JP2000147557A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the manufacturing yield and reliability of products by providing common wiring for protecting static electricity in pixel signal electrode wiring and connecting the static electricity protecting common wiring with the pixel signal electrode wiring through a resistance element. SOLUTION: The static electricity protection wiring 104 electrically connected to common electrode wiring terminals 112A, 112B is formed on the opposite side parallel to one side forming the pixel signal electrode wiring terminals 114 and placing holding an effective display area between them. Then, the static electricity protection wiring 104 is connected to respective image signal electrode wiring 101 through the resistance elements 105. Then, the image signal electrode wiring 101 are connected to the common electrode formed on a color filter substrate through the resistance elements 105. Thus, a threshold value of a thin film transistor 40 is adjusted by grounding the common electrode with an external connection terminal 117C, that is, grounding the counter electrode and the image signal electrode wiring 101 and applying a negative voltage from the terminals 113' to scan electrode wiring side static electricity protection diode common line 120 of scan electrode wiring 100.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active matrix type liquid crystal display device, and more particularly, to a display quality by correcting a characteristic change caused by static electricity and a variation in a threshold value of a thin film transistor when the thin film transistor is used as a switching element. The present invention relates to an improved liquid crystal display device.

[0002]

2. Description of the Related Art An active matrix type liquid crystal display device using thin film transistors as a switching element is widely used as a liquid crystal display device used for monitors of various video equipment and information equipment.

In this type of liquid crystal display device, an active matrix substrate in which a large number of thin film transistors for selecting pixels are formed on an insulating substrate and a color filter substrate in which a common electrode and a color filter are formed are attached to each other. And a driving circuit incorporated in a liquid crystal panel configured to hold the liquid crystal panel.

[0004] With the recent increase in screen size and definition, it has become increasingly difficult to make uniform the characteristics of thin film transistors formed on an active matrix substrate.
In addition, destruction and characteristic deterioration of the thin film transistor due to static electricity in a manufacturing process are also serious problems.

Conventionally, as a method of making the threshold values of the thin film transistors uniform, a heat treatment or the like has been performed when the thin film transistors are completed. As a countermeasure against static electricity, a wiring connected to a wiring of a thin film transistor is provided on a substrate portion which is cut and removed when the liquid crystal panel is completed.

[0006]

In the above prior art, there is a limit to the uniformity of the threshold value of the thin film transistor by heat treatment in the manufacturing process of the active matrix substrate, and the characteristics of each thin film transistor still vary. I have. For this reason, uneven brightness occurs due to variation in the voltage applied to the liquid crystal.

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal display device which solves the above-mentioned problems of the prior art and has improved production yield and product reliability.

[0008]

In order to achieve the above-mentioned object, the present invention provides a common wiring for protecting static electricity (static protection common wiring) on a pixel signal electrode wiring of an active matrix substrate constituting a liquid crystal display device. The static electricity protection common wiring and the pixel signal electrode wiring are connected to a resistive element (preferably a resistive element made of a semiconductor material) or a transistor (preferably a thin film transistor similar to that for pixel selection).
This is achieved by having a configuration connected via

At this time, one electrostatic protection common line is formed for all the pixel signal electrode lines, or one line is formed for each of the odd-numbered and even-numbered pixel signal electrode lines. Further, either one or two of the sides on which the pixel signal electrode wiring terminals for supplying pixel signals to the pixel signal electrode wiring are formed or the opposite sides parallel to and sandwiching the effective display area are arranged together or Each one is placed on each side.

The electrostatic protection common wiring is connected to a common electrode wiring terminal for connecting to a common electrode of a color filter substrate which is an opposite substrate. Further, when the static electricity protection common wiring is connected to the pixel signal electrode wiring via the thin film transistor, a control wiring (gate electrode wiring) for controlling the thin film transistor may be separately provided to perform a defect inspection of the thin film transistor. .

The typical constitutions of the present invention are as follows. That is, (1) a color filter substrate having a common electrode formed on an insulating substrate and a plurality of color filters,
(Configuration A) A plurality of scanning electrode wirings formed on an insulating substrate, a plurality of image signal electrode wirings formed so as to intersect the scanning electrode wirings, and an effective connection to the scanning electrode wirings and the image signal electrode wirings. A plurality of thin film transistors two-dimensionally arranged so as to form a display area, a pixel electrode connected to each of the thin film transistors, and an additional capacitor connected to the pixel electrode;
A common electrode wiring terminal for connecting to a common electrode formed on the color filter substrate; a scanning electrode wiring terminal extending from the scanning electrode wiring and the image signal electrode wiring to one side outside the effective display area; An image signal electrode wiring terminal extending to the side and a protective insulating film covering at least a thin film transistor are provided, and are disposed to face a color filter substrate at a predetermined gap, and a liquid crystal is sandwiched in the gap to form a liquid crystal panel. Active matrix substrate,... (Configuration B) A scanning electrode driving circuit and an image signal electrode driving circuit for supplying a signal voltage for display to the scanning electrode wiring terminal and the image signal electrode wiring terminal,. ) The pixel signal electrode wiring terminal is formed on the opposite side parallel to one side where the pixel signal electrode wiring terminal is formed and sandwiching the effective display area, and electrically connected to the common electrode wiring terminal. And electrostatic protective wiring connection, a resistive element connected between a ... (Configuration D) electrostatic protection lines and the image signal electrode wiring, with a ... (Configuration E).

(2) The arrangements A, B, and C of (1) are formed on opposite sides of the effective display area in parallel with one side on which the pixel signal electrode wiring terminals are formed, and are electrically connected to the common electrode wiring terminals. A first static electricity protection wiring to be electrically connected, a second static electricity protection wiring formed on the one side and electrically connected to the common electrode wiring terminal,... (Configuration F) A first resistance element and a second resistance element that connect the second electrostatic protection wiring to every other image signal electrode wiring, and the like (Configuration G).

