Precision positioning device and automatic optical axis precision positioning method

Abstract

The application discloses a kind of precision positioning equipment and automatic optical axis precision positioning method, precision positioning equipment includes rack, moving mechanism, center light pipe, top angle light pipe and control module.Moving mechanism can move lens;Center light pipe can emit first light to lens, image sensor can receive first image;Top angle light pipe can emit second light to lens, image sensor can receive second image;Control module can adjust the position of lens according to the image received by image sensor, wherein, center light pipe and top angle light pipe are configured as parallel light pipe, and the rotation angle of first image and second image received by image sensor is different.Thereby, center light pipe can be effectively utilized, without setting center cross light pipe, simplify the structure of assembly equipment, reduce the cost of production, without manual operation, alignment accuracy is high, and can be suitable for the production demand of multiple camera.

Description

Technical Field

[0001] This invention relates to the technical field of camera module assembly process, and more specifically to a precision positioning device and an automatic optical axis precision positioning method. Background Technology

[0002] Automatic optical axis adjustment, also known as automatic alignment, is a technology that determines the relative positions of components such as the camera and imaging chip during assembly. The packaging process of a camera module involves the assembly of multiple components, including the lens and image sensor. The accuracy of optical axis positioning directly affects the assembly quality of the camera module.

[0003] Currently, optical axis positioning in camera module production lines is mainly achieved through manual positioning or by adding a central crosshair optical tube to the assembly equipment. Manual positioning suffers from drawbacks such as large optical axis center deviation, low precision, and low production capacity. Furthermore, prolonged repetitive work can reduce worker motivation and efficiency. Adding a central crosshair increases the complexity of the production equipment and raises production costs.

[0004] Therefore, there is a need to provide a precision positioning device and an automatic optical axis precision positioning method to at least partially solve the above problems. Summary of the Invention

[0005] The summary section introduces a series of simplified concepts, which will be further explained in detail in the detailed description section. The summary section of this invention is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0006] According to a first aspect of the present invention, a precision positioning device is provided for mounting a lens and an image sensor in a camera module, the precision positioning device comprising:

[0007] frame;

[0008] A moving mechanism, which is mounted on the frame, is capable of moving the lens to be assembled above the image sensor;

[0009] A central light tube is provided, which can emit a first light beam downward in a vertical direction toward the lens, and the image sensor can receive a first image corresponding to the first light beam.

[0010] A apex light tube, wherein the apex light tube is capable of emitting a second light ray toward the lens, and the image sensor is capable of receiving a second image corresponding to the second light ray; and

[0011] The control module is electrically connected to the image sensor and is capable of controlling the moving mechanism to adjust the position of the lens based on the image received by the image sensor.

[0012] The central light tube and the apex light tube are both constructed as parallel light tubes, and the rotation angles of the first image and the second image received by the image sensor are different.

[0013] Optionally, the first image received by the image sensor is rotated 30° to 90° relative to the second image.

[0014] Optionally, the number of the apex light tubes is 4 to 8.

[0015] Optionally, the precision positioning device further includes an arc-shaped bracket, and the apex optical tube is mounted on the arc-shaped bracket and can move along the arc-shaped bracket.

[0016] Optionally, the precision positioning device further includes a conveyor belt and a conveyor table, the conveyor table being disposed on the conveyor belt and capable of moving along the conveying direction of the conveyor belt, the conveyor table being capable of loading a lens and an image sensor.

[0017] Optionally, the precision positioning device further includes a lifting mechanism disposed on at least one side of the conveyor belt, the lifting mechanism being used to lift the conveyor platform to a preset height.

[0018] Optionally, the moving mechanism is disposed on at least one side of the conveyor belt, and the moving mechanism is used to move the lens on the conveyor table located at the preset height above the image sensor.

[0019] Optionally, the moving mechanism includes a six-axis motion device and a gripper device disposed on the six-axis motion device, the gripper device being capable of gripping a lens located on the conveyor table at the preset height.

