OIS chip anti-shake performance debugging system for camera module

Abstract

The utility model discloses an OIS chip anti-shake performance debugging system for a camera module, and the system comprises a vibration table which is used for installing the camera module provided with an OIS chip and can set different vibration frequencies and vibration angles; the lamp box is arranged in front of the camera module; a test chart is arranged on the lamp box, so that the camera module can shoot test point images under different test conditions; and the processing unit is connected with the camera module, receives the test point image, calculates the quantitative index value of the anti-shake effect, and screens out the optimal Gyro gain according to the quantitative index value of the anti-shake effect. According to the utility model, the anti-shake performance debugging of the OIS chip is realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to optical anti -shake technical field, especially related to a kind of OIS chip anti -shake performance debugging system for camera module. BACKGROUND

[0002] With the continuous development of photography technology, optical anti-shake technology has become one of the key factors to improve the quality of shooting. Especially in the photographic and video equipment with zoom lens, since the optical centers of different focal lengths of zoom lens are different, the optical image stabilizer (OIS) needs to set gyro gain for each focal point of zoom lens, to ensure that the best shock suppression effect can be achieved at various focal lengths. Therefore, the performance debugging of OIS chip anti-shake becomes particularly important.

[0003] The statements herein only provide background technology related to the utility model, and do not necessarily constitute prior art. UTILITY MODEL CONTENT

[0004] The utility model aims to provide a kind of OIS chip anti-shake performance debugging system for camera module, to realize the performance debugging of OIS chip anti-shake.

[0005] In order to achieve the above purpose, the utility model realizes by the following technical scheme:

[0006] An OIS chip anti-shake performance debugging system for camera module, comprising: a vibration table for installing a camera module provided with an OIS chip, and capable of setting different vibration frequencies and vibration angles; a light box arranged in front of the camera module; the light box is provided with a test chart, so that the camera module can shoot test point images under different test conditions; a processing unit connected with the camera module, receives the test point images and calculates the quantitative index value of anti-shake effect, and selects the best gyro gain according to the quantitative index value of anti-shake effect.

[0007] Optionally, it further comprises: a teleconverter installed between the light box and the camera module, for adjusting the object distance to simulate long-focus scenes.

[0008] Optionally, it further comprises: a support table, wherein the vibration table, the light box and the teleconverter can be arranged on the support table.

[0009] Optionally, the vibration table comprises a vibration shaft, a mounting plate arranged on the vibration shaft and driven to vibrate by the vibration shaft, a PCB plate arranged on the mounting plate and used for powering the camera module and enabling the camera module to communicate with the processing unit through the PCB plate, and a test fixture arranged on the PCB plate and used for fixing the camera module.

[0010] Optionally, an angle between the X-axis and the Y-axis of the camera module and a center line of the vibration shaft of the vibration table is 45 degrees.

[0011] Optionally, an inclination angle of the test chart on a mounting surface of the light box is the same as an angle between the X-axis and the Y-axis of the camera module and the center line of the vibration shaft of the vibration table.

[0012] Optionally, the test points in the test chart are in a rectangular shape.

[0013] Optionally, the test points in the test chart are in a circular shape.

[0014] The utility model has following technical effects one of:

[0015] The utility model provides a kind of OIS chip anti-shake performance debugging system for camera module, realizes the anti-shake performance debugging of OIS chip.

[0016] The utility model is equipped with zoom lens, is used to adjust object distance to simulate long focus scene, realizes the anti-shake performance of the OIS chip of long focal length camera module and is debugged. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 For the structure diagram of a kind of OIS chip anti-shake performance debugging system for camera module provided in an embodiment of the utility model;

[0018] Figure 2 For the schematic diagram of three images photographed using camera module provided in an embodiment of the utility model;

[0019] Figure 3 For the schematic diagram of full focus section gain curve provided in an embodiment of the utility model;

[0020] Figure 4 For the front view of vibration table provided in an embodiment of the utility model;

[0021] Figure 5 For the top view of vibration table provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0022] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, provides a structural schematic diagram of an OIS chip image stabilization performance adjustment system for a camera module according to this utility model. The advantages and features of this utility model will become clearer from the following description. It should be noted that the drawings are in a very simplified form and use non-precise proportions, used only to facilitate and clearly illustrate the embodiments of this utility model. Please refer to the drawings to make the objectives, features, and advantages of this utility model more apparent and understandable. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for illustrative purposes to aid those skilled in the art and are not intended to limit the implementation conditions of this utility model. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to the size, without affecting the effects and objectives achieved by this utility model, should still fall within the scope of the technical content disclosed in this utility model.

