JPH1173132A - Conductive foreign matter detecting method for liquid panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a liquid crystal panel having a conductive foreign matter which is likely to short-circuit with a counter electrode on a signal wiring or a scanning line wiring, by disposing a metal plate having a grid, which diagonally crosses the liquid panel, under the liquid panel. SOLUTION: The metal plate 3 having the grid 3a, which diagonally crosses the liquid panel 2, is set on the back light 4. Next, on the plate 3, the liquid panel 2 having a conductive foreign matter, which is likely to short-circuit with a counter electrode on the signal wiring or the scanning line wiring, is set to a tester. In this state, a liquid crystal driving signal is inputted to the liquid panel 2 through a liquid panel driving signal feeding probe 1. At this time, a pressure 5 is added onto the surface of the liquid crystal panel 2, thereby, the conductive foreign matter on the signal wiring or the scanning line wiring and the opposing electrode are short-circuited. In this case, since the diagonal grid 3a exists in the metal plate 3, the light of the back light is made incident on the liquid panel from the gap, and then the defect of the signal line or the scanning line is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method for detecting conductive foreign matter on a liquid crystal panel.

[0002]

2. Description of the Related Art In recent years, liquid crystal panels have been used for a variety of applications, such as personal computer displays, and are expected to expand in the future. Things to do increase. In this case, since a stress is directly applied to the surface of the liquid crystal panel, if there is a conductive foreign matter just before contact with the counter electrode in the liquid crystal panel, when the stress is applied to the liquid crystal panel, a signal is generated between the counter electrode and the signal. There is a problem that a line or a scanning line wiring is short-circuited to cause a line defect, and it has been required to be able to reliably detect these in a process stage.

[0003] A conventional method for detecting a liquid crystal panel in which a conductive foreign substance is present on a certain signal line will be described below.

FIG. 2 is a conceptual sectional view of a liquid crystal panel inspection apparatus. In FIG. 2, reference numeral 7 denotes a liquid crystal panel, 8 denotes a backlight, 9 denotes a probe for supplying a liquid crystal panel drive signal, and 10 denotes a liquid crystal panel cradle. It is.

[0005] The operation of the liquid crystal panel inspection apparatus configured as described above will be described below.

First, a method of displaying an image on a liquid crystal panel will be briefly described.

FIG. 3 shows an equivalent circuit of a liquid crystal panel, in which 11 is a scanning line, 12 is a pixel transistor, 13 is a pixel electrode and a liquid crystal layer, 14 is an auxiliary capacitor, 15 is a signal line signal supply driving circuit, 16 Is a scanning line signal supply drive circuit, 17 is a signal line, 18
Is a counter electrode.

In FIG. 3, a signal line signal supply driving circuit 15
From the scanning line signal supply drive circuit 16
From the pixel transistor through the scanning line 11
12 is applied to the gate side. The pixel transistor 12 receives the gate signal, that is, the signal applied to the signal line 17 when receiving the signal of the scanning line 11, and outputs the signal applied to the signal line 17 to the pixel electrode.
13, the pixel electrode 13 and the opposing electrode 14
The twist of the liquid crystal changes according to the signal applied to the
By changing the transmittance of the liquid crystal, light incident on the liquid crystal panel can be controlled to display an image.

Next, a problem that arises when there is a conductive foreign matter on the signal line wiring will be described.

FIG. 4 is a conceptual diagram of a cross section of a liquid crystal panel in which a conductive foreign matter is present on a certain signal line wiring and is just before contact with a counter electrode. In FIG. 4, reference numeral 19 denotes a pixel transistor (TFT). Formed substrate glass, 20 is a signal line wiring (corresponding to 17 in FIG. 3), 21 is a conductive foreign substance, and 22 is a counter electrode (18 in FIG. 3).
23) color filter substrate glass, 24 is the pressure applied to the liquid crystal panel surface, 25 is the semiconductor layer, 26 is the insulating film, 27
Is a pixel electrode (corresponding to 13 in FIG. 3), and 28 is a scanning line wiring (11 in FIG. 3).
Correspondence).

In FIG. 4, signal line wiring 20 of the liquid crystal panel is shown.
When the conductive foreign matter 21 on the upper surface comes in contact with the counter electrode 22, even if a signal for displaying an image enters the signal line wiring 20, regardless of a change in the signal, the signal line wiring 20 and the counter electrode 22 are not affected. Of the liquid crystal panel is transmitted through the liquid crystal panel as it is, and the corresponding signal line wiring 20
Appear as line defects on the image.

Therefore, when performing the liquid crystal panel inspection, pressure is applied to the liquid crystal panel surface in order to detect the signal line wiring 20 where the conductive foreign matter 21 is present.

[0013]

However, in the configuration of the liquid crystal panel inspection apparatus as shown in FIG. 2, there is a gap G between the backlight 8 and the liquid crystal panel 7, and the liquid crystal panel is made of glass. Causes some deflection. For this reason, there is a problem that the pressure 24 applied to the liquid crystal panel surface as shown in FIG. 4 is not sufficiently transmitted, and the conductive foreign matter 21 does not contact the counter electrode 22 and cannot be detected.

