JPH0611455A - Optical failure inspection device for color liquid crystal display - Google Patents

Abstract

PURPOSE:To provide an optical type inspection device for failure of liquid crystal color display, with which failure inspection can be made accurately despite poor resolution of an image sensor used. CONSTITUTION:A liquid crystal color display 3 is loaded on a movable stage 2, and pattern data generated by a pattern generator 10 is indicated on the display 3, and the stage 2 is moved bit by bit in one direction in conformity to pulse signals generated by a pulse generator 8. A CCD unit 4 reads from above the patterns indicated on the display 3, and a personal computer 5 summarizes reading outputs of the CCD unit 4 as the data corresponding to one picture element, and on the basis of this data obtained, judgement is passed whether any failure is included, for example failed lighting-up, unevenness in the brightness, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical liquid crystal color display defect inspection apparatus, and more particularly to an optical liquid crystal color display for optically inspecting pixel defects of a liquid crystal color display, such as defective lighting and uneven brightness. Defect inspection device.

[0002]

2. Description of the Related Art Recently, liquid crystal displays are being widely used in various electronic devices. Moreover, the number of liquid crystal color displays is increasing. The liquid crystal color display has three times as many pixels as a monochrome display, and it is necessary to make the wiring pattern between the liquid crystal display units thin. However, if the pattern density is increased, adjacent patterns may be electrically connected to each other in a pattern etching process or the like.

As a method for inspecting such a defect of a liquid crystal color display, a liquid crystal color display in a cell or module state is turned on, and it is optically read and compared with standard data, and it must be in agreement. For example, a method of discriminating the defect can be considered.

Conventionally, in order to detect such a defect,
Visual inspection, image processing inspection by CCD area sensor, and image processing inspection method by CCD linear sensor have been used.

[0005]

However, the conventional visual inspection method requires a long time for inspection, and the CCD area sensor system is affected by moire. Also,
The device is large and expensive because a dedicated computer is required for high-speed operation of a large amount of data and a plurality of CCD linear image sensors are required. The CCD linear image sensor has a drawback that an accurate inspection cannot be performed because the resolution of the sensor is insufficient as compared with the pixels of the liquid crystal color display.

Therefore, a main object of the present invention is to provide an optical liquid crystal color display defect inspection apparatus capable of accurately performing a defect inspection of a liquid crystal color display even if the resolution of an image sensor is insufficient. That is.

[0007]

SUMMARY OF THE INVENTION The present invention is an optical liquid crystal color display defect inspection apparatus for inspecting a liquid crystal color display for defects, including a movable stage for moving the liquid crystal color display in one direction and a liquid crystal. Display control means for displaying a pattern for inspection on the color display, an image sensor for reading the image pattern of the liquid crystal color display from above the movable stage, and image information for each pixel of the liquid crystal color display that is wider than the number of pixels. The sensor output is added and the pixel information is used to determine a defect in the color display.

[0008]

In the optical liquid crystal color display defect inspection apparatus according to the present invention, the output data of the linear image sensor is calculated for each pixel of RGB of the liquid crystal color display to make the data of one pixel of the liquid crystal color display constant. This increases the detection rate of lighting defects or defects such as uneven brightness.

[0009]

1 is a schematic block diagram of an embodiment of the present invention. Referring to FIG. 1, movable stage 2 is provided on table 1. The movable stage 2 moves the liquid crystal color display 3 in one direction and the other direction, and is driven by, for example, a linear motor or a ball screw. A CCD unit 4 is provided above the movable stage 2. CCD unit 4 is movable stage 2
LCD color display 3 that moves in one direction by
Is read from above and, for example, a CCD linear image sensor is used.

A personal computer 5 is provided to perform overall control. Personal computer 5
In order to control the CCD unit 4, the CCD control circuit 6 outputs a control signal to the CCD drive circuit 7,
The drive circuit 7 drives the CCD unit 4 according to the control signal. At this time, the personal computer 5 outputs a data acquisition signal of the CCD unit 4, and C
The data of the CD unit 4 is read by the personal computer 5.

Further, the personal computer 4 generates a pulse signal from the pulse generator 8, and this pulse signal is given to the table positioning unit 9, and the table positioning unit 9 moves the movable stage 2 in one direction according to the pulse signal. The movable stage 2 is sequentially moved and positioned. The personal computer 5 further causes the pattern generator 10 to generate display pattern data for inspection. This pattern data is given to the liquid crystal display drive circuit 11. The liquid crystal display drive circuit 11 drives the liquid crystal color display 3 to display the pattern according to the given pattern data.

