Chart environment device and fast defocus method based on small 3D chart

Abstract

The present application provides a Chart environment device and a fast defocus method based on a small 3D Chart, wherein the Chart environment device comprises a plurality of parallel light tubes, each of which is arranged to point to a specific field of view point, and each of which corresponds to a different test field of view, the parallel light tube comprises a light tube body, a light source arranged in the light tube body and a Chart, the Chart is arranged at the front end of the light exit direction of the light source, and the Chart is arranged obliquely in the light tube body.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical testing, in particular to a Chart environment device and a fast defocus method based on a small 3D Chart. BACKGROUND

[0002] The so-called AA process, namely Active Alignment, is a technology for determining the relative position in the assembly process of parts. The device of the AA process detects the semi-finished product being assembled when assembling each part, and actively adjusts according to the actual situation of the semi-finished product being assembled, and then assembles the next part in place. This active adjustment technology can adjust the lens alignment to 6 degrees of freedom (X, Y, Z, Tx, Ty, Tz), effectively reducing the assembly tolerance of the entire module, effectively improving the consistency of the camera product, and creating the possibility of higher-order camera product packaging.

[0003] Chart, as a core component in the AA process, is required to be higher and higher as the functional requirements of camera products become higher and higher. The AA process equipment at the present stage occupies more and more space, and the corresponding cost is also higher and higher, and the size of the Chart environment is one of the important factors determining the volume of the equipment, so the miniaturization of the Chart environment is an essential link to realize the miniaturization of the equipment. The Chart environment required by the current super wide-angle module AA is larger in size, and it is difficult to realize it only by modifying the existing machine, so the miniaturized Chart environment compatible with large wide-angle modules is of great significance.

[0004] An important adjustment item in the AA process is the tilt between the Lens and the Sensor, and the existing tilt calculation method needs to collect 10-12 frames of images at different defocus positions to obtain the defocus curve, which becomes a key bottleneck limiting the efficiency of AA. The existing AA test distance and field of view switching need to be adjusted manually, and the precision is difficult to guarantee, and a new Chart needs to be printed and made, and the reuse rate is very low.

[0005] Therefore, the present application provides a method for improving the Chart environment, realizing the miniaturization of the Chart environment, and further improving the AA efficiency, which is also of great help to the subsequent assembly process. SUMMARY

[0006] One of the main advantages of the present application is to provide a Chart environment device and a fast defocus method based on a small 3D Chart, wherein the Chart environment device is small in size, which is conducive to the miniaturization of the Chart environment.

[0007] Another advantage of the present application is to provide a Chart environment device and a fast defocus method based on a small 3D Chart, wherein the Chart environment device comprises a plurality of parallel light pipes, each of which comprises a light source, a Chart and a magnifying lens, which can effectively reduce the size of the Chart environment and realize miniaturization of the Chart environment.

[0008] Another advantage of the present application is to provide a Chart environment device and a fast defocus method based on a small 3D Chart, wherein the Chart environment device adopts a 3D Chart mode, acquires a single frame of picture and cooperates with an algorithm to obtain different object distance information of different fields of view, calculate a defocus curve and a tilt, and improve the AA efficiency.

[0009] Another advantage of the present application is to provide a Chart environment device and a fast defocus method based on a small 3D Chart, wherein a conventional horizontal Chart is placed obliquely, so that imaging points of different object distances can be obtained in a single frame of picture, and then an object distance-focal curve is obtained to realize OneShot function.

[0010] Another advantage of the present application is to provide a Chart environment device and a fast defocus method based on a small 3D Chart, wherein each parallel light pipe can integrate a light source, and different test fields of view correspond to different parallel light pipes, so that the size is minimized.

[0011] Another advantage of the present application is to provide a Chart environment device and a fast defocus method based on a small 3D Chart, wherein the FOV of each parallel light pipe is set to be small, so that it can be applied to different FOV modules, and then it can effectively be compatible with a large wide-angle module.

[0012] Another advantage of the present application is to provide a Chart environment device and a fast defocus method based on a small 3D Chart, wherein the distance between the Chart and the magnifying lens in each parallel light pipe and the position and angle of each light pipe can be accurately adjusted by software, so that intelligent switching of different test distances and fields of view is realized.

[0013] Another advantage of the present application is to provide a Chart environment device and a fast defocus method based on a small 3D Chart, wherein the perfect combination of Chart environment miniaturization and OneShot algorithm is realized, which not only effectively reduces the size of the Chart environment and achieves the purpose of miniaturization, but also improves the AA efficiency and improves the yield in the AA process.