[0020] According to a second aspect of the present invention, an automatic optical axis precision positioning method is provided, which can be used in a precision positioning device according to a first aspect of the present invention, the automatic optical axis precision positioning method comprising:

[0021] The lens is moved between the image sensor and the central light tube to perform coarse positioning of the lens;

[0022] The image sensor acquires the first image from the central light tube, and adjusts the position of the lens in the vertical direction according to the first image received by the image sensor;

[0023] The first image received by the image sensor is compared with the template image to obtain a correspondence, and the position of the lens in the horizontal plane is adjusted according to the correspondence so that the center point of the central light tube, the center point of the lens and the center point of the image sensor are collinear, so as to perform precise positioning of the lens.

[0024] The image sensor acquires the second image from the apex light tube, and adjusts the tilt of the lens using the second image.

[0025] Optionally, before coarsely positioning the lens, the method further includes:

[0026] Move the image sensor so that the line connecting the center point of the central light tube and the center point of the image sensor is perpendicular to the horizontal plane.

[0027] According to the precision positioning device of the present invention, the lens and image sensor can be positioned using the same central optical tube and apex optical tube. It makes full use of the parallel optical tube used for sharpness testing, eliminating the need for a central cross optical tube for positioning. This simplifies the structure of the assembly equipment, reduces production costs, and allows for automatic optical axis positioning through the control module's own program, eliminating the need for manual operation. It boasts high production capacity, high production efficiency, and high alignment accuracy, making it suitable for the production needs of various cameras. Attached Figure Description

[0028] The following drawings, which are incorporated herein by reference as part of this invention, are provided for understanding the invention. The drawings illustrate embodiments of the invention and their descriptions, serving to explain the principles of the invention.

[0029] In the attached image:

[0030] Figure 1 This is a schematic diagram of the structure of a precision positioning device according to an embodiment of the present invention;

[0031] Figure 2 for Figure 1 A schematic diagram of the six-axis motion device in the precision positioning equipment shown; and

[0032] Figure 3 This is a schematic diagram of the first and second images.

[0033] Explanation of reference numerals in the attached figures:

[0034] 100: Frame; 200: Moving mechanism

[0035] 210: Six-axis motion device; 220: Gripper device

[0036] 300: Top corner light pipe; 400: Center light pipe

[0037] 500: Conveyor belt; 600: Lifting mechanism

[0038] 700: Curved bracket Detailed Implementation

[0039] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that embodiments of the invention may be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid confusion with embodiments of the invention.

[0040] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of the stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or combinations thereof.

[0041] Exemplary embodiments according to the present invention will now be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. It should be understood that these embodiments are provided so that the disclosure of the invention is thorough and complete, and that the concept of these exemplary embodiments is fully conveyed to those skilled in the art. In the drawings, the same reference numerals denote the same elements, and therefore their description will be omitted.

[0042] This invention provides a precision positioning device for assembling camera modules, which enables automatic and precise positioning of the lens and image sensor within the camera module. The following will refer to... Figures 1 to 3 As shown, a precision positioning device according to a preferred embodiment of the present invention will be described in detail.

[0043] like Figure 1 and Figure 2As shown, in one embodiment of the present invention, a precision positioning device for assembling a camera module is provided. The device includes a frame 100, a moving mechanism 200, a central light tube 400, a top-angle light tube 300, and a control module. The moving mechanism 200 is capable of moving the lens to be assembled above the image sensor and adjusting the lens position according to control signals from the control module. The central light tube 400 is mounted on the frame 100 and located above the lens, emitting a first light beam vertically downwards towards the lens. The top-angle light tube 300 is mounted on the frame 100 and at least partially located above the lens, emitting a second light beam towards the lens. The control module is electrically connected to the image sensor and can control the moving mechanism 200 to adjust the lens position based on the image received by the image sensor. In this embodiment, during the assembly of the lens and image sensor, the lens needs to be moved above the image sensor first. At this time, both the lens and the image sensor are in a focusing position, and the light emitted by the central light tube 400 and the top-angle light tube 300 can pass through the lens and be received by the image sensor.

