Camera module suitable for oblique shooting, AA equipment and calibration method

Abstract

The invention discloses a camera module suitable for oblique shooting, AA equipment and a calibration method.The camera module comprises a circuit board, an imaging chip, a support, an optical filter, a lens base and a lens, the imaging chip is attached to the circuit board through glue, the support is fixedly connected with the circuit board through glue, the optical filter is arranged on the support, and the lens base is fixedly connected with the circuit board through glue; the lens base is arranged on the support, the lens is arranged on the lens base, the included angle between the center line of the optical axis of the lens and the normal direction of the plane where the imaging chip is located is a, the included angle between the plane where the imaging chip is located and a shot plane during shooting is b, and the image plane, the lens plane and the shot plane meet the Simmer's law. And the camera module meeting the inclined shooting scene can be obtained through automatic calibration of the AA equipment. The invention has the beneficial effects that the effects of large aperture and wide depth-of-field range during oblique shooting can be realized at the same time; the lens does not need custom design of a dip angle adjustable Sammer lens.

Description

Technical Field

[0001] The present invention relates to the field of camera modules, and in particular to a camera module suitable for oblique shooting, an AA device, and a calibration method. Background Art

[0002] With the trend toward the Internet of Everything, camera modules, as a key carrier of visual solutions, are becoming a crucial component of smart electronic devices. Consumers are increasingly demanding higher clarity from camera modules when using smart electronic devices, and the shooting scenarios are becoming increasingly diverse. Oblique shooting is a common scenario in real-world use. When the surface being photographed is tilted relative to the camera module, such as when a learning machine photographs textbooks and test papers on a desk, conventional camera modules suffer from a depth of field that fails to cover the entire surface, resulting in blurred image edges. Related technologies attempt to address the depth of field problem in oblique shooting by reducing the aperture. However, reducing the aperture can lead to issues such as insufficient exposure, and the aperture cannot be reduced indefinitely. Resolving the contradiction between a large aperture and a difficult depth of field in oblique shooting scenarios has become a pressing need for camera modules in many smart electronic devices. Schaum's law states that when the extended planes of the photographed plane, the image plane, and the lens plane intersect on a straight line, a fully clear image is achieved. This can be used to address the contradiction between a large aperture and a difficult depth of field. In the existing technology, it is necessary to customize the design of the Sham lens and adjust the lens tilt angle according to the shooting scene, which is very costly. In addition, the existing technology has problems such as poor consistency of the camera module and high manufacturing difficulty. Summary of the Invention

[0003] In view of the above-mentioned deficiencies in the prior art, the present invention provides a camera module suitable for tilted shooting, which solves the contradiction between large aperture and difficulty in covering depth of field when the camera module is tilted for shooting.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A camera module suitable for oblique shooting, characterized in that it includes: a circuit board, an imaging chip, a bracket, a filter, a lens base, and a lens, the imaging chip is attached to the circuit board using glue, the bracket is fixedly connected to the circuit board by glue, the filter is arranged on the bracket, the lens base is arranged on the bracket, and the lens is arranged on the lens base. The angle between the optical axis center line of the lens and the normal direction of the plane where the imaging chip is located is a, and the angle between the plane where the imaging chip is located and the photographed plane during shooting is b, so that the image plane, the lens plane, and the photographed plane satisfy Schaam's law.

[0006] Furthermore, the plane where the filter is located is perpendicular to the normal line of the imaging chip.

[0007] Furthermore, the top surface of the bracket is inclined at a certain angle, and the inclination angle c is consistent with the angle a between the lens plane and the image plane.

[0008] It also aims to provide an AA device (active calibration device) for a camera module suitable for oblique shooting, characterized in that it includes a device host and a device rack, the device rack is arranged on the device host, a light source board is provided on the device rack, the light source board is arranged obliquely, the position of the light source board is adjustable, a chart is provided on the light source board, a camera module is provided on the top surface of the device host, and the device host automatically calibrates the camera module to meet the requirements of oblique scene shooting.

[0009] Furthermore, the light source board includes a distant view light source board and a near view light source board, the distant view light source board provides a parallel light source, a chart is placed on the distant view light source board, the near view light source board provides a parallel light source, a chart is placed on the near view light source board, the distant view light source board is arranged above the near view light source board, and the near view light source board and the distant view light source board are adjustable in angle on the equipment rack.

[0010] Furthermore, the light source panel includes a distant view light source panel, a mid-view light source panel, and a near view light source panel that are spaced apart from each other from top to bottom, wherein the number of the mid-view light source panels is one or more, and the width of the mid-view light source panel is limited to not blocking the effective identification area of ​​the chart on the distant view light source panel, other mid-view light source panels, and the near view light source panel.

