JP2000338522A - Testing method for liquid crystal display element, and testing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a testing method for liquid crystal display element and a testing, device which can easily detect defects. SOLUTION: For a liquid crystal display element having a 'Cs on Gate' structure or a 'Cs on COM' structure, a signal A11 formed of an ON signal defining one frame period and an OFF signal following the ON signal is applied to a gate bus line via a wiring for the gate bus line, a signal B11 having an arbitrary voltage ahead of each addition of the ON signal for the succeeding two frames and changing the voltage level during the ON signal is applied to a source bus line via a wiring for the source bus line, and a signal C11 fixed at an optimum counter voltage is applied to a counter electrode. The signal A11, the signal B11 and the signal C11 are each generated by a voltage signal generating part provided at a detecting device of the liquid crystal display element.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for inspecting a liquid crystal display device.

[0002]

2. Description of the Related Art A liquid crystal display device (liquid crystal display device) has a CR
A display device that has a display quality not inferior to T (Cathode Ray Tube), and has excellent characteristics compared to CRT, such as space convenience (saving space, etc.) and low power consumption. In recent years. However, the manufacture of the above-mentioned liquid crystal display element includes a step of forming a number of thin films, and it is difficult to secure a 100% yield. Furthermore, in order to respond to the recent demand for larger size and higher definition, more accurate formation of the thin film and the fine structure is required.

Therefore, in the manufacturing process of the liquid crystal display element, in order to improve the manufacturing yield and reduce the risk of outflow of defective products, two substrates are bonded together, and after injecting liquid crystal between the substrates, An inspection (lighting inspection) for lighting a panel (liquid crystal display element) is performed to find a defect or the like. Hereinafter, the structures of some liquid crystal display elements and their inspection methods will be described.

[0004] A liquid crystal display element includes, for example, an active matrix substrate in which picture element electrodes are arranged in a matrix and opposed to each other with a liquid crystal layer interposed therebetween, and a counter substrate. As shown in FIG. 10, the active matrix substrate includes gate bus lines 101 functioning as scanning lines on an insulating substrate.
Are arranged in parallel with each other, and are orthogonal to the gate bus lines 101 and serve as signal buses.
Are wired in parallel. The odd-numbered gate bus lines 101 are connected to the gate bus line wiring 107, and the even-numbered gate bus lines 101 are connected to the gate bus line wiring. That is, one of the two adjacent gate bus lines 101 is connected to the wiring 107, and the other is connected to the wiring 108.

[0005] A TFT 103 is disposed near each intersection of the bus lines 101 and 102.
(Gate electrode, source electrode) are connected to both bus lines 101 and 102. This TFT103
Furthermore, adjacent gate bus lines 101
And a picture element electrode 105 provided in each region (picture element) surrounded by the adjacent source bus lines 102, 102 via a terminal (drain electrode).

On the opposite substrate facing the active matrix substrate, an opposite electrode 106 is formed so as to face each pixel electrode 105, and a pixel capacitance (liquid crystal capacitance) Clc is formed between the pixel electrode 105 and the pixel electrode 105. Is formed. Further, an auxiliary capacitance 104 is formed in parallel with the pixel capacitance Clc. One of the auxiliary capacitors 104 is connected to a pixel electrode 105.
The other is connected to another gate bus line 101 adjacent to the gate bus line 101 to which the pixel electrode 105 is connected with the pixel electrode 105 interposed therebetween. That is, this liquid crystal display element has a Cs on Gate structure.

In such an inspection of the liquid crystal display element having the Cs on Gate structure, for example, a signal A101 as shown in FIG. A102
Are connected to the even-numbered gate bus line 1
01 ... Further, the signal B101 is transmitted to the source bus line 10 via the source bus line wiring 109.
2 and the signal C101 is applied to the counter electrode 106.

The above signals A101 and A102
Is a signal for turning on / off the gate electrodes of the TFTs 103, and is usually the same signal with only the timing shifted.
Further, the signal B101 is a signal which does not change even after writing in each picture element until the next frame is written.
1 is a signal fixed to the optimum voltage.

Another liquid crystal display element shown in FIG. 12 comprises an active matrix substrate having pixel electrodes arranged in a matrix on an insulating substrate with a liquid crystal layer interposed therebetween, and a counter substrate. In the active matrix substrate, gate bus lines 201 functioning as scanning lines are arranged in parallel, and a large number of source bus lines 202 functioning as signal lines are arranged in parallel to the gate bus lines 201. ing. The above gate bus line 201 ...
Are connected to the wiring 207 for the gate bus line.

A TFT 203 is disposed near each intersection of the bus lines 201 and 202.
(Gate electrode, source electrode) are connected to both bus lines 201 and 202. This TFT 203
Further, adjacent gate bus lines 201
And a pixel electrode 205 provided in each region surrounded by the adjacent source bus lines 202, 202 via a terminal (drain electrode).