(3) In the configuration of (1) or (2), the resistance element is formed of a semiconductor resistance material.・ ・
(Configuration H) (4) The configuration A, B, and C of (1) and a common electrode wiring terminal formed on the opposite side parallel to one side of the pixel signal electrode wiring terminal and located across the effective display area. (Configuration I) Plural transistors connected between the electrostatic protection wiring and the image signal electrode wiring so as to be turned on / off, and an on / off of the transistor (Constitution J) A transistor scanning terminal for connecting the transistor control wiring and externally supplying a control signal, and (Constitution K).

(5) In the constitution (4), the transistor control wiring comprises a first transistor control wiring and a second transistor control wiring for connecting the image signal electrode wiring to every other one of the electrostatic protection wirings. (Configuration L) wherein the transistor scanning terminal has a first transistor scanning terminal and a first transistor scanning terminal connected to the first transistor control wiring and the second transistor control wiring, respectively. . (Configuration M) (6) The configuration A, B, and C of (1) and the common electrode formed on the opposite side that is parallel to one side on which the pixel signal electrode wiring terminal is formed and that is located across the effective display area. A first electrostatic protection wiring electrically connected to the wiring terminal, a second electrostatic protection wiring formed on the one side and electrically connected to the common electrode wiring terminal,... (Configuration N) A plurality of first transistors and a plurality of second transistors interposed between the electrostatic protection wiring, the second electrostatic protection wiring and every other image signal electrode wiring so as to be turned on / off; (Structure O) First transistor control wiring and second transistor control wiring for controlling on / off of the first transistor and the second transistor,... (Configuration P) First transistor and second transistor The first tiger connected to the transistor A first transistor scanning terminal and a second transistor scanning terminal for connecting the transistor control wiring and the second transistor control wiring, respectively, and applying a control signal from the outside;

(7) The configuration A, B, C of (1) and the first side formed parallel to one side of the pixel signal electrode wiring terminal and formed on one of the opposite sides sandwiching the effective display area. A first electrostatic protection wiring electrically connected to the common electrode wiring terminal;.. (Configuration R) a second electrostatic protection wiring electrically connected to the second common electrode wiring terminal; Configuration S) The first electrostatic protection wiring and the second electrostatic protection wiring are interposed between every other image signal electrode wiring and turned on / off.
A plurality of first transistors and a plurality of second transistors connected so as to be turned off, (Configuration T) a first transistor control wiring for controlling on / off of the first transistor and the second transistor Second transistor control wiring, ... (Configuration U) The first transistor control wiring and the second transistor control wiring connected to the first transistor and the second transistor are connected to each other, and a control signal is supplied from outside. , A first transistor scanning terminal and a second transistor scanning terminal for providing the same.

(8) In (7), the first electrostatic protection wiring, a plurality of first transistors, a first transistor control wiring, and a first transistor scanning terminal; The two static electricity protection wirings, the plurality of second transistors, the second transistor control wiring, and the second transistor scanning terminal are sandwiched between one side where the pixel signal electrode wiring terminal is formed and the effective display area in parallel with this side. Formed on each side of the opposite side located at (configuration X).

(9) In any one of (1) to (8),
The transistor scanning terminal is provided at a position where either the scanning wiring terminal or the external connection terminal is formed.
(Configuration Y).

According to the configuration of the present invention, the countermeasure against static electricity by the static electricity protection wiring can be taken, the voltage can be applied to the thin film transistor constituting the pixel, the variation of the threshold can be corrected, and the image signal electrode wiring and the scanning electrode wiring can be corrected. Inspection of short-circuits and other wirings can be performed, the production yield can be improved, and a high-quality liquid crystal display device can be provided.

It should be noted that the present invention is not limited to the above configuration and the embodiments described later, and various modifications can be made without departing from the technical idea of the present invention.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to examples. In this embodiment, a so-called chip-on-glass (COG) type liquid crystal display device in which a semiconductor element forming a part of a driving circuit is directly mounted on a terminal portion on an active matrix substrate is shown as an example. The entire circuit is mounted on a substrate outside the liquid crystal panel, and can be similarly applied to a TAB (tape automated bonding) type liquid crystal display device.

FIG. 1 is an equivalent circuit diagram of an active matrix substrate for explaining a first embodiment of a liquid crystal display device according to the present invention. FIG. 1 shows a circuit mounted on a final substrate before the active matrix substrate is cut from the original substrate (mother substrate) and bonded to a color filter substrate (not shown).

In the present embodiment, a plurality of scanning electrode wirings 100 formed on a substrate (insulating substrate, here, a glass substrate, the same applies hereinafter) and a plurality of image signals formed so as to intersect the scanning electrode wirings 100 are provided. A two-dimensionally arranged matrix that forms an effective display area by connecting thin film transistors 40 corresponding to pixels to intersections of the electrode wirings 101 is configured.

A pixel electrode 103 is connected to each of the thin film transistors 40, and an additional capacitor 41 is connected to the pixel electrode. Common electrode wiring terminals 112A, 112
B, 112C and 112D are terminals for connection to a common electrode formed on a color filter substrate (not shown).

A scanning electrode wiring terminal 113 and an image signal electrode wiring terminal 114 are drawn out of the scanning electrode wiring 101 and the image signal electrode wiring 100 to one side outside the effective display area, and these wiring terminals are connected to the scanning electrode driving lines indicated by broken lines. Each output of the circuit 115 and the image signal electrode driving circuit 116 is connected.

The input terminals of the scan electrode drive circuit 115 and the image signal electrode drive circuit 116 have external connection terminals 117A and 1
17B is connected.

Reference numeral 117C denotes an external connection terminal connected to the common electrode wiring terminal 112A, and 117D denotes a common electrode wiring terminal 11A.
The external connection terminal connected to 2D is shown. Although the common electrode wiring terminals are provided at each corner, at least one common terminal is sufficient.

On the scanning electrode wiring terminal 113 side and the opposite side, scanning electrode wiring side electrostatic protection diode common lines 120 are laid, respectively, and are connected to the scanning electrode wiring 100 by the scanning electrode wiring side electrostatic protection diode 119. I have.

