JP3053653B2 - Optical liquid crystal display defect inspection system - Google Patents

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 display defect inspection apparatus and, more particularly, to an optical liquid crystal display defect inspection apparatus for inspecting defects such as electrodes formed on a liquid crystal display.

[0002]

2. Description of the Related Art Recently, liquid crystal displays have been widely used in various electronic devices. In addition, the amount of information displayed on the liquid crystal display is increasing, and a liquid crystal display with a high display density is required. In order to increase the display density, it is necessary to make the wiring pattern between the liquid crystal display and the terminal thinner and to reduce the interval between adjacent patterns. However, when the pattern density is increased, adjacent patterns may be electrically connected to each other due to insufficient etching in the pattern etching process.

Conventionally, in order to detect such a defect, a blowing method has been used in which a visual inspection is carried out, or a pin is provided on an electrode to supply a current to check for the presence or absence of contact. However, the visual method requires a long time for the inspection, and the blowing method requires pinning the electrode each time, which requires a large amount of labor for the inspection.

[0004]

Therefore, a liquid crystal display is placed on a table, a pattern for inspection is displayed on the liquid crystal display while the table is moved in one direction, and the pattern is displayed using an image sensor. A method of comparing the read data, the read output, and the standard data, judging that they are good if they match, and judging defective if they do not match, and inspecting the defect of the liquid crystal display can be considered. However, when a liquid crystal display for inspection is loaded on the table, the liquid crystal display may be inclined with respect to the table. When the display pattern is read by the image sensor in such a state, the correspondence between the display pattern and the standard data is lost, and the display pattern is determined to be defective despite being good, or is determined to be good despite being defective. It may be determined that there is.

[0005] Therefore, a main object of the present invention is to provide a liquid crystal display which is mounted on a table at an angle.
An object of the present invention is to provide an optical liquid crystal display defect inspection apparatus capable of inspecting a defect of a liquid crystal display by correcting the inclination.

[0006]

SUMMARY OF THE INVENTION The present invention relates to an optical liquid crystal display defect inspection apparatus for inspecting defects in a liquid crystal display, comprising a movable stage for moving the liquid crystal display in one direction, and a movable stage for moving the liquid crystal display in one direction. Rotating means for rotating the liquid crystal display, display control means for displaying a pattern for detecting the inclination of the liquid crystal display and a pattern for inspection, and a pattern displayed on the liquid crystal display An image sensor for reading from the LCD and a pattern for detecting inclination on the liquid crystal display.
Is displayed on moving the LCD contrast in a direction by the movable stage, and calculates the inclination of the liquid crystal display in accordance with the output of the image sensor, to return the movable stage to drive the rotation means so as to correct the inclination, Arithmetic control means for displaying a pattern for inspection on the liquid crystal display, moving the liquid crystal display in one direction, and comparing the output of the image sensor with a predetermined standard pattern to determine a defect in the liquid crystal display; It is composed.

[0007]

The optical liquid crystal display defect inspection apparatus according to the present invention displays a pattern for detecting tilt on the liquid crystal display, moves the liquid crystal display in one direction, and adjusts the liquid crystal in accordance with the output of the image sensor at that time. The tilt of the display is calculated, the liquid crystal display is rotated so as to correct the tilt, the movable stage is returned, and the display is moved in one direction while displaying a pattern for inspection on the liquid crystal display. The defect of the liquid crystal display is determined by comparing with a predetermined display pattern.

[0008]

FIG. 2 is a schematic block diagram of an embodiment of the present invention, and FIG. 3 is an external perspective view of the θ-axis table shown in FIG.

Referring to FIG. 2 and FIG. 3, a movable stage 2 is provided on a table 1. The movable stage 2 slides on the table 1 in one direction and in the opposite direction, and is driven by, for example, a linear motor or a ball screw. A θ-axis table 20 as shown in FIG. 3 is provided on the movable stage 2. The θ-axis table 20 holds the liquid crystal display 3 and corrects its inclination. That is, the θ-axis table 20 is
The rotating table 21 includes a rotating bearing 21 rotatable thereon, and a holding table 22 for holding the liquid crystal display 3 is provided on the rotating bearing 21. An actuator 23 is provided on a side surface of the movable stage 2. A motor is built in the actuator 23, and the rod 24 is rotated by the rotation of the motor.
Moves linearly in the direction of the arrow. The tip of the rod 24 is connected to a pin 26 provided at an angle 25. The angle 25 is connected to the side surface of the holder 22. Therefore, when the rod 24 of the actuator 23 linearly moves in the direction of the arrow, the angle 25 rotates, and the holding table 22 also rotates about the rotary bearing 21 to correct the tilt of the liquid crystal display 3.