On the counter substrate facing the active matrix substrate, a counter electrode 206 is formed facing each pixel electrode 205, and a pixel capacitance Clc is formed between the counter electrode 206 and the pixel electrode 205. . Furthermore, this picture element capacity Clc
A storage capacitor 204 is formed in parallel with the above. One of the storage capacitors 204 is connected to the pixel electrode 205, and the other is connected to a storage capacitor wiring (a storage capacitor common wiring) 210. That is, this liquid crystal display element has Cs on C
It has an OMMON (hereinafter referred to as Cs on COM) structure.

In such an inspection of the liquid crystal display element having the Cs on COM structure, for example, a signal A103 as shown in FIG. 13 is applied to the gate bus lines 201 through the wiring 207. When the signal B101 is 20
9 and the signal C101 is applied to the counter electrode 206.

The signal A103 is a signal for turning on / off the gate electrodes of the TFTs 203, and the signal B101 is
It is a signal that does not change even after writing in each picture element until the writing of the next frame. The signal C101 is a signal fixed to the optimum voltage.

[0014] However, the above-mentioned Cs on G
Even if a defect occurs in the liquid crystal display element having the ate structure and the Cs onCOM structure, the inspection method using such a conventional inspection apparatus, for example, has the following reasons.
In some cases, it is difficult to sufficiently detect a defect and to determine a defect mode (type of defect).

That is, since the signal B101 shown in FIGS. 11 and 13 does not change until the next frame is written even after writing to each picture element, for example, a leak is generated between the source electrode and the drain electrode. TFT103
Alternatively, even when the off characteristic of the TFT 203 is poor,
It is always constant. Therefore, TFT103 or TF
The off defect mode of T203 cannot be detected. Also,
Pixel electrode 105 (or 205) and source bus line 1
Similarly, in the case where a leak occurs between 02 and (or 202), the off failure defect mode cannot be detected.

[0016]

Therefore, in order to solve the above-mentioned problem, the following Cs on Ga is used.
An inspection method and an inspection apparatus for an active matrix substrate such as a liquid crystal display element having a te structure and a Cs on COM structure have been proposed. More specifically, an ON signal that determines the period of one frame and an OFF signal that follows the ON signal are alternately applied to the scanning line (gate bus line), and before the ON signal is applied to each of two successive frames. A first pattern for changing the level of the voltage applied to the signal line, and a second pattern for changing the level of the voltage applied to the signal line before and after the application of the ON signal of each of the two successive frames. A configuration and method are adopted in which the third pattern for changing the level of the voltage applied to the signal line after all the ON signals are applied to each of the two frames is performed or selectively performed to determine the defect mode.

However, even in the above conventional inspection method,
It is often difficult to detect a defect in a normally white mode liquid crystal display element or to determine a defect mode. In a normally black mode liquid crystal display element, most defects are displayed as black points (dark display). (Or the same display as a normal picture element), it is difficult to detect a defect or determine a defect mode. In particular, a defect such as a TFT characteristic defect is displayed as a thin black dot, which causes a problem such as oversight of the defect and a case where a defective product flows out in a subsequent process.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a method and an apparatus for inspecting a liquid crystal display element in which a defect can be easily detected.

[0019]

In order to solve the above-mentioned problems, a method for inspecting a liquid crystal display element according to the present invention includes two substrates opposed to each other with a liquid crystal layer interposed therebetween, and the two substrates are disposed between the substrates. A plurality of scanning lines and a plurality of signal lines wired so as to cross each other, and a switching element provided near each intersection of the scanning line and the signal line, the switching element being connected to the scanning line and the signal line; , A pixel electrode connected to the scanning line and the signal line via each switching element,
An auxiliary capacitor formed corresponding to each pixel electrode is connected to another scanning line adjacent to the scanning line to which the pixel electrode is connected, with the pixel electrode interposed therebetween. A method for inspecting a liquid crystal display element provided with a counter electrode opposite to the above, wherein a first signal consisting of an ON signal defining a period of one frame and an OFF signal subsequent to the ON signal is applied to the scanning line. And applying a second signal whose voltage level is changed during the ON signal to the signal line before the ON signal is applied to each of the two successive frames. I have.

Further, in order to solve the above-mentioned problems, a method for inspecting a liquid crystal display element according to the present invention includes two substrates facing each other with a liquid crystal layer interposed therebetween, and the two substrates intersect each other so as to intersect each other. A plurality of wired scanning lines and a plurality of signal lines are wired, and near each intersection of the scanning line and the signal line, a switching element provided connected to the scanning line and the signal line,
A picture element electrode connected to the scanning line and the signal line via each switching element is provided, and an auxiliary capacity formed corresponding to each picture element electrode is connected to an auxiliary capacity common wiring. A method for inspecting a liquid crystal display element provided with a counter electrode facing a picture element electrode, wherein an on signal defining a period of one frame and an off signal subsequent to the on signal are provided on the scanning line. And a second signal having an arbitrary voltage on the signal line before the application of the ON signal to each of the two successive frames, and the voltage level of which changes during the ON signal. Is given.