An electrostatic protection wiring 104 electrically connected to the common electrode wiring terminals 112A and 112B is formed on a pair of sides parallel to one side of the pixel signal electrode wiring terminal 114 and sandwiching the effective display area. In addition, a resistance element 105 connects between the electrostatic protection wiring 104 and each image signal electrode wiring 101. This resistive element can be formed in the step of forming the thin film transistor 40 by using the same material as the semiconductor material forming the thin film transistor 40.

With such a configuration, the image signal electrode wiring 101 is connected to the common electrode formed on the color filter substrate as the opposite substrate via the resistance element 105. Therefore, this common electrode is connected to the external connection terminal 117.
C, that is, the counter electrode and the image signal electrode wiring 10
1 is grounded and a negative voltage of several tens of volts is applied from the terminal 113 ′ to the scanning electrode wiring side electrostatic protection diode common line 120 of the scanning electrode wiring 100 (this voltage depends on the number of pixels of the liquid crystal panel, the capacity of the wiring, etc. By applying (different), the threshold value of the thin film transistor 40 can be adjusted.

For example, the above voltage is set to -50 V, and this voltage is applied for 10 seconds. As a result, the thin film transistor whose threshold value has shifted to a higher value has a lower threshold value,
Regarding display unevenness due to variation in the voltage applied to the liquid crystal, a sufficient voltage is applied to the liquid crystal, so that the display unevenness is reduced and display defects are improved. Note that a thin film transistor whose threshold value has become excessively low in this process can be returned to its original state by heat treatment.

Further, when the color filter substrate is charged during the manufacturing process, the liquid crystal panel of the conventional configuration cannot eliminate the potential difference between the active matrix substrate and the color filter substrate. For this reason, a potential difference acts on the thin film transistor via the liquid crystal during the manufacturing process, which is one of the factors for shifting the threshold value.

On the other hand, according to the structure of this embodiment, when the color filter substrate is charged, the resistance element 105
, The common electrode and the image signal electrode wiring 101 have the same potential, and the potential difference between the common electrode and the active matrix substrate is eliminated. As a result, generation of electric shock can be avoided, and damage to the thin film transistor and the like due to static electricity can be prevented.

As described above, according to the present embodiment, it is possible to reduce the variation in display by aligning the threshold values of the thin film transistors shifted due to manufacturing variations or static electricity during the manufacturing process, and to reduce the configuration of the thin film transistors and the like due to static electricity. Circuit damage can be prevented.

FIG. 2 is an equivalent circuit diagram of an active matrix substrate for explaining a second embodiment of the liquid crystal display device according to the present invention. This embodiment is different from the first embodiment in that the first electrostatic protection common wiring 104 connected to the common electrode wiring terminals 112A and 112B and the common electrode wiring terminal 112C
ESD protection common wiring 10 connected to
8 is provided, and every other image signal electrode wiring 101 is connected via the first resistance element 105 and the second resistance element 109. The other configuration is the same as that of the first embodiment, and the description is omitted. Note that the first static electricity protection common wiring 104 is the same as the first static electricity protection common wiring 104 of the first embodiment, and the second static electricity protection common wiring 108 is grounded to the external connection terminal 117D drawn out from the common electrode wiring terminal 112D. This is done by grounding.

According to the structure of this embodiment, in addition to the effects of the first embodiment, the presence or absence of a short circuit between the adjacent image signal electrode wirings 101 can be inspected in the manufacturing process of the thin film transistor.

As described above, it is possible to align the threshold values of the thin film transistors shifted due to manufacturing variations or static electricity during the manufacturing process, to inspect the presence or absence of a short circuit between adjacent image signal electrode wirings, and to improve the display quality. Variation can be reduced, and damage to constituent circuits such as thin film transistors due to static electricity can be prevented.

FIG. 3 is an equivalent circuit diagram of an active matrix substrate for explaining a third embodiment of the liquid crystal display device according to the present invention. In the present embodiment, the static electricity protection common wiring 104 is provided on the side opposite to the image signal electrode wiring terminal 114 across the effective display area, and a thin film transistor 106 (hereinafter, referred to as a first thin film transistor) that is different from the one forming the pixel ), A control wiring 107 (transistor control wiring, gate electrode wiring) for the thin film transistor 106 is provided, and a lead-out terminal (transistor scanning terminal) 113A is provided for the transistor control wiring 107. . Except for this configuration, the configuration is the same as that of the first embodiment, and the description is omitted.

The common electrode wiring terminals 112 A and 112 B and the image signal electrode wiring 101 are connected via the first thin film transistor 106.

In the case of normal image display, a potential on the low potential side of the gate of the first thin film transistor 106 is applied to the transistor control wiring 107, and the first thin film transistor 106 is turned off.

At the time of adjusting the threshold value of the thin film transistor 40 constituting the pixel and inspecting the active matrix substrate, the common electrode wiring terminal 112A and the static electricity protection common wiring 104 are grounded by grounding the external connection terminal 117C.

Then, a voltage of, for example, 20 V is applied to the transistor control wiring 107, and the first thin film transistor 1
06 is turned on, and the image signal electrode wiring 101 is grounded via the common electrode wiring terminal 112A.

Then, a negative voltage of several tens of volts is applied from the terminal 113 ′ to the electrostatic protection diode common line 120 of the scanning electrode wiring 100. This voltage varies depending on the number of pixels of the liquid crystal panel, the capacitance of the wiring, and the like. As an example, a voltage of about −50 V is applied for 10 seconds.

As a result, the threshold value of the thin film transistor 40, whose threshold value has shifted to a higher value, can be reduced. Regarding display unevenness caused by variations in the applied voltage to the liquid crystal, even if the applied voltage varies, Since a sufficient voltage is applied, display unevenness is eliminated.

When the color filter substrate is charged during the manufacturing process, the liquid crystal panel having the conventional structure cannot eliminate the potential difference between the active matrix substrate and the color filter substrate. Therefore, a potential acts on the thin film transistor 40 forming the pixel via the liquid crystal during the manufacturing process, and this is one of the factors that shift the threshold value of the thin film transistor.

