specific implementation, the vertical angle between the at least one connection surface included in the deformation support part and the lens axis is less than 30 degrees. Thus, the image sensor can move along the lens axis without tilting, accurately positioned, and will not affect the camera imaging.

[0038] In this embodiment, the total area of ​​at least one connection surface included in the support connection part is greater than one-half of the image sensor. The metal part in the support connection part is connected to the image sensor, which can effectively transfer the heat of the image sensor to the support connection part, and then transfer it to the housing through thermal radiation and heat convection, effectively reducing the temperature and noise of the image sensor. In this embodiment, the deformation support part 23 is composed of more than two layers of deformation support part monomers 232, and gaps 233 are provided between adjacent deformation support part monomers. This layered design can reduce the thickness of the deformation support part monomer, effectively reduce the spring constant of the deformation support part in the direction of optical axis displacement, and reduce the power consumption required for autofocus.

[0039] In this embodiment, the deformation support part is electrically connected to the circuit board body, and the deformation support part 23 includes an annular frame with a notch 234. The image sensor is arranged in the middle of the annular frame; the two ends of the notch of the annular frame are electrically connected to the mounting seat through the bent flexible connection parts 25. The flexible connection part enables the deformation of the deformation support part to be uniform, so that the deformation of the deformation support part is more stable. When the circuit board body moves up and down, the image sensor is driven to move up and down. The image sensor is arranged in the middle of the annular frame. The annular frame is arranged around the image sensor. The annular frame has a certain elasticity. While meeting the elastic deformation, the structure is compact and occupies a small space. The deformation support part can be a Flexible Printed Circuit (FPC). It is easy to manufacture and has low cost.

[0040] In this embodiment, the connection between the annular frame and the supporting connection part is a straight edge, and the annular frame with a notch is a rectangular annular frame with a notch, so that it is easy to manufacture and has low cost. In the specific implementation, the annular frame with a notch can also be an elliptical annular frame with a notch, a polygonal annular frame with a notch, or a special-shaped annular frame with a notch.

[0041] Although the specific embodiments of the present invention are described in detail in conjunction with the accompanying drawings, it should not be understood as limiting the scope of protection of the present invention. Within the scope described in the claims, various modifications and variations that can be made by those skilled in the art without creative work still belong to the scope of protection of the present invention.

Claims

1. A core-actuated autofocus camera module, the camera module comprising a housing, a lens disposed on the housing, a circuit board disposed in the housing, and an image sensor disposed on the circuit board corresponding to the lens, characterized in that: The circuit board includes a circuit board body, the image sensor is located on the circuit board body, the shell includes an outer shell and a movable seat, the movable seat is slidably arranged in the outer shell along the axial direction of the lens, the circuit board body is installed on the movable seat, the camera module also includes a driving mechanism for driving the movable seat to move relative to the lens, and the movable seat is also provided with a position sensor for detecting the displacement of the image sensor. The circuit board also includes a supporting connection part connected to the circuit board body and moving up and down with the circuit board body, a flexible deformation support part connected to the supporting connection part, and a mounting seat connected to the deformation support part, a through hole is provided in the middle of the deformation support part corresponding to the image sensor, and the minimum distance from the plane where the deformation support part is located to the image sensor is greater than one tenth of the corresponding lens height; the mounting seat is electrically connected to the circuit board body, and the mounting seat is installed in the outer shell; the angle between the plane where the deformation support part is located and the image sensor is less than 20 degrees; the vertical angle between at least one connecting surface included in the supporting connection part and the axial direction of the lens is less than 30 degrees.

2. The core-activated auto-focus camera module according to claim 1, characterized in that: The shell is provided with more than two lenses, and each lens is respectively provided with a movable seat, a circuit board, an image sensor, a driving mechanism and a position sensor.

3. The core-actuated auto-focus camera module according to claim 1, characterized in that: The driving mechanism is a voice coil motor driving mechanism, the first coil of the voice coil motor driving mechanism is installed on the movable seat, and the first magnet of the voice coil motor is installed on the shell.

4. The core-actuated auto-focus camera module according to claim 3, characterized in that: One side of the movable seat is connected to the shell by ball rolling, a magnetic seat is provided on the side of the movable seat corresponding to the ball, and a second magnet adsorbed to the magnetic seat is provided on the side of the shell corresponding to the ball.

5. The core-actuated auto-focus camera module according to claim 4, characterized in that: The first coil is arranged on the other side of the movable seat adjacent to the magnetic conductive seat, and the first magnet is arranged corresponding to the first coil. The first magnet adopts single-sided bipolar magnetization, the upper surface of the first magnet facing the coil is the north pole, and the lower surface of the first magnet facing the coil is the south pole.

6. The core-actuated auto-focus camera module according to claim 4, characterized in that: The first coil is arranged on the other side of the movable seat adjacent to the magnetic conductive seat, the first magnet is arranged corresponding to the first coil, and the first magnet includes a third magnet and a fourth magnet arranged opposite to each other up and down, and the third magnet and the fourth magnet have opposite magnetic poles facing the first coil; a second coil is arranged on the other side of the movable seat opposite to the first coil, and a fifth magnet and a sixth magnet are arranged opposite to each other up and down on the outer shell corresponding to the second coil, and the fifth magnet and the sixth magnet have opposite magnetic poles facing the second coil.

7. A core-driven auto-focus camera module according to any one of claims 1 to 6, characterized in that: The deformation support portion is composed of more than two layers of deformation support portion monomers, and gaps are provided between adjacent deformation support portion monomers.

8. A core-driven autofocus camera module according to any one of claims 1 to 6, characterized in that: The total area of ​​at least one connection surface included in the supporting connection portion is larger than one half of the image sensor.

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