An imaging system and control method for detecting defects on a cylindrical lens grating glass substrate

Abstract

The present invention discloses an imaging system and a control method for detecting defects of a cylindrical lens grating glass substrate. The system includes: a light source, a three-axis motion module, a cylindrical lens grating glass substrate to be measured, an image acquisition module, an image calculation module, and a multi-channel coupling control module; the light source is arranged on the three-axis motion module; the light source is used to irradiate the cylindrical lens grating glass substrate to be measured; the image acquisition module is used to collect the light reflected by the cylindrical lens grating glass substrate to be measured to obtain a self-coherent grating image, and send the self-coherent grating image to the image calculation module; the image calculation module is used to calculate the clarity and stripe flatness of the self-coherent grating image, and send the clarity and stripe flatness to the multi-channel coupling control module; the multi-channel coupling control module is used to control the motion of the three-axis motion module according to the clarity and stripe flatness to adjust the pose of the light source. It can effectively obtain a self-coherent grating image for detecting defects of the cylindrical lens grating glass substrate.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of machine vision, and in particular, to an imaging system and a control method for detecting defects of a lenticular grating glass substrate. Background Art

[0002] Since observers do not need to wear special glasses or other auxiliary tools, there is a huge demand for naked-eye 3D displays in scenarios such as advertising, media, demonstrations, and exhibitions. With the further development of its technology, it can be gradually applied in personal daily display scenarios such as mobile phones, tablets, and vehicles. Among them, 3D display based on lenticular gratings is the mainstream technology in the current 3D display field due to its strong practicability, easy processing, high brightness, etc., and the lenticular grating glass substrate is the most core component among them.

[0003] During the production and processing of lenticular grating glass substrates, defective products such as foreign objects, bubbles, bumps, and scratches will occur. Defect detection is an essential key process in the production and processing process. However, due to the special optical structure of the lenticular grating glass substrate, it is very difficult to use ordinary imaging methods of machine vision with line scanning or area array. After the light path is refracted and reflected by the substrate cylindrical lens, the distortion is serious, the real defect angle changes greatly, it is not easy to capture, and the background texture is complex and changes with the model. The optical detection layout suitable for a certain model may be completely ineffective for another model. The method of using a microscope for microscopic local inspection can detect defects and the light path is relatively stable, but its field of view is very small. Using this method for global inspection of glass substrates will result in an extremely complex system and high costs. Summary of the Invention

[0004] The embodiments of the present invention provide an imaging system and a control method for detecting defects of a lenticular grating glass substrate, which can effectively obtain a self-coherent grating image for detecting defects of a lenticular grating glass substrate.

[0005] In a first aspect, the embodiments of the present invention provide an imaging system for detecting defects of a lenticular grating glass substrate, including: a light source, a three-axis motion module, a measured lenticular grating glass substrate, an image acquisition module, an image calculation module, and a multi-channel coupling control module;

[0006] Wherein, the light source is a surface light source attached with a plurality of uniformly arranged special-shaped strip lens cylinders; the light source is arranged on the three-axis motion module; the light source and the image acquisition module are located above the measured lenticular grating glass substrate; the image acquisition module is connected to the image calculation module, the image calculation module is connected to the multi-channel coupling control module, and the multi-channel coupling control module is connected to the three-axis motion module;

[0007] The light source is used to irradiate the cylindrical lens grating glass substrate to be measured; the image acquisition module is used to acquire the light reflected by the cylindrical lens grating glass substrate to be measured to obtain a self-coherent grating image, and send the self-coherent grating image to the image calculation module; the image calculation module is used to calculate the clarity and stripe flatness of the self-coherent grating image, and send the clarity and stripe flatness to the multi-channel coupling control module; the multi-channel coupling control module is used to control the movement of the three-axis motion module according to the clarity and the stripe flatness to adjust the pose of the light source.

[0008] In a second aspect, an embodiment of the present invention further provides a control method for an imaging system for detecting defects in a cylindrical lens grating glass substrate. The method is used for the imaging system for detecting defects in a cylindrical lens grating glass substrate in this embodiment, and includes:

[0009] Obtain a self-coherent grating image; wherein, the self-coherent grating image is obtained by collecting the light reflected by the cylindrical lens grating glass substrate to be measured;

[0010] Determine the clarity and stripe flatness of the self-coherent grating image, and judge whether the clarity and stripe flatness meet preset conditions;

[0011] If the clarity and / or stripe flatness do not meet the preset conditions, adjust the pose of the light source according to the clarity and / or the stripe flatness, and return to execute the operation of obtaining the self-coherent grating image until the clarity and stripe flatness meet the preset conditions; wherein, the light source is used to irradiate the cylindrical lens grating glass substrate to be measured.