In this embodiment, the first thin film transistor 1
The channel portion of 06 acts as a resistance element when no voltage is applied to the gate electrode. In that case, when the color filter substrate is charged, the image signal electrode wiring 101
Have the same potential, and the potential difference between the counter substrate and the color filter substrate is eliminated.

According to this embodiment, as compared with the embodiment using the above-described resistance element, the leakage current at the time of off is suppressed,
A larger amount of current can flow at the time of turning on, and a greater effect can be obtained when the thresholds of the thin film transistors 40 are made uniform by voltage application.

As described above, it is possible to equalize the threshold values of the thin film transistors shifted due to manufacturing variations or static electricity during the manufacturing process, to inspect the presence / absence of a short circuit between adjacent image signal electrode wirings, and to improve the display quality. Variation can be reduced, and damage to constituent circuits such as thin film transistors due to static electricity can be prevented.

FIG. 4 is an equivalent circuit diagram of an active matrix substrate for explaining a fourth embodiment of the liquid crystal display device according to the present invention. In the present embodiment, the static electricity protection common wiring 104 is provided on the side opposite to the image signal electrode wiring terminal 114 across the effective display area, and a plurality of thin film transistors 106 (first thin film transistors) different from those constituting a pixel are provided. To the image signal electrode wiring 101 via At this time, a first transistor control wiring 107 and a second transistor control wiring 111 of the thin film transistor 106 are provided,
The first and second transistor control lines 107 and 111
Lead terminals (transistor scanning terminals) 113A and 1
13B were connected every other. Except for this configuration, the third embodiment is the same as the third embodiment, and a description thereof will not be repeated.

The common electrode wiring terminals 112 A and 112 B and the image signal electrode wiring 101 are connected via the first thin film transistor 106.

In the case of normal image display, the potential on the low potential side of the gate of the first thin film transistor 106 is applied to the first and second transistor control wirings 107 and 111.
The first thin film transistor 106 is off.

At the time of adjusting the threshold value of the thin film transistor 40 constituting the pixel and inspecting the active matrix substrate, the external connection terminal 117C is grounded to connect the common electrode wiring terminal 112A and the first static electricity protection common wiring 104.
To ground.

A voltage of, for example, 20 V is applied to the first or second transistor control wiring 107 or 111 or both.
And turning on all or every other first thin film transistor 106 to turn on the image signal electrode wiring 1
01 or every other one of the common electrode wiring terminals 11
Ground via 2A.

Then, a negative voltage of several tens of volts is applied from the terminal 113 ′ to the electrostatic protection diode common line 120 of the scanning electrode wiring 100. This voltage varies depending on the number of pixels of the liquid crystal panel, the capacitance of the wiring, and the like. As an example, a voltage of about −50 V is applied for 10 seconds.

As a result, the threshold value of the thin film transistor 40, whose threshold value has shifted to a higher value, can be reduced. Regarding display unevenness due to variation in the applied voltage to the liquid crystal, even if the applied voltage varies, Since a sufficient voltage is applied, display unevenness is eliminated.

When the color filter substrate is charged during the manufacturing process, the liquid crystal panel having the conventional structure cannot eliminate the potential difference between the active matrix substrate and the color filter substrate. Therefore, a potential acts on the thin film transistor 40 forming the pixel via the liquid crystal during the manufacturing process, and this is one of the factors that shift the threshold value of the thin film transistor.

In this embodiment, the first thin film transistor 1
The channel portion of 06 acts as a resistance element when no voltage is applied to the gate electrode. In that case, when the color filter substrate is charged, the image signal electrode wiring 101
Have the same potential, and the potential difference between the counter substrate and the color filter substrate is eliminated.

According to the present embodiment, similarly to the effect of the above embodiment, the threshold values of the thin film transistors shifted due to manufacturing variations or static electricity during the manufacturing process are aligned, and the presence or absence of a short circuit between adjacent image signal electrode wirings is determined. Inspection can be performed for every other image signal electrode wiring, display variation can be reduced, and damage to constituent circuits such as thin film transistors due to static electricity can be prevented.

FIG. 5 is an equivalent circuit diagram of an active matrix substrate for explaining a fifth embodiment of the liquid crystal display device according to the present invention. In this embodiment, the first static electricity protection common wiring 104 is provided on the side opposite to the image signal electrode wiring terminal 114 across the effective display area, and the second static electricity protection common wiring is provided on the side on the image signal electrode wiring terminal 114 side. The wiring 108 was provided.

The first and second electrostatic protection common wirings 10
4 and 108 are alternately connected to the image signal electrode wiring 101 via a plurality of thin film transistors 106 and 110 (first thin film transistors) different from those constituting a pixel. At this time, the first transistor control wiring 107 of the thin film transistor 106 and the second transistor control wiring 111 of the thin film transistor 110 are provided on each side of the effective display area, and the first and second transistor control wirings 107 and 111 are provided. Outgoing terminals (transistor scanning terminals) 113A and 113B were connected alternately. Except for this configuration, the fourth embodiment is the same as the fourth embodiment, and a description thereof will not be repeated.

The common electrode wiring terminals 112 A and 112 B are connected to every other image signal electrode wiring 101 via the first thin film transistor 106. The common electrode wiring terminals 112C, 1C are connected via the second thin film transistor 110.
12D and every other image signal electrode wiring 101 are connected.

In the case of normal image display, the potential on the low potential side of the gate of the first thin film transistor 106 is applied to the first and second transistor control wirings 107 and 111.
The first and second thin film transistors 106 and 110 are off.

At the time of adjusting the threshold value of the thin film transistor 40 constituting the pixel and inspecting the active matrix substrate, the external connection terminals 117C and 117D are grounded to connect the common electrode wiring terminals 112A and 112D and the first and second electrostatic protection common wiring. 104 and 111 are grounded.

Then, for example, 20 V is applied to the first or second transistor control wiring 107 or 111 or both.
Of the first and second thin film transistors 106
All or every other image signal line 110 is turned on, and all or every other image signal electrode wiring 101 is grounded via the common electrode wiring terminal 112A or 112D.