[0014] According to an aspect of the present application, a Chart environment device of the present application capable of achieving the above-mentioned and other objects and advantages comprises:

[0015] a plurality of collimator tubes, wherein each of the collimator tubes is arranged to point to a specific field of view point, and each of the collimator tubes corresponds to a different test field of view, the collimator tube comprising a collimator tube body, a light source arranged in the collimator tube body, and a Chart, wherein the Chart is arranged at the front end of the light exit direction of the light source, and the Chart is arranged obliquely in the collimator tube body.

[0016] According to an embodiment of the present application, the number of collimator tubes is 5, and the collimator tubes are respectively located at the center, the upper left, the upper right, the lower left, and the lower right from the perspective of top view.

[0017] According to an embodiment of the present application, further comprising a plurality of extender lenses, wherein the extender lenses are arranged at the end of the collimator tube body, and wherein the Chart is located between the light source and the extender lens.

[0018] According to an embodiment of the present application, the size of the collimator tube is 155.4*φ55mm, and the FOV of the collimator tube and the extender lens is 8-10°.

[0019] According to an embodiment of the present application, the Chart is a half-circular light shield arranged obliquely.

[0020] According to another aspect of the present application, the present application further provides a fast defocus method based on a small 3D Chart, wherein the fast defocus method based on the small 3D Chart comprises the following steps:

[0021] (a) establishing a mapping relationship model of the actual distance of the Chart to the extender lens and the simulated distance, wherein the Chart is arranged obliquely in the collimator tube;

[0022] (b) positioning the near end point and the far end point of the Chart of different fields of view, and forming an object distance focus curve according to the actual distance and the simulated object distance relationship model; and

[0023] (c) obtaining the object distance focus curve corresponding to the Chart image of different fields of view, and fitting to obtain the peak position of each field of view defocus curve, and calculating the Tilt and adjusting according to the difference of the peak position of different fields of view.

[0024] According to an embodiment of the present application, step (a) of the fast defocus method based on the small 3D Chart is to establish an extender lens relationship model:

[0025] Based on the discrete points of the actual distance of the Chart to the extender lens and the simulated distance corresponding to each other, a mapping relationship model of the actual distance of the Chart to the extender lens and the simulated distance is established, so as to obtain the corresponding relationship of any point.

[0026] According to an embodiment of the present application, the step (b) of the fast defocus method based on small 3D Chart further comprises a calibration of Chart environment device, wherein the calibration step comprises:

[0027] angle calibration, calculating the angle of each said parallel light pipe according to the size of module chip, adjusting the coarse positioning angle, and positioning the image near-far reference point, judging whether the reference center is located in the specific field of view coordinate, and fine-tuning according to the offset;

[0028] height calibration, calculating the distance H1,…,H5 between each field of view near-far reference point, comparing the difference with the Golden distance, and adjusting the height of each said parallel light pipe according to the difference.

[0029] According to an embodiment of the present application, the step (b) of the fast defocus method based on small 3D Chart is the step of positioning the minimum / maximum object distance point of image:

[0030] positioning the near end point and the far end point of the Chart of different field of view based on corner point detection algorithm, and fixing the near end point and the far end point of the Chart.

[0031] According to an embodiment of the present application, the step (c) of the fast defocus method based on small 3D Chart further comprises the step of extracting object distance focus information:

[0032] (c.1) positioning to the minimum / maximum object distance point, uniformly sampling between the two end points to obtain the actual distance corresponding to different object distance points on the semicircular straight edge, wherein the distance is continuous;

[0033] (c.2) mapping the sampled actual distance to simulated object distance U1,U2,…,Un according to the relationship model of actual distance and simulated object distance; and

[0034] (c.3) calculating the sharpness value of each sampling point region, and forming the object distance focus curve.

[0035] According to an embodiment of the present application, the step (c) of the fast defocus method based on small 3D Chart further comprises Tilt calculation:

[0036] (c.4) based on object distance extraction algorithm, each field of view Chart image can obtain an object distance focus curve, and the object distance focus curves of different fields of view are obtained comprehensively; and

[0037] (c.5) based on polynomial fitting, the peak position of each field of view defocus curve is obtained, that is, the object distance with the maximum sharpness.

[0038] According to one embodiment of the present application, in step (c) of the fast defocus method based on small 3D Chart, the peak position object distance U is converted to the peak position image distance V according to 1 / f = 1 / U + 1 / V, the field point XY coordinates are used as the chip (image side) position coordinates, and the final tilt result is obtained.