[0012] An imaging system for detecting defects of a cylindrical lens grating glass substrate and a control method thereof are provided in an embodiment of the present invention. The system includes: a light source, a three-axis motion module, a cylindrical lens grating glass substrate to be measured, an image acquisition module, an image calculation module, and a multi-channel coupling control module; wherein, the light source is a surface light source attached with a plurality of specially-shaped strip-shaped lens cylinders arranged uniformly; the light source is arranged on the three-axis motion module; the light source and the image acquisition module are located above the cylindrical lens grating glass substrate to be measured; the image acquisition module is connected to the image calculation module, the image calculation module is connected to the multi-channel coupling control module, and the multi-channel coupling control module is connected to the three-axis motion module; the light source is used for irradiating the cylindrical lens grating glass substrate to be measured; the image acquisition module is used for acquiring the light reflected by the cylindrical lens grating glass substrate to be measured to obtain a self-coherent grating image, and sending the self-coherent grating image to the image calculation module; the image calculation module is used for calculating the clarity and the stripe flatness of the self-coherent grating image, and sending the clarity and the stripe flatness to the multi-channel coupling control module; the multi-channel coupling control module is used for controlling the motion of the three-axis motion module according to the clarity and the stripe flatness to adjust the pose of the light source. The imaging system for detecting defects of a cylindrical lens grating glass substrate provided in the embodiment of the present invention adjusts the pose of the light source through the clarity and the stripe flatness of the self-coherent grating image until the clarity and the stripe flatness of the obtained self-coherent grating image meet the defect detection conditions, and can effectively obtain a self-coherent grating image for detecting defects of a cylindrical lens grating glass substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic structural diagram of an imaging system for detecting defects of a cylindrical lens grating glass substrate in Embodiment 1 of the present invention;

[0014] Figure 2 is an exemplary diagram of a specially-shaped strip-shaped lens cylinder in Embodiment 1 of the present invention;

[0015] Figure 3 is a sectional view of a surface light source attached with a plurality of specially-shaped strip-shaped lens cylinders in Embodiment 1 of the present invention;

[0016] Figure 4 is an exemplary diagram of the motion of a three-axis motion module in Embodiment 1 of the present invention;

[0017] Figure 5 is a principle block diagram of an imaging system for detecting defects of a cylindrical lens grating glass substrate in an embodiment of the present invention;

[0018] Figure 6 is a flowchart of an imaging method for detecting defects of a cylindrical lens grating glass substrate in Embodiment 2 of the present invention;

[0019] Figure 7 is a schematic diagram of a self-coherent grating image in Embodiment 2 of the present invention. Detailed implementation mode

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. In addition, it should be noted that for the convenience of description, only parts related to the present invention rather than all structures are shown in the drawings.

[0021] Embodiment 1

[0022] Figure 1 The following is a schematic structural diagram of an imaging system for detecting defects in a cylindrical lens grating glass substrate provided in Embodiment 1 of the present invention. As Figure 1 shown, the system includes: a light source 11, a three-axis motion module 12, a cylindrical lens grating glass substrate to be measured 13, an image acquisition module 14, an image calculation module 15, and a multi-channel coupling control module 16.

[0023] Among them, the light source 11 is a surface light source attached with a plurality of uniformly arranged special-shaped strip-shaped lens cylinders; the light source is arranged on the three-axis motion module; the light source and the image acquisition module are located above the cylindrical lens grating glass substrate to be measured. The image acquisition module 14 is connected to the image calculation module 15, the image calculation module 15 is connected to the multi-channel coupling control module 16, and the multi-channel coupling control module 16 is connected to the three-axis motion module 12.