Then, a negative voltage of several tens V is applied from the terminal 113 ′ to the electrostatic protection diode common line 120 of the scanning electrode wiring 100. This voltage varies depending on the number of pixels of the liquid crystal panel, the capacitance of the wiring, and the like. As an example, a voltage of about −50 V is applied for 10 seconds.

As a result, the threshold value of the thin film transistor 40, whose threshold value has shifted to a higher value, can be reduced. Regarding display unevenness caused by variation in the applied voltage to the liquid crystal, even if the applied voltage varies, Since a sufficient voltage is applied, display unevenness is eliminated.

In this embodiment, the channel portions of the first and second thin film transistors 106 and 110 function as resistance elements when no voltage is applied to the gate electrodes. In this case, when the color filter substrate is charged, the image signal electrode wiring 101 has the same potential, and the potential difference between the image signal electrode wiring 101 and the counter substrate (color filter substrate) is eliminated.

According to the present embodiment, in addition to the effect of the fourth embodiment, in the manufacturing process of the thin film transistor, a short circuit between the adjacent image signal electrode wirings 101 is caused by turning on the first and second thin film transistors 106 and 110. The determination can be made only by measuring the resistance between the first and second electrostatic protection common wirings 104 and 108.

Therefore, the short-circuit inspection between the image signal electrode wirings 101 can be performed without directly applying the probe needle of the inspection apparatus to each wiring, and the positional accuracy of the probe needles can be increased.

Conventionally, each image signal electrode wiring 101
Is separated from the common line by laser cutting. However, according to this embodiment, laser cutting is not required, and the number of steps can be reduced. For this reason, it is possible to eliminate defects such as short-circuits due to laser cutting and remaining uncut parts and reattachment of flying matter during the cutting.

FIG. 6 is an equivalent circuit diagram of an active matrix substrate for explaining a sixth embodiment of the liquid crystal display device according to the present invention. In the present embodiment, a thin film transistor 116 different from the thin film transistor forming the pixel region in the fourth embodiment described with reference to FIG. 4 is alternately divided into first and second thin film transistors 106 and 110. The first and second static electricity protection common wirings 104A and 104A
B, and the first and second thin film transistors 106 and 1
10 and are connected to every other image signal electrode wiring 101.

At this time, a first transistor control wiring 107 and a second transistor control wiring 111 of the thin film transistor 106 are provided, and an extraction terminal (transistor scanning terminal) 113A is connected to the first and second transistor control wirings 107 and 111. And 113B were connected alternately. Other than this configuration is the same as the fourth embodiment,
Description is omitted.

A common electrode wiring terminal 112 A is connected via the first thin film transistor 106, and a common electrode wiring terminal 112 B is connected via the second thin film transistor 110 to every other image signal electrode wiring 101.

In the case of a normal image display, a potential on the lower potential side of the gates of the first and second thin film transistors 106 and 110 is applied to the first and second transistor control lines 107 and 111, respectively. The second thin film transistors 106 and 110 are off.

At the time of adjusting the threshold value of the thin film transistor 40 constituting the pixel and inspecting the active matrix substrate, the first and second electrostatic protection common wirings 104A and 104B are grounded via the common electrode wiring terminals 112A and 112B.

Then, for example, 20 V is applied to the first or second transistor control wiring 107 or 111 or both.
And turning on all or every other first thin film transistor 106 to turn on the image signal electrode wiring 1
01 or every other one of the common electrode wiring terminals 11
Ground through 2A and 112B.

Then, a negative voltage of several tens of volts is applied from the terminal 113 ′ to the electrostatic protection diode common line 120 of the scanning electrode wiring 100. This voltage varies depending on the number of pixels of the liquid crystal panel, the capacitance of the wiring, and the like. As an example, a voltage of about −50 V is applied for 10 seconds.

As a result, the threshold value of the thin film transistor 40, whose threshold value has shifted to a higher value, can be reduced. Regarding display unevenness caused by variation in the applied voltage to the liquid crystal, even if the applied voltage varies, Since a sufficient voltage is applied, display unevenness is eliminated.

In this embodiment, the channel portions of the first and second thin film transistors 106 and 110 function as resistance elements when no voltage is applied to the gate electrodes. In this case, when the color filter substrate is charged, the image signal electrode wiring 101 has the same potential, and the potential difference between the image signal electrode wiring 101 and the counter substrate (color filter substrate) is eliminated.

According to the present embodiment, in addition to the effect of the fourth embodiment, in the manufacturing process of the thin film transistor, a short circuit between the adjacent image signal electrode wirings 101 is performed and the first and second thin film transistors 106 and 110 are turned on. The determination can be made only by measuring the resistance between the first and second electrostatic protection common wirings 104 and 108.

Therefore, a short-circuit test between the image signal electrode wires 101 can be performed without directly touching each wire with the probe needle of the inspection apparatus, and the margin of positional accuracy of the probe needle can be increased.

Conventionally, each image signal electrode wiring 101
Is separated from the common line by laser cutting. However, according to this embodiment, laser cutting is not required, and the number of steps can be reduced. For this reason, it is possible to eliminate defects such as short-circuits due to laser cutting and remaining uncut parts and reattachment of flying matter during the cutting.

FIG. 7 is an equivalent circuit diagram of an active matrix substrate for explaining a sixth embodiment of the liquid crystal display device according to the present invention. In this embodiment, the first static electricity protection common wiring 10
4 and the second electrostatic protection common wiring 108 were separated from the common electrode wiring terminal 112.

The first static electricity protection common wiring 194 is connected to the external connection terminal 117E, the second static electricity protection common wiring 108 is connected to the external connection terminal 117H, and the first transistor control wiring 1
17 is connected to the external connection terminal 117F, and the second transistor control wiring 111 is connected to the external connection terminal 117G.