[0044] Understandably, after the lens and image sensor in the camera module are moved into the precision positioning device, the first light emitted by the central light tube 400 passes through the lens and is received by the image sensor, resulting in the image sensor receiving a first image. The second light emitted by the apex light tube 300 passes through the lens and is received by the image sensor, resulting in the image sensor receiving a second image. In other words, when both the lens and the image sensor reach the focusing position, both the central light tube 400 and the apex light tube 300 can emit light towards the lens, and the image sensor can receive the image corresponding to the light. Then, the control module can determine the current position of the lens based on the first and second images, and adjust the lens position accordingly until the positional relationship between the lens and the image sensor meets the installation requirements. As one implementation, the image sensor can be electrically connected to a display screen, allowing operators to see the first and second images received by the image sensor on the screen.

[0045] Furthermore, in this embodiment, both the central light tube 400 and the apex light tube 300 are constructed as parallel light tubes. That is, both the central light tube 400 and the apex light tube 300 are light tubes capable of emitting light for sharpness adjustment, and are not central crosshairs used for positioning. To distinguish the light emitted by the central light tube 400 and the apex light tube 300, the mounting angle of the central light tube 400 can be adjusted so that the rotation angles of the first image and the second image received by the image sensor are different.

[0046] According to the precision positioning device of the present invention, the lens and image sensor can be positioned using the same central optical tube and apex optical tube. It makes full use of the parallel optical tube used for sharpness testing, eliminating the need for a central cross optical tube for positioning. This simplifies the structure of the assembly equipment, reduces production costs, and allows for automatic optical axis positioning through the control module's own program, eliminating the need for manual operation. It boasts high production capacity, high production efficiency, and high alignment accuracy, making it suitable for the production needs of various cameras.

[0047] Preferably, the central light tube 400 is used for both lens centering and adjusting lens sharpness, while the apex light tube 300 is primarily used for adjusting lens sharpness. Since the central light tube 400 and the apex light tube 300 have identical structures, the images displayed on the image sensor by their emitted light are identical. To clearly distinguish between the first and second images emitted by the central light tube 400 and the apex light tube 300 to the image sensor, in this embodiment, the central light tube 400 can be mounted with a rotation of 30° to 90° relative to the apex light tube 300, so that the first image received by the image sensor is rotated 30° to 90° relative to the second image. For example, the central light tube 400 can be mounted with a 60° rotation relative to the apex light tube 300, thereby rotating the first image received by the image sensor by 60° relative to the second image.

[0048] Furthermore, when adjusting the lens position, in order to ensure that the lens tilt in all directions meets the installation requirements, the precision positioning equipment needs to be equipped with a sufficient number of apex light tubes 300; therefore, the number of apex light tubes 300 is 4 to 8. For example... Figure 1 As shown, the precision positioning device in this embodiment is equipped with four apex light tubes 300. Of course, in other embodiments not shown, other numbers of apex light tubes 300 can be provided, such as six or eight.

[0049] More preferably, such as Figure 3 As shown, the light emitted by the central light tube 400 and the corner light tubes 300 can form an image with a four-quadrant black and white cross pattern. In this image, the first image corresponding to the central light tube 400 is located at the center, and the four second images corresponding to the corner light tubes 300 are located at the four corners.