[0011] It is also intended to provide a calibration method for an AA device of a camera module suitable for oblique shooting, characterized in that: based on the AA device of the camera module, according to the actual oblique shooting scene, the angle b between the photographed plane and the image plane is used to find the photographed plane, the length of the area where the object to be photographed is L3, and the projections of the two ends of L3 on the normal line of the image plane correspond to the near-view chart position L1 and the far-view chart position L2,

[0012] The intersection of the captured plane and the perspective chart plane is connected to the center of the lens. The angle between this line and the normal of the image plane corresponds to angle d. The effective recognition area layout of the perspective chart is determined based on angle d and the field of view of the lens. The angle d must be less than the half field of view of the lens to ensure that the perspective chart can be fully captured.

[0013] The intersection of the photographed plane and the near-view chart plane is connected to the center of the lens. The angle between this line and the normal of the image plane corresponds to angle e. The effective recognition area layout of the near-view chart is determined based on angle e and the field of view of the lens. The angle e must be less than the half field of view of the lens to ensure that the near-view chart can be fully captured.

[0014] By setting the positions of the distant and near-view charts, and designing the layout of the effective recognition areas of the charts, the AA device can automatically calibrate the lens plane to a certain angle relative to the image plane, which is approximately equal to a, so that the positional relationship between the image plane, the lens plane and the photographed plane satisfies Schaam's law.

[0015] The beneficial effects of the present invention include: 1. It can simultaneously achieve the effects of large aperture and wide depth of field when shooting at an angle;

[0016] 2. Improve the clarity of the edges of the photographed surface when shooting at an angle;

[0017] 3. The lens does not require custom design, and the tilt angle can be adjusted by Sham lens, so the cost is controllable;

[0018] 4. It can ensure the imaging consistency of camera modules and realize mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the camera module of the present invention;

[0020] Figure 2 It is a schematic diagram of the tilted shooting scene and imaging principle of the camera module of the present invention;

[0021] Figure 3 Schematic diagram of the structure of the camera module bracket of the present invention;

[0022] Figure 4 1 is a structural diagram of the camera module AA device of Example 1 of the present invention;

[0023] Figure 5 yes Figure 4 A diagram showing the location and layout of the AA equipment chart;

[0024] Figure 6 1 is a structural diagram of a camera module AA device according to Example 2 of the present invention;

[0025] Figure 7 yes Figure 6 A diagram showing the location and layout of the AA equipment chart;

[0026] Figure 8 is a structural diagram of a camera module AA device according to another embodiment of the present invention;

[0027] Figure 9 yes Figure 8 Schematic diagram of the chart position and layout principle of the AA equipment. DETAILED DESCRIPTION

[0028] The present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0029] A kind of Figure 1-2 The illustrated camera module suitable for oblique photography includes a circuit board 1, an imaging chip 2, a bracket 3, a filter 4, a lens base 5, and a lens 6. The imaging chip 2 is glued to the circuit board 1 and electrically connected to the circuit board. The imaging chip receives light from the lens and converts it into an image. The bracket 3 is fixed to the circuit board 1 with glue. The filter 4 is mounted on the bracket 3, with the plane of the filter 4 perpendicular to the normal of the chip. This filter filters infrared light, preventing the imaging chip from receiving any or minimal infrared light, allowing for a more realistic image of the subject. The filter is secured in place within the bracket's filter slot with glue. The lens base 5 is mounted on the bracket 3 and serves to support the lens mount and lens. The lens 6 is mounted on the lens base 5 and receives and processes light. It is screwed to the lens mount and secured with glue. After the lens mount and lens are locked, they are automatically calibrated using an AA device and then secured to the bracket with glue. The angle between the centerline of the optical axis of the lens 6 and the normal to the plane where the imaging chip 2 is located is a, and the angle between the plane where the imaging chip 2 is located and the plane being photographed is b. In actual applications, the plane where the lens center is located is the lens plane, the plane where the object is located is the photographed plane, and the plane where the imaging chip is located is the image plane. Depending on the actual tilt shooting scene, the angle a between the centerline of the optical axis of the lens and the normal to the plane of the imaging chip needs to be adjusted so that the positional relationship between the image plane, the lens plane, and the plane being photographed satisfies Schaam's law, as follows: Figure 2 As shown, all objects on the photographed plane observed by the camera module can be clearly imaged to obtain the best imaging effect, meet the shooting needs of smart electronic devices, and improve consumer satisfaction.