[0024] Among them, the uniform arrangement of the special-shaped strip-shaped lens cylinders can be understood as that the distance between two adjacent special-shaped strip-shaped lens cylinders on the surface light source is equal. The end face of the special-shaped strip-shaped lens cylinder is special-shaped. The special shape can be understood as an irregular shape. Exemplarily, Figure 2 is an example diagram of a special-shaped strip-shaped lens cylinder in this embodiment. As Figure 2 shown, the end face of the strip-shaped lens cylinder is special-shaped, that is, at least one side of the figure is a curve. In this embodiment, the maximum radius envelope of the special-shaped strip-shaped lens cylinder matches the size of the cylindrical lens grating in the cylindrical lens grating glass substrate to be measured, that is, the difference between the maximum radius envelope of the special-shaped strip-shaped lens cylinder and the size of the cylindrical lens grating in the cylindrical lens grating glass substrate to be measured is within a preset range, and the length of the special-shaped strip-shaped lens cylinder is determined according to the camera field of view size, such as set to be between 200-300 mm. This can enable the cylindrical lens grating glass substrate to be imaged normally.

[0025] In this embodiment, after the special-shaped strip lens columns are designed, a plurality of special-shaped strip lens columns are attached to a surface light source with uniform light emission and surface cleaning treatment according to process requirements, and the part of the surface light source where no special-shaped strip lens columns are attached is shaded, so that the light source has periodic grid characteristics. That is, the spatial distribution frequency domain characteristics of the special-shaped strip lens columns in the light source and the spatial distribution frequency domain characteristics of the cylindrical lens grating in the measured cylindrical lens grating glass substrate are in a specific proportional relationship. Among them, this proportional relationship can be a value between 0.5 and 1.2. Exemplarily, Figure 3 is a cross-sectional view of a surface light source with a plurality of special-shaped strip lens columns attached in this embodiment, as Figure 3 shown, the special-shaped strip lens columns are uniformly arranged on the surface light source, and the part where no special-shaped strip lens columns are attached is shaded. In this embodiment, by using the optical characteristics of the measured cylindrical lens grating glass substrate itself, the light source with the above-mentioned periodic grid characteristics is used to irradiate the measured cylindrical lens grating glass substrate to excite and obtain a self-coherent grating image for defect detection. The self-coherent grating image with light and dark intervals generated by this system can be effectively used for defect detection, and has the advantages of stable background, clear and stable imaging of defects (including weak defects), and compatibility with different models. It effectively overcomes the disadvantages of other imaging methods, such as complex and variable background, numerous angles required for defect imaging, and large differences in models. In addition, another important advantage of the self-coherent grating image generated by this system is that except for individual large filaments and foreign objects, most of the surface dust (non-genuine defects) can be shielded, while general imaging methods will cause weak dust to be imaged, and the features cannot be effectively distinguished from genuine defects. This optical system achieves the goals of "low cost", "simple and reliable", and "global inspection" compared with the microscopic inspection method. In addition, this light source will not generate a grating image on ordinary glass, and it is not the conventional grating projection principle. The conventional grating projection principle cannot image on the cylindrical lens grating glass.

[0026] Among them, the image acquisition module is a camera and an acquisition card. The three-axis motion module can rotate and translate around three axes (X-axis, Y-axis, Z-axis). Exemplarily, Figure 4 is a motion example diagram of a three-axis motion module in this embodiment, as Figure 4 shown, the adjustable amounts of the three-axis motion module are the rotation angle ∅(x) around the x-axis, the rotation angle ∅(y) around the y-axis, the rotation angle ∅(z) around the z-axis, and the translation along the x-axis. The light source is arranged on the three-axis motion module, so that the three-axis motion module drives the light source to rotate around three axes and translate microscopically along the x-axis when moving, so as to adjust its pose. The multi-channel coupling control module is used to control the movement of the three-axis motion module.

[0027] Specifically, the light source is used to irradiate the cylindrical lens grating glass substrate to be measured; the image acquisition module is used to collect the light reflected by the cylindrical lens grating glass substrate to be measured to obtain a self-coherent grating image, and send the self-coherent grating image to the image calculation module; the image calculation module is used to calculate the clarity and stripe flatness of the self-coherent grating image, and send the clarity and stripe flatness to the multi-channel coupling control module; the multi-channel coupling control module is used to control the movement of the three-axis motion module according to the clarity and stripe flatness to adjust the pose of the light source.