[0039] According to one embodiment of the present application, in step (c) of the fast defocus method based on small 3D Chart, the peak position object distance U is directly used, the field point XY coordinates are used as the actual reticle (object side) position coordinates, and the final tilt result is obtained.

[0040] Further objects and advantages of the present application can be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0041] These and other objects, features and advantages of the present application will become apparent from the following detailed description of the application taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 is a schematic diagram of the optical tilt between a lens and a chip in the AA process.

[0043] Figure 2 is a schematic diagram of the Chart environment structure of the prior art.

[0044] Figure 3 is a schematic diagram of the structure of the Chart environment device according to the first preferred embodiment of the present application.

[0045] Figure 4 is a schematic diagram of the Chart environment of a single collimator tube of the Chart environment device according to the first preferred embodiment of the present application.

[0046] Figure 5 is a schematic diagram of a single frame image containing different field of view and different object distance information according to the above first preferred embodiment of the present application.

[0047] Figure 6 is a schematic diagram of the magnifying mirror relationship model of the fast defocus method based on small 3D Chart according to the above first preferred embodiment of the present application.

[0048] Figure 7 is a schematic diagram of the object distance focus curve of the fast defocus method based on small 3D Chart according to the above first preferred embodiment of the present application.

[0049] Figure 8 is a schematic diagram of the object distance focus curve of the single frame image method according to the above first preferred embodiment of the present application.

[0050] Figure 9is a method step schematic diagram of the single-frame image method according to the above preferred embodiment of the present application. DETAILED DESCRIPTION

[0051] The following description is presented to enable any person skilled in the art to practice the present application as claimed. The preferred embodiments disclosed herein are merely examples of the present application and variations are possible without departing from the spirit and scope of the present application. The present application defined in the claims is not intended to be limited by the preferred embodiments disclosed herein.

[0052] Those skilled in the art will understand that, in the disclosure of the present application, the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the above terms cannot be understood as a limitation of the present application.

[0053] It can be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of one element can be one, and in another embodiment, the number of the element can be multiple, and the term "one" cannot be understood as a limitation on the number.

[0054] As shown in Figure 1 In the AA process, adjusting the optical tilt between the lens and the sensor is the main process at the present stage, and there is an optical tilt between the optical lens and the photosensitive chip, and the AA process needs to improve the optical tilt, and the existing optical tilt calculation method needs to collect 10-12 frames of images at different defocus positions to obtain a defocus curve, which becomes a key bottleneck limiting the AA efficiency. Therefore, the most important way to break through the AA efficiency bottleneck is to avoid the defocus process, and to realize single-frame image calculation tilt through the combination of software and hardware, that is, OneShot method.

[0055] In the existing Chart environment, it is usually required that the camera module can shoot images within the full FOV, such as Figure 2As shown, the Chart environment changes with the size of the field of view, and there are corresponding requirements for the light source. The larger the angle range, the larger the size of the Chart environment, and the larger the area occupied. In the actual AA process, only the area information of a specific field of view at a specific position is required, so the required Chart size is also reduced, and the purpose of miniaturization can be achieved. It should be noted that in the existing detection environment for the AA process of the camera module, only a Chart is usually horizontally arranged, and the Chart environment is mainly composed of the Chart and the light source arranged thereon, as shown in Figure 2 When the camera module to be detected exceeds the range of the field of view FOV covered by the Chart environment, the image will not be collected in the lens, so the camera module is required to be able to take an image within the full FOV. Such a setting at least has three disadvantages. First, as shown in Figure 2 The size of the Chart arranged horizontally usually changes with the size of the required FOV. The larger the required FOV angle range, the larger the size of the Chart environment must be. Second, higher requirements are placed on the light source arranged on the Chart. Third, the larger area of the Chart determines that the detection device occupies more space. However, in the actual AA process, only the area information of a specific field of view at a specific position is required, so the position and size of the Chart can be flexibly arranged to reduce the size of the Chart environment, thereby reducing the space occupied by the entire detection device. Based on this, the design scheme of the present application is proposed.

[0056] Reference will now be made to the drawings, wherein Figures 3 to 8 As shown, the Chart environment device and the fast defocus method based on a small 3D Chart according to the first preferred embodiment of the present application are described below. The Chart environment device provides a Chart environment for the AA process of an optical imaging device (camera module), wherein the Chart environment device includes a plurality of parallel light pipes 10, each of which is arranged to point to a specific field of view point, and each of which corresponds to a different test field of view. The parallel light pipe 10 includes a light pipe body 11, a light source 12 arranged in the light pipe body 11, and a Chart 13 arranged at the front end of the light exit direction of the light source 12. It is worth mentioning that in this preferred embodiment of the present application, the parallel light pipe 10 is a three-in-one parallel light pipe mode of integrated light source, Chart, and extender, which effectively reduces the size of the Chart environment and is conducive to the miniaturization of the Chart environment.

