JP2002116423A - Liquid crystal display device and its inspecting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display device whose inspection can be performed easily although it has a digital source driver. SOLUTION: This device is provided with a pixel part 3 having a TFT(thin film transistor) 1 and a storage capacitor 2 a gate driver 5 turning on and off the pixel part 3 through a gate source line and a digital source driver 18 supplying a picture signal to the pixel part 3 through a source bus line 9. Moreover, in this inspecting method, an inspecting line 27 is connected to the source bus line 9 via an analog switch 25. The analog switch 25 is turned ON, OFF by a switch driving circuit 30. The current from the storage capacitor 2 to which the picture signal is supplied and on which charge is stored is drawn to the inspecting line 27 by turning the switch 25 ON with the switch driving circuit 30 to be measured with the current measuring device connected to the inspection terminal 28 of the line 27. Thus, the liquid crystal display device can be inspected easily and correctly not through the digital source driver 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal display device,
In particular, the present invention relates to an active matrix type liquid crystal display device and an inspection method thereof.

[0002]

2. Description of the Related Art Conventionally, an active matrix type liquid crystal display device has a TFT 1 and a TFT 1 as shown in FIG.
A pixel section 3 having a storage capacitor 2 for storing charges connected to T1 is arranged in a matrix, a gate bus line 6 and a source bus line 9 are arranged to be orthogonal to each other, and the gate of the TFT 1 is connected to a gate bus. The source of the TFT 1 is connected to the source bus line 9. The gate driver 5 sends a scanning signal to the gate electrode of the TFT 1 via the gate bus line 6 to
On the other hand, the source driver 8 controls on / off of the analog switch 10 provided on the source bus line 9 to control the image signal input from the video input terminal 12. On the other hand, the terminal of the storage capacitor 2 not connected to the TFT 1 is connected to a common electrode wiring 15 in a direction parallel to the gate bus line 6, that is, in a direction orthogonal to the source bus line 9. 15 is
It is connected to one terminal 16.

In the active matrix type liquid crystal display device, an inspection is required in the manufacturing process to detect, for example, a defect in the TFT 1, the gate bus line 6, and the source bus line 9. Eliminating defective products during the production of a liquid crystal display device is very important in terms of production costs.

The above liquid crystal display device is inspected as follows. After an image signal is supplied to the pixel unit 3 to charge the storage capacitor 2, a current measuring device (not shown) is connected to the video input terminal 12. Then, the source driver 8
Then, the gate driver 5 is operated to discharge the electric charge written in the storage capacitor 2, and a current caused by the discharge is measured by the current measuring device via the video line 13. Based on the measured current, for example, a failure of the switching operation of the TFT 1, a failure of the storage capacitor 2, or a failure of the gate bus line 6 and the source bus line 9 are detected.

[0005] This method of testing a liquid crystal display device utilizes the fact that the video line 13 and the source bus line 9 can transmit signals bidirectionally via the analog switch 10. That is, the signal read by the current measuring device flows through the source bus line 9 in the opposite direction to the case where the image signal is sent to the pixel unit 3, and flows through the analog switch 10 to the video line 13.

There is also an inspection method for a liquid crystal display device in which a current generated by discharging the electric charge written in the storage capacitor 2 is measured through the common electrode wiring 15 and read out. That is, after writing a signal to the storage capacitor 2, the current measuring device is connected to the terminal 16, and then the source driver 8 and the gate driver 5 are operated to discharge the discharge current from the storage capacitor 2 to the common electrode wiring. The data is read out by the current measuring device via 15. Even with this inspection method, defects of the TFT 1, the storage capacitor 2, the source bus line 9, and the gate bus line 6 are detected.

In recent years, a so-called monolithic panel type in which a driver circuit such as a gate driver 5 and a source driver 8 is formed together with a pixel portion including a TFT and a storage capacitor, instead of mounting a driver externally on the same substrate. Liquid crystal display devices are being used. This monolithic panel-type liquid crystal display device uses poly-Si having good electric performance such as electron mobility, and uses a gate driver as a driving circuit and a digital source driver to which a digital image signal is input, as described above. It is formed on the same substrate together with the TFT and the storage capacitor of the portion. This monolithic panel type liquid crystal display device is easy to achieve high definition and small size,
It is being used.