[0028] In this embodiment, the light source adjusts its height and angle according to the arrangement direction of the cylindrical lens grating to be measured, and a rough self-coherent grating image can be basically obtained. Due to the sensitivity of self-coherent grating imaging to angle and levelness, the accuracy of general manual adjustment cannot meet the requirements. Moreover, for different models, due to the differences in grating layout, the pose of the light source must be readjusted. Therefore, the imaging system for detecting defects in the cylindrical lens grating glass substrate in this embodiment is a feedback self-adjusting system. Figure 5 It is the principle block diagram of the imaging system for detecting defects in the cylindrical lens grating glass substrate in the embodiment of the present invention. As Figure 5 shown, the working principle of the system is as follows: Place the light source on a motion module with adjustable levelness and rotation degree. Establish a feedback control system with the clarity and stripe flatness of the self-coherent grating image as the state variables and the rotation degree adjustment amount of the three-axis motion module as the control variable, so as to obtain the best self-coherent grating image in an adaptive adjustment manner. That is, use the clarity and / or stripe flatness as the state variables, and use the multi-channel coupling control module to control the pose of the light source, so that the light source and the cylindrical lens grating glass substrate to be measured generate a self-coherent mechanism and obtain a self-coherent grating image whose clarity and stripe flatness meet the preset conditions.

[0029] In this embodiment, the target values of the imaging system are that the clarity and flatness meet the preset conditions. It should be noted that the clarity here excludes the influence of lens focusing factors and only refers to the clarity of the grating image caused by the self-coherent process. The factors affecting the clarity are the rotation degree around the central z-axis, the rotation degree around the x-axis, and the rotation degree around the y-axis. Therefore, its independent variables are ∅(z), ∅(x), ∅(y), where ∅(z) is the main variable and plays a decisive role in the clarity of the self-coherent process; the factors affecting the stripe flatness are the rotation degree around the x-axis and the rotation degree around the y-axis. Therefore, its independent variables are ∅(x), ∅(y).

[0030] Among them, the image calculation module is used to calculate the clarity and flatness of the currently collected self-coherent grating image. The specific calculation method can be seen in the subsequent embodiments.

[0031] In this embodiment, the multi-channel coupling control module is further configured to, when the clarity and the stripe straightness do not meet the preset conditions, control the three-axis motion module to rotate along at least one axis according to the clarity deviation amount and / or the stripe straightness deviation amount, so as to adjust the pose of the light source.

[0032] Among them, the clarity deviation amount is the deviation between the clarity of the current self-coherent grating image and the target clarity; the stripe straightness deviation amount is the deviation between the stripe straightness of the current self-coherent grating image and the upper target stripe straightness. It can be seen from the above embodiments that the control process in this embodiment is a dual-channel coupling control. The clarity and stripe straightness of the current self-coherent grating image and the target clarity and target stripe straightness are input into the multi-channel coupling control module to obtain the clarity deviation amount ΔD(t) and the stripe straightness deviation amount ΔS(t). The multi-channel coupling control module generates a control command (the command includes ∅(z), ∅(x), ∅(y)) according to the clarity deviation amount and the stripe straightness deviation amount, and sends the control command to the three-axis motion module to control the three-axis motion module to rotate along at least one of the X, Y, and Z axes to adjust the pose of the light source. After the pose of the light source is adjusted, the image acquisition module continues to acquire the self-coherent grating image and sends the latest acquired self-coherent grating image to the image calculation module. After the image calculation module completes the state calculation, it feeds back to the self-coherent grating image until a self-coherent grating image that meets the requirements is obtained.

[0033] In this embodiment, the multi-channel coupling control module is further configured to, when the clarity and / or the stripe straightness meet the preset conditions, control the three-axis motion module to translate in a direction perpendicular to the grating in the measured cylindrical lens grating glass substrate to drive the light source to translate; correspondingly, the image acquisition module is configured to acquire the self-coherent grating image corresponding to the translated light source.