[0057] The light pipe body 11 has an internal space, the light source 12 and the Chart 13 are arranged in the internal space of the light pipe body 11, and the Chart 13 is located in the light emission direction of the light source 12 and is irradiated in a specific direction by the light source 12. In this preferred embodiment of the present application, the light pipe body 11 of each parallel light pipe 10 has an irradiation direction, and the light projected by the light source 12 is emitted along the irradiation direction of the light pipe body 11. Each parallel light pipe 10 points to a specific field of view point and forms an image at the required position. As shown in the figure, in this preferred embodiment of the present application, each parallel light pipe of the Chart environment device corresponds to a different field of view, and the parallel light pipes 10 at different positions and angles are located at different spatial positions. Therefore, it can be understood that in this preferred embodiment of the present application, the Chart environment device provides a miniaturized 3D Chart environment. Figure 4

[0058] It is worth mentioning that in this preferred embodiment of the present application, the parallel light pipes 10 can all integrate light sources, and different test fields of view correspond to different parallel light pipes, so as to achieve size minimization.

[0059] As shown in the figure, the Chart 13 is arranged obliquely in the internal space of the light pipe body 11, so that it can obtain imaging points of different object distances in a single frame image, and then obtain the object distance focal curve. Figure 4

[0060] It is worth mentioning that in this preferred embodiment of the present application, since N fields of view need to be tested in the AA process, the number of parallel light pipes 10 of the Chart environment device is the same as the number of fields of view to be tested, so as to obtain image information of different fields of view by collecting single frame images.

[0061] As an example, in this preferred embodiment of the present application, 5 fields of view need to be tested in the AA process, the number of parallel light pipes 10 of the Chart environment device is 5, and the parallel light pipes 10 correspond to Chart information of 5 fields of view including center, upper left, lower left, upper right and lower right respectively.

[0062] ​​It is worth mentioning that in the preferred embodiment of the present application, each of the parallel light pipes 10 of the Chart environment device points to a specific field of view point, and images only at the required position. The Chart 13 is obliquely arranged in the internal space of the light pipe body 11, and the corresponding oblique angle and direction of the Chart 13 of each of the parallel light pipes 10 are different, so that when the camera module collects a single frame of image, it can obtain imaging points of different object distances in a single frame of image, and then obtain the object distance focus curve.

[0063] It is worth mentioning that in the preferred embodiment of the present application, the Chart environment device adopts a 3D Chart mode, so that different object distance information of different fields of view can be obtained by collecting a single frame of image and cooperating with an algorithm, and the defocus curve and tilt can be calculated to improve the AA efficiency.

[0064] In addition, those skilled in the art can understand that, unlike the prior art, in the preferred embodiment of the present application, the conventional horizontal Chart is obliquely arranged, so that imaging points of different object distances can be obtained in a single frame of image, and then the object distance focus curve is obtained to realize the OneShot function.

[0065] The Chart environment device further comprises a plurality of magnifying mirrors 20, wherein the magnifying mirrors 20 are arranged at the end of the light pipe body 11, and the Chart 13 is located between the light source 12 and the magnifying mirror 20, so that the Chart environment size is enlarged through the magnifying mirror 20, and a certain distance is saved. The magnifying mirror 20 is arranged at the bottom of the light pipe body 11, so that the size of the Chart environment formed by each light pipe body 11 is enlarged, thereby reducing the distance between the parallel light pipe and the object to be detected, and further reducing the size of the entire detection device.

[0066] According to one embodiment of the present application, the light pipe body 11 of the parallel light pipe can be constructed as a column with different cross sections as required, and the magnifying mirror 20 also needs to be constructed as a lens with the same cross-sectional shape, and then the light pipe body 11 and the magnifying mirror 20 form a sealed structure. The pipe body is made of a material that does not transmit light, so as not to affect the parallel light in the light pipe body 11. According to one embodiment of the present application, the field of view angle of the parallel light pipe is adjustable within the range of 8-10 degrees. Since the relative position of the magnifying mirror 20 and the parallel light pipe is fixed, it can be considered that the field of view angle of the magnifying mirror 20 is adjustable within the range of 8-10 degrees.

