KR20160101436A

KR20160101436A - Method for inspectiong the outside of panels

Info

Publication number: KR20160101436A
Application number: KR1020150023982A
Authority: KR
Inventors: 정성훈; 김종민; 박진영
Original assignee: 박진영
Priority date: 2015-02-17
Filing date: 2015-02-17
Publication date: 2016-08-25

Abstract

More particularly, the present invention relates to a method for inspecting a foreign object on a surface of a display panel and a polarizing film, To a method for inspecting a foreign object on a surface that can accurately detect the type and position of the object and provide information to the user.
A method of photographing an image of a surface of a display panel or a polarizing film by using a line scan camera according to an embodiment of the present invention includes the steps of: photographing a surface of an object to be inspected with a line scan camera to obtain an image; Analyzing a surface state from the image to recognize a foreign object; Extracting information on the foreign object when the foreign object is recognized in the image, comparing the extracted foreign object information with previously stored foreign object information data, and detecting the type of the foreign object; And displaying the type and location of the detected foreign object to a user.

Description

[0001] The present invention relates to a method for inspecting foreign objects on a surface,

More particularly, the present invention relates to a method for inspecting a foreign object on a surface of a display panel and a polarizing film, To a method for inspecting a foreign object on a surface that can accurately detect the type and position of the object and provide information to the user.

A display device such as a liquid crystal display (LCD), an organic light emitting diode (OLED), a plasma display panel (PDP), an electrophoretic display (EPD) Are manufactured through various processes. Such a manufacturing process includes an inspection process for checking whether the display panel used in the display device is normally operated and whether the display panel is adhered with foreign matter or scratching.

The polarizing film is adhered to one surface or both surfaces of the liquid crystal cell and used as a part of the liquid crystal display panel. A liquid crystal display (LCD) is a display device developed to replace a cathode ray tube (CRT) used in monitors such as TVs and computers. It has advantages such as lightweight and thin design, high image quality and low power consumption It is now widely used in various industrial fields.

The basic structure of a polarizing film is a polarizing element for controlling polarization characteristics by dyeing iodine or dye to PVA (Poly Vinyl Alcohol), and a TAC (Tri-Acetyl-Cellulose) film for protecting the polarization element, And a pressure sensitive adhesive such as PSA (Pressure Sensitive Adhesive) for attaching to the upper and lower panels of the panel is formed to constitute a polarizing film. Further, a release film made of PET (polyethylene terephthalate) for protecting the pressure sensitive adhesive is adhered to the upper part of the pressure sensitive adhesive so as to protect the polarizing film, and a PET protective film is attached to the back side of the TAC film .

However, the polarizing film thus formed adheres to the liquid crystal cell and functions as a component of the display panel, so that if the polarizing film is interposed with foreign matter, the display quality is deteriorated. Examples of the foreign substances include a bulge generated when a polarizing function is imparted to a polarizing element, and a stretched white point such as a wide view liquid crystal crack. Bubbles generated by attaching a TAC film to both sides of the polarizing element, There may be a white spot. In addition, the releasing film constituting the outer surface of the polarizing film may have a self-defective releasing film pit formed thereon, or the outer surface of the releasing film and the protective film may have a surface such as an adhesive, a surface scratch, Can be formed.

Meanwhile, the foreign matter inspection process of the display panel and the film member according to the related art has been performed by a visual inspection by an operator or a light inspection. That is, conventionally, an inspection process is performed on a display panel by a method in which an operator looks at a display panel driven by an inspection signal with a naked eye and determines a portion that is not normally operated, or the polarizing film is irradiated with light, And the foreign matter is inspected by detecting the transmitted light.

However, there is a problem that reliability of the inspection result is deteriorated because the operator's skill, experience, concentration, etc. affect the inspection result on the display panel. It takes a long time to perform the inspection, and there is a disadvantage that the yield for the display panel manufacturing process is lowered.