According to the above method, for example, in the case of a normally black mode liquid crystal display element, most defective picture elements are displayed as bright spots (or have a different display from normal picture elements), and the detection of defects is not possible. An easy inspection method for a liquid crystal display element can be provided. In particular, a picture element or the like having a TFT characteristic defect, which has been difficult to recognize in the past, can be clearly displayed by displaying a bright point. In other words, the inspection accuracy is improved, the risk of defective products being overlooked and flowing out to subsequent processes can be eliminated, and the inspection time can be reduced.

Also, for example, various defect modes can be easily performed by combining a signal whose voltage level is changed before and after the application of an ON signal to each of two consecutive frames with an inspection method applied to a signal line. Can be determined. Therefore, it is also possible to specify a previous process that causes the defect.

In order to solve the above-mentioned problems, the inspection apparatus for a liquid crystal display element of the present invention has two substrates opposed to each other with a liquid crystal layer interposed therebetween, and is wired between the substrates so as to intersect each other. A plurality of scanning lines and a plurality of signal lines are wired, and a switching element provided near the intersection of the scanning line and the signal line and connected to the scanning line and the signal line; A pixel electrode connected to the scanning line and the signal line, and an auxiliary capacitor formed corresponding to each pixel electrode is connected to the scanning line to which the pixel electrode is connected. Is an inspection device for a liquid crystal display element, which is connected to another scanning line adjacent to the pixel electrode and is provided with a counter electrode facing the pixel electrode, and is provided to the scanning line. An ON signal that determines the period of one frame and the ON signal following the ON signal A first signal consisting of an off signal and an arbitrary voltage given to the signal line before the on signal is applied to each of the two successive frames, and the voltage level is changed during the on signal. And a voltage signal generating unit for generating a second signal.

Further, in order to solve the above-mentioned problems, the inspection apparatus for a liquid crystal display element according to the present invention has two substrates opposed to each other with a liquid crystal layer interposed therebetween, and intersects each other between the substrates so as to cross each other. A plurality of wired scanning lines and a plurality of signal lines are wired, and near each intersection of the scanning line and the signal line, a switching element provided connected to the scanning line and the signal line,
A picture element electrode connected to the scanning line and the signal line via each switching element is provided, and an auxiliary capacity formed corresponding to each picture element electrode is connected to an auxiliary capacity common wiring. A liquid crystal display element inspection device provided with a counter electrode opposed to a picture element electrode, wherein an on signal applied to the scanning line and defining a period of one frame and a signal subsequent to the on signal are provided. A first signal consisting of an off signal, and an arbitrary voltage applied to the signal line before the on signal is applied to each of two successive frames,
A voltage signal generating unit that generates a second signal whose voltage level is changed during the ON signal.

According to the above configuration, for example, in the case of a normally black mode liquid crystal display element, most defective picture elements are displayed as bright spots (or display different from normal picture elements), and defect detection is not performed. An easy inspection device for a liquid crystal display element can be provided. In particular, a picture element or the like having a TFT characteristic defect, which has been difficult to recognize in the past, can be clearly displayed by displaying a bright point. In other words, the inspection accuracy is improved, the risk of defective products being overlooked and flowing out to subsequent processes can be eliminated, and the inspection time can be reduced.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] The following will describe one embodiment of the present invention with reference to the drawings. Note that the present invention is not limited by this.

In the present embodiment, the liquid crystal display element to be inspected includes an active matrix substrate having pixel electrodes arranged in a matrix on an insulating substrate and a counter substrate opposed to each other with a liquid crystal layer interposed therebetween. .

In the active matrix substrate, as shown in FIG. 2, gate bus lines 11 functioning as scanning lines are arranged in parallel on an insulating substrate, and signal lines A large number of source bus lines 12 are arranged in parallel. The odd-numbered gate bus lines 11 are connected to the gate bus line wiring 17, and the even-numbered gate bus lines 11 are connected to the gate bus line wiring 18. That is, one of two adjacent gate bus lines 11 is connected to the wiring 17, and the other is connected to the wiring 18.

A TFT (switching element) 13 is arranged near each intersection of the bus lines 11 and 12.
The TFT 13 is connected to both bus lines 11 and 12 via terminals (gate electrode, source electrode). This TF
T13 further includes an adjacent gate bus line 11
And a picture element electrode 15 provided in each area (picture element) surrounded by the adjacent source bus lines 12 and 12 via a terminal (drain electrode).