[0067] It can be understood that, since the position and angle of each collimator can be flexibly adjusted, the plurality of collimator bodies 11 respectively point to specific field of view points according to needs, and only image from the required FOV at the required position; each collimator body 11 includes a Chart, and a plurality of distributed Charts jointly constitute a Chart environment, so that the size of each collimator body 11 can be greatly reduced to achieve the same or even better effect of the traditional Chart environment, while reducing the manufacturing cost of the Chart environment device.

[0068] It is worth mentioning that, in the preferred embodiment of the present application, each collimator can integrate a light source, and different test fields of view correspond to different collimators, so as to minimize the size. Those skilled in the art can understand that, by setting a smaller FOV for each collimator, the collimator can be applied to different FOV modules, thereby effectively compatible with a large-angle module.

[0069] In the preferred embodiment of the present application, the Chart environment device adopts five collimators 10, which are respectively located at the center, upper left, upper right, lower left and lower right from the top view. As an example, in the preferred embodiment of the present application, the size of the collimator 10 is 155.4*φ55mm, and the FOV of the collimator 10 and the extender lens 20 is 8-10°. As shown in Figure 3 and Figure 4 In the preferred embodiment of the present application, the Chart 13 is a half-circular light shield placed obliquely, and the size of the Chart environment is set to be less than 180mm*180mm*150mm. Therefore, in the preferred embodiment of the present application, the size of each collimator 10 is much smaller than the size of the conventional Chart environment, which meets the design requirement of miniaturization. Since the Chart environment device does not need external view angle, the Chart environment is reduced.

[0070] Since each parallel light pipe 10 corresponds to a different test field of view, in this preferred embodiment of the present application, 5 fields of view need to be tested in the AA process, accordingly, the Chart environment device has 5 parallel light pipes 10. When the camera module captures a single frame image, the image contains the tilt Chart information of the center, upper left, upper right, lower left and lower right 5 fields of view. Taking the center field of view imaging as an example, one end of the semicircular edge of the Chart represents the minimum object distance point, the other end represents the maximum object distance point, and each point on the semicircular straight edge represents the object distance point between the minimum and maximum object distance points. Further calculation of the sharpness at different object distance points gives the object distance-focal curve. It is worth mentioning that the semicircular edge is the same shape as the inner wall of the light pipe body 11, and the parallel light is incident into the magnifying mirror 20 from the side that is not blocked by the Chart 13. On this basis, the imaging points of the parallel light pipe at different object distances in a single frame image can be obtained.

[0071] It is worth mentioning that since the distance between the Chart 13 and the magnifying mirror 20 can be precisely adjusted, the Chart environment device can adapt to different test distances and intelligent switching of fields of view. Further, the same Chart environment device contains multiple parallel light pipes, and the position and angle of the parallel light pipes can be precisely adjusted, thereby further meeting the needs of intelligent switching of different test distances and fields of view. Therefore, the Chart environment device has the characteristics of flexible arrangement, making it have a wider range of application scenarios.

[0072] As can be understood by those skilled in the art, the AA process does not require full FOV information, but only requires information of a specific field of view and a specific position area. Therefore, in this preferred embodiment of the present application, the positions and angles of the multiple parallel light pipes of the Chart environment device can be adjusted to facilitate imaging of specific demand fields of view and specific positions. Therefore, in this preferred embodiment of the present application, the Chart environment device is compatible with AA processes of wide-angle and super-wide-angle modules. In addition, it can be understood that in this preferred embodiment of the present application, the distance between the Chart and the magnifying mirror in each parallel light pipe and the position and angle of each parallel light pipe can be precisely adjusted by software or other means, thereby realizing intelligent switching of different test distances and fields of view.

[0073] According to another aspect of the present application, the present application further provides an AA process detection system based on a Chart environment device, wherein the AA process detection system comprises the Chart environment device, a detection platform and a driving assembly, wherein the detection platform is used for fixing a camera module to be detected, and the camera module to be detected is arranged in a field of view angle range of the light pipe unit, wherein the driving assembly adjusts the position and angle of the parallel light pipe and the position of Chart 13 in the parallel light pipe. It is worth mentioning that the driving assembly comprises a processing module, a storage module and a communication module, the storage module at least stores the position and angle information of Chart 13 and the parallel light pipe, and transmits the information to the processing module through the communication module, and the processing module adjusts the position and angle of Chart 13 and the parallel light pipe.

[0074] It is worth mentioning that the AA process detection device based on the Chart environment device can calculate the tilt through a single frame image, that is, in a OneShot mode. In detail, the AA process detection device based on the Chart environment device can calculate the corresponding tilt and adjust through a single shooting mode according to the corresponding lens type.