In addition, the inspection method for detecting foreign matter by detecting transmitted light has a problem in that it is detected after the internal object existing inside, especially the internal object such as threader or elongated white spot, is low and thus attached to the panel. Also, since the false detection rate is high due to the penetration test, it is not possible to accurately detect the internal matter even if the reflection test is performed in parallel.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a display device and a polarizing film in which a foreign matter attached to a flat surface and a back surface of a polarizing film is photographed through a camera, The present invention provides a method for inspecting a foreign object on a surface that can accurately detect the type and position of a foreign object and provide information to a user.

Another object of the present invention is to provide a display panel and a polarizing film which can reduce the time taken to perform the inspection on the display panel and the polarizing film, thereby improving the yield of the display panel manufacturing process, And to provide a method for inspecting a foreign object on a surface on which a work can be performed.

A method of photographing an image of a surface of a display panel or a polarizing film by using a line scan camera according to an embodiment of the present invention includes the steps of: photographing a surface of an object to be inspected with a line scan camera to obtain an image; Analyzing a surface state from the image to recognize a foreign object; Extracting information on the foreign object when the foreign object is recognized in the image, comparing the extracted foreign object information with previously stored foreign object information data, and detecting the type of the foreign object; And displaying the type and location of the detected foreign object to a user.

In the step of detecting the type of the object, the shape information of the object can be extracted as a pixel value and compared with the previously stored object information data, or the information of at least one of the density, pattern and texture information of the object can be extracted It is possible to detect it by comparing it with previously stored foreign object information data. At this time, the concentration information of the foreign object is analyzed by analyzing the contrast distribution of the foreign object through the pixel value.

And displaying the detected type and location of the foreign object on the user, removing the foreign substance on the surface to be inspected by using the foreign object removing method corresponding to the detected foreign object information.

The present invention can acquire a test image for automatically detecting whether or not the display panel and the polarizing film are defective, and thus, an inspection process for the display panel can be implemented by an automatic inspection method. Further, it is possible to reduce the time required for the inspection process for the display panel and the polarizing film, thereby improving the yield for the display panel manufacturing process. Also, accuracy and reliability of inspection results can be improved by preventing the operator's skill, experience, concentration, etc. from influencing the inspection results on the display panel.

1 is a flow chart of a method for inspecting a foreign object on a surface according to an embodiment of the present invention.
2 is an exemplary view of an apparatus for inspecting a surface of an object to be inspected for a method of inspecting a foreign object on a surface according to an embodiment of the present invention.
3 is a diagram illustrating an example of a UI for providing information on a foreign object to a user in a method for inspecting a foreign object on a surface according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings. It should be understood, however, that the terminology or words of the present specification and claims should not be construed in an ordinary sense or in a dictionary, and that the inventors shall not be limited to the concept of a term It should be construed in accordance with the meaning and concept consistent with the technical idea of the present invention based on the principle that it can be properly defined. Therefore, the embodiments described in the present specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention, and not all of the technical ideas of the present invention are described. Therefore, It is to be understood that equivalents and modifications are possible.

FIG. 1 is a flow chart of a method for inspecting a foreign substance on a surface according to an embodiment of the present invention, FIG. 2 is an exemplary view of an apparatus for inspecting a surface of an object to be inspected for a method of inspecting foreign objects on a surface according to an embodiment of the present invention, 3 is an exemplary view of a UI for providing information of a foreign object to a user in a method of inspecting foreign objects on a surface according to an embodiment of the present invention.

Referring to FIGS. 1 to 3, in a method of photographing an image of a surface of a display panel or a polarizing film by using a line scan camera and inspecting a foreign object, the surface of the object to be inspected is photographed by a line scan camera (S20) of recognizing a foreign object by analyzing a surface state from a video image (S20). The foreign object information is extracted and compared with previously stored foreign object information data (S30) of detecting the type of the foreign object and displaying (S40) the type and position of the detected foreign object to the user.

In step S10 of acquiring a video image by causing the line scan camera to shoot the surface of the object to be inspected, a display panel or a polarizing film to be inspected is placed on a test plate through a foreign body inspection apparatus shown in Fig. 2 One or more cameras are moved in order to capture all of the surface of the object to be inspected. When all of the surface of the object to be inspected is photographed, the control unit acquires the image of the surface. The camera includes at least one camera that obtains a video image of an appearance of an inspection object through a line scan method or an area photographing method.