One or a plurality of opposing electrodes 16 are formed on the opposing substrate opposing the active matrix substrate so as to oppose each pixel electrode 15.
5, a pixel capacitance Clc is formed. Further, an auxiliary capacitance 14 is formed in parallel with the pixel capacitance Clc. One of the auxiliary capacitors 14 is connected to the pixel electrode 15 and the other is connected to the gate bus line 1 to which the pixel electrode 15 is connected.
1 is connected to another gate bus line 11 adjacent to the picture element electrode 15 therebetween. That is, this liquid crystal display element has a Cs on Gate structure.
Although not shown, connection terminals are provided on both ends of the wirings 17, 18, and 19 and on the counter electrode 16.

Hereinafter, a method and an apparatus for inspecting a liquid crystal display element having such a Cs on Gate structure will be described in detail.

An inspection apparatus for a liquid crystal display element is, for example, as shown in FIG.
As shown in FIG. 7, a voltage signal generating section including a gate power supply, a gate signal generating circuit, a source power supply, and a source signal generating circuit is provided, and connection terminals provided at both ends of each of the wirings 17, 18, and 19 ( A contact is made with a probe (probe) or the like to a connection terminal provided on the counter electrode 16 and a gate terminal and a source terminal shown in FIG. 9 to apply a signal described below. . FIG. 9 does not show a circuit for generating a voltage signal applied to the counter electrode 16, connection terminals, and the like. Further, the voltage signal generator may be configured to generate a plurality of different voltage signals from a single power supply, for example.

In this embodiment, the presence or absence of a defect,
In order to specify the position of the defective picture element and determine the defect mode, first to third inspections described below are performed.
In the following description, a case where the display mode of the liquid crystal display element is a normally black mode is taken as an example, but it goes without saying that the present invention can be applied to a case where the display mode is a normally white mode.

The first inspection is, for example, as shown in FIG. 1, 1) a signal (first signal) A consisting of an ON signal for defining a period of one frame and an OFF signal following the ON signal.
11 is applied to the gate bus lines 11 through the wiring 17 (or the wiring 18), and 2) an arbitrary voltage (0 V may be applied) before applying the ON signal to each of the two successive frames, A signal (second signal) B11 of which the voltage level is changed is applied to the source bus lines 12 through the source bus line wiring 19,
3) The signal C11 fixed to the optimal counter voltage value that does not cause flicker or the like is applied to the counter electrode 16.

The second inspection is, for example, as shown in FIG. 3, 1) applying the signal A11 to the wiring 17 (or the wiring 1);
8) is applied to the gate bus lines 11 through 2), and 2) a signal B12 whose voltage level is changed before and after the application of the ON signal to each of the two successive frames is applied to the source bus lines 12 through the wiring 19, 3) The signal C11 is applied to the counter electrode 16.

The signal B12 is not particularly limited to the signal having the above-mentioned waveform. For example, the signal B12 whose voltage level is changed before the application of the ON signal to each of two successive frames is provided. Alternatively, the voltage level may be changed after the application of the ON signal to each of the two preceding and succeeding frames.

The third inspection is, for example, as shown in FIG. 4, 1) applying the signal A11 to the odd-numbered (or even-numbered) gate bus lines 11 through the wiring 17 and the signal A13 Is applied to the even-numbered (or odd-numbered) gate bus lines 11 through the wiring 18, 2) the signal B12 is applied to the source bus lines 12 through the wiring 19, and 3) the signal C11 is
This is applied to the counter electrode 16.

The order in which the first to third inspections are performed is not particularly limited. Further, depending on the type of defect mode to be specified, the first inspection and the second inspection may be performed, or the first inspection and the third inspection may be performed. Furthermore, when it is desired to simply confirm the presence or absence of a defect or the position of a defective picture element, only the first inspection may be performed.

Next, Table 1 shows the display modes of the respective defect modes in the normally black mode by performing the above-described first to third inspections. That is, Table 1 is a table for determining the defect mode.

[0040]

[Table 1]

The inspection of each defect mode shown in Table 1 will be specifically described below.

First, the TFT characteristic failure will be described with reference to FIGS. In order to display a pixel having a TFT characteristic defect as a bright point, a signal A21 shown in FIG. 5 is supplied to the odd-numbered gate bus lines 11 via a wiring 17, and a signal A21 'is supplied via a wiring 18. Are supplied to the even-numbered gate bus lines 11. A signal (second signal) B21 is supplied to the source bus lines 12 via the wiring 19, and a signal C21 is supplied to the counter electrode 16.

The above signals (first signals) A21 and A21 '
Is a signal for turning on / off the TFT 13, and is equivalent to the signal A11 shown in FIG. Also, the signal C21
Is equivalent to the signal C11 shown in FIG. Further, the signal B21 is a signal having an arbitrary voltage before the application of the ON signal to each of the two consecutive frames, like the signal B11 shown in FIG. 1, and whose voltage level is changed during the ON signal. . More specifically, it is a signal that has an arbitrary voltage before the application of the ON signal to each of two consecutive frames, and whose voltage level is reduced (to 0 V) during the ON signal. That is, the test using each signal shown in FIG. 5 corresponds to the first test described above.

