阅读说明：本技术 一种屏缺陷检测方法和系统 (Screen defect detection method and system ) 是由 洪志坤 张胜森 欧昌东 郑增强 于 2019-08-26 设计创作，主要内容包括：本发明涉及一种屏缺陷检测方法和系统。所述屏缺陷检测方法,包括：采用设置在屏前不同角度的第一成像装置和第二成像装置对屏进行连续成像获取第一视图和第二视图；根据所述第一视图和第二视图获取缺陷点,并根据所述第一视图中所述缺陷点到预设参考点的第一距离和所述第二视图中同一所述缺陷点到所述预设参考点的第二距离的比较判断该缺陷点在所述屏的层位置。通过采用上述方法,可以判定缺陷所在层位置,从而对缺陷进行区分处理。(The invention relates to a screen defect detection method and a system. The screen defect detection method comprises the following steps: adopting a first imaging device and a second imaging device which are arranged in front of the screen at different angles to continuously image the screen to acquire a first view and a second view; and acquiring a defect point according to the first view and the second view, and judging the layer position of the defect point on the screen according to the comparison between the first distance from the defect point to a preset reference point in the first view and the second distance from the same defect point to the preset reference point in the second view. By adopting the method, the position of the layer where the defect is located can be judged, so that the defect is distinguished and processed.)

1. A screen defect detection method is characterized by comprising the following steps:

adopting a first imaging device and a second imaging device which are arranged in front of the screen at different angles to continuously image the screen to acquire a first view and a second view;

and acquiring a defect point according to the first view and the second view, and judging the layer position of the defect point on the screen according to the comparison between the first distance from the defect point to a preset reference point in the first view and the second distance from the same defect point to the preset reference point in the second view.

2. The method for detecting the screen defect of claim 1, wherein the step of judging the layer position of the defect point on the screen specifically comprises the following steps:

if the difference value between the first distance and the second distance is smaller than or equal to a first preset threshold value, the defect point is judged to be located on the upper surface of the screen, and if the difference value is larger than the first preset threshold value, the defect point is judged to be located on the lower layer of the screen.

3. The method for detecting the screen defect of claim 2, wherein the step of judging that the defect point is located at the lower layer of the screen specifically comprises the steps of:

the specific layer position of the defect point on the lower layer of the screen is determined according to the difference value of the first distance and the second distance, namely the larger the difference value is, the farther the layer where the defect point is located is from the upper surface of the screen.

4. The screen defect detecting method of claim 2, wherein said first preset threshold is preset based on a horizontal coordinate position of said defect spot in a plane coordinate system parallel to the screen surface.

5. The screen defect detecting method according to any one of claims 1 to 4, wherein the first imaging device is disposed right in front of the screen, and the second imaging device is disposed in front of the screen side.

6. The screen defect detecting method of claim 5, wherein the first imaging device and/or the second imaging device is a line scan camera.

7. A screen defect detection system, comprising:

the first imaging device and the second imaging device are arranged in front of the screen at different angles and are used for continuously imaging the screen to acquire a first view and a second view;

and the control device is used for acquiring a defect point according to the first view and the second view, and judging the layer position of the defect point on the screen according to the comparison between the first distance from the defect point to a preset reference point in the first view and the second distance from the defect point to the preset reference point in the second view.

8. The screen defect detection system of claim 7, wherein the first imaging device is disposed directly in front of the screen and the second imaging device is disposed laterally in front of the screen.

9. The screen defect detecting system of claim 7 or 8, wherein the first imaging device and/or the second imaging device are both line scan cameras.

10. The screen defect detecting system of claim 7 or 8, wherein an angle formed by a line connecting the first imaging device to the screen center point and a line connecting the second imaging device to the screen center point is in a range of 30 ° to 45 °.

Technical Field

The invention relates to the technical field of display, in particular to a screen defect detection method and system.