[0075] It is worth mentioning that in the preferred embodiment of the present application, the Chart environment device adopts a 3D Chart mode, wherein the AA process detection device acquires a single frame picture and cooperates with an algorithm to obtain different object distance information of different fields of view, calculate the defocus curve and the tilt, and improve the AA efficiency. A magnifying mirror relationship model is established, discrete points corresponding to the actual distance and the simulated distance from the Chart to the magnifying mirror are used to establish a mapping relationship model of the actual distance and the simulated distance from the Chart to the magnifying mirror, so as to obtain the corresponding relationship of any point. From the distribution of the discrete points, a mixture Gaussian model is used to represent the mapping relationship, which can reasonably express the mapping relationship, and the curve formed by the discrete points is most consistent with the function image, without overfitting or underfitting.

[0076] The Chart image is shot, and the minimum and maximum object distance points are located through the shot Chart image. The position of the tilt Chart in the parallel light pipe is fixed, so the actual distance of the near end point and the far end point is known, that is, the distance of the minimum object distance point and the maximum object distance point is known, and the positions of the two end points can be accurately located in the image. The Chart near end point and the far end point of different fields of view are located respectively, and the positioning method is not limited to the corner point detection algorithm, the Chart near end point and the far end point are welded to form two fixed points, and the like; wherein the positioning algorithm requires high accuracy to avoid causing the peak position of the defocus curve to deviate. Figure 7 and Figure 8As shown, when the Chart environment device is photographed, the Chart has at least one clear edge during the photographing process, and the corresponding distance from the focus curve has a peak value.

[0077] According to the Chart image extract distance from focus information, first, locate the minimum / maximum object distance point, and uniformly sample between the two endpoints to obtain the actual distance corresponding to different object distance points on the semicircular straight edge, wherein the distance is continuous; second, according to the actual distance and the simulation object distance relationship model, the sampled actual distance is mapped to the simulation object distance U1, U2, …, Un; then the sharpness value of each sampling point region is calculated to form the object distance from focus curve. As shown in Figure 5 According to the Chart environment device, a corresponding single-frame image is obtained by photographing, wherein the single-frame image contains different field of view and different object distance information.

[0078] According to the obtained object distance from focus curve, Tilt is calculated. Using the object distance extraction algorithm, each field of view Chart image can obtain an object distance from focus curve, and the object distance from focus curves of different fields of view are obtained. The peak position of each field of view defocus curve is obtained by using conventional polynomial fitting, that is, the object distance with the maximum sharpness. According to the difference between the peak positions of different fields of view, the existence of Tilt is calculated and adjusted.

[0079] Therefore, by tilting the Chart in the conventional parallel light tube, the application realizes the perfect combination of the Chart environment miniaturization and the OneShot algorithm, effectively reduces the size of the Chart environment, achieves the purpose of miniaturization, and also improves the AA efficiency and the yield in the AA process.

[0080] As shown, according to another aspect of the application, the application further provides a fast defocus method based on a small 3D Chart, wherein the fast defocus method based on a small 3D Chart comprises the following steps: Figures 5 to 9

[0081] (a) establishing a mapping relationship model of the actual distance from the Chart 13 to the magnifying mirror 20 and the simulation distance;

[0082] (b) locating the near end point and the far end point of the Chart 13 of different fields of view, and forming the object distance from focus curve according to the actual distance and the simulation object distance relationship model; and

[0083] (c) obtaining the object distance from focus curve corresponding to the Chart image of different fields of view, and fitting to obtain the peak position of each field of view defocus curve, and calculating and adjusting the existence of Tilt according to the difference between the peak positions of different fields of view.

[0084] ​The step (a) of the quick defocus method based on the small 3D Chart in the present application is to establish the teleconverter relationship model:

[0085] Based on the discrete points of the Chart 13 to the actual distance of the teleconverter 20 corresponding to the simulated distance, the mapping relationship model of the Chart 13 to the actual distance of the teleconverter 20 and the simulated distance is established, so as to obtain the corresponding relationship of any point.

[0086] Preferably, in this preferred embodiment of the present application, the mapping relationship is characterized by using a Gaussian mixture model, which can reasonably express the mapping relationship, and the curve formed by the discrete points is most consistent with the function image, neither overfitting nor underfitting.

[0087] The step (b) of the quick defocus method based on the small 3D Chart in the present application is the step of image positioning the minimum / maximum object distance point:

[0088] Since the position of the Chart 13 in the light pipe main body 11 of the parallel light pipe 10 is fixed, the actual distance of the near end point and the far end point is known, that is, the distance of the minimum object distance point and the maximum object distance point is known, and the positions of the two end points can be accurately positioned in the image.

[0089] Therefore, the step (b) of the quick defocus method based on the small 3D Chart further comprises the steps of:

[0090] Based on the corner point detection algorithm, the near end point and the far end point of the Chart 13 in different fields of view are positioned respectively. The near end point and the far end point of the Chart 13 are welded to form two fixed points. It is worth mentioning that the positioning algorithm requires high accuracy to avoid the peak position of the defocus curve from being offset.

[0091] The step (c) of the quick defocus method based on the small 3D Chart in the present application further comprises the step of extracting object distance focus information:

[0092] (c.1) positioning to the minimum / maximum object distance point, uniformly sampling between the two end points to obtain the actual distance corresponding to different object distance points on the semicircular straight edge, wherein the distance is continuous;

[0093] (c.2) according to the actual distance and the simulated object distance relationship model, mapping the sampled actual distance to the simulated object distance U1, U2, …, Un; and

[0094] (c.3) calculating the sharpness value of each sampling point region, and forming the object distance focus curve.

[0095] The step (c) of the fast defocus method based on small 3D Chart further comprises Tilt calculation:

[0096] (c.4) Based on the object distance extraction algorithm, the Chart image of each field of view can obtain an object distance focus curve, and the object distance focus curves of different fields of view are obtained comprehensively; and

[0097] (c.5) Based on polynomial fitting, the peak position of each field of view defocus curve is obtained, that is, the object distance with the maximum sharpness.

[0098] Preferably, in the step (c) of the fast defocus method based on small 3D Chart, the peak position object distance U is converted to the peak position image distance V according to 1 / f=1 / U+1 / V, the field point XY coordinate uses the chip (image side) position coordinate, and the final tilt result is obtained.

[0099] Optionally, in the step (c) of the fast defocus method based on small 3D Chart, the peak position object distance U is directly used, and the field point XY coordinate uses the actual target (object side) position coordinate, and the final tilt result is obtained.

[0100] In the step (c.5) of the fast defocus method based on small 3D Chart, at least one clear edge exists in the process of shooting the Chart, which corresponds to the peak value of the object distance focus curve.

[0101] The fast defocus method based on small 3D Chart needs to point a plurality of parallel light tubes 10 to a specific field of view, so when using the Chart environment device, the parallel light tubes 10 of the Chart environment device need to be calibrated to adapt to a specific environment.

[0102] The step (b) of the fast defocus method based on small 3D Chart further comprises calibration of the Chart environment device, wherein the calibration step comprises:

[0103] Angle calibration, the angle of each parallel light tube 10 is calculated according to the size of the module chip, the coarse positioning angle is adjusted, and the near and far reference points of the positioning image are positioned, whether the reference center is located in the specific field of view coordinate is judged, and fine adjustment is made according to the offset.

[0104] Height calibration, the distance H1,…,H5 between the near and far reference points of each field of view is calculated, the difference between the distance and the Golden distance is compared, and the height of each parallel light tube 10 is adjusted according to the difference.

[0105] Figure 7 And Figure 8is the schematic diagram of the object distance focus curve of the small 3D Chart based quick defocus method and the schematic diagram of the object distance focus curve of the single frame image method according to the above preferred embodiment of the present application, wherein it can be understood that in the actual process of Chart shooting, there will be at least one sharpest edge, and the sharpest edge corresponds to the peak of the object distance focus curve.

[0106] It is worth mentioning that in this preferred embodiment of the present application, the distance between the far and near reference points corresponding to the Chart 13 of the parallel light tube 10 in the center position field of view is H1, the distance between the far and near reference points corresponding to the Chart 13 of the parallel light tube 10 in the upper left position field of view is H2, the distance between the far and near reference points corresponding to the Chart 13 of the parallel light tube 10 in the upper right position field of view is H3, the distance between the far and near reference points corresponding to the Chart 13 of the parallel light tube 10 in the lower left position field of view is H4, and the distance between the far and near reference points corresponding to the Chart 13 of the parallel light tube 10 in the lower right position field of view is H5.

[0107] It should be understood by those skilled in the art that the above description and the embodiments of the present application shown in the drawings are only examples and do not limit the present application. The purpose of the present application has been fully and effectively achieved. The function and structural principle of the present application has been shown and explained in the embodiments, and the embodiments of the present application can be any modification or modification without departing from the principle.