With this configuration, in addition to the effects of the above-described embodiments, when the liquid crystal panel is completed, defect inspection is performed by driving the liquid crystal panel with a DC voltage by simply applying probe needles to a few terminals. Can be. For example, first, the transistor control wiring 1 of the first thin film transistor 106
07, and a positive DC voltage of 20 V is applied to the transistor control wiring 111 of the second thin film transistor 110 to turn on the first thin film transistor 106 and the second thin film transistor 110. Next, a positive DC voltage of 20 V is applied to the scanning electrode wiring side electrostatic protection diode common line 120, and a rectangular wave having a frequency of 30 Hz is input to the first electrostatic protection common wiring 104 and the second electrostatic protection common wiring. . The inspection is performed by changing the amplitude of this rectangular wave from 0 V to about 5 V.

As a result, the number of probe needles connected to the liquid crystal panel can be reduced, and the inspection throughput can be increased. In addition, since the terminals can be shared, even if the size of the liquid crystal panel changes or the specification changes, one type of inspection device can handle all the liquid crystal panels.

FIG. 8 is a schematic sectional view for explaining a configuration example of a liquid crystal panel according to the present invention. This liquid crystal panel includes a thin film transistor (TFT) 40, a load capacitance (Cadd) 41, and a pixel electrode (ITO1) 103 formed in an effective display area.
And an active matrix substrate 200 having an orientation film (ORI1) 201 and a black matrix (BM) 2
05, color filter (FIL) 206, common electrode (C
OM) 207 and a color filter substrate 204 on which an alignment film (ORI2) 208 is formed. Then, a liquid crystal (LC) 209 is provided in the bonding gap.
And the periphery thereof is fixed with a sealing material (SL) 203.

The common electrode wiring terminals 112 of the active matrix substrate 200 and the common electrodes 207 of the color filter substrate 204 are electrically connected via the conductive paste 202.

The image signal electrode wiring terminal 114 drawn out from the common electrode wiring terminal 112 is located outside the sealing material SL, and extends between the external connection terminal 117 and the image signal electrode driving circuit (IC chip). ) 116 are implemented.

The external connection terminal 117 is connected to a terminal of an external drive circuit wiring (printed board or the like) 118.

The liquid crystal (LC) 209 has two alignment films 201.
At the interface between (ORI1) and 208 (ORI2), initial alignment is performed according to the alignment control ability provided to each alignment film.

FIG. 8 shows an image signal electrode wiring terminal 114.
Of the scanning electrode wiring terminal 11
The structure on the drawer side of No. 3 is similar to this.

A backlight (BL) 119 composed of a light guide plate and a linear lamp is provided on the back of the liquid crystal panel, and an image formed in an effective display area of the liquid crystal panel when the liquid crystal panel is illuminated from the back. To visualize.

FIG. 9 is a plan view for explaining the structure of one pixel of an active matrix type liquid crystal display device to which the present invention is applied and the periphery thereof. Each pixel is arranged in an intersecting region (in an area surrounded by four lines) between two adjacent scanning electrode lines 100 (GL) and two adjacent image signal electrode lines 101 (DL). ing.

Each pixel includes a thin film transistor TFT (here, the thin film transistor is composed of a pair of TFT1 and TFT2), a pixel electrode 103 (ITO1), and a storage capacitor 41 (Cadd). Scan electrode wiring 10
0 extends in the column direction, and a plurality of 0s are arranged in the row direction.
The image signal electrode wiring 101 (DL) extends in the row direction, and a plurality of the image signal electrode wirings are arranged in the column direction. In the figure, SD1 is a source electrode. SD2 indicates a drain electrode.

On the basis of the liquid crystal LC, a thin film transistor 40 (TFT) and a transparent pixel electrode 103 (ITO1) are formed on the active matrix substrate side, and a color filter FIL and a light shielding black matrix BM are formed on the color filter substrate side. I have. The two substrates have a thickness of, for example, about 1.1 mm or 0.7 mm.

FIG. 10 is an exploded perspective view for explaining the overall structure of an active matrix type liquid crystal display device to which the present invention is applied. FIG. 1 illustrates a specific structure of a liquid crystal display device (hereinafter, referred to as a module in which a liquid crystal panel, a circuit board, a backlight, and other components are integrated: MDL) according to the present invention.

SHD is a shield case (also called a metal frame) made of a metal plate, WD is a display window, INS1
To 3 are insulating sheets, PCB1 to 3 are circuit boards (PCB1
Is a drain side circuit board: an image signal wiring 101 drive circuit board, and PCB2 is a gate side circuit board: scan electrode wiring 100
Drive circuit, PCB3 is an interface circuit board), J
N1 to N3 are joiners for electrically connecting the circuit boards PCB1 to PCB3, and CH11 is an image signal electrode driving circuit 116 and CH12 directly mounted on the active matrix substrate.
Is the scan electrode drive circuit 115, PN
L is a liquid crystal display panel, GC is a rubber cushion, ILS is a light shielding spacer, PRS is a prism sheet, SPS is a diffusion sheet, GLB is a light guide plate, RFS is a reflection sheet, and MCA.
Is a lower case (mold frame) formed by integral molding, MO is an MCA opening, LP is a fluorescent tube, LPC
Denotes a lamp cable, GB denotes a rubber bush for supporting the fluorescent tube LP, BAT denotes a double-sided adhesive tape, BL denotes a backlight BL made of a fluorescent tube, a light guide plate, and the like. The module MDL is assembled.

The liquid crystal display module MDL has two kinds of storage / holding members of a lower case MCA and a shield case SHD, and includes insulating sheets INS1 to INS3 and circuit boards PCB1 to PCB1.
3. A metal shield case SHD in which the liquid crystal panel PNL is stored and fixed, and a lower case MCA in which a backlight BL including a linear lamp LP, a light guide plate GLB, a prism sheet PRS and the like are stored are combined.

The interface circuit board PCB3 is provided with an integrated circuit chip that receives a video signal from an external host, receives a control signal such as a timing signal, and a timing converter TCON that processes a timing to generate a clock signal.

In FIG. 10, the drive circuit (integrated circuits CH1, CH2) of the liquid crystal panel is directly mounted on an active matrix substrate, that is, the so-called COG method has been described. However, the present invention is applied to a liquid crystal panel of such a mounting method. The present invention is not limited thereto, and the present invention can be similarly applied to a conventional mounting method using a TCP (tape carrier package).

FIG. 11 is a perspective view of a notebook computer for explaining a mounting example of the liquid crystal display device according to the present invention. The notebook computer (portable personal computer) includes a keyboard unit (main body unit) and a display unit connected to the keyboard unit by a hinge. The keyboard section houses a keyboard and signal generation functions such as a host (host computer) and a CPU. The display case CASE has a liquid crystal panel PNL.
C2, PCB with control chip TCON,
Power supply board IV as power supply for backlight
Are implemented.

This portable personal computer is equipped with a liquid crystal panel having the structure described in the above embodiment, and can provide high-quality image display without display unevenness.

[0103]

As described above, according to the present invention,
Provided is a liquid crystal display device capable of uniforming a variation in threshold value of a thin film transistor caused by static electricity generated during a process after manufacturing a liquid crystal panel, improving manufacturing yield and reliability, and displaying high quality images without uneven display. can do.

[Brief description of the drawings]

FIG. 1 is an equivalent circuit diagram of an active matrix substrate for explaining a first embodiment of a liquid crystal display device according to the present invention.

FIG. 2 is an equivalent circuit diagram of an active matrix substrate for explaining a second embodiment of the liquid crystal display device according to the present invention.

FIG. 3 is an equivalent circuit diagram of an active matrix substrate for explaining a third embodiment of the liquid crystal display device according to the present invention.

FIG. 4 is an equivalent circuit diagram of an active matrix substrate for explaining a fourth embodiment of the liquid crystal display device according to the present invention.

FIG. 5 is an equivalent circuit diagram of an active matrix substrate for explaining a fifth embodiment of the liquid crystal display device according to the present invention.

FIG. 6 is an equivalent circuit diagram of an active matrix substrate for explaining a sixth embodiment of the liquid crystal display device according to the present invention.

FIG. 7 is an equivalent circuit diagram of an active matrix substrate for explaining a seventh embodiment of the liquid crystal display device according to the present invention.

FIG. 8 is a schematic sectional view illustrating a configuration example of a liquid crystal panel according to the present invention.

FIG. 9 is a plan view illustrating a configuration of one pixel of an active matrix type liquid crystal display device to which the present invention is applied and the periphery thereof.

FIG. 10 is an exploded perspective view illustrating an overall configuration of an active matrix liquid crystal display device to which the present invention is applied.

FIG. 11 is a perspective view of a notebook computer for explaining a mounting example of a liquid crystal display device according to the present invention.

[Explanation of symbols]

REFERENCE SIGNS LIST 100 scanning electrode wiring 101 image signal electrode wiring 40 thin film transistor 41 additional capacitance 103 pixel electrode 112A, 112B, 112C, 112D common electrode wiring terminal 113 scanning electrode wiring terminal 114 image signal electrode wiring terminal 115 scan electrode driving circuit 116 image signal electrode driving circuit 117A, 117B, 117C, 117D External connection terminal 120 Scan electrode wiring side electrostatic protection diode common line 119 Scan electrode wiring side electrostatic protection diode.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Hiroshi Ogawara 3300 Hayano Mobara-shi, Chiba Prefecture Electronic Device Division, Hitachi, Ltd. (72) Inventor Masaaki Matsuda 3300 Hayano Mobara-shi, Chiba Electronic Device Business Hitachi, Ltd. (72) Inventor Tetsuya Kawamura 3300 Hayano, Mobara-shi, Chiba F-term (Reference) 2H048 BB02 BB14 BB44 2H092 GA50 GA51 GA60 JA24 NA14 NA24 NA29 PA08 5F110 AA08 AA22 BB01 NN72

Claims (8)