[0050] The precision positioning device in this embodiment also includes an arc-shaped bracket 700, with each corner light tube 300 correspondingly mounted on one arc-shaped bracket 700, and the corner light tubes 300 are movable along the arc-shaped bracket 700. Figure 1As shown, the precision positioning device in this embodiment is equipped with four arc-shaped supports 700, and the four arc-shaped supports 700 are approximately located on the same spherical surface. The light emitted by the apex light tube 300 as it moves along the arc-shaped supports 700 is aligned with the center of the sphere. Therefore, the apex light tube 300 can adjust its position according to the lens and image sensor to better perform tilt tests. Preferably, the tops of the four arc-shaped supports 700 can be fixedly connected, and when the position of the apex light tube 300 needs to be adjusted, the four arc-shaped supports 700 can be moved simultaneously in the vertical direction.

[0051] Furthermore, the precision positioning equipment also includes a conveyor belt 500 and a conveyor table. The conveyor table is mounted on the conveyor belt 500 and can move along the conveying direction of the conveyor belt 500. The conveyor table can also hold lenses and image sensors. Thus, the lenses and image sensors to be assembled can be conveyed to the precision positioning equipment via the conveyor belt 500. After focusing and position adjustment, the mutually positioned lenses and image sensors can be conveyed to the next workstation via the conveyor belt 500.

[0052] The precision positioning device also includes a lifting mechanism 600, which is disposed on at least one side of the conveyor belt 500 and is capable of lifting the conveyor platform to a preset height. In this embodiment, after the lens and image sensor to be assembled are moved to the precision positioning device by the conveyor belt 500, the lifting mechanism 600 can lift the conveyor platform, along with the lens and image sensor placed on the conveyor platform, vertically to a preset height. At this preset height, the image sensor is aligned with the central optical tube 400, facilitating subsequent adjustment of the lens's position relative to the image sensor.

[0053] In order to move the lens sufficiently, the moving mechanism 200 includes a six-axis motion device 210 and a gripper device 220 disposed on the six-axis motion device 210. The six-axis motion device 210 can move in multiple directions and can drive the gripper device 220 to move. The gripper device 220 can grasp the lens located on the conveyor table at a preset height and move it above the image sensor, and can adjust the position of the lens according to the control signal of the control module.

[0054] In one implementation, the conveyor table has grooves or protrusions for placing the lens and image sensor, and the end of the gripper device 220 has a clamp for grasping the lens. When the conveyor table containing the lens and image sensor is lifted to a preset height by the lifting mechanism 600, the gripper device 220 grasps the lens and moves it above the image sensor. The center light tube 400 and the apex light tube 300 emit light towards the lens, which passes through the lens and is received by the image sensor. Then, the control module adjusts the position of the lens based on the image received by the image sensor.

[0055] According to a second embodiment of the present invention, an automatic optical axis precision positioning method is also provided. This automatic optical axis precision positioning method can be used in the precision positioning device in the above embodiments and can realize the automatic precision positioning of the lens and image sensor in the camera module.

[0056] Specifically, the automatic precision optical axis positioning method includes:

[0057] The lens is moved between the image sensor and the central light tube to perform coarse positioning of the lens;

[0058] Specifically, when it is necessary to assemble a lens and an image sensor, the lens needs to be moved between the central light tube and the image sensor so that the first light emitted by the central light tube can pass through the lens and be received by the image sensor.

[0059] The image sensor acquires the first image from the central light tube, and adjusts the position of the lens in the vertical direction according to the first image received by the image sensor;

[0060] Specifically, after the lens moves to the position between the central light tube and the image sensor, the central light tube emits a first light beam towards the lens. The first light beam passes through the lens, and the image sensor receives the first image corresponding to the first light beam. The moving mechanism moves the lens vertically, and the control module determines whether the imaging effect of the first image has achieved the predetermined effect. If so, the lens movement stops, thereby determining the lens's position in the vertical direction. As one implementation, a six-axis motion device can control the lens to move vertically. The control module reads image information from the image sensor and refreshes the acquisition in real time at a specific frequency. Then, the control module adjusts the lens position vertically according to the resolution of the acquired image.

[0061] The first image received by the image sensor is compared with the template image to obtain a correspondence, and the position of the lens in the horizontal plane is adjusted according to the correspondence so that the center point of the central light tube, the center point of the lens and the center point of the image sensor are collinear, so as to perform precise positioning of the lens.