[0008]

However, in some cases, the above-described conventional method for inspecting a liquid crystal display device cannot be applied to the above-described monolithic panel type liquid crystal display device. That is, as shown in FIG.
The image signal is input from the digital video input terminal 22 and the digital video line 23
Through a latch circuit and a DAC (digital-to-analog conversion circuit). Since the latch circuit and the DAC do not flow a reverse current, the current due to the charge released by the storage capacitor 2 of the pixel unit 3 is transferred to the digital video input terminal 2 via the digital video line 23.
2 cannot be read. Therefore, the conventional inspection method for a liquid crystal display device, in which the discharge current from the storage capacitor 2 is measured by a current measuring device connected to the video input terminal,
It cannot be applied to a liquid crystal display device having the digital source driver 18.

Inspection of the liquid crystal display device for measuring a current to the storage capacitor 2 via a common electrode wiring 15 which can be used commonly for a liquid crystal display device having a digital source driver or a liquid crystal display device having an analog source driver. The method has a problem that the current to the storage capacitor 2 cannot be measured accurately. That is, the common electrode wiring 15 is
Since the wiring is arranged substantially orthogonal to the source bus line 9, a stray capacitance is generated in a portion 24 orthogonal to the source bus line 9 where an image signal which is a relatively strong current flows. The capacitance value of the stray capacitance is several pF (picofaraday) to several tens pF, which is much larger than a storage capacitance having a capacitance value of about 0.1 pF. Therefore, the current to the storage capacitor 2 is buried by the current due to the stray capacitance.
Current cannot be measured accurately. As a result, there is a problem that the liquid crystal display device cannot be inspected correctly.

Accordingly, an object of the present invention is to provide a liquid crystal display device which can be easily inspected in spite of a monolithic panel type liquid crystal display device having a digital source driver, and a method of inspecting the liquid crystal display device. Is to do.

It is another object of the present invention to provide a method of inspecting a liquid crystal display device which can obtain an accurate result through a common electrode wiring.

[0012]

In order to achieve the above object, in a liquid crystal display device according to the present invention, a pixel portion including a TFT and a storage capacitor, a digital source driver to which a digital signal is input, and a gate driver are the same. In the liquid crystal display device of the monolithic panel type formed on the substrate of (1), each source bus line connecting the digital source driver and the pixel unit is connected to an inspection circuit, and the analog switch is sequentially controlled. A switch control circuit.

According to the present invention, an analog switch and a switch control circuit for controlling the analog switch are provided on the source bus line separately from the digital source driver. The analog switches are sequentially driven by this switch control circuit to discharge the electric charges stored in the storage capacitors of the pixel units. The current due to the discharge is guided to the test circuit via the analog switch, and is measured by, for example, a current measuring device connected to the test circuit. Therefore, although the liquid crystal display device is a monolithic panel type liquid crystal display device having the digital source driver that does not flow a current in a direction opposite to the direction of the display operation of the pixel portion, a current measuring device is used as in the related art. The inspection of the liquid crystal display device is performed by using.

In one embodiment of the invention, the switch control circuit has a shift register and a NAND circuit.

According to the above embodiment, the switch control circuit sequentially drives the analog switches to discharge the storage capacity of the pixel portion in which the charges are stored in advance, and the current resulting from the discharge is conducted to the inspection circuit. I will The current guided to this inspection circuit is measured using a conventional current measuring device, and the liquid crystal display device is inspected.

In one embodiment of the present invention, a test circuit for testing a liquid crystal display device measures an electric charge stored in the storage capacitor by a test circuit connected to the analog switch.