[0034] Specifically, after the imaging system can acquire a self-coherent grating image that meets the preset conditions, that is, the self-coherent grating image acquired by the imaging system meets the requirements. Considering that the best capture range of the grating image for defects is the transition section of the light and dark stripes, and at the same time considering the process accuracy requirements of the customized light source special-shaped strip lens column, in order to cover the entire detection area and avoid blind spots, when the clarity and / or the stripe straightness meet the preset conditions, the image acquisition module acquires the self-coherent grating image; the three-axis motion module performs multiple micro-translations to drive the light source to perform micro-translations, and acquires the self-coherent grating image after each micro-translation of the light source to complete the image acquisition of the current area; the external translation mechanism drives the image acquisition module and the three-axis motion module as a whole to translate to the adjacent area, and repeats the operation of the three-axis motion module performing multiple micro-translations to drive the light source to perform micro-translations and acquiring the self-coherent grating image after each micro-translation of the light source until the image acquisition of the measured cylindrical lens grating glass substrate is completed.

[0035] The imaging system for detecting defects of a cylindrical lens grating glass substrate disclosed in this embodiment includes: a light source, a three-axis motion module, the cylindrical lens grating glass substrate to be measured, an image acquisition module, an image calculation module, and a multi-channel coupling control module; wherein, the light source is a surface light source attached with a plurality of special-shaped strip lens cylinders; the light source is arranged on the three-axis motion module; the light source and the image acquisition module are located above the cylindrical lens grating glass substrate to be measured; the image acquisition module is connected to the image calculation module, the image calculation module is connected to the multi-channel coupling control module, and the multi-channel coupling control module is connected to the three-axis motion module; the light source is used to irradiate the cylindrical lens grating glass substrate to be measured; the image acquisition module is used to collect the light reflected by the cylindrical lens grating glass substrate to be measured to obtain a self-coherent grating image and send the self-coherent grating image to the image calculation module; the image calculation module is used to calculate the clarity and stripe flatness of the self-coherent grating image and send the clarity and stripe flatness to the multi-channel coupling control module; the multi-channel coupling control module is used to control the motion of the three-axis motion module according to the clarity and stripe flatness to adjust the pose of the light source. The imaging system for detecting defects of a cylindrical lens grating glass substrate provided by the embodiment of the present invention adjusts the pose of the light source through the clarity and stripe flatness of the self-coherent grating image until the clarity and stripe flatness of the obtained self-coherent grating image meet the defect detection conditions, which can improve the accuracy and efficiency of defect detection of the cylindrical lens grating glass substrate.

[0036] Embodiment 2

[0037] Figure 6 is a flowchart of an imaging method for detecting defects of a cylindrical lens grating glass substrate provided by Embodiment 2 of the present invention. This method is used for the imaging system for detecting defects of a cylindrical lens grating glass substrate in the above embodiment. As Figure 6 shown, this method includes the following steps:

[0038] S510, obtain a self-coherent grating image.

[0039] Among them, the self-coherent grating image is obtained by collecting the light reflected by the cylindrical lens grating glass substrate to be measured. In this embodiment, in order to form an image on the cylindrical lens grating glass substrate, the light source is a surface light source attached with a plurality of uniformly arranged special-shaped strip lens cylinders, and the number of special-shaped strip lens cylinders included in the light source is in a set ratio to the cylindrical lens gratings in the cylindrical lens grating glass substrate to be measured; and the part of the surface light source without the attached special-shaped strip lens cylinders is subjected to light shielding treatment. And the special-shaped strip lens cylinder meets the following conditions: the end face is special-shaped; the maximum radius envelope of the special-shaped strip lens cylinder matches the size of the cylindrical lens gratings in the cylindrical lens grating glass substrate to be measured.

[0040] In this embodiment, when the light source irradiates the lenticular grating glass substrate at the height and angle according to the arrangement direction of the lenticular grating, the lenticular grating glass substrate reflects the incident light to form a self-coherent grating image. In order to accurately detect defects based on the self-coherent grating image, the clarity and stripe straightness of the self-coherent grating image need to meet preset conditions. Therefore, it is necessary to adjust the pose of the light source to obtain a self-coherent grating image with clarity and stripe straightness meeting the preset conditions.

[0041] S520. Determine the clarity and stripe straightness of the self-coherent grating image, and judge whether the clarity and stripe straightness meet the preset conditions; if the clarity and / or stripe straightness do not meet the preset conditions, then execute S530; if the clarity and / or stripe straightness meet the preset conditions, then execute S540.