Background

During the manufacture of display panels, the display panels may have defects for various reasons, including scratches, foreign objects, lint, scratches, dirt, etc. The production yield of factory products is reduced due to the defects, the display screen with the defects can be detected through defect detection, and the shipment quality is improved.

The existing display screen defect detection method generally adopts a mode as shown in figure 1, a side light source is used for lighting, and foreign matters in a screen film and outside the film can illuminate light, so that when a camera is used for detection, the foreign matters in the film or outside the film can be detected, and a screen with the foreign matters is marked as a defect screen.

However, the existing display screen defect detection method cannot distinguish the layer position of the defect, namely the defect is on the surface or the lower layer, once the screen is marked as a defective screen, the screen needs to be completely replaced, and the screen production cost is high.

Disclosure of Invention

Aiming at the defects or the improvement requirements of the prior art, the invention provides a screen defect detection method and a screen defect detection system, which can detect the layer position of the screen defect.

According to one aspect of the present invention, a screen defect detecting method of the present invention includes:

adopting a first imaging device and a second imaging device which are arranged in front of the screen at different angles to continuously image the screen to acquire a first view and a second view;

and acquiring a defect point according to the first view and the second view, and judging the layer position of the defect point on the screen according to the comparison between the first distance from the defect point to a preset reference point in the first view and the second distance from the same defect point to the preset reference point in the second view.

By adopting the method, the position of the layer where the screen defect is located can be judged, so that whether the screen defect is located on the upper surface or the inner layer can be distinguished, and distinguishing processing can be carried out in a matched manner, the defective screen does not need to be completely replaced, and the screen production cost can be greatly reduced.

As a further improvement of the present invention, the step of judging the layer position of the defect point on the screen specifically comprises:

if the difference value between the first distance and the second distance is smaller than or equal to a first preset threshold value, the defect point is judged to be located on the upper surface of the screen, and if the difference value is larger than the first preset threshold value, the defect point is judged to be located on the lower layer of the screen.

As a further improvement of the present invention, the determining that the defect point is located in the lower layer of the screen specifically includes:

the specific layer position of the defect point on the lower layer of the screen is determined according to the difference value of the first distance and the second distance, namely the larger the difference value is, the farther the layer where the defect point is located is from the upper surface of the screen.

As a further improvement of the present invention, the first preset threshold is preset based on a horizontal coordinate position of the defective dot in a plane coordinate system parallel to the screen surface.

As a further improvement of the present invention, the first imaging device is disposed right in front of the screen, and the second imaging device is disposed in front of the screen side.

As a further improvement of the present invention, the first imaging device and/or the second imaging device are both line scan cameras.

By adopting the line scanning camera, the distance can be accurately positioned, so that the detection accuracy is higher.

According to another aspect of the present invention, there is provided a screen defect detecting system including: the first imaging device and the second imaging device are arranged in front of the screen at different angles and are used for continuously imaging the screen to acquire a first view and a second view;

and the control device is used for acquiring a defect point according to the first view and the second view, and judging the layer position of the defect point on the screen according to the comparison between the first distance from the defect point to a preset reference point in the first view and the second distance from the defect point to the preset reference point in the second view.

In summary, compared with the prior art, the above technical solution contemplated by the present invention has the following beneficial effects: the position of the layer where the screen defect is located can be judged, so that whether the screen defect is located on the upper surface or the inner layer can be distinguished, the screen can be distinguished and processed in a matched mode, the defective screen does not need to be replaced completely, and the screen production cost can be greatly reduced. If the defect is located on the cover glass plate on the upper surface of the screen, the defect can be removed by wiping to remove dust or dirt from the cover glass plate or only replacing the cover glass plate without completely replacing the defective screen. The cost of wiping or replacing the glass cover plate is far less than the cost of replacing the whole screen, so that the production cost of the screen can be greatly reduced.