According to the above embodiment, the current from the storage capacitor in which electric charges are stored in advance is measured via the source bus line and the analog switch. That is, instead of connecting a current measuring device to a conventional video line, a current measuring device is connected to, for example, a test line as the test circuit. Then, based on the current measured by the current measuring device, for example, a failure of the switching operation of the TFT, a failure of the storage capacitor, or a failure of the source bus line and the gate bus line are detected.

According to the liquid crystal display device of the present invention, a pixel portion including a TFT and a storage capacitor, a gate driver and a source driver for driving the pixel portion, a gate bus line connecting the gate driver and the pixel portion, In a liquid crystal display device including a source bus line connecting a source driver and a pixel portion, and a common electrode line connected to a terminal of the storage capacitor that is not connected to the TFT, the common electrode line includes the source bus line. It is located in a direction that does not easily cross the bus line.

According to the present invention, since the common electrode wiring is arranged in a direction hardly intersecting with the source bus line, there is almost no floating capacitance between the common electrode wiring and the source bus line. Therefore, since the current from the storage capacitor is hardly buried by the current due to the floating capacitance, the current from the storage capacitor is accurately measured via the common electrode wiring. As a result, the liquid crystal display device is accurately inspected.

In one embodiment, the common electrode wiring is arranged in a comb shape, and is substantially parallel to the source bus line.

According to the above embodiment, since the common electrode wiring is arranged in a comb shape and is substantially parallel to the source bus line, the common electrode wiring does not cross the source bus line. Therefore, since no stray capacitance is generated in the common electrode wiring, the current from the storage capacitor is accurately measured, and the liquid crystal display device is accurately inspected.

In one embodiment, the common electrode wiring is divided into a plurality of groups, and each of the plurality of groups is connected to one terminal.

According to the above embodiment, the common electrode wiring is divided into a plurality of groups, and each of the plurality of groups is connected to one terminal. Therefore, a current measuring device is connected to each of these terminals. By doing so, currents from the pixel units corresponding to the number of the groups are measured at a time. As a result, the inspection time of the liquid crystal display device is reduced.

In one embodiment of the present invention, a method for inspecting a liquid crystal display device measures a current from the pixel portion via the common electrode wiring.

According to the above-described embodiment, the current from the storage capacitor of the pixel portion can be accurately measured without being buried in the current due to the floating capacitance via the common electrode wiring where the floating capacitance hardly occurs between the source bus line. Measured. As a result, a defective switching operation of, for example, a TFT of the liquid crystal display device, a defective storage capacitor, or a defective source bus line and a gate bus line can be accurately detected.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

FIG. 1 is a diagram showing a liquid crystal display device as a first embodiment of the present invention. A part of this liquid crystal display has the same configuration as the liquid crystal display shown in FIG.
The same parts as those of the liquid crystal display device shown in FIG. 8 are denoted by the same reference numerals, and detailed description will be omitted.

In the liquid crystal display device of the present invention, an analog switch 25 is provided on each of the plurality of source bus lines 9 for transmitting the image signal sent from the digital source driver 18 to the pixel section 3. This plurality of analog switches 2
A test line 27 as a test circuit is connected to the plurality of source bus lines 9 via the reference numeral 5. An inspection terminal 28 is provided at an end of the inspection line 27 on the side where the analog switch 25 is not connected. Further, the liquid crystal display device is provided with a switch control circuit 30 for controlling the plurality of analog switches 25.

This liquid crystal display is inspected as follows.

First, in a state where the source bus line 9 and the inspection line 27 are cut off by the analog switch 25,
An image signal is written to the pixel section 3 by the gate driver 5 and the digital source driver 18. That is, charges are accumulated in the storage capacitor 2 of the pixel unit 3 turned on by the gate driver 5 by an image signal sent from the digital source driver 18 via the source bus line 9.