[0042] Among them, the self-coherent grating image is an image composed of light and dark alternating stripes. Therefore, the clarity can be represented by the black-and-white contrast of the self-coherent grating image, and the stripe straightness can be represented by the straightness of each bright stripe in the self-coherent grating image. Exemplarily, Figure 7 is a schematic diagram of a self-coherent grating image in this embodiment. As Figure 7 shown, the self-coherent grating image is composed of light and dark alternating stripes. The preset conditions can be that the clarity and stripe straightness are greater than a certain value.

[0043] Optionally, the method for determining the clarity of the self-coherent grating image can be: dividing the self-coherent grating image into multiple sub-images; determining the black-and-white contrast of each sub-image; statistically calculating the mean, variance and extreme values of the black-and-white contrasts of the multiple sub-images; and determining the clarity of the self-coherent grating image based on the mean, variance and extreme values of the black-and-white contrasts.

[0044] Among them, the extreme value includes the maximum value or the minimum value. The method of dividing the self-coherent grating image into multiple sub-images can be to divide the self-coherent grating image in a grid manner, so as to obtain multiple sub-images. Exemplarily, the self-coherent grating image can be divided in an N*N grid manner. The method of determining the black-and-white contrast of each sub-image can be: for each sub-image, obtain the gray values of each pixel point in the sub-image; determine the average gray value of the pixel points whose gray values are less than the first set threshold as the first average gray value; determine the average gray value of the pixel points whose gray values are greater than the second set threshold as the second average gray value; determine the ratio of the second average gray value to the second average gray value as the black-and-white contrast of the sub-image. Among them, the first set threshold is less than the second set threshold. For example, the first set threshold is set to 0.3 and the second set threshold is set to 0.7. After determining the black-and-white contrast of each sub-image, determine the mean, variance and extreme value of the black-and-white contrast of multiple sub-images, and finally perform weighted summation on the mean, variance and extreme value of the black-and-white contrast to obtain the sharpness of the self-coherent grating image.

[0045] Optionally, the method of determining the stripe flatness of the self-coherent grating image can be: crop the stripes in the self-coherent grating image to obtain multiple stripe sub-images; extract the stripe centerlines of the used stripe sub-images; calculate the distances from multiple pixel points on the stripe edges to the stripe centerlines, and calculate the variance of the multiple distances as the first variance; calculate the multiple widths of the stripe, and calculate the variance of the multiple widths as the second variance; perform weighted summation on the first variance and the second variance to obtain the flatness of the stripe in the stripe sub-image.

[0046] Among them, the stripe is a bright stripe or a dark stripe. In this embodiment, only the bright stripes in the self-coherent grating image are cropped or only the dark stripes in the self-coherent grating image are cropped. The distances from multiple pixel points on the stripe edge to the centerline can be understood as: the distances from multiple pixel points on one side of the stripe to the stripe centerline.

[0047] S530, adjust the pose of the light source according to the sharpness and / or the stripe flatness, and return to execute the operation of obtaining the self-coherent grating image until the sharpness and the stripe flatness meet the preset conditions.

[0048] Among them, the light source is used to irradiate the measured cylindrical lens grating glass substrate. The light source is installed on a three-axis motion module, and the pose of the light source is adjusted by adjusting the pose of the three-axis motion module.

[0049] Optionally, the method of adjusting the pose of the light source according to the sharpness and / or the stripe flatness can be: determine the sharpness deviation amount and the stripe flatness deviation amount; adjust the pose of the light source according to the sharpness deviation amount and / or the stripe flatness deviation amount.

[0050] Among them, the clarity deviation amount is the deviation between the clarity of the current self - coherent grating image and the target clarity; the stripe flatness deviation amount is the deviation between the stripe flatness of the current self - coherent grating image and the target stripe flatness. The target clarity can be understood as the clarity that meets the conditions, and the target stripe flatness can be understood as the stripe flatness that meets the conditions. In this embodiment, the process of adjusting the pose of the light source according to the clarity deviation amount and / or the stripe flatness deviation amount can be as follows: First, determine the rotation degrees of the three axes, that is, the rotation degree of the X - axis, the rotation degree of the Y - axis, and the rotation degree of the Z - axis, based on the clarity deviation amount and / or the stripe flatness deviation amount. Then, control the three - axis motion module to rotate around the three axes based on the rotation degrees of the three axes to drive the light source to rotate around the three axes, thereby adjusting the pose of the light source.