[0062] Specifically, once the vertical position of the lens is determined, the control module compares the first image with the template image using its own stored image matching algorithm to obtain the corresponding relationship, in order to determine whether the lens has reached the center position, that is, whether the center point of the lens is collinear with the center point of the central light tube and the center point of the image sensor.

[0063] As one implementation, the image matching algorithm includes two stages. In the first stage, the algorithm extracts preset feature information for image matching from a template image, and this preset feature information is stored in the template image in a way that facilitates searching. In the second stage, the algorithm compares a first image with the template image. During the comparison, target feature information for image matching is extracted from the first image, and the target feature information of the first image is matched with the preset feature information of the template image. The similarity and consistency between them are analyzed to determine the matching regions between the first image and the template image, obtain the correspondence, and perform similarity matching. During the image comparison process, the template image and the first image can be used as input parameters, and the output includes the number, position, and angle of matches, etc., to represent the degree of similarity with a score. A similarity score is calculated, and when the similarity score reaches a preset threshold, it indicates that the optical axis center has been found. At this point, the position of the optical axis center is calculated, and then the lens is moved to the position of the optical axis center.

[0064] The second image is acquired from the apex light tube by the image sensor, and the tilt of the lens is adjusted by the second image.

[0065] Specifically, once the lens reaches the center position, the corner light tubes emit second light rays towards the lens. The image sensor receives the second image corresponding to the second light rays. The control module determines the lens tilt based on the second image and controls the moving mechanism to move the lens to adjust the tilt. As one implementation, the image sensor can simultaneously acquire the second images from all four corner light tubes, adjusting the lens tilt to ensure uniform resolution across the four second images, ultimately determining the lens position for assembly of the camera components.

[0066] Preferably, in the automatic optical axis precision positioning method of this embodiment, before coarse positioning of the lens, the method further includes:

[0067] Move the image sensor so that the line connecting the center point of the central light tube and the center point of the image sensor is perpendicular to the horizontal plane.

[0068] Specifically, during the process of lifting the conveyor platform by the lifting mechanism, the image sensor is also moved at the same time, so that the line connecting the center point of the central light tube and the center point of the image sensor is perpendicular to the horizontal plane, so that the lens can be more accurately positioned later.

[0069] Preferably, in the automatic optical axis precision positioning method of this embodiment, after the lens is precisely positioned, the method further includes:

[0070] The first image is compared with the template image, and the position of the lens is adjusted accordingly to facilitate further adjustment of the lens position.

[0071] Specifically, after the lens has been precisely positioned, the first image and the template image can be compared again, and the image matching algorithm described above can be repeated to redetermine the position of the optical axis center. This allows for secondary correction and compensation of the lens's center position, ensuring that the final deviation of the lens's center position is within one pixel. For example, when the input image resolution is 1280*960, the pixel value of the optical axis center position can be 640*480. There is a relative positional relationship between the lens and the image sensor. When the input image resolution is 1280*960, the pixel coordinates of the image sensor center position should be (640, 480). This ensures that the lens center position and the image sensor center position are on the same vertical line; this relative position is the optical axis center position.

[0072] In one implementation, once the positions of the lens and image sensor are determined, the lens and image sensor can be assembled, the lifting mechanism lowers, and the lens and image sensor are transported away by a conveyor belt. Then, the next set of lenses and image sensors can be assembled.

[0073] The present invention has been described through the above embodiments. However, it should be understood that the above embodiments are for illustrative purposes only and are not intended to limit the invention to the scope of the described embodiments. Furthermore, those skilled in the art will understand that the present invention is not limited to the above embodiments, and many more variations and modifications can be made based on the teachings of the present invention, all of which fall within the scope of protection claimed by the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A precision positioning device, characterized in that, The precision positioning device is used to install the lens and image sensor in the camera module, and the precision positioning device includes: frame; A moving mechanism, which is mounted on the frame, is capable of moving the lens to be assembled above the image sensor; A central light tube is provided, which can emit a first light beam downward in a vertical direction toward the lens, and the image sensor can receive a first image corresponding to the first light beam. A apex light tube, wherein the apex light tube is capable of emitting a second light ray toward the lens, and the image sensor is capable of receiving a second image corresponding to the second light ray; and The control module is electrically connected to the image sensor and is capable of controlling the moving mechanism to adjust the position of the lens based on the image received by the image sensor. The central optical tube and the apex optical tube are both constructed as collimators, and the rotation angles of the first image and the second image received by the image sensor are different. The control module compares the first image with the template image using a stored image matching algorithm to obtain a correspondence, in order to determine whether the center point of the lens is collinear with the center point of the central optical tube and the center point of the image sensor. The image matching algorithm includes: Extract preset feature information for image matching from the template image; The first image is compared with the template image. During the comparison, target feature information for image matching is extracted from the first image. The target feature information of the first image is matched with the preset feature information of the template image, and their similarity and consistency are analyzed to determine the regions where the first image and the template image match each other, thereby obtaining the correspondence. Simultaneously, similarity matching is performed to calculate the position of the optical axis center. The moving mechanism adjusts the position of the lens in the horizontal plane according to the correspondence to drive the lens to the position of the center of the optical axis, so that the center point of the central light tube, the center point of the lens and the center point of the image sensor are collinear, so as to perform precise positioning of the lens.

2. The precision positioning device according to claim 1, characterized in that, The first image received by the image sensor is rotated 30° to 90° relative to the second image.

3. The precision positioning device according to claim 1, characterized in that, The number of the apex corner light tubes is 4 to 8.

4. The precision positioning device according to claim 1, characterized in that, The precision positioning device also includes an arc-shaped bracket, and the apex optical tube is mounted on the arc-shaped bracket and can move along the arc-shaped bracket.

5. The precision positioning device according to claim 1, characterized in that, The precision positioning device also includes a conveyor belt and a conveyor table. The conveyor table is disposed on the conveyor belt and can move along the conveying direction of the conveyor belt. The conveyor table can be loaded with a lens and an image sensor.

6. The precision positioning device according to claim 5, characterized in that, The precision positioning device also includes a lifting mechanism, which is disposed on at least one side of the conveyor belt and is used to lift the conveyor platform to a preset height.

7. The precision positioning device according to claim 6, characterized in that, The moving mechanism is disposed on at least one side of the conveyor belt, and the moving mechanism is used to move the lens on the conveyor platform located at the preset height above the image sensor.

8. The precision positioning device according to claim 7, characterized in that, The moving mechanism includes a six-axis motion device and a gripper device disposed on the six-axis motion device, the gripper device being capable of gripping a lens located on the conveyor platform at the preset height.

9. An automatic optical axis precision positioning method, characterized in that, The automatic optical axis precision positioning method is used in the precision positioning device according to any one of claims 1 to 8, and the automatic optical axis precision positioning method includes: The lens is moved between the image sensor and the central light tube to perform coarse positioning of the lens; The image sensor acquires the first image from the central light tube, and adjusts the position of the lens in the vertical direction according to the first image received by the image sensor; The first image received by the image sensor is compared with the template image to obtain a correspondence, and the position of the lens in the horizontal plane is adjusted according to the correspondence so that the center point of the central light tube, the center point of the lens and the center point of the image sensor are collinear, so as to perform precise positioning of the lens. The image sensor acquires the second image from the apex light tube, and adjusts the tilt of the lens using the second image.

10. The automatic optical axis precision positioning method according to claim 9, characterized in that, Before coarsely positioning the lens, the following steps are also included: Move the image sensor so that the line connecting the center point of the central light tube and the center point of the image sensor is perpendicular to the horizontal plane.

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