As shown in FIG. 2, a CCD unit 4 is provided above the movable stage 2. CCD unit 4
Is for reading the display pattern of the liquid crystal display 3 which moves in one direction by the movable stage 2, and CC
A D image sensor is used.

A personal computer 5 is provided for performing overall control. Personal computer 5
Outputs a control signal from the CCD control circuit 6 to the CCD drive circuit 7 to control the CCD unit 4;
The drive circuit 7 drives the CCD unit 4 according to the control signal. The read output of the CCD unit 4 is given to a personal computer 5. Further, the personal computer 5 generates pulse signals from the pulse generators 8 and 31, and the pulse signals are given to the table positioning unit 9. The table positioning unit 9 sequentially moves the movable stage 2 in one direction according to the pulse signals. Then, the movable stage 2 is positioned. The pulse signal generated from the pulse generator 31 is provided to the rotation control circuit 32. The rotation control circuit 32 drives the actuator 23 of the θ-axis table 20 according to the pulse signal. The personal computer 5 further generates display pattern data for detecting the inclination of the liquid crystal display 3 and display pattern data for detecting a defect from the pattern generator 10. The pattern data is provided to the LCD drive circuit 11, and the LCD drive circuit 11 drives the liquid crystal display 3 to display the pattern according to the provided pattern data.

FIG. 1 is a flowchart for explaining the operation of one embodiment of the present invention. FIG. 4 is a flowchart showing a subroutine for detecting the inclination and position of the liquid crystal display. FIGS. 6 and 7 are flowcharts showing a subroutine for calculating coordinates of points required for calculating the tilt of the liquid crystal display. FIGS. 6 and 7 are diagrams for explaining a method of detecting the tilt of the liquid crystal display.

Next, a specific operation of one embodiment of the present invention will be described with reference to FIGS. First, the liquid crystal display 3 is loaded on the holding table 22 of the θ-axis table 20. At this time, it is assumed that the liquid crystal display 3 is loaded at an angle θ with respect to the movable stage 2. The personal computer 5 detects the inclination and the position of the liquid crystal display 3. That is, the personal computer 5 proceeds to a subroutine shown in FIG. The personal computer 5 generates pattern data from the pattern generator 10 so as to display “L” with dark pixels as shown in FIG. 6B. LCD drive circuit 11
Causes the liquid crystal display 3 to display a display pattern according to the pattern data. Personal computer 5
Generates a pulse signal from the pulse generator 8, and the table positioning unit 9 sequentially moves the movable stage 2 in one direction according to the pulse signal. The personal computer 5 generates a control signal from the CCD control circuit 6,
The CCD drive circuit 7 drives the CCD unit 4 according to the control signal. The CCD unit 4 displays “L” displayed on the liquid crystal display 3 on the movable stage 2 that moves sequentially.
And outputs the read output to the personal computer 5.

Here, as shown in FIG.
The data of the i-th row and j-th column output from the unit 4 is represented by C
(I, j). A threshold value for determining a bright pixel and a dark pixel of a liquid crystal pixel is S. The personal computer 5 takes in the data of the l-th column, the m-th column, and the n-th row from the output of the CCD unit 4 as shown in FIG. Then, the personal computer 5 is connected to the a shown in FIG.
Point coordinates (a _x, a _y) and, for b coordinates (b _x, b _y)
And the coordinates (c _x , c _y ) of point c are obtained. That is,
To obtain the coordinates of the point a, the personal computer 5
Is set to i = 1 as shown in FIG. 5A, and it is determined whether or not the data C (i, l) (i is a variable) in the first column is larger than a threshold value. The value of i is incremented by 1 to determine whether or not the value is larger than the threshold value again. Display pattern "L"
Is displayed as a dark pixel. If the data C (i, l) is smaller than the threshold value S, the coordinates (a _x , a _y ) of the point a as shown in FIG. , L). Similarly, when obtaining the coordinates of the point b, as shown in FIG. 5B, the data C (i, m) in the m-th column is equal to the threshold value S.
It is determined whether or not it is greater than i.
If it is smaller, the coordinates (i, m) of the point are set to the coordinates (b _x , b _y ) of the point b as shown in FIG. 7B.

Similarly, as shown in FIG. 5C, the coordinate of the point c is determined as to whether or not the data C (n, j) (j is a variable) in the n-th row is larger than the threshold value S. Judgment is made, and if it is large, j is incremented by 1;
As shown in (c), the coordinates of point c are (c _x , _cy ).

Next, the personal computer 5 calculates the inclination of the display pattern "L". That is, assuming that the inclination is θ, the personal computer 5 uses the coordinates (a _x , a _y ) of the point a and the coordinates (b _x , b _y ) of the point b in accordance with the following equation, as shown in FIG. Calculate the slope θ.

Θ = tan ⁻¹ (b _x −a _x ) / (b _y −a _y ) Further, the personal computer 5 calculates the position of the display pattern “L”, thereby calculating the inclination and the position of the liquid crystal display 3. Then, the movable stage 2 is returned to the origin.

The personal computer 5 returns to the processing shown in FIG. 1 again, and generates pulse signals of the number corresponding to the inclination θ from the pulse generator 31 in order to correct the inclination θ. The rotation control circuit 32 drives the actuator 23 of the θ-axis table 20 according to the pulse generated from the pulse generator 31. As a result, the actuator 23 moves the holding base 2 so that the inclination θ of the liquid crystal display 3 is corrected.
2 is rotated clockwise or counterclockwise to make the end of the liquid crystal display 3 and the end of the movable stage 2 parallel.

Next, the personal computer 5 causes the pattern generator 10 to generate pattern data for inspection. The LCD drive circuit 11 displays a display pattern on the liquid crystal display 3 according to the pattern data. The personal computer 5 generates a pulse signal from the pulse generator 8, and the table positioning unit 9 sequentially moves the movable stage 2 in one direction according to the pulse signal. The personal computer 5 generates a control signal from the CCD control circuit 6, and the CCD drive circuit 7 drives the CCD unit 4 according to the control signal. CCD
The unit 4 reads the pattern displayed on the liquid crystal display 3 and gives it to the personal computer 5. The personal computer 5 processes the data from the read output and determines whether the data matches a standard pattern stored in advance. If they do not match, the inspected liquid crystal display 3 is determined to be defective and processed. If it is good, the non-defective product is processed and the result is printed by a printer (not shown).
Alternatively, it is displayed on a CRT display (not shown).
Thereafter, the personal computer 5 moves the movable stage 2 in the reverse direction, and unloads the liquid crystal display 3 when returning to the original position. Then, the above-described operation is repeated to inspect the next liquid crystal display.

In the above-described embodiment, the liquid crystal display 3 is of a reflection type, but is not limited thereto, and may be of a transmission type. In that case, light may be emitted from the lower part of the liquid crystal display 3.

[0021]

As described above, according to the present invention, the liquid crystal display is moved in one direction while displaying the pattern for detecting the tilt on the liquid crystal display, and the tilt of the liquid crystal display is changed according to the output of the image sensor. The LCD is rotated so as to correct the inclination, a pattern for inspection is displayed on the LCD, and the LCD is moved in one direction again, and the output of the image sensor and the predetermined standard pattern are compared. The defect of the liquid crystal display can be determined by comparison.
Therefore, even if the liquid crystal display is tilted and loaded, the inclination can be corrected and the defect of the liquid crystal display can be inspected, so that the possibility of a defective determination result can be reduced.

[Brief description of the drawings]

FIG. 1 is a flowchart for explaining the operation of an embodiment of the present invention.

FIG. 2 is a schematic block diagram of one embodiment of the present invention.

FIG. 3 is an external perspective view of the θ-axis table shown in FIG. 2;

FIG. 4 is a flowchart showing a subroutine for detecting a tilt and a position of a liquid crystal display.

FIG. 5 is a flowchart showing a subroutine for calculating coordinates of points required for calculating the inclination of the liquid crystal display.

FIG. 6 is a diagram for explaining a method of detecting the inclination of the liquid crystal display.

FIG. 7 is a diagram for explaining a method of detecting the inclination of the liquid crystal display.

[Explanation of symbols]

 Reference Signs List 1 table 2 movable stage 3 liquid crystal display 4 CCD unit 5 personal computer 6 CCD control circuit 7 CCD drive circuit 8, 31 pulse generator 9 table positioning unit 10 pattern generator 11 LCD drive circuit 20 θ axis table 21 rotating bearing 22 holding stand 23 Actuator 24 Rod 25 Pin 26 Angle 32 Rotation control circuit

Claims (1)

(57) [Claims] 1. An optical liquid crystal display defect inspection apparatus for inspecting a defect of a liquid crystal display, comprising: a movable stage for moving the liquid crystal display in one direction; Rotation means for rotating the display, display control means for displaying a pattern for detecting the inclination of the liquid crystal display and a pattern for inspection, and displaying the pattern displayed on the liquid crystal display from above the liquid crystal display. an image sensor, and the pattern of the liquid crystal Disupu for detecting a tilt of the liquid crystal display by said display control means for reading
By displaying the ray moves the LCD contrast in a direction in the movable stage, and calculates the inclination of the front Symbol LCD according to an output of the image sensor, driving the rotation means so as to correct the inclination to return the pre <br/> Symbol movable table together, the displays a pattern for inspecting the liquid crystal display by moving the liquid crystal display contrast in a direction in the movable stage, predetermined output of the image sensor standard of comparing the pattern with an arithmetic control means for determining a defect of <br/> the liquid crystal display, an optical liquid crystal display defect inspection apparatus.