Drawings

FIG. 1 is a schematic diagram of a prior art screen defect detection method;

fig. 2 to 4 are schematic diagrams of a screen defect detection method according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific examples described herein are intended to be illustrative only and are not intended to be limiting. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

According to the scheme provided by the embodiment of the invention, the first imaging device and the second imaging device which are positioned at different angles of the screen can be adopted to image the screen to judge the layer position of the screen defect, so that whether the screen defect is positioned on the upper surface or the inner layer can be distinguished, the defect treatment can be carried out in a matched manner, the defect screen does not need to be completely replaced, and the screen production cost can be greatly reduced.

FIG. 2 is a schematic diagram of the screen defect detection method and system of the present invention applied to actual screen inspection. The invention can be applied to the existing industries of computers, communication, consumer electronics and the like, and screens referred to herein include, but are not limited to, various types of panels, LED display screens, LCD display screens, OLED display screens, mobile phone screens, game machine screens, glass, acrylic plates and the like.

The screen defect detection system comprises a first imaging device and a second imaging device which are arranged in front of the screen at different angles and used for continuously imaging the screen to acquire a first view and a second view; and a control device (not shown in the figure) configured to obtain a defective point according to the first view and the second view, and determine a layer position of the defective point according to a first distance from the defective point in the first view to a preset reference point and a second distance from the defective point in the second view to the preset reference point.

Preferably, the first imaging device is disposed directly in front of the screen, and the second imaging device is disposed in front of the screen side.

Preferably, a line connecting the first imaging device to the center point of the screen and a line connecting the second imaging device to the center point of the screen form an included angle ranging from 30 ° to 45 °. The first distance and the second distance acquired at the angle are accurate, and the test verifies that better detection precision can be obtained.

Preferably, the first imaging device and the second imaging device are both line scan cameras. The area-array camera can shoot a whole image every time, but the depth of field is insufficient, namely, the defects in a certain depth range can be judged, the defects exceeding the depth of field range cannot be shot, and the distance cannot be determined. The line scan camera only shoots one line image at a time, and the whole image is synthesized by continuously picking up images and splicing, so that the distance can be accurately positioned, and the defect detection precision is higher than that of an area-array camera.

The first imaging device is taken as a front view scan camera, and the second imaging device is taken as a side view scan camera. According to the accuracy to be detected and the focal length of the line scanning lens, the required working distance, namely the distance from the center point of the line scanning camera lens to the surface of the screen along the shooting direction, is calculated. The normal line-of-sight camera and the side line-of-sight camera satisfy WD (1+ L/L). Wherein WD is the working distance of the line-scan camera, f is the focal length of the lens, L is the width of the field of view shot by the line-scan camera, and L is the width of the target surface of the line-scan camera.

Two sides of the screen are respectively provided with a side light source, and the angle of the light source needs to be adjustable. Other lighting schemes, such as backlight sources, can be provided, and the implementation of the patent is not affected.

The screen detecting method of the present invention is explained with reference to fig. 3 to 4 including the steps of:

s1 acquiring a first view and a second view by successively imaging the screen with the first imaging device and the second imaging device disposed at different angles in front of the screen. The belt line/carrying platform controls the movement of the screen to be detected, and the first imaging device and the second imaging device perform continuous imaging on the screen to obtain two images at different angles.

S2 defect points are obtained according to the first view and the second view, and the layer position of the defect points on the screen is judged according to the comparison of the first distance from the defect points to a preset reference point in the first view and the second distance from the defect points to the preset reference point in the second view. Any method in the prior art can be used to obtain the defect from the image and how to find out the defect point from the shot picture, for example, by calculating the difference between the average image gray value and the background gray value of each small area, the gray of the defect is generally larger than the gray of the background.

The first imaging device is taken as a normal line-of-sight scanning camera, and the first imaging device is taken as a side line-of-sight scanning camera as an example to explain how to judge the layer position of the defect point.

Assuming that the defect point a is acquired, because the imaging is in a two-dimensional plane and the image has no depth information, in the picture taken by the front view line scan camera, the horizontal distance from the edge point O of the screen to the defect point a taken, that is, the distance from the intersection point of the line connecting the defect point a and the front view camera and the surface layer to the point O is La1, and in the picture taken by the side view line scan camera, the horizontal distance from the edge point O of the screen to the defect point a taken, that is, the distance from the intersection point C of the line connecting the defect point a and the side view camera and the surface layer to the point O is La 2. The distances La1 and La2 can be represented by the number of pixels between the points A and O in the two views. Since the a defect exists in the lower layer of the panel under test, the difference between the distances La1 and La2 is large. Assuming that the defect point B as shown in the figure is acquired, in the picture taken by the front-view line scan camera, the horizontal distance from the defect point B to the screen edge point O is Lb1, and in the picture taken by the side-view line scan camera, the horizontal distance from the defect point B to the screen edge point O is Lb2, and the distances Lb1 and Lb2 can be represented by the number of pixels spaced from the point B to the point O in the two views. Since the B defect exists on the upper surface of the screen to be measured, the difference between the distances Lb1 and Lb2 may be equal or close due to a shooting error.

Therefore, it can be determined whether the difference between the distances La1 and La2 or Lb1 and Lb2 is less than or equal to a first preset threshold, and if the difference is less than or equal to the first preset threshold, it is determined that the defect point is located on the upper surface of the screen, and if the difference is greater than the first preset threshold, it is determined that the defect point is located in a lower layer of the screen, that is, a layer below the upper surface of the screen. In the experiment, for a 16k line scan camera, the distance difference is generally within 10 pixels, so the first preset threshold value can be set to 10. And judging that the point A is positioned in the lower screen layer because the difference between La1 and La2 is larger than a first preset threshold value. And if the Lb1 and Lb2 are smaller than or equal to the first preset threshold, the point B is determined to be positioned on the screen upper surface.

Alternatively, it can also be determined which of the lower layers of the panel the defect is located in based on the difference between the distances La1 and La2, generally the greater the difference as the defect is farther from the upper surface of the panel. If the difference is greater than the first preset threshold and less than or equal to the second preset threshold, determining that the defect point is located in the lower screen layer and close to the first layer of the surface layer, if the difference is greater than the second preset threshold, determining that the defect point is located in the lower screen layer and far away from the second layer of the surface layer, and the second preset threshold is greater than the first preset threshold. The screen of the corresponding layer can be replaced according to the judgment result to remove the defects, and the cost is reduced.

The first and second preset thresholds may be predefined according to the horizontal coordinate position of said defect point in a planar coordinate system parallel to the screen surface. Generally, when a defect point is located at a lower layer of the screen, the closer the defect point is to the center of the screen, the smaller the distance difference is, the farther the defect point is from the center of the screen, the larger the distance difference is, multiple sets of different first preset thresholds and second preset thresholds can be preset for different positions in a plane coordinate system parallel to the surface of the screen in advance, and after the defect point is obtained, the corresponding first preset threshold and second preset threshold are obtained according to the position of the defect point.

Through the parallax of the imaging devices at different angles, the distance difference from the defect point to the preset reference point is obtained from the two views, so that the layer position of the screen defect on the screen can be judged, and the screen defect can be distinguished from the upper surface or the lower layer or the specific layer on the lower layer, so that the screen defect can be distinguished and processed in a matched manner without completely replacing the defect screen, and the production cost of the screen can be greatly reduced. If the defect is located on the cover glass plate on the upper surface of the screen, the defect can be removed by wiping to remove dust or dirt from the cover glass plate or only replacing the cover glass plate without completely replacing the defective screen. The cost of wiping or replacing the glass cover plate is far less than the cost of replacing the whole screen, so that the production cost of the screen can be greatly reduced. And the imaging device can adopt a line scan camera, or the angle of the imaging device can be set, so that the distance difference from the defect point to the preset reference point can be more accurately acquired from the two views, and the detection precision of the layer position of the defect can be further improved. Meanwhile, the system is very simple in composition and strong in applicability.

It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.