Thereafter, the digital source driver 18
Is disconnected from the source bus line 9, the analog switch 25 is sequentially turned on by the switch control circuit 30, and the source bus line 9 is sequentially connected to the inspection line 27. Then, the charges stored in the storage capacitor 2 of the pixel unit 3 are discharged, and a current flows to the inspection line 27 via the source bus line 9. This current
The measurement is performed by a current measuring device (not shown) connected to the inspection terminal 28 of the inspection line 27. Based on the measurement result of the current, for example, a failure of the switching operation of the TFT 1, a failure of the storage capacitor 2, or a failure of the source bus line 9 and the gate bus line 6 are detected. Therefore, despite the fact that the liquid crystal display device of the present embodiment has the digital source driver 18, the current from the pixel section 3 is transmitted by the inspection line 27 via the analog switch 25 driven by the switch control circuit 30. By performing the measurement, the inspection of the liquid crystal display device can be easily performed as in the related art.

Note that the switch control circuit 30 corresponds to FIG.
As shown in (a), the circuit includes shift registers SR1, SR2,... And NAND circuits 33, 33,. The signals to the shift registers SR1, SR2,...
25 are turned on and off. More specifically, by inputting signals having the waveforms shown in FIGS. 2B and 2C to the enable signal line 34, the shift registers SR1, S2
The analog switches 25 are sequentially turned on in response to the input signals to R2. On the other hand, except for the time of inspection, a signal having a waveform shown in FIG.
Alternatively, all the analog switches 25, 25... Are turned off by making the enable signal line 34 float. After the inspection is completed, the analog switches 25, 25,... Are all kept off by setting the enable signal lines 25, 25.

At the time of inspection of the liquid crystal display device, the switch control circuit 30 functions similarly to the source driver 8 at the time of inspection of the conventional liquid crystal display device of FIG.
More specifically, the switch control circuit 30 drives the analog switch 25 on and off in the same manner as the source driver 8 controls the analog switch 10 on and off in the related art. However, the switch control circuit 30
The driving frequency of the shift register differs from that of the conventional source driver 8. This is because the conventional source driver 8 needs to perform a write operation of 60 frames per second in order to prevent flicker during the display operation of the pixel unit 3. Therefore, the shift register of the source driver 8 has a high driving frequency. Therefore, in order to enable charging and discharging of the write charge in a short time,
The conventional source driver 8 is provided with a relatively large-capacity transistor. On the other hand, the switch control circuit 30 according to the present invention sequentially supplies the current from the pixel unit 3 to the inspection line 2.
7, only the analog switch 25 is controlled, and there is no need to consider the display quality of the pixel unit 3.
The transistor of the switch control circuit 30 may be small, and it is not necessary to form a wide wiring in order to reduce the wiring resistance. Therefore, the analog switch 25
In the switch control circuit 30, the area formed on the substrate of the liquid crystal display device is relatively small. The analog switch 25 and the switch control circuit 30 in which the formed area is relatively small, and the switch control circuit input terminal 31
And the inspection line 27 and the inspection terminal 28 are formed in a seal area having a width of about 1 to 2 mm in the outer peripheral portion of the display area of the liquid crystal display device. Thus, a liquid crystal display device that can be easily inspected without increasing the size of the liquid crystal display device is obtained.

In the above embodiment, a plurality of source bus lines 9, 9,... Are connected to a test line 27, and a plurality of pixel sections are connected by one current measuring device connected to a test terminal 28 of the test line 27. Although the currents from the pixel units 3 are sequentially measured, the currents from the pixel units 3 may be simultaneously measured by connecting a plurality of source bus lines directly to a plurality of current measuring devices. By doing so, the inspection time of the liquid crystal display device can be reduced.

FIG. 3A is a view showing a liquid crystal display device according to a second embodiment of the present invention. Parts having the same functions as those of the liquid crystal display device shown in FIG. The detailed description is omitted by attaching a reference number.

In this liquid crystal display device, a comb-shaped common electrode wiring 15 is arranged substantially parallel to the source bus line 9 in a display region where the pixel portion 3 is formed.

In this liquid crystal display device, when inspecting the liquid crystal display device, the pixel section 3 is operated for display by the gate driver 5 and the digital source driver 18, and the current flowing through the common electrode wiring 15 at that time is measured. Based on this current, a defect of the liquid crystal display device is detected.