The change in the voltage held by the picture element electrode 15 when the signal is input is indicated by voltage levels D11 and D12. More specifically, voltage level D11 is equal to TF
In a picture element having a poor T characteristic, it indicates a voltage applied between the picture element electrode 15 and the counter electrode 16, and the voltage level D 12 is between the picture element electrode 15 and the counter electrode 16 in a normal picture element. 1 shows the voltage applied to the power supply.

If there is a TFT characteristic defect, it takes time to write a signal supplied through the source bus lines 12. Therefore, the signal B2 is not supplied until the TFT 13 is turned off.
1 cannot be sufficiently written. Therefore, the voltage level D
11 is a state where the high level is maintained. When the display mode of the liquid crystal display element is the normally black mode, white display is performed if the voltage applied between the pixel electrode 15 and the counter electrode 16 is high, so that the defective pixel becomes a bright point. .

Although the defective picture elements which are displayed as bright spots by the first inspection are present in addition to those having defective TFT characteristics, they can be distinguished from other defect modes by performing the second inspection. Is clear from Table 1.

Next, the leakage failure between the source and the pixel electrode (the source bus line 12 and the pixel electrode 15) will be described with reference to FIGS. A signal A21 shown in FIG.
7, and the signal A21 'is applied to the even-numbered gate bus lines 11 via the wiring 18. The signal B22 is
Given to the source bus lines 12 through the wiring 19,
The signal C21 is provided to the counter electrode 16. The signal B22
Is a signal whose voltage level is changed before and after the application of the ON signal to each of two adjacent frames, similarly to the signal B12 shown in FIG. That is, the test using each signal shown in FIG. 6 corresponds to the second test described above.

The change in the voltage held by the picture element electrode 15 when the above signal is input is as shown by the voltage levels D13 and D14. More specifically, the voltage level D13 indicates a voltage applied between the picture element electrode 15 and the counter electrode 16 in a picture element having a leak failure between the source picture element electrodes. This shows the voltage applied between the picture element electrode 15 and the counter electrode 16 in a normal picture element.

If there is a leak failure between the source and the pixel electrode, the potential of the source bus lines 12 is written to the pixel electrode 15 even when the TFT 13 is turned off. Therefore, the voltage level D13 also increases during the off period of the TFT 13. When the display mode of the liquid crystal display element is a normally black mode, white display is obtained if the voltage applied between the pixel electrode 15 and the counter electrode 16 is high, so that a pixel having this defect is displayed as a bright point. Is done.

It is to be noted that defective picture elements which are displayed as bright spots by the above-mentioned second inspection are present in addition to those having a leak defect between the source and the picture element electrodes. What distinguishes it from other defect modes is
It is clear from Table 1.

FIGS. 2 and 4 show a leakage defect between the auxiliary capacitance electrodes (that is, a leakage defect between the picture element electrode 15 and the electrode forming the auxiliary capacitance 14 opposed to the picture element electrode 15). Will be described with reference to FIG. A signal A11 shown in FIG. 4 is applied to the odd-numbered (or even-numbered) gate bus lines 11 through the wiring 17 in order to display only the picture elements having the leak failure between the auxiliary capacitance electrodes as bright spots. Signal A1
3 is supplied to the even-numbered (or odd-numbered) gate bus lines 11 via the wiring 18. The signal B12
Are applied to the source bus lines 12 via the wiring 19, and the signal C11 is applied to the counter electrode 16. That is, the test using each signal shown in FIG. 4 corresponds to the third test described above. In order to input the signal A13 to the gate bus lines 11,...
.. May be connected to GND (Ground).

The change of the voltage held by the picture element electrode 15 when the above signal is input is as shown by the voltage level D15. More specifically, the voltage level D15 indicates a voltage applied between the picture element electrode 15 and the counter electrode 16 in a picture element having a leak failure between the auxiliary capacitance electrodes or a normal picture element.

Therefore, at this time, two kinds of defects (a leak defect between the gate and the picture element electrode and a leak defect between the auxiliary capacitance electrodes) which have become bright spots in the first and second inspections are performed.
Can be determined. That is, the picture element having the leak failure between the gate and the picture element electrode remains in the bright spot display,
A picture element having a leak failure between the auxiliary capacitance electrodes is displayed as a normal picture element.