[0030] like Figure 3 As shown, the top surface of the bracket is tilted at a certain angle, and the tilt angle c is consistent with the angle a between the lens plane and the image plane, that is, c = a. Figure 3 This ensures that after AA automatic calibration, the glue thickness between the lens base and the bracket is consistent, and the glue can shrink or expand evenly during curing, preventing lens deflection after curing, thereby ensuring stable performance and improved consistency of the camera module.

[0031] like Figure 6-7The present application provides an AA device with a camera module suitable for oblique shooting, including a device host 10 and a device rack 11. The device rack 11 is arranged on the device host 10. A light source board 14 is provided on the device rack 11. The light source board 14 is arranged at an angle, and the angle of the light source board 14 is adjustable. A chart is provided on the light source board 14, and the chart is used to detect the AA effect to determine whether the AA effect has achieved the best effect; the camera module of claim 1 is set on the top surface of the device host 10, and the device host 10 automatically calibrates the camera module to make it meet the requirements of oblique scene shooting.

[0032] The light source board 14 is placed at an angle, and a chart is placed on the light source board 14. The chart coincides with the plane to be photographed, and the position and size of the chart include the area L3 where the object to be photographed is located. Figure 7 shown.

[0033] The AA equipment rack can adjust the tilted light source panel to any angle, thus meeting the production needs of camera modules for different tilt shooting scenes. At the same time, it can also meet the production needs of conventional camera modules.

[0034] like Figure 4 Another embodiment of the AA device of the present invention is shown, the light source board 14 includes a distant light source board 12 and a near view light source board 13, the distant light source board 12 provides a parallel light source, and a chart is placed on the distant light source board 12, the near view light source board 13 provides a parallel light source, and a chart is placed on the near view light source board 13, the distant light source board 12 is arranged above the near view light source board 13, and the positions of the near view light source board 13 and the distant light source board 12 are adjustable on the equipment rack 11.

[0035] Furthermore, the positions of the distant view light source panel and the near view light source panel need to be adjusted according to the actual tilt shooting scene, such as Figure 5As shown. The camera module is arranged above the AA device host and directly below the distant and near view light source panels. According to the actual oblique shooting scene, the photographed plane is found through the angle b between the photographed plane and the image plane. The length of the area where the object is to be photographed is L3. The projections of both ends of L3 on the normal of the image plane correspond to the near view chart position L1 and the distant view chart position L2. The intersection of the photographed plane and the distant view chart plane is connected with the center of the lens. The angle between this line and the normal of the image plane corresponds to angle d. The effective recognition area layout of the distant view chart is determined according to angle d and the field of view of the lens. Among them, angle d needs to be smaller than the half field of view of the lens to ensure that the distant view chart can be fully captured. The intersection of the photographed plane and the near-view chart plane is connected by a line with the center of the lens. The angle between this line and the normal to the image plane corresponds to angle e. The effective recognition area layout of the near-view chart is determined based on angle e and the lens's field of view. Angle e must be less than half the lens's field of view to ensure that the near-view chart can be fully captured. By setting the positions of the distant and near-view charts and designing the layout of the chart's effective recognition area, the AA device can automatically calibrate the lens plane to a certain angle relative to the image plane. This angle is approximately equal to a, so that the positional relationship between the image plane, lens plane, and photographed plane satisfies Schaum's law.

[0036] Of course, it is not limited to the above two implementations. In other embodiments, the number of light source panels can be increased to 3 or more. Figure 8 As shown. AA equipment includes AA equipment host, AA equipment rack, distant light source board, middle light source board and near light source board, among which there can be 2 or more middle light source boards, such as Figure 9 As shown. The width L4 of the mid-view light source panel should not be too large so as not to block the effective recognition area of ​​the camera for capturing the distant and near view charts. When there are multiple mid-view light source panels, the width of the mid-view light source panel should not block the effective recognition area of ​​other mid-view charts. The calibration principle is the same as above.

[0037] The characteristics of the present invention are:

[0038] 1. The camera module satisfies Sham's law in corresponding oblique shooting scenarios, eliminating the problem of inability to cover the depth of field, and can simultaneously adopt a large aperture lens to improve the amount of light entering and image quality.

[0039] 2. The camera module can improve the clarity of the edge of the photographed plane in corresponding tilted shooting scenarios, thereby increasing the user satisfaction of consumers of smart electronic devices.

[0040] 3. The lens of the camera module does not need to be customized to be a Sham lens with adjustable tilt angle. The camera module can be automatically calibrated by the AA device to comply with Sham's law, meet the needs of tilted shooting scenarios, and control costs.