During the inspection of the liquid crystal display device, a relatively large current supplied from the digital source driver 18 flows through the source bus line 9. However, the common electrode wiring 15 is arranged substantially parallel to the source bus line 9 and does not cross the source bus line 9. Therefore, the stray capacitance generated at the intersection of the source bus line and the common electrode line in the conventional liquid crystal display device does not occur in the common electrode line 15 of the present embodiment. As a result, at the time of inspection of the liquid crystal display device, the current from the storage capacitor 2 is not buried by the current due to the stray capacitance.
That is, the current from the storage capacitor 2 can be accurately read out with almost no influence of the stray capacitance, and the failure of the TFT 1, the storage capacitor 2, or the source bus line and the gate bus line of the liquid crystal display device can be accurately determined. Can be detected.

FIG. 3B is a modification of the liquid crystal display device shown in FIG. In this liquid crystal display device, one common source bus line 9
, One common electrode wiring 15 is formed.
This common electrode wiring 15 is also arranged in parallel with the source bus line 9 in the display area where the pixel section 3 is arranged,
A terminal 16 is provided at an end of the common electrode wiring 15. In this liquid crystal display device, a current measuring device is connected to each of the plurality of terminals 16, 16..., And the current from the plurality of pixel units 3 can be measured at the same time. After the inspection of the liquid crystal display device is completed, the FPC (flexible printed circuit) wiring provided with a predetermined pattern is connected to the terminals 16, 16,. Can be connected and bound together. Then, the driving operation of the pixel portion 3 is not affected when the liquid crystal display device is completed, and the step of connecting the common electrode wirings 15, 15,... After the inspection can be omitted.

FIG. 4 shows a liquid crystal display device according to a third embodiment of the present invention. This liquid crystal display device has a common electrode wiring 15
Are arranged substantially orthogonal to the source bus line 9 and substantially parallel to the gate bus line 6. Common electrode wiring 15
Intersects with the source bus line 9 that induces a stray capacitance, but one common electrode wiring 15 is arranged corresponding to one gate bus line 6, and a terminal 16 is provided for each common electrode wiring 15. I have. Thus, one common electrode wiring 1
The number of source bus lines 9 that intersect with each other at 5 is reduced to minimize the influence of stray capacitance due to the source bus lines 9. Therefore, as compared with a conventional case in which one terminal is provided on the common electrode wiring formed in a comb shape and all the effects of the stray capacitance induced at the intersection with the source bus line are concentrated, as compared with the related art. Terminal 16 of
The effect of stray capacitance is small. Therefore, at the time of inspection of the liquid crystal display device, the current flowing through the common electrode wiring 15 can be read out almost accurately by a current measuring device (not shown) connected to the terminal 16, and a defect of the liquid crystal display device can be detected satisfactorily.

By the way, in the second embodiment shown in FIG. 3A, when the current from the plurality of pixel units 3 on the turned-on gate bus line is measured via the common electrode wiring 15, the pixel unit In order to specify the number 3, a signal corresponding to the number of the pixel units 3 on the gate bus line 6 is used. That is, the signals Sa, Sb, Sc, Sd, S shown in FIG.
e, Sf are connected to the pixel unit 3 via the source bus lines a, b, c, d, e, f in the liquid crystal display device of FIG.
a, 3b, 3c, 3d, 3e, 3f. The pixel 3 on the gate bus line 6on which is turned on by a current measuring device (not shown) connected to the terminal 16.
a, 3b... are sequentially measured. Thus,
The liquid crystal display device is inspected by specifying the pixel portions 3a, 3b,. However, this liquid crystal display device is 1024 × 768.
In the case of a liquid crystal display device having the number of pixels, 1024 signals are sequentially applied to one gate bus line, so that the number of signal data and the inspection time become enormous.