The picture element having a leak failure between the gate and the picture element electrode can be easily identified because it becomes a luminescent spot in the first to third inspections as needed. It should be noted that a leak defect between the upper and lower electrodes (that is, a leak defect between the pixel electrode 15 and the counter electrode 16) cannot be made into a bright spot because there is no potential difference between the pixel electrode 15 and the counter electrode 16. , It is barely possible to detect on a monochrome (R, G, B solid) screen. In addition, the leak failure between the gate and the pixel electrode, or
The reason why a defective pixel having a leak failure between the auxiliary capacitance electrodes is displayed as a bright spot by the first inspection is that a signal A21 or a signal A21 ′ having a high voltage is written to the pixel. .

That is, as is apparent from Table 1 above, in particular, by performing the first inspection, picture elements and the like having TFT characteristic defects, which were conventionally difficult to recognize, are displayed as bright spots. Can be clearly recognized. In addition, by performing the first to third inspections, various defect modes can be easily determined in a panel state.

Therefore, in the conventional inspection method, the defective picture element displayed as a black point (in the case of the normally black mode) can be displayed as a bright point, so that the inspection accuracy can be improved and the inspection time can be reduced. Becomes In addition, since there is no possibility that a defective product is overlooked and flows out to a subsequent process, there is no possibility that a driver IC or the like is mounted on the defective product. In addition, since various defect modes can be easily determined, it is also possible to specify a previous process that causes the defect.

The second signal has, for example, an arbitrary voltage (may be 0 V) before the application of the ON signal to each of the two consecutive frames, and the voltage level increases during the ON signal. Signal may be used. As described above, it takes time to write the second signal to the defective picture element having the TFT characteristic defect. Therefore, even when the TFT 13 is turned off, the picture element maintains the low voltage level. Become. On the other hand, the normal picture element has a high voltage level due to the writing of the second signal, so that both can be distinguished.

[Second Embodiment] The following will describe another embodiment of the present invention with reference to the drawings. Note that the present invention is not limited by this.

In the present embodiment, the liquid crystal display element to be inspected includes an active matrix substrate in which pixel electrodes are arranged in a matrix on an insulating substrate and a counter substrate, which are opposed to each other with a liquid crystal layer interposed therebetween. .

The above-mentioned active matrix substrate has the structure shown in FIG.
As shown in FIG. 3, gate bus lines 21 functioning as scanning lines are wired in parallel, and are orthogonal to the gate bus lines 21 so that source bus lines 22 functioning as signal lines.
Are wired in parallel. Each of the gate bus lines 21 is connected to a wiring 27 for the gate bus line,
Are connected to the source bus line wiring 29.

A TFT (switching element) 23 is disposed near each intersection of the bus lines 21 and 22.
The TFT 23 is connected to both bus lines 21 and 22 via terminals (gate electrode, source electrode). This TF
T23 further includes an adjacent gate bus line 21
And a pixel electrode 25 provided in each region surrounded by the adjacent source bus lines 22 and 22 via a terminal (drain electrode).

One or a plurality of opposing electrodes 26 are formed on the opposing substrate opposing the active matrix substrate so as to oppose each pixel electrode 25.
, A pixel capacitance Clc is formed. Further, an auxiliary capacitance 24 is formed in parallel with the pixel capacitance Clc.
One of the auxiliary capacitances 24 is connected to the picture element electrode 25 and the other is connected to an auxiliary capacitance wiring (auxiliary capacitance common wiring) 31. That is, this liquid crystal display element has Cs on
COMMON (hereinafter referred to as Cs on COM)
It has a structure. The wiring position of the auxiliary capacitance wiring is
There is no particular limitation. For example, it may be parallel to the gate bus lines 21.
... may be parallel.

As the inspection device for the liquid crystal display element having the Cs on COM structure, the inspection device described in the first embodiment can be used. In the present embodiment, both ends of each of the wirings 27 and 29 and each connection terminal provided on the counter electrode 26 are contacted with a probe (probe) using the inspection device. The first and second inspections described above and the third inspection described below are performed.

The third inspection is, for example, as shown in FIG. 8, 1) applying a signal A31 equivalent to the above-mentioned signal A11 to the gate bus lines 21 through the wiring 27 and 2) The above signal B
A signal B32 equivalent to 12 is applied to the source bus lines 22 through the wiring 29, and 3) a signal C31 equivalent to the above-mentioned signal C11 is applied to the counter electrode 26.

The first and second inspections and the third
The order in which the inspections are performed is not particularly limited. Further, depending on the type of defect mode to be specified, the first inspection and the second inspection may be performed, and the first inspection and the third inspection may be performed.
An inspection may be performed. Furthermore, when it is desired to simply confirm the presence or absence of a defect or the position of a defective picture element, only the first inspection may be performed.

Next, Table 2 shows the display modes of the respective defect modes in the normally black mode by performing the first, second, and third inspections. That is, Table 2 is a discrimination table of the defect mode.

[0067]

[Table 2]

In the inspection of each defect mode shown in Table 2,
Detection and determination methods other than leak failure between auxiliary capacitance electrodes are as follows.
Since the method of the first embodiment can be applied as it is, the description is omitted.

On the other hand, with respect to the leak failure between the auxiliary capacitance electrodes, by performing the above-described third inspection, only the picture element having the leak failure can be displayed as a bright spot. More specifically, referring to FIG. 8, by inputting the signal A31 to the auxiliary capacitance wiring 31, in the pixel having a leak failure between the auxiliary capacitance electrodes, the pixel A is connected between the pixel electrode 15 and the counter electrode 16. Such a change in voltage will be indicated by voltage level D16. That is, a higher voltage is applied to a picture element having a leak failure between the auxiliary capacitance electrodes than a normal picture element, so that the picture element having the leak failure is displayed as a bright point.

That is, in the inspection apparatus for the liquid crystal display element having the Cs on COM structure, the above inspection is performed to improve the inspection accuracy, reduce the inspection time, and perform the post-process of the defective product described in the first embodiment. The effect of preventing outflow to the device and the ability to identify the previous process that causes the defect can be obtained.

In the leak failure between the upper and lower electrodes, as in the first embodiment, since a potential difference cannot be formed between the picture element electrode 25 and the counter electrode 26, a bright spot cannot be formed.
(G, B solid) detection on a screen is barely possible.

In addition, the above-described first to third inspections, and
The waveform of each signal used in the third inspection can be easily produced by providing the voltage signal generator with, for example, a signal generator (such as a source / gate signal generator circuit shown in FIG. 9). Detailed description is omitted. Further, the signal generator can be incorporated in an automatic inspection device.

[0073]

As described above, according to the method for inspecting a liquid crystal display element of the present invention, the auxiliary capacitance formed corresponding to each picture element electrode is different from the scanning line to which the picture element electrode is connected. A liquid crystal display element connected to another scanning line adjacent to the pixel electrode, or a storage capacitor, a method for testing a liquid crystal display element connected to a storage capacitor common line, wherein the scanning line, A first signal consisting of an ON signal that determines the period of one frame and an OFF signal following the ON signal is given, and an arbitrary voltage is applied to the signal line before the ON signals are given to each of two successive frames. And a second signal whose voltage level is changed during the ON signal.

According to the above-described method, for example, in the case of a normally black mode liquid crystal display element, most defective picture elements are displayed as bright spots (or display different from normal picture elements), and defect detection is not performed. There is an effect that an easy method for inspecting a liquid crystal display element can be provided.

As described above, according to the liquid crystal display device inspection apparatus of the present invention, the auxiliary capacitance formed corresponding to each picture element electrode is different from the scanning line to which the picture element electrode is connected. A liquid crystal display element connected to another scanning line adjacent to the liquid crystal display element, or an auxiliary capacitor, a liquid crystal display element inspection device connected to an auxiliary capacitance common line, which is provided to the scanning line; A first signal consisting of an ON signal defining a period of one frame and an OFF signal following the ON signal, and an arbitrary voltage applied to the signal line before the ON signals are applied to each of the two consecutive frames And a voltage signal generating unit for generating a second signal whose voltage level is changed during the ON signal.

According to the above configuration, for example, in the case of a normally black mode liquid crystal display element, most defective picture elements are displayed as luminescent spots (or displayed differently from normal picture elements), and defect detection is not performed. There is an effect that an inspection device for a liquid crystal display element which can be easily provided can be provided.

[Brief description of the drawings]

FIG. 1 shows a Cs on Gate structure or Cs o
FIG. 4 is a diagram illustrating a waveform of a signal used for a first inspection of a liquid crystal display element having an nCOM structure.

FIG. 2 is an explanatory diagram showing a schematic configuration of a liquid crystal display element to be inspected in an embodiment of the present invention.

FIG. 3 shows a Cs on Gate structure or Cs o
It is a figure showing the waveform of the signal used for the 2nd inspection of the liquid crystal display element of n COM structure.

FIG. 4 is a diagram showing a waveform of a signal used for a third test of the liquid crystal display element shown in FIG. 2;

FIG. 5 is a graph showing T.sub.T during the first inspection of the liquid crystal display device shown in FIG.
FIG. 7 is a diagram illustrating changes in voltage levels held by a picture element electrode of a picture element having an FT characteristic defect and a picture element electrode of a normal picture element.

6 is a diagram showing a state in which a pixel electrode having a leak defect between a source electrode and a pixel electrode and a pixel electrode of a normal pixel during the second inspection of the liquid crystal display element shown in FIG. FIG. 6 is a diagram showing a change in voltage level of the voltage.

FIG. 7 is an explanatory diagram showing a schematic configuration of a liquid crystal display element to be inspected in another embodiment of the present invention.

8 is a diagram showing a change in a voltage level held by a picture element electrode of a picture element having a leak failure between auxiliary capacitance electrodes at the time of a third inspection of the liquid crystal display element shown in FIG.

FIG. 9 is a block diagram showing a main configuration of a liquid crystal display element inspection apparatus according to an embodiment of the present invention.

FIG. 10 is an explanatory diagram showing a schematic configuration of a conventional liquid crystal display element.

FIG. 11 is a diagram showing waveforms of signals used for testing the liquid crystal display element shown in FIG.

FIG. 12 is an explanatory diagram showing a schematic configuration of another conventional liquid crystal display element.

13 is a diagram showing waveforms of signals used for testing the liquid crystal display element shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Gate bus line (scanning line) 12 Source bus line (signal line) 13 TFT (switching element) 14 Auxiliary capacitance 15 Picture element electrode 16 Counter electrode 21 Gate bus line (scanning line) 22 Source bus line (signal line) 23 TFT (Switching element) 24 Auxiliary capacitance 25 Pixel electrode 26 Counter electrode 31 Auxiliary capacitance wiring (auxiliary capacitance common wiring) A11 signal (first signal) A21 signal (first signal) A21 'signal (first signal) B11 signal (second signal) B21 signal (second signal)

Claims (4)

[Claims] A plurality of scanning lines and a plurality of signal lines, which are arranged so as to intersect each other, are arranged between said substrates, wherein said plurality of scanning lines and a plurality of signal lines are arranged between said substrates; In the vicinity of each intersection with the signal line, a switching element connected to the scanning line and the signal line is provided, and a pixel electrode connected to the scanning line and the signal line via the switching element is provided. Further, the auxiliary capacitance formed corresponding to each picture element electrode is:
Inspection of a liquid crystal display element in which the scanning line to which the picture element electrode is connected is connected to another scanning line adjacent to the picture element electrode and is provided with a counter electrode facing the picture element electrode. A method comprising: providing a first signal consisting of an ON signal defining a period of one frame and an OFF signal subsequent to the ON signal to the scanning line; A method for testing a liquid crystal display element, characterized in that an arbitrary voltage is applied before the application of the ON signal, and a second signal whose voltage level is changed during the ON signal is provided. 2. A semiconductor device comprising: two substrates facing each other with a liquid crystal layer interposed therebetween; a plurality of scanning lines and a plurality of signal lines wired so as to intersect each other between the substrates; In the vicinity of each intersection with the signal line, a switching element connected to the scanning line and the signal line is provided, and a pixel electrode connected to the scanning line and the signal line via the switching element is provided. Further, the auxiliary capacitance formed corresponding to each picture element electrode is:
An inspection method for a liquid crystal display element connected to an auxiliary capacitance common line and provided with a counter electrode opposed to a picture element electrode, wherein an on signal for defining a period of one frame is provided to the scanning line. A first signal consisting of an off signal following the signal is provided, and the signal line has an arbitrary voltage before the on signal is applied to each of two successive frames, and the voltage level is included in the on signal. Providing a second signal which changes the voltage of the liquid crystal display element. 3. A semiconductor device comprising: two substrates facing each other with a liquid crystal layer interposed therebetween; a plurality of scanning lines and a plurality of signal lines wired so as to cross each other between the substrates; In the vicinity of each intersection with the signal line, a switching element connected to the scanning line and the signal line is provided, and a pixel electrode connected to the scanning line and the signal line via the switching element is provided. Further, the auxiliary capacitance formed corresponding to each picture element electrode is:
Inspection of a liquid crystal display element in which the scanning line to which the picture element electrode is connected is connected to another scanning line adjacent to the picture element electrode and is provided with a counter electrode facing the picture element electrode. An apparatus, comprising: a first signal provided to the scanning line, the signal being an ON signal defining a period of one frame, and an OFF signal subsequent to the ON signal; and two successive signals provided to the signal line. The liquid crystal display device according to claim 1, further comprising a voltage signal generation unit having an arbitrary voltage before the application of the ON signal to each frame, and generating a second signal whose voltage level is changed during the ON signal. Inspection equipment. 4. A semiconductor device comprising: two substrates facing each other with a liquid crystal layer interposed therebetween; a plurality of scanning lines and a plurality of signal lines wired so as to intersect each other between the substrates; In the vicinity of each intersection with the signal line, a switching element connected to the scanning line and the signal line is provided, and a pixel electrode connected to the scanning line and the signal line via the switching element is provided. Further, the auxiliary capacitance formed corresponding to each picture element electrode is:
An inspection device for a liquid crystal display element connected to an auxiliary capacitance common line and provided with a counter electrode opposite to a picture element electrode, comprising: an ON signal applied to the scanning line for defining a period of one frame; A first signal consisting of an off signal following the on signal, and an arbitrary voltage given to the signal line before the on signal is applied to each of two successive frames, and An inspection apparatus for a liquid crystal display element, comprising: a voltage signal generation unit that generates a second signal whose voltage level is changed.