[0051] Optionally, the method of adjusting the pose of the light source according to the clarity deviation amount and / or the stripe flatness deviation amount can be: Determine the main control channel currently controlled according to the change trend of the clarity deviation amount and / or the stripe flatness deviation amount; Adjust the pose of the light source according to the main control channel.

[0052] Among them, the main control channel is the clarity control channel (rotating around the Z - axis) or the flatness control channel (rotating around the X - axis and the Y - axis). In this embodiment, since the factors affecting clarity are independent variables ∅(z), ∅(x), ∅(y), and ∅(z) is the main variable, therefore, mainly control the light source to rotate along the Z - axis according to the clarity deviation amount. Since the factors affecting stripe flatness are independent variables ∅(x), ∅(y), the stripe flatness deviation amount controls the light source to rotate around the X - axis and the Y - axis.

[0053] In this embodiment, after adjusting the pose of the light source, return to execute the operation of acquiring the self - coherent grating image; Determine the clarity and stripe flatness of the self - coherent grating image, and judge whether the clarity and stripe flatness meet the preset conditions, until the clarity and stripe flatness meet the preset conditions.

[0054] S540, the image acquisition module acquires the self - coherent grating image; the three - axis motion module makes multiple micro - translations to drive the light source to make micro - translations, and acquires the self - coherent grating image after each micro - translation of the light source to complete the image acquisition of the current area; the external translation mechanism drives the image acquisition module and the three - axis motion module as a whole to translate to the adjacent area, and repeats the operation of the three - axis motion module making multiple micro - translations to drive the light source to make micro - translations and acquiring the self - coherent grating image after each micro - translation of the light source until the image acquisition of the measured cylindrical lens grating glass substrate is completed. Finally, defect detection is performed based on the multiple acquired self - coherent grating images. Thereby improving the accuracy of defect detection.

[0055] Among them, the three - axis motion module making multiple micro - translations to drive the light source to make micro - translations can be that the three - axis motion module makes multiple micro - translations along the x - axis of the three - axis motion platform.

[0056] The technical solution of this embodiment is to obtain a self - coherent grating image, where the self - coherent grating image is obtained by collecting the light reflected by the cylindrical lens grating glass substrate to be measured; determine the clarity and stripe straightness of the self - coherent grating image, and judge whether the clarity and stripe straightness meet the preset conditions; if the clarity and / or stripe straightness do not meet the preset conditions, adjust the pose of the light source according to the clarity and / or the stripe straightness, and return to execute the operation of obtaining the self - coherent grating image until the clarity and stripe straightness meet the preset conditions. This can improve the efficiency and accuracy of defect detection of the cylindrical lens grating glass substrate.

[0057] It should be understood that various forms of the processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in the present invention can be executed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved, and no limitation is made herein.

[0058] The above - mentioned specific embodiments do not constitute a limitation on the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub - combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. An imaging system for detecting defects in a cylindrical lens grating glass substrate, characterized in that, Including: A light source, a three-axis motion module, a cylindrical lens grating glass substrate to be measured, an image acquisition module, an image calculation module, and a multi-channel coupling control module; Among them, the light source is a surface light source attached with a plurality of specially-shaped strip-shaped lens cylinders arranged uniformly; the light source is arranged on the three-axis motion module; the light source and the image acquisition module are located above the cylindrical lens grating glass substrate to be measured; the image acquisition module is connected to the image calculation module, the image calculation module is connected to the multi-channel coupling control module, and the multi-channel coupling control module is connected to the three-axis motion module; The light source is used to irradiate the cylindrical lens grating glass substrate to be measured; the image acquisition module is used to collect the light reflected by the cylindrical lens grating glass substrate to be measured to obtain a self-coherent grating image, and send the self-coherent grating image to the image calculation module; the image calculation module is used to calculate the clarity and stripe flatness of the self-coherent grating image, and send the clarity and stripe flatness to the multi-channel coupling control module; The multi-channel coupling control module is used to control the movement of the three-axis motion module according to the clarity and the stripe flatness to adjust the pose of the light source.

2. The system according to claim 1, wherein The end face of the specially-shaped strip-shaped lens cylinder is specially-shaped; the maximum radius envelope of the specially-shaped strip-shaped lens cylinder matches the size of the cylindrical lens grating in the cylindrical lens grating glass substrate to be measured.