In view of the foregoing, it is an object of the present invention to apply a pressure applied to the surface of a liquid crystal panel completely to the surface of the liquid crystal panel, and to detect conductive foreign substances on the counter electrode and signal line wiring or scanning line wiring. I do.

[0015]

In order to achieve the above object, the present invention provides a liquid crystal panel in which a metal plate having an obliquely intersecting lattice is disposed in the gap between the liquid crystal panel and the backlight. The detection of the conductive foreign matter is performed by completely applying the applied pressure to the liquid crystal panel.

According to the present invention, by completely applying the pressure applied to the liquid crystal panel surface to the liquid crystal panel, it is possible to detect a conductive foreign matter on the signal line wiring or the scanning line wiring which is likely to short-circuit with the counter electrode. it can.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is directed to a liquid crystal panel.
By placing a metal plate with a grid that crosses obliquely at an angle of 20 to 60 ° to maximize the stress on the liquid crystal panel, the conductivity on the signal line wiring or scanning line wiring that is likely to short-circuit with the counter electrode Sexual foreign matter is reliably detected.

(Embodiment 1) FIG. 1 is a diagram showing a foreign matter detection method for a liquid crystal panel according to Embodiment 1 of the present invention.

In FIG. 1, 1 is a signal supply probe for driving a liquid crystal panel, 2 is a liquid crystal panel, 3 is a metal plate having a grid 3a obliquely intersecting the liquid crystal panel at an angle of approximately 20 to 60 °, 4 Is a backlight, 5 is a liquid crystal panel 2
Reference numeral 6 denotes a liquid crystal panel receiving base.

Next, the operation of the detection method when the conductive foreign matter 21 exists on the signal line wiring 20 or the scanning line wiring 28, which is likely to be short-circuited with the counter electrode 22 as described with reference to FIG. 4, will be described.

First, a metal plate 3 having a lattice 3 a obliquely intersecting with a liquid crystal panel 2 is set on a backlight 4. Next, a liquid crystal panel 2 having a conductive foreign matter likely to be short-circuited to the counter electrode on the signal line wiring or the scanning line wiring is set on the inspection device (not shown). In this state, a liquid crystal panel driving signal is input to the liquid crystal panel 2 through the liquid crystal panel driving signal supply probe 1 through the signal line wiring and the scanning line wiring. At this time, a pressure 5 is applied to the surface of the liquid crystal panel 2 to short-circuit the conductive foreign matter 21 on the signal line wiring 20 or the scanning line wiring 28 shown in FIG.

Since the oblique grating 3a is provided on the metal plate 3 below the liquid crystal panel 2 shown in FIG. 1, the light of the backlight can be made to enter the liquid crystal panel from the gap. Defects can be detected.

As described above, according to this embodiment,
The pressure applied to the surface of the liquid crystal panel can be completely applied to the liquid crystal panel, and a liquid crystal panel having a conductive foreign matter likely to be short-circuited with the counter electrode on the signal wiring or the scanning line wiring can be detected.

[0024]

As described above, according to the present invention,
By placing a metal plate with a grid obliquely intersecting the liquid crystal panel under the liquid crystal panel, the pressure applied to the liquid crystal panel surface is completely applied to the liquid crystal panel, so that the counter electrode is placed on the signal wiring or scanning line wiring. Liquid crystal panel with conductive foreign matter that is likely to be short-circuited,
It is extremely effective in practical use.

[Brief description of the drawings]

FIG. 1 is a diagram showing a method for detecting foreign matter on a liquid crystal panel according to Embodiment 1 of the present invention.

FIG. 2 is a conceptual sectional view of a liquid crystal panel inspection apparatus.

FIG. 3 is a diagram showing an equivalent circuit of the liquid crystal panel.

FIG. 4 is a diagram showing a conceptual diagram of a cross section of a liquid crystal panel in a state where a conductive foreign matter is present on a certain signal line wiring and a counter electrode is just before contact.

[Explanation of symbols]

1, 9 ... probe for supplying a liquid crystal panel driving signal, 2,
7: liquid crystal panel, 3: metal plate having a grid obliquely intersecting with the liquid crystal panel, 3a: grid, 4, 8: backlight, 5, 24: pressure applied to the liquid crystal panel surface,
6, 10: liquid crystal panel support, 11: scanning line, 12: pixel transistor, 13: pixel electrode and liquid crystal layer, 14: auxiliary capacitance, 15: signal line signal supply drive circuit, 16: scanning line signal supply drive circuit, 17 ... signal line, 18, 22 ... counter electrode, 19 ... TFT forming substrate glass, 20 ... signal line wiring,
21: conductive foreign matter, 23: color filter substrate glass,
25 ... semiconductor layer, 26 ... insulating film, 27 ... pixel electrode, 28
... Scanning line wiring.

Claims (1)

[Claims] 1. A liquid crystal panel having a lattice that crosses obliquely with respect to the liquid crystal panel is disposed in a gap between the liquid crystal panel and the backlight so that pressure applied to the liquid crystal panel surface is completely applied to the liquid crystal panel. A method for detecting conductive foreign matter on a signal line wiring or a scanning line wiring which is likely to short-circuit with a counter electrode.