FIG. 6A is a diagram showing a liquid crystal display device according to the fourth embodiment. This liquid crystal display device can perform inspection with a small number of signal data and inspection time. As shown in FIG. 6A, this liquid crystal display device includes common electrode wirings divided into a plurality of common electrode wiring groups 151, 152, and 153. The common electrode wiring groups 151 and 15
Each of 2,153 includes electrode terminals 161,162,163. The common electrode wiring group 151 includes the pixels 3a, 3
b, and the common electrode wiring group 152 is connected to the pixels 3c,
3d, and the common electrode wiring group 153 is connected to the pixel 3
e, 3f. Then, the signal S shown in FIG.
1, S2 are sequentially transferred to source bus lines a, b, c, d,
The pixel units 3a, 3b, 3c, 3d, 3e,
3f. The pixel portions 3a, 3c, 3
e at the same time, a signal S2 is applied to the pixel portions 3b and 3
Signals are applied to d and 3f at the same time. At this time, the terminal 16
Pixel units 3a, 3c, 3e via 1, 162, 163
And currents from the pixel units 3b, 3d, 3f are simultaneously observed. Thus, by dividing the common electrode wiring into a plurality of groups, the pixel units 3a, 3b, 3c, 3
The number of signals applied to d, 3e, 3f can be reduced, and
The time required for inspection of the liquid crystal display device can be reduced.

In the fourth embodiment, the common electrode wiring is divided into three groups. However, the common electrode wiring may be divided into any number of groups corresponding to the number of currents from the pixel unit to be measured simultaneously. Further, the number of pixel units measured by the group of the common electrode wirings may be any number.

[0044]

As is apparent from the above description, the liquid crystal display device of the present invention is a monolithic panel type liquid crystal display device having a digital source driver to which a digital signal is inputted. Since each of the source bus lines includes an analog switch that connects to the inspection circuit and a switch control circuit that sequentially controls the analog switch, the pixel section of the pixel unit is connected via the analog switch driven by the switch control circuit. Since the current from the storage capacitor can be measured, the inspection can be performed using the same current measuring device as before, despite having the digital source driver that does not allow the current to flow in the opposite direction to the display operation of the pixel portion. .

In the liquid crystal display device of one embodiment, since the switch control circuit has a shift register and a NAND circuit, the analog switch is driven by the switch control circuit having the same configuration as the conventional source driver. The inspection of the liquid crystal display device can be performed by measuring the current from the storage capacitor of the pixel portion.

In the inspection method of the liquid crystal display device for inspecting the liquid crystal display device according to the embodiment, the electric charge stored in the storage capacitor is measured by the inspection circuit connected to the analog switch. As in the case where the current measuring device is connected, a current measuring device is connected to the inspection circuit to measure the current due to the charge, and for example, TF
A failure in the switching operation of T, a failure in the storage capacitance, or a failure in the source bus line and the gate bus line can be detected.

According to the liquid crystal display device of the present invention, a pixel portion including a TFT and a storage capacitor, a gate driver and a source driver for driving the pixel portion, a gate bus line connecting the gate driver and the pixel portion, In a liquid crystal display device including a source bus line connecting a source driver and a pixel portion, and a common electrode line connected to a terminal of the storage capacitor that is not connected to the TFT, the common electrode line includes the source bus line. Since the stray capacitance is hardly generated between the common electrode wiring and the source bus line since the stray capacitance is arranged in a direction that does not easily cross the bus line, the current from the storage capacitor is buried by the current due to the stray capacitance. A liquid crystal display device which can be accurately measured without any trouble and can be accurately inspected is obtained.

In the liquid crystal display device of one embodiment, since the common electrode wiring is arranged in a comb shape and is substantially parallel to the source bus line, the common electrode wiring does not intersect with the source bus line. The current from the storage capacitor can be accurately measured without causing a stray capacitance in the common electrode wiring, and as a result, the liquid crystal display device can be accurately inspected.

In the liquid crystal display device according to one embodiment, the common electrode wiring is divided into a plurality of groups, and the plurality of groups are connected to one terminal, respectively. By doing so, it is possible to measure currents from the pixel units corresponding to the number of the groups at one time, and as a result, the inspection time of the liquid crystal display device can be reduced.