3. The system according to claim 1 or 2, characterized in that, The spatial distribution frequency domain characteristics of the specially-shaped strip-shaped lens cylinders in the light source and the spatial distribution frequency domain characteristics of the cylindrical lens gratings in the cylindrical lens grating glass substrate to be measured present a specific proportional relationship, where the proportional relationship is a value between 0.5 and 1.2; and the part of the surface light source without the attached specially-shaped strip-shaped lens cylinders is shaded to make the light source have periodic grid characteristics.

4. The system according to claim 1, wherein Taking the clarity and / or the stripe flatness as a state quantity, using the multi-channel coupling control module to control the pose of the light source, so that the light source and the cylindrical lens grating glass substrate to be measured generate a self-coherent mechanism and obtain a self-coherent grating image whose clarity and stripe flatness meet preset conditions.

5. The system according to claim 1, wherein When the clarity and the stripe flatness meet the preset conditions, the image acquisition module collects the self-coherent grating image; the three-axis motion module performs multiple micro translations to drive the light source to perform micro translation, and collects the self-coherent grating image after each micro translation of the light source to complete the image acquisition of the current area; the external translation mechanism drives the image acquisition module and the three-axis motion module as a whole to translate to an adjacent area, and repeats the operation of the three-axis motion module performing multiple micro translations to drive the light source to perform micro translation and collecting the self-coherent grating image after each micro translation of the light source until the image acquisition of the cylindrical lens grating glass substrate to be measured is completed.

6. A control method for an imaging system used for detecting defects on a cylindrical lens grating glass substrate, characterized in that, The method is used for the imaging system for defect detection of a cylindrical lens grating glass substrate according to any one of claims 1-5, including: Obtaining a self-coherent grating image; wherein, the self-coherent grating image is obtained by collecting the light reflected by the cylindrical lens grating glass substrate to be measured; Determining the clarity and stripe flatness of the self-coherent grating image, and judging whether the clarity and stripe flatness meet the preset conditions; If the clarity and stripe straightness do not meet the preset conditions, adjust the pose of the light source according to the clarity and / or the stripe straightness, and return to perform the operation of obtaining the self-coherent grating image until the clarity and stripe straightness meet the preset conditions; wherein, the light source is used to irradiate the measured cylindrical grating glass substrate.

7. The method according to claim 6, wherein Determining the clarity of the self-coherent grating image includes: Dividing the self-coherent grating image into multiple sub-images; Determining the black-and-white contrast of each of the sub-images; Statistically calculating the mean, variance, and maximum and minimum values of the black-and-white contrasts of the multiple sub-images; wherein, the maximum and minimum values include the maximum value or the minimum value; Determining the clarity of the self-coherent grating image based on the mean, variance, and maximum and minimum values of the black-and-white contrasts.

8. The method according to claim 6, characterized in that, Determining the stripe straightness of the self-coherent grating image includes: Cropping the stripes in the self-coherent grating image to obtain multiple stripe sub-images; wherein, the stripes are bright stripes or dark stripes; Extracting the stripe centerlines of the used stripe sub-images; Calculating the distances of multiple pixel points on the stripe edges from the stripe centerlines, and calculating the variance of the multiple distances as the first variance; Calculating the multiple widths of the stripe, and calculating the variance of the multiple widths as the second variance; Performing a weighted sum of the first variance and the second variance to obtain the straightness of the stripe in the stripe sub-image.

9. The method according to claim 6, wherein Adjusting the pose of the light source according to the clarity and / or the stripe straightness includes: Determining the clarity deviation amount and the stripe straightness deviation amount; wherein, the clarity deviation amount is the deviation between the clarity of the current self-coherent grating image and the target clarity set as the target; the stripe straightness deviation amount is the deviation between the stripe straightness of the current self-coherent grating image and the target stripe straightness set as the target; Adjusting the pose of the light source according to the clarity deviation amount and the stripe straightness deviation amount.

10. The method according to claim 9, wherein Adjusting the pose of the light source according to the clarity deviation amount and the stripe straightness deviation amount includes: Determining the main control channel of the current control according to the change trends of the clarity deviation amount and the stripe straightness deviation amount; wherein, the main control channel is the clarity control channel or the straightness control channel; Controlling the pose of the light source to be adjusted according to the main control channel.

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