In the step S20 of analyzing the surface state from the image after acquiring the image image, the control unit analyzes the surface state from the image to recognize the foreign object. Since the entire image of the surface is acquired, it is possible to recognize that the foreign matter exists at the corresponding position when the pixel value is changed in comparison with the surrounding background in the entire image.

If the foreign object is recognized in the image after analyzing the presence of the foreign object, the information of the foreign object is extracted and compared with the previously stored foreign object information data to detect the kind of foreign object (S30) It is possible to detect what kind of foreign object through the foreign object information data. The foreign substance information data basically has various information about foreign substances frequently occurring in the display panel and the polarizing film.

As described above, not only the scratches frequently occurring in the display panel but also the elongation points such as the elongation occurring in the polarizing film, the wide view liquid crystal cracking, the bubbles generated by attaching the TAC film to both sides of the polarizing element, The release film pits which are self-defects in the release film constituting the outer surface, the release film on the outer surface of the release film and the protective film during the polarizing film production process, the surface scratches, etc., The information will be stored.

On the other hand, in step S30, it is possible to extract the shape information of the foreign object as a pixel value, and compare the extracted shape information with previously stored foreign matter information data. And comparing the pixel value of the foreign object recognized in the image of the surface with the preliminarily stored data to grasp the morphologically similar foreign object first. Of course, since the direction can be variable, a shape comparison through the pixel values can be performed in consideration of such a point.

In addition, it is also possible to extract information of at least one of the density, pattern and texture information of the foreign object, and compare the extracted information with previously stored foreign object information data. The concentration of the foreign object can be extracted by analyzing the distribution of light and darkness of the foreign object through the pixel value. Since the contours from the center to the peripheral edge are formed differently depending on the foreign objects, it is possible to compare the concentrations to determine the kinds of foreign objects. Likewise, pattern and texture information can also be obtained by analyzing the pixel values of the captured image.

In step S40, the type and location of the foreign object are displayed to the user after detecting the type of foreign object, various information about the surface image of the object to be inspected and information on the detected foreign object are provided to the user. As shown in FIG. 3, the display can provide information through the UI, and such UI is provided to output various information. A surface image of the object to be inspected, an enlarged image of the foreign object extracted therefrom, position and type information of the detected foreign object, size information, and contrast information. The user can easily grasp the desired information of the foreign object through the UI.

The method may further include a step (S50) of displaying the information on the foreign object to the user and removing the foreign object on the surface to be inspected using the foreign object removing method corresponding to the detected foreign object information. A foreign substance removal module is separately formed on the foreign substance inspection device on the surface, and the foreign substance is removed by carrying out a proper removal method through the kind information of the foreign substance detected by the control part. Dust and spruce can be removed by wind pressure. In the case of chemical foreign matter, it is possible to remove the foreign matter by injecting a disinfectant or chemical which can be removed.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it is possible to make various modifications and variations without departing from the spirit and scope of the invention. Accordingly, the scope of the appended claims should include all such modifications and changes as fall within the scope of the present invention.

Claims

A method of inspecting a foreign object by photographing a surface of a display panel or a polarizing film with a line scan camera,
Capturing a surface of an object to be inspected with a line scan camera to obtain an image image;
Analyzing a surface state from the image to recognize a foreign object;
Extracting information on the foreign object when the foreign object is recognized in the image, comparing the extracted foreign object information with previously stored foreign object information data, and detecting the type of the foreign object; And
And displaying the detected type and position of the foreign object to the user.

The method according to claim 1,
Wherein the type information of the object is detected by comparing the shape information of the object with pixel values and compared with previously stored object information data.

The method according to claim 1,
Wherein the step of detecting the kind of the foreign object comprises the step of extracting at least one of the density, pattern and texture information of the foreign object and comparing the extracted information with previously stored foreign object information data.

The method of claim 3,
Wherein the density information of the foreign object is extracted by analyzing the density distribution of the foreign object through the pixel value.

The method according to claim 1,
After the step of displaying to the user the type and position of the detected foreign object
Further comprising the step of removing foreign objects on the surface to be inspected using a foreign object removing method corresponding to the detected foreign object information.