FIG. 2 is a diagram for explaining the captured data of the CCD linear image sensor and the calculation method thereof.
Next, the relationship between the CCD linear image sensor and the liquid crystal color display 3 will be described with reference to FIG. First, regarding the relationship between the liquid crystal color display 3 and the CCD linear image sensor, the liquid crystal color display 3
When a large number of pixels of the CCD linear image sensor are included in one pixel of, the resolution of the CCD linear image sensor is sufficient, so the value of the CCD linear image sensor when scanning near the center of one pixel of the liquid crystal color display is Can be used for inspection.

However, the pixel size of the CCD linear image sensor as shown in FIGS. 2A and 2B is not so small as the pixel size of the liquid crystal color display 3 (when the resolution is low), and the CCD linear image is also small. When the pixel of the sensor and the pixel of the liquid crystal color display 3 have different pitches, the capture position changes as shown in FIG. 2 (a) or (b). CC when scanned
When the value of the D linear image sensor is used, the value of the data greatly varies. For this reason, it is not possible to detect defects such as variations in brightness or color unevenness.

Therefore, in order to obtain an accurate luminance of one pixel of the liquid crystal color display 3, the pixels of the CCD linear image sensor within the one pixel size of the liquid crystal color display 3 and the pixels in the vicinity thereof are added to each other, and the liquid crystal color display 3 is displayed. Data of 1 pixel. Although the above description has been made in the horizontal direction of the liquid crystal color display 3, the same applies to the vertical direction. The measurement is performed three times for each color of RGB.

FIG. 3 is a flow chart for explaining a specific operation of the embodiment of the present invention. Next, a specific operation of the embodiment of the present invention will be described with reference to FIGS. First, the liquid crystal color display 3 is loaded on the movable stage 2. The personal computer 5 causes the pattern generator 10 to generate pattern data. This pattern data is, for example,
Display patterns of RGB single colors such as solid red and solid blue are used, and the liquid crystal display drive circuit 11 causes the liquid crystal color display 3 to display the display pattern according to the pattern data. The personal computer 5 causes the pulse generator 8 to generate a pulse signal, and the table positioning unit 9 sequentially moves the movable stage 2 in one direction in response to the pulse signal. In response to a control signal from the personal computer 5, the CCD from the CCD control circuit 6
Control signal is generated, and the CCD drive circuit 7 drives the CCD unit 4 according to the control signal. The CCD unit 4 reads the pattern displayed on the liquid crystal color display 3 on the movable stage 2 which moves sequentially from above,
The read output is given to the personal computer 5.
At this time, the CCD unit 4 takes in a plurality of data for each pixel of the LCD and outputs the data to the personal computer 5.

The personal computer 5 adds all the read outputs of the CCD unit 4 to the data for one pixel of the LCD as shown in FIG. 2, for example, and the addition result is the data of other non-defective pixels. It will be the same size. From this, it can be seen that when the data value becomes large or small, the pixel is defective. If there is a defective pixel, it is judged that the inspected liquid crystal color display 3 is a defective product and is processed. If there is no defective pixel, it is processed as a non-defective product, and the result is printed or printed on a CRT display. After that, the personal computer 5 moves the movable stage 2 in the opposite direction, and when it returns to the original position, the liquid crystal color display 3
Unload. Then, the above operation is repeated to perform the next operation of the liquid crystal color display.

The CC used in the CCD unit 4
The D linear image sensor can be used in both a contact type and a reduction type, and can also be used in liquid crystal cells and modules.

[0018]

As described above, according to the present invention, the output data of the image sensor is stored in the liquid crystal color display.
By performing the calculation for each pixel and making the data of one pixel of the liquid crystal color display constant, the defect inspection of the liquid crystal color display such as lighting defect and uneven brightness can be accurately performed in a short time.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of an embodiment of the present invention.

FIG. 2 is a diagram for explaining data captured by a CCD linear image sensor and a method for calculating the data.

FIG. 3 is a flow chart for explaining a specific operation of the embodiment of the present invention.

[Explanation of symbols]

 1 table 2 movable stage 3 liquid crystal color display 4 CCD unit 5 personal computer 6 CCD control circuit 7 CCD drive circuit 8 pulse generator 9 table positioning unit 10 pattern generator 11 liquid crystal display drive circuit

Claims (1)

[Claims] 1. An optical liquid crystal color display defect inspection apparatus for inspecting a defect of a liquid crystal color display, comprising: a movable stage for moving the liquid crystal color display in one direction; Display control means for displaying the pattern, an image sensor for reading the pattern of the liquid crystal display from above the movable stage, and each pixel information of the liquid crystal color display, the result of adding the image sensor output in a wider range than the pixel size. And an optical liquid crystal color display defect inspection apparatus comprising a discrimination means for discriminating a defect of the color display from the respective pixel information.