[0041] 4. The top surface of the camera module bracket adopts an inclined design, which can effectively ensure the consistency of the thickness of the AA glue, so that the lens does not deflect during the glue curing process, and can ensure the imaging quality and consistency of the camera module.

[0042] 5. The camera module AA device can automatically calibrate the tilt of the lens to satisfy Sham's law, ensure the imaging consistency of the camera module, and achieve mass production; at the same time, it is compatible with the production of conventional camera modules and improves the equipment utilization rate.

[0043] The technical solutions provided by the embodiments of the present invention are introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the embodiments of the present invention. The description of the above embodiments is only applicable to help understand the principles of the embodiments of the present invention. At the same time, for those skilled in the art, according to the embodiments of the present invention, there may be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present invention.

Claims

1. A camera module suitable for oblique shooting, characterized in that: The invention comprises a circuit board (1), an imaging chip (2), a bracket (3), a filter (4), a lens base (5), and a lens (6); the imaging chip (2) is attached to the circuit board (1) by glue; the bracket (3) is fixedly connected to the circuit board (1) by glue; the filter (4) is arranged on the bracket (3); the lens base (5) is arranged on the bracket (3); the lens (6) is arranged on the lens base (5); the angle between the center line of the optical axis of the lens (6) and the normal direction of the plane where the imaging chip (2) is located is a; when shooting, the angle between the plane where the imaging chip (2) is located and the plane being photographed is b, so that the image plane, the lens plane, and the plane being photographed satisfy Schaum's law.

2. A camera module suitable for oblique shooting according to claim 1, characterized in that: The plane where the filter (4) is located is perpendicular to the normal line of the imaging chip (2).

3. The camera module suitable for oblique shooting according to claim 1, characterized in that: The top surface of the bracket (3) is inclined at a certain angle c, and the angle c is consistent with the angle a between the lens plane and the image plane.

4. An AA device for a camera module suitable for oblique shooting, characterized in that: The device comprises a device host (10) and a device frame (11), wherein the device frame (11) is arranged on the device host (10), a light source board (14) is arranged on the device frame (11), the light source board (14) is arranged at an angle, the angle of the light source board (14) is adjustable, a chart is arranged on the light source board (14), the camera module according to claim 1 is arranged on the top surface of the device host (10), and the device host (10) automatically calibrates the camera module to meet the requirements of tilted scene shooting.

5. The AA device of the camera module suitable for oblique shooting according to claim 4, characterized in that: The light source board (14) comprises a distant view light source board (12) and a near view light source board (13); the distant view light source board (12) provides a parallel light source, a chart is placed on the distant view light source board (12); the near view light source board (13) provides a parallel light source, a chart is placed on the near view light source board (13); the distant view light source board (12) is arranged above the near view light source board (13); and the near view light source board (13) and the distant view light source board (12) are positionally adjustable on the equipment rack (11).

6. The AA device of the camera module suitable for oblique shooting according to claim 5, characterized in that: The light source panel (14) comprises a distant view light source panel (12), a middle view light source panel (15), and a near view light source panel (13) which are arranged in sequence from top to bottom, wherein the number of the middle view light source panels (15) is one or more, and the width of the middle view light source panel (15) is limited to not blocking the effective identification area of ​​the chart on the distant view light source panel (12), other middle view light source panels (15), and the near view light source panel (13).

7. A calibration method for an AA device of a camera module suitable for tilted shooting, characterized in that: Based on the AA device of the camera module described in claim 4, according to the actual tilt shooting scene, the shot plane is found through the angle b between the shot plane and the image plane. The length of the area where the object to be shot is located is L3, and the projections of the two ends of L3 on the normal line of the image plane correspond to the near view chart position L1 and the far view chart position L2. The intersection of the photographed plane and the perspective chart plane is connected with the center of the lens. The angle between the connecting line and the normal of the image plane corresponds to the angle d. The effective recognition area layout of the perspective chart is determined according to the angle d and the field of view of the lens. The angle d needs to be smaller than the half field of view of the lens to ensure that the perspective chart can be completely captured. The angle between the intersection of the photographed plane and the near-view chart plane and the line connecting the center of the lens and the normal of the image plane corresponds to the angle e. The effective recognition area layout of the near-view chart is determined according to the angle e and the field of view of the lens; wherein the angle e needs to be smaller than the half field of view of the lens, so as to ensure that the near-view chart can be completely captured and imaged; By setting the positions of the distant and near-view charts, and designing the layout of the effective recognition area of ​​the charts, the AA device can automatically calibrate the lens plane to a certain angle relative to the image plane, which is approximately equal to a, so that the positional relationship between the image plane, the lens plane and the photographed plane satisfies Sham's law.

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