Claims

1. A chart environmental device, characterized in that, include: The system comprises multiple collimators and multiple teleconverters, wherein each collimator is positioned to point to a specific field of view and corresponds to a different test field of view. Each collimator includes a main body, a light source disposed on the main body, and a chart. The chart is positioned at the front end of the light source in the direction of light emission and is tilted on the main body. There are five collimators, which are located at the center, upper left, upper right, lower left, and lower right respectively when viewed from above. The teleconverter is disposed at the end of the main body. The chart is located between the light source and the teleconverter and is a tilted semi-circular light shield.

2. The Chart environmental device according to claim 1, wherein the size of the collimator is 155.4*φ55mm, and the FOV of the collimator and the teleconverter is 8-10°.

3. A rapid defocusing method based on a small 3D chart, employing the chart environment device as described in claim 1 or 2, characterized in that, The fast defocusing method based on a small 3D chart includes the following steps: (a) Establish a mapping model between the actual distance from the Chart to the teleconverter and the simulated distance, wherein the Chart is tilted and positioned on the collimator; (b) Locate the near and far ends of the Chart in different fields of view, and form the object distance-focus curve based on the actual distance and the simulated object distance relationship model; as well as (c) Obtain the object distance-to-focus curves corresponding to the Chart images of different fields of view, and fit the peak position of the defocus curve of each field of view. Calculate the existence of Tilt based on the difference in peak position of different fields of view and adjust it.

4. The fast defocusing method based on a small 3D chart according to claim 3, wherein step (a) of the fast defocusing method based on a small 3D chart is to establish a teleconverter relationship model: Based on discrete points where the actual distance and simulated distance from the Chart to the teleconverter correspond one-to-one, a mapping model between the actual distance and simulated distance from the Chart to the teleconverter is established, thereby obtaining the correspondence between any points.

5. The fast defocusing method based on a small 3D chart according to claim 4, wherein step (b) of the fast defocusing method based on a small 3D chart is the step of locating the minimum / maximum object distance point of the image: Based on the corner detection algorithm, the near and far endpoints of the Chart in different fields of view are located and fixed.

6. The fast defocusing method based on a small 3D chart according to claim 3, wherein the fast defocusing method based on a small 3D chart further includes, prior to step (b), calibration of the chart environment device, wherein the calibration step includes: Angle calibration involves calculating the angle of each collimator based on the module chip size, adjusting the coarse positioning angle, and determining whether the reference center is located at a specific field of view coordinate based on the positioning image near and far reference points. Fine-tuning is then performed based on the offset. and Height calibration involves calculating the distances H1, ..., H5 between the near and far reference points of each field of view, comparing their differences with the Golden distance, and adjusting the height of each collimator based on the differences.

7. The fast defocusing method based on a small 3D chart according to claim 5, wherein step (c) of the fast defocusing method based on a small 3D chart further includes the step of extracting defocusing information: (c.1) Locate the minimum / maximum object distance point, perform uniform sampling between the two endpoints, and obtain the actual distances corresponding to different object distance points on the edge of the semi-circular straight line, where this distance is continuous; (c.2) Based on the relationship model between actual distance and simulated object distance, map the sampled actual distances to simulated object distances U1, U2, ..., Un; and (c.3) Calculate the sharpness value for each sampling point area and form the object-to-focus curve.

8. The fast defocusing method based on a small 3D chart according to claim 7, wherein step (c) of the fast defocusing method based on a small 3D chart further includes Tilt calculation: (c.4) Based on the object distance extraction algorithm, an object distance-to-focus curve is obtained for each field of view's Chart image, and the object distance-to-focus curves for different fields of view are obtained by combining them; and (c.5) Based on polynomial fitting, the peak position of the defocus curve of each field of view is obtained, and the object distance with the greatest sharpness is obtained.

9. The fast defocusing method based on a small 3D chart according to claim 8, wherein in step (c.5) of the fast defocusing method based on a small 3D chart, there is at least one sharp edge in the chart during the shooting process, which corresponds to the peak of the object distance focus curve.

10. The fast defocusing method based on a small 3D Chart according to claim 8, wherein in step (c) of the fast defocusing method based on a small 3D Chart, the peak position object distance U is converted to the peak position image distance V according to 1 / f = 1 / U + 1 / V, and the XY coordinates of the field of view point are used with the chip position coordinates to obtain the final tilt result.

11. The fast defocusing method based on a small 3D Chart according to claim 8, wherein in step (c) of the fast defocusing method based on a small 3D Chart, the peak position object distance U is directly used, and the XY coordinates of the field of view point are the actual chart position coordinates to obtain the final tilt result.

Images