[0023] like Figure 1 As shown, this embodiment provides an OIS chip image stabilization performance debugging system for a camera module, including: a vibration table 11 for mounting a camera module 12 equipped with an OIS chip, and capable of setting different vibration frequencies and vibration angles; a light box 13, disposed in front of the camera module 12; the light box 13 is provided with a test chart (…). Figure 1 (not shown in the image) so that the camera module 12 can capture test point images under different test conditions; the processing unit 15 is connected to the camera module 12, receives the test point images and calculates the quantitative index value of the image stabilization effect, and selects the best Gyro gain according to the quantitative index value of the image stabilization effect.

[0024] This embodiment provides an OIS chip image stabilization performance debugging system for camera modules, which enables the debugging of the image stabilization performance of OIS chips.

[0025] Please continue to refer to this. Figure 1 As shown, this embodiment also includes a teleconverter 14, installed between the lightbox 13 and the camera module 12, used to adjust the object distance to simulate a telephoto scene. Since telephoto lenses are mostly used at infinity, it is difficult to achieve such a distance in a laboratory space. The teleconverter 14 can simulate object distances of 10m, 20m, 100m or infinity. Therefore, the teleconverter 14 provided in this embodiment can adjust the object distance to simulate a telephoto scene, thereby enabling the adjustment of the image stabilization performance of the OIS chip of the telephoto camera module.

[0026] Please continue to refer to this. Figure 1 As shown, it also includes: a support platform 10, and the vibration table 11, the light box 13 and the teleconverter 14 can all be mounted on the support platform 10.

[0027] In this embodiment, as Figure 4 As shown, the vibration table 11 includes: a vibration shaft 113; a mounting plate 110 disposed on the vibration shaft 113, the vibration shaft 113 driving the mounting plate 110 to vibrate; a PCB board 111 disposed on the mounting plate 110, used to power the camera module 12 and enable the camera module 12 to communicate with the processing unit 15 through the PCB board 111; and a test fixture 112 disposed on the PCB board 111 for fixing the camera module 12. In this embodiment, the vibration table 11 may include one vibration shaft 113, i.e., a single-axis vibration table, or it may include two vibration shafts 113, i.e., a dual-axis vibration table. A single-axis vibration table is more economical and can save debugging costs.

[0028] like Figure 5 As shown, when the single-axis vibration table 11 is selected, the angles between the X-axis and Y-axis of the camera module 12 and the center line O of the vibration axis of the vibration table 11 are both 45 degrees. This ensures that the OIS stabilization function in the OIS chip is not enabled, and when the vibration table vibrates, the first image will be blurred in both the X and Y directions (e.g., Figure 2 As shown in Figure (b), the OIS chip can be jittered in both the X and Y directions using single-axis vibration. It can be understood that the X and Y directions in this article refer to the X and Y axes of the three-dimensional coordinate system formed by the OIS chip according to its length and width, where the optical axis of the zoom lens of the camera module 12 is the Z axis of the three-dimensional coordinate system, and the Z axis is perpendicular to the OIS chip.

[0029] In this embodiment, when the test points in the test diagram are rectangular, the tilt angle of the test diagram on the mounting surface of the light box 13 is the same as the angle between the X-axis and Y-axis of the camera module 12 and the center line of the vibration axis of the vibration table 11. This ensures that the images of the test points captured by the camera module 12 are in a horizontal or vertical state, which facilitates the processing unit 15 to process and calculate the test point images.

[0030] In some other embodiments, the test points in the test pattern are circular. In this case, it is not necessary for the tilt angle of the test pattern on the mounting surface of the light box 13 to be the same as the tilt angle of the camera module 12 on the mounting surface of the vibration table 11. Since the test points are circular, the image of the test points captured when the optical axis of the zoom lens in the camera module 12 is tilted during shooting will also be straight.

[0031] To better understand the above system, the working principle of the system provided in this embodiment is as follows:

[0032] The camera module 12 is installed on the vibration table 11; wherein the vibration table 11 can support setting different vibration frequencies and vibration angles. To adapt to the maximum anti-shake capability it has at the current focal length point, for example, the maximum anti-shake capability of the OIS chip at the current focal length point is 0.5 degrees, that is, the vibration angle of the vibration table 11 is set to 0.5 degrees, and the second image is shot under this condition as described below, which is used for subsequent calculation of anti-shake ratio (quantitative index value or dB value of anti-shake effect) to find the best Gyro gain.

[0033] When the vibration table 11 is closed and the OIS anti-shake function in the OIS is not turned on, a reference image is shot by the camera module 12, which can be referred to in Figure 2 (a) of the figure, wherein the black square in (a) is a test point image; thus the image shot at this moment does not exist jitter and jitter compensation, thus it can be used as a reference image quality.

[0034] When the vibration table 11 is turned on and the OIS anti-shake function in the OIS chip is not turned on, a first image is shot by the camera module 12, which can be referred to in Figure 2 (b) of the figure, that is, the first image shot is an image that exists jitter, but does not perform jitter compensation.

[0035] For each focal length point of the zoom lens, a first Gyro gain range is set, and a plurality of first Gyro gain values are selected in the first Gyro gain range with a first step; a plurality of first Gyro gain values are set in the corresponding OIS chip, and in the state of turning on the vibration table 11 and the OIS anti-shake function in the OIS chip, a second image corresponding to each first Gyro gain value is shot by the camera module 12, which can be referred to in Figure 2 (c) of the figure, that is, the second image shot is an image that exists jitter, but has performed jitter compensation.

[0036] The reference image, the first image and each second image are calculated by the processing unit 15 using an image processing algorithm, and a plurality of anti-shake ratios corresponding to the focal length point are obtained; a plurality of anti-shake ratios are compared, and the maximum value of the anti-shake ratio is found out; the first Gyro gain value corresponding to the maximum value of the anti-shake ratio is the initial best Gyro gain of the focal length point, and this process is similar to the coarse adjustment process.

[0037] Based on the initial optimal Gyro gain, a second Gyro gain range is set, and a plurality of second Gyro gain values are selected in the second Gyro gain range with a second step size; the plurality of second Gyro gain values are respectively set in corresponding OIS chips, and a second image corresponding to the second Gyro gain is respectively captured by the camera module in a state of turning on the vibration table and the OIS chip; the reference image, the first image and each second image are calculated by the processing unit 15 using the image processing algorithm, and a plurality of anti-shake ratio values of the focal length point are obtained; the plurality of anti-shake ratio values are compared, and the maximum value of the anti-shake ratio value is found out, and the second Gyro gain value corresponding to the maximum value of the anti-shake ratio value is the optimal Gyro gain of the focal length point, and then the pairing relationship between all focal length points in the zoom lens and the optimal Gyro gain is obtained; this process is similar to the fine adjustment process; wherein the first step size is greater than the second step size.

[0038] Then, the focal length point is taken as the abscissa, the Gyro gain is taken as the ordinate, and the full-focus gain curve is drawn according to the pairing relationship between all focal length points and the optimal Gyro gain, which can be referred to as shown in Figure 3

[0039] In this embodiment, the anti-shake ratio value of each focal length point in each focal length is calculated by the following formula:

[0040] (1)

[0041] In the formula, SR X represents the anti-shake ratio value in the X direction, unit dB, X0 represents the pixel abscissa of the image point of the reference image; X1 represents the pixel abscissa of the image point of the first image; X2 represents the pixel abscissa of the image point of the second image;

[0042] (2)

[0043] In the formula, SR Y represents the anti-shake ratio value in the Y direction, unit dB, Y0 represents the pixel ordinate of the image point of the reference image; Y1 represents the pixel ordinate of the image point of the first image; Y2 represents the pixel ordinate of the image point of the second image.

[0044] It can be understood that although the anti-shake ratio value has X and Y two direction values, due to the small difference between the Gyro gain values in the X and Y directions, the anti-shake ratio value in one direction is selected for comparison.

[0045] ​Understandably, during the factory calibration of the camera module 12 and the physical debugging of the image stabilization algorithm, the corresponding image stabilization ratio is calculated for each Gyro gain adjustment to see how well the shake is canceled out. The higher the image stabilization ratio, the better the image stabilization effect.

[0046] Therefore, it can be seen that finding the optimal Gyro gain at a focal length point of a zoom lens through physical adjustment methods requires two processes: coarse adjustment and fine adjustment. Both coarse and fine adjustments require scanning with multiple scan steps, which consumes a lot of adjustment time. Moreover, for long focal length zoom lenses, there are more focal lengths and focal length points, making the process of adjusting the image stabilization algorithm for such lenses even longer, which seriously reduces the adjustment efficiency. Furthermore, the testing process mostly relies on manual labor, which leads to a reduction in testing accuracy.

[0047] In this embodiment, the processing unit 15 is further configured to perform cubic polynomial fitting on a certain number of fitting points selected from the full focal length gain curve using the least squares method to obtain the fitting equation, and to burn the parameters of the fitting equation into the register of the OIS chip, so that the OIS chip can calculate the optimal Gyro gain for image stabilization control based on the real-time read current focal length point and the fitting equation during the actual zooming process of the zoom lens.

[0048] In this embodiment, the fitting equation is as follows:

[0049] (3)

[0050] In the formula, y It represents Gyro Gain. x Indicates the focal point. a , b , c and d Both represent constants.

[0051] In this embodiment, the selection of the fitting points can be... Figure 3 Several representative points in the significant change region of the full focal length gain curve shown are selected as fitting points. The selection method of fitting points in this embodiment can be flexibly adjusted according to the product structure to improve the image stabilization effect.

[0052] In some other embodiments, only the full-focus gain curve of one zoom lens in each type of zoom lens is obtained. That is, the full-focus gain curve is obtained only once for each type of zoom lens through physical testing means, and this full-focus gain curve can be used for subsequent OIS chip anti-shake debugging of all batches of zoom lenses of the same type. That is, the subsequent OIS chip anti-shake debugging of zoom lenses of the same type is based on the full-focus gain curve to obtain a corresponding number of fitting points to obtain a fitting formula, and to verify the fitting formula to realize the OIS chip anti-shake debugging of the zoom lenses of the same type, which can ensure the debugging accuracy and improve the debugging efficiency.

[0053] In the present embodiment, for each zoom lens of the same type, the fitting points are selected from the full-focus gain curve of the zoom lens of the same type, and the corresponding fitting equation is fitted. The fitting function parameters of the corresponding fitting equation are burned into the register of the OIS chip of the corresponding zoom lens. The present embodiment has both accuracy and practicality. By burning the fitting formula into the register of the OIS chip, the MCU of the camera module 12 can automatically call it, which is suitable for automatic production process, improves the consistency of the product (zoom lens of the camera module), and reduces the involvement of manual work.

[0054] The present embodiment is suitable for various types of OIS chip structures, including Lens shift OIS (lens shift optical image stabilization, which compensates for image blur caused by hand jitter or other vibrations by moving lens components inside the lens) and Sesnor shift OIS (sensor shift optical image stabilization, which compensates for image blur caused by hand jitter or other vibrations by moving the image sensor inside the camera body).

[0055] It should be noted that in the present text, the term "comprises", "includes" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitations, the element defined by the statement "comprises a" does not exclude the presence of another identical element in the process, method, article or device that includes the element.

[0056] In the description of the utility model, it is understood that the orientation or positional relationship indicated by the terms "center", "height", "thickness", "upper", "lower", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the utility model. In the description of the utility model, unless otherwise specified and limited, the meaning of "a plurality of" is two or more than two.

[0057] In the description of the utility model, unless otherwise specified and limited, the terms "mounting", "connection", "connection", "fixing" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrated; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the communication between two elements or the interaction relationship between two elements. For ordinary skilled persons in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0058] In the utility model, unless otherwise specified and limited, the "upper" or "lower" of the first feature to the second feature can include that the first and second features are in direct contact, or the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the "upper", "upper" and "upper" of the first feature to the second feature include that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The "below", "below" and "below" of the first feature to the second feature include that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0059] Although the content of the utility model has been described in detail by the above preferred embodiments, it should be recognized that the above description should not be considered as a limitation on the utility model. After reading the above content, various modifications and alternatives of the utility model will be obvious to those skilled in the art. Therefore, the protection scope of the utility model should be limited by the appended claims.

Claims

1. An OIS chip anti-shake performance debugging system for a camera module, characterized in that, The application relates to a vibration table, a light box and a processing unit. The vibration table is used for mounting a camera module provided with an OIS chip and can set different vibration frequencies and vibration angles. The light box is arranged in front of the camera module. The light box is provided with a test picture so that the camera module can shoot test point images under different test conditions. The processing unit is connected with the camera module, receives the test point images, calculates a quantitative index value of an anti-shake effect, and selects an optimal gyro gain according to the quantitative index value of the anti-shake effect. 2.The OIS chip anti-shake performance debugging system for a camera module of claim 1, wherein, The application further comprises a zoom lens which is installed between the light box and the camera module and is used for adjusting an object distance to simulate a long-focus scene. The application further comprises a support table on which the vibration table, the light box and the zoom lens are arranged. 3.The OIS chip anti-shake performance debugging system for a camera module of claim 2, wherein, The vibration table comprises a vibration shaft, An installation plate is arranged on the vibration shaft, and the vibration shaft drives the installation plate to vibrate. 4.The OIS chip anti-shake performance debugging system for a camera module of claim 1, wherein, A PCB is arranged on the installation plate and is used for supplying power for the camera module and enabling the camera module to communicate with the processing unit through the PCB. A test fixture is arranged on the PCB and is used for fixing the camera module. An angle between the X axis and the Y axis of the camera module and a center line of the vibration shaft of the vibration table is 45 degrees. An inclination angle of the test picture on a mounting surface of the light box is the same as the angle between the X axis and the Y axis of the camera module and the center line of the vibration shaft of the vibration table. 5.The OIS chip anti-shake performance debugging system for a camera module of claim 4, wherein, The test points in the test picture are in a rectangular shape. 6.The OIS chip anti-shake performance debugging system for a camera module of claim 5, wherein, The test points in the test picture are in a circular shape. 7.The OIS chip anti-shake performance debugging system for a camera module of claim 6, wherein, ​ 8.The OIS chip anti-shake performance debugging system for a camera module of claim 1, wherein, ​

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