In the liquid crystal display device inspection method for inspecting the liquid crystal display device according to one embodiment, the current from the pixel portion is measured through the common electrode wiring where little stray capacitance is generated between the source bus line and the source bus line. Therefore, the current from the storage capacitor in the pixel portion is accurately measured without being buried in the current due to the stray capacitance, and the switching operation of the TFT of the liquid crystal display device is defective, the storage capacitance is defective, or the source bus line and the gate are defective. Defective bus lines can be accurately detected.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a liquid crystal display device according to a first embodiment of the present invention.

FIG. 2A is a diagram illustrating a switch control circuit 30 according to the first embodiment, and FIGS. 2B, 2C, and 2C;
(D) is a diagram showing a signal supplied to the enable signal line of the switch control circuit 30 to the enable signal line.

FIG. 3A is a view showing a liquid crystal display device according to a second embodiment of the present invention, and FIG. 3B is a view showing FIG.
It is a modification of the liquid crystal display device shown in FIG.

FIG. 4 is a view illustrating a liquid crystal display according to a third embodiment of the present invention.

FIG. 5A is a diagram illustrating signals supplied from a digital source driver 18 to pixel units 3a, 3b, 3c, 3d, 3e, and 3f in the liquid crystal display device according to the second embodiment. FIG. 5B is a diagram showing a liquid crystal display device when the signal of FIG. 5A is supplied to the pixel units 3a, 3b, 3c, 3d, 3e, and 3f.

FIG. 6A is a view showing a liquid crystal display according to a fourth embodiment of the present invention, and FIG. 6B is a view showing FIG.
When inspecting the liquid crystal display device of (a), the pixel units 3a, 3
It is the figure which showed the signal supplied to b, 3c, 3d, 3e, 3f.

FIG. 7 is a diagram showing a conventional liquid crystal display device.

FIG. 8 is a view showing a conventional monolithic panel type liquid crystal display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 TFT 2 Storage capacity 3 Pixel part 5 Gate driver 6 Gate bus line 8 Source driver 9 Source bus line 15 Common electrode wiring 16 Terminal 18 Digital source driver 22 Digital video input terminal 23 Digital video line 25 Analog switch 27 Test line 28 Test terminal 30 Switch control circuit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2G036 AA19 AA27 BA33 CA10 2H088 FA11 HA08 MA20 2H092 JA24 JA37 JA41 JB67 NA29 NA30 2H093 NA16 NA41 NC22 NC26 NC34 ND53 ND56 NE10

Claims (7)

[Claims] 1. A monolithic panel-type liquid crystal display device in which a pixel portion including a TFT and a storage capacitor, a digital source driver to which a digital signal is input, and a gate driver are formed on the same substrate. A liquid crystal display device comprising: an analog switch for connecting each source bus line connecting a driver and a pixel portion to a circuit for inspection; and a switch control circuit for sequentially controlling the analog switch. 2. The liquid crystal display device according to claim 1, wherein the switch control circuit includes a shift register and a NAND circuit.
A liquid crystal display device having a circuit. 3. The method for testing a liquid crystal display device according to claim 1, wherein the charge stored in the storage capacitor is measured by a test circuit connected to the analog switch. Inspection method for a liquid crystal display device. 4. A pixel section including a TFT and a storage capacitor; a gate driver and a source driver for driving the pixel section; a gate bus line connecting the gate driver and the pixel section; And a common electrode line connected to a terminal of the storage capacitor not connected to the TFT, wherein the common electrode line hardly intersects with the source bus line. A liquid crystal display device characterized by being arranged in a direction. 5. The liquid crystal display device according to claim 4, wherein the common electrode wiring is arranged in a comb shape, and is substantially parallel to the source bus line. 6. The liquid crystal display according to claim 4, wherein the common electrode wiring is divided into a plurality of groups, and the plurality of groups are connected to one terminal, respectively. apparatus. 7. A method for testing a liquid crystal display device for testing a liquid crystal display device according to claim 4, wherein the charge stored in the storage capacitor is measured via the common electrode wiring. A method for inspecting a liquid crystal display device, comprising: