KR20140068543A - Inspectiing device of display panel and inspecting method of the same - Google Patents

Abstract

According to the present invention, a display panel inspecting device provides a stage; a display panel which is mounted on the stage and formed with sub-pixels for displaying an image; a probe unit which is connected with signal lines of the display panel; a signal generator for applying a test pattern to the probe unit; a camera for imaging the test pattern displayed on the display panel; and a client computer for extracting a respective center coordinate of the sub-pixels directly on the basis of the test pattern input by the camera, for setting a search range including a candidate defect position on the basis of the respective center coordinate, and for testing whether the display panel has any defect within the search range.

Description

TECHNICAL FIELD [0001] The present invention relates to a display panel inspection apparatus and a method of inspecting the same,

The present invention relates to a display panel inspection apparatus and a method of inspecting the same.

Recently, as the demand for various portable electronic devices such as mobile phones, PDAs, and notebook computers, and TVs has increased, technologies for display devices have been remarkably developed. The display device has a display panel for image display. The display panel is manufactured through various processes, and the manufacturing process includes an inspection process for checking whether or not the display panel is normally operated.

There are various inspection methods that can be used in the inspection process, and among them, an automatic probe inspection method using a Vision Auto Probe device is representative. In the vision auto-probe inspection method, an inspection image displayed on a display panel is acquired using an area camera or a line camera, and the obtained inspection image is read to determine whether the display panel is defective or defective.

In this vision auto-probe inspection method, it is necessary to know the center position of each sub-pixel constituting the display panel before acquiring the inspection image through the camera. However, the conventional vision auto-probe inspection method has the following problems. In the conventional vision auto-probe inspection method, a calibration pattern is separately input to a display panel to detect the center position of a sub-pixel, a specific reference center point is found in a calibration image obtained through a camera, And the center coordinate value of the corresponding subpixel was obtained. According to the conventional vision auto-probe inspection method, a dedicated pattern for performing the calibration work for each resolution and each product is required, and since a separate calibration image must be obtained while moving the camera prior to acquisition of the inspection image, Time to be long.

Accordingly, it is an object of the present invention to provide a display panel inspection apparatus and an inspection method thereof that can simplify an operation of finding a center position of each subpixel constituting a display panel, thereby shortening an inspection time.

In order to achieve the above object, a display panel inspection apparatus according to an embodiment of the present invention includes a stage; A display panel that is seated on the stage and has subpixels for image display; A probe unit contacting the signal lines of the display panel; A signal generator for applying an inspection pattern to the probe unit; A camera for capturing an inspection pattern displayed on the display panel; And extracting the center coordinates of the subpixels based on the inspection pattern input from the camera, setting a search area including a candidate defective position based on the center coordinates, And a client computer for checking whether or not the panel is defective.

According to another aspect of the present invention, there is provided a method of inspecting a display panel inspection apparatus having a stage, a display panel that is seated on the stage and has subpixels for image display, and a probe unit that contacts signal lines of the display panel, Applying a test pattern to the probe unit through a signal generator; Capturing an inspection pattern displayed on the display panel through a camera; Extracting center coordinates of the subpixels based on a test pattern input from the camera; And setting a search area including a candidate defective position based on each of the center coordinates and checking whether the display panel is defective in the search area.

Since the present invention extracts the center position of the subpixels based on the inspection pattern acquired from the camera, a separate calibration pattern is not required in addition to the inspection pattern. The present invention can omit an additional work process due to the calibration pattern, simplifying the task of finding the center position of each sub-pixel, and consequently shortening the inspection time.

1 is a block diagram showing a display panel inspection apparatus according to an embodiment of the present invention;
FIG. 2 is a flowchart sequentially showing an operation of extracting the center coordinates of subpixels in the client computer and an operation of performing the defect inspection based on the extracted center coordinates.
3A is a diagram showing a comparison between an inspection pattern input image and a check pattern emphasis image.
FIG. 3B shows a Gaussian filter used to emphasize the center of the test pattern image. FIG.
3C shows an example in which a Gaussian filter is applied as a 5x5 mask.
4 is a view showing a process of extracting the center coordinates of subpixels in a display panel.
FIG. 5 is a diagram showing the coordinates of the center of all subpixels extracted by the method of FIG. 4; FIG.
6 shows locations of subpixels for candidate defective positions, search regions, and search region settings;
Fig. 7 is a diagram showing that a defect is checked in a search area; Fig.
FIG. 8 is a view showing an example of setting various coordinates of a test pattern and a center coordinate of a subpixel and detecting whether or not there is a defect. FIG.

Hereinafter, preferred embodiments of the present invention will be described with reference to FIGS. 1 to 8. FIG.

A display panel inspecting apparatus according to the present invention is an inspecting apparatus for inspecting a display panel of a display device for image display by lighting. Specifically, the display panel inspection apparatus according to the present invention is intended to simplify the task of finding the position of each sub-pixel constituting the display panel as a pre-stage for detecting a point defect and a linear defect. The display device includes a liquid crystal display (LCD), an organic light emitting diode (OLED), a plasma display panel (PDP), an electrophoretic display (EPD) Lt; / RTI > The display panel inspection apparatus according to the present invention acquires inspection images for inspection of a display panel and extracts the center positions of the respective subpixels based on the inspection images. The display panel inspection apparatus according to the present invention may further comprise a detection device for detecting whether or not the display panel is defective. When the display panel inspection apparatus according to the present invention provides the obtained inspection image to the detection apparatus, the detection apparatus can detect the defectiveness of the display panel using the inspection image. For example, the detection device can detect whether or not the display panel is defective by comparing the reference image for the normally operated display panel with the obtained inspection image. The detecting device may detect whether there is a defect with respect to the display panel by comparing the obtained inspection images with each other to detect a difference in brightness or the like.

1, the display panel inspection apparatus according to the embodiment of the present invention includes a stage 11, a display panel 12 which is seated on the stage 11 and has subpixels for image display, A signal generator 20 for applying an inspection pattern to the probe unit 13, a camera 40 for imaging an inspection pattern displayed on the display panel 12, a stage 11 and a camera (not shown) 40, a moving unit 30 for moving at least one of the plurality of subpixels, a controller 40 for extracting a center position of the subpixels based on the inspection pattern input from the camera 40, And a computer 50. The inspection apparatus according to the embodiment of the present invention may further include a host computer 60 that receives inspection results from the client computer 50, determines whether the inspection results are defective, and classifies defect types.

The display panel 12 is seated on the stage 11. The stage 11 may be fixed or may be moved in one direction by the moving unit 30. [ A plurality of gate lines and data lines are formed in the display panel 12, and subpixels for image display are formed at intersections of the gate lines and the data lines. In the inspecting step, the gate lines and the data lines are brought into contact with the probe unit 13 to receive a necessary signal from the probe unit 13. The gate lines can receive a scan signal from the probe unit 13 and the data lines can receive a test pattern from the probe unit 13. [

The signal generator 20 can supply an inspection pattern to the probe unit 13 together with the scan signal. The inspection pattern may be variously set according to the application. For example, the inspection pattern may include a red pattern, a green pattern, a blue pattern, a black pattern, a white pattern, a 127 gray pattern, and the like as shown in FIG.

The camera 40 can be driven by the moving part 30 and moved with the stage 11 or can be moved alone. When moved together with the stage 11, the camera 40 can be driven to move in the direction opposite to the stage 11. In this case, the moving path of the camera 40 is reduced, and the inspection time is shortened. The camera 40 captures an image displayed on the display panel 12 while moving along a specific direction to acquire an inspection pattern. When a plurality of inspection patterns are sequentially applied as shown in FIG. 8, the camera 40 acquires a red pattern while moving along a forward direction (first direction), and then acquires a green pattern while moving along a reverse direction After acquiring a blue pattern while moving along the forward direction, acquiring a black pattern while moving along the reverse direction, acquiring a white pattern while moving along the forward direction, and moving along the reverse direction to obtain 127 gray patterns . That is, the camera 40 acquires the first inspection pattern while moving in the first direction on the display panel 12, and acquires the second inspection pattern while moving in the second direction opposite to the first direction. By doing so, the present invention reduces the time required to obtain the inspection pattern.

The client computer 50 extracts the center position of the sub pixels based on the inspection pattern applied from the camera 40 directly. The client computer 50 does not need a separate calibration pattern other than the inspection pattern to extract the center position of the subpixels. It is possible to omit the process of acquiring the calibration pattern by further applying the calibration pattern and moving the camera, thereby saving the inspection time.

The client computer 50 may extract the positions of the subpixels in the forward direction coordinates or the backward direction coordinates as shown in FIG. The forward coordinates indicate the coordinates of the center of the extracted subpixels based on the first inspection pattern (red pattern) acquired while the camera first moves in the forward direction (first direction). The backward coordinates indicate the center coordinates of the extracted subpixels based on the second inspection pattern (green pattern) acquired while the camera first moves in the reverse direction (second direction). The center coordinates of the extracted sub-pixels are used to set the search area including the candidate defective position. The client computer 50 checks whether the display panel is defective or not in each search pattern in the search area.

The operation of extracting the center coordinates of the subpixels in the client computer 50 and performing the defect inspection based on the extracted center coordinates will be described with reference to FIGS. 2 to 7 as follows.

2, the client computer 50 receives the test pattern image acquired by the camera 40 from the camera 40. (S1) The client computer 50 acquires the test pattern image from the camera 40 3a, the input test pattern image is emphasized for each subpixel (S2). The client computer 50 emphasizes the center of the test pattern image for each subpixel using the Gaussian filter shown in FIG. 3B. In FIG. 3B, "x" is the position of the mask and "G (x)" is the weight according to the position on the mask. In Fig. 3B, "0" in the x-axis is the center portion of the mask and is the edge portion of the mask toward +/-. The weight (G (x)) is largest at the center of the mask, and gradually decreases toward the edge. If such a Gaussian filter is applied as a 5x5 mask as shown in Fig. 3C, the values in the mask should not be all "0 ", and the sum of the coefficients should be close to" 1 ".

The client computer 50 applies the emphasized inspection pattern image to a predetermined center extraction algorithm to extract the center coordinates of the outermost sub-pixels arranged in a row along the Y direction on the display panel 12 as shown in FIG. )

4, the client computer 50 sequentially moves by a predetermined pitch in the X direction perpendicular to the Y direction with respect to the center coordinates of the outermost subpixels, and the center coordinates of the remaining subpixels of the display panel 12 (S4) The center coordinates of all subpixels extracted in this way are shown in FIG.

The client computer 50 stores the coordinates of the center of each extracted sub-pixel (S5)

6, the client computer 50 sets four sub-pixel positions P1 (P1) corresponding to vertexes of the rectangles (P1 (P6, P3, P4) from the stored center coordinates. (S6) The candidate defective position can be set in advance to a place where defects frequently occur in view of accumulated manufacturing experience, and the model, size And the like.

The client computer 50 scans the search area to the left and right as shown in FIG. 7 and applies the scan results to each pattern algorithm (color / black / white / smudge pattern algorithm) of FIG. )

As described above, since the present invention extracts the center position of the subpixels based on the inspection pattern obtained from the camera, no additional calibration pattern is required in addition to the inspection pattern as in the conventional method. The present invention can omit an additional work process due to the calibration pattern, simplifying the task of finding the center position of each sub-pixel, and consequently shortening the inspection time.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

11: stage 12: display panel
13: probe unit 20: signal generator
30: moving part 40: camera
50: client computer 60: host computer

Claims (11)

stage;
A display panel that is seated on the stage and has subpixels for image display;
A probe unit contacting the signal lines of the display panel;
A signal generator for applying an inspection pattern to the probe unit;
A camera for capturing an inspection pattern displayed on the display panel; And
Pixels of the subpixels are extracted based on the inspection pattern input from the camera, and a search area including candidate defective positions is set based on the center coordinates, And a client computer for checking whether or not the display panel is defective. The method according to claim 1,
Wherein the client computer uses the Gaussian filter as a mask to emphasize the center of the inspection pattern corresponding to each of the subpixels so that the center coordinates of the subpixels are easily extracted. . 3. The method of claim 2,
Wherein the client computer applies the emphasized inspection pattern to a predetermined center extraction algorithm to extract center coordinates of the outermost sub-pixels arranged in a row along the Y direction in the display panel. The method of claim 3,
The client computer sequentially extracts and stores the coordinates of the center of each of the remaining sub-pixels of the display panel, the predetermined coordinates being shifted by a predetermined pitch in the X direction perpendicular to the Y direction with respect to the center coordinates of the outermost sub- A display panel inspection device. 5. The method of claim 4,
Wherein the client computer sets four subpixel positions corresponding to vertexes of the tetragonal shape from the stored center coordinates so as to set the search area to surround the candidate defective position, which is known in advance, The display panel inspection apparatus comprising: The method according to claim 1,
Further comprising a moving unit for moving at least one of the stage and the camera;
The camera being driven by the moving part to move with the stage or to be moved alone;
Wherein when the camera and the stage are simultaneously moved, the camera is driven to move in a direction opposite to the stage. A method for inspecting a display panel inspection apparatus having a stage, a display panel which is seated on the stage and on which subpixels are formed for image display, and a probe unit which is in contact with signal lines of the display panel,
Applying a test pattern to the probe unit through a signal generator;
Capturing an inspection pattern displayed on the display panel through a camera;
Extracting center coordinates of the subpixels based on a test pattern input from the camera; And
And checking whether the display panel is defective in the search area after setting a search area including a candidate defective position based on the respective center coordinates. 8. The method of claim 7,
Wherein extracting the respective center coordinates of the subpixels comprises:
Wherein a center of an inspection pattern corresponding to each of the subpixels is emphasized by using a Gaussian filter as a mask so that the respective center coordinates of the subpixels are easily extracted. 9. The method of claim 8,
Wherein extracting the respective center coordinates of the subpixels comprises:
And applying the emphasized inspection pattern to a predetermined center extraction algorithm to extract center coordinates of the outermost sub-pixels arranged in a row along the Y direction in the display panel. 10. The method of claim 9,
Wherein extracting the respective center coordinates of the subpixels comprises:
Wherein the center coordinates of the remaining sub-pixels of the display panel are extracted and stored while sequentially moving by a predetermined pitch in the X direction perpendicular to the Y direction with respect to each center coordinate of the outermost sub-pixels. Inspection method of the device. 8. The method of claim 7,
Wherein the step of checking whether the display panel is defective in the search area comprises:
The four subpixel positions corresponding to the vertexes of the tetragonal shape are derived from the stored center coordinates so as to set the search region in which the candidate defective position that is known in advance is surrounded by a quadrangle having the shortest distance, The method comprising the steps of:

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