[Claims] A color filter substrate having a common electrode formed on an insulating substrate and a plurality of color filters, a plurality of scanning electrode wirings formed on the insulating substrate, and a plurality of scanning electrode wirings intersecting the scanning electrode wirings. A plurality of formed image signal electrode wirings, a plurality of thin film transistors two-dimensionally arranged to be connected to the scanning electrode wirings and the image signal electrode wirings to form an effective display area, and a pixel connected to each of the thin film transistors An additional capacitance connected to the electrode and the pixel electrode;
A common electrode wiring terminal for connecting to a common electrode formed on the color filter substrate; a scanning electrode wiring terminal extending from the scanning electrode wiring and the image signal electrode wiring to one side outside the effective display area; An image signal electrode wiring terminal extending to the side and a protective insulating film covering at least a thin film transistor are provided, and are disposed to face a color filter substrate at a predetermined gap, and a liquid crystal is sandwiched in the gap to form a liquid crystal panel. An active matrix substrate; a scan electrode driving circuit for supplying a signal voltage for display to the scanning electrode wiring terminal and the image signal electrode wiring terminal; and an image signal electrode driving circuit, and one side on which the pixel signal electrode wiring terminal is formed. An electrostatic protection wiring formed in parallel, on the opposite side positioned across the effective display area, and electrically connected to the common electrode wiring terminal; A liquid crystal display device comprising a resistive element connected between the electrostatic protection lines and the image signal electrode lines, that was formed from. 2. A color filter substrate having a common electrode formed on an insulating substrate, a color filter of a plurality of colors, a plurality of scanning electrode wirings formed on the insulating substrate, and intersecting the scanning electrode wirings. A plurality of formed image signal electrode wirings, a plurality of thin film transistors two-dimensionally arranged to be connected to the scanning electrode wirings and the image signal electrode wirings to form an effective display area, and a pixel connected to each of the thin film transistors An additional capacitance connected to the electrode and the pixel electrode;
A common electrode wiring terminal for connecting to a common electrode formed on the color filter substrate; a scanning electrode wiring terminal extending from the scanning electrode wiring and the image signal electrode wiring to one side outside the effective display area; An image signal electrode wiring terminal extending to the side and a protective insulating film covering at least a thin film transistor are provided, and are disposed to face a color filter substrate at a predetermined gap, and a liquid crystal is sandwiched in the gap to form a liquid crystal panel. An active matrix substrate, a scan electrode driving circuit for supplying a signal voltage for display to the scanning electrode wiring terminal and the image signal electrode wiring terminal, and an image signal electrode driving circuit; The first static electricity protection formed parallel to the opposite side of the effective display area and electrically connected to the common electrode wiring terminal A second static electricity protection wire formed on the one side and electrically connected to the common electrode wiring terminal; and one of the image signal electrode wires between the first static electricity protection wire and the second static electricity protection wire. A liquid crystal display device comprising: a first resistance element and a second resistance element connected alternately. 3. A color filter substrate provided with a common electrode formed on an insulating substrate, a color filter of a plurality of colors, a plurality of scanning electrode wirings formed on the insulating substrate, and intersecting the scanning electrode wirings. A plurality of formed image signal electrode wirings, a plurality of thin film transistors two-dimensionally arranged to be connected to the scanning electrode wirings and the image signal electrode wirings to form an effective display area, and a pixel connected to each of the thin film transistors An additional capacitance connected to the electrode and the pixel electrode;
A common electrode wiring terminal for connecting to a common electrode formed on the color filter substrate; a scanning electrode wiring terminal extending from the scanning electrode wiring and the image signal electrode wiring to one side outside the effective display area; An image signal electrode wiring terminal extending to the side and a protective insulating film covering at least a thin film transistor are provided, and are disposed to face a color filter substrate at a predetermined gap, and a liquid crystal is sandwiched in the gap to form a liquid crystal panel. An active matrix substrate; a scan electrode driving circuit for supplying a signal voltage for display to the scanning electrode wiring terminal and the image signal electrode wiring terminal; and an image signal electrode driving circuit, and one side on which the pixel signal electrode wiring terminal is formed. An electrostatic protection wiring formed in parallel, on the opposite side positioned across the effective display area, and electrically connected to the common electrode wiring terminal; A plurality of transistors connected between the electrostatic protection wiring and the image signal electrode wiring so as to be turned on / off, a transistor control wiring for controlling the on / off of the transistor, and a transistor control wiring connected to the outside to connect the transistor control wiring A liquid crystal display device comprising: a transistor scanning terminal for providing a control signal. 4. The transistor control wiring according to claim 1, wherein said transistor control wiring comprises a first transistor control wiring and a second transistor control wiring for connecting every other image signal electrode wiring to said electrostatic protection wiring, and said transistor scanning terminal. 4. The liquid crystal display device according to claim 3, wherein the device has a first transistor scanning terminal and a first transistor scanning terminal connected to the first transistor control wiring and the second transistor control wiring, respectively. 5. A color filter substrate provided with a common electrode formed on an insulating substrate, a color filter of a plurality of colors, a plurality of scanning electrode wirings formed on the insulating substrate, and intersecting the scanning electrode wirings. A plurality of formed image signal electrode wirings, a plurality of thin film transistors two-dimensionally arranged to be connected to the scanning electrode wirings and the image signal electrode wirings to form an effective display area, and a pixel connected to each of the thin film transistors An additional capacitance connected to the electrode and the pixel electrode;
A common electrode wiring terminal for connecting to a common electrode formed on the color filter substrate; a scanning electrode wiring terminal extending from the scanning electrode wiring and the image signal electrode wiring to one side outside the effective display area; An image signal electrode wiring terminal extending to the side and a protective insulating film covering at least a thin film transistor are provided, and are disposed to face a color filter substrate at a predetermined gap, and a liquid crystal is sandwiched in the gap to form a liquid crystal panel. An active matrix substrate; a scan electrode driving circuit for supplying a signal voltage for display to the scanning electrode wiring terminal and the image signal electrode wiring terminal; and an image signal electrode driving circuit, and one side on which the pixel signal electrode wiring terminal is formed. The first static electricity protection formed parallel to the opposite side of the effective display area and electrically connected to the common electrode wiring terminal A second static electricity protection wire formed on the one side and electrically connected to the common electrode wiring terminal; and every other one of the first static electricity protection wire, the second static electricity protection wire, and the image signal electrode wire. A plurality of first transistors and a plurality of second transistors interposed therebetween so as to be turned on / off; a first transistor control wiring for controlling on / off of the first transistor and the second transistor; A second transistor control wiring, a first transistor for connecting the first transistor control wiring and the second transistor control wiring connected to the first transistor and the second transistor, respectively, and providing a control signal from outside A liquid crystal display device comprising a scanning terminal and a second transistor scanning terminal. 6. A color filter substrate provided with a common electrode formed on an insulating substrate, a color filter of a plurality of colors, a plurality of scanning electrode wirings formed on the insulating substrate, and intersecting the scanning electrode wirings. A plurality of formed image signal electrode wirings, a plurality of thin film transistors two-dimensionally arranged to be connected to the scanning electrode wirings and the image signal electrode wirings to form an effective display area, and a pixel connected to each of the thin film transistors An additional capacitance connected to the electrode and the pixel electrode;
A common electrode wiring terminal for connecting to a common electrode formed on the color filter substrate; a scanning electrode wiring terminal extending from the scanning electrode wiring and the image signal electrode wiring to one side outside the effective display area; An image signal electrode wiring terminal extending to the side and a protective insulating film covering at least a thin film transistor are provided so as to face a color filter substrate at a predetermined gap, and a liquid crystal is sandwiched in the gap to form a liquid crystal panel. An active matrix substrate, a scan electrode driving circuit for supplying a signal voltage for display to the scanning electrode wiring terminal and the image signal electrode wiring terminal, and an image signal electrode driving circuit; A second parallel electrode is formed on one of the opposite sides of the effective display area and electrically connected to the first common electrode wiring terminal. One of the image signal electrode wiring for the first electrostatic protection wiring, the second electrostatic protection wiring electrically connected to the second common electrode wiring terminal, and the first electrostatic protection wiring and the second electrostatic protection wiring ON /
A plurality of first transistors and a plurality of second transistors connected so as to be turned off; a first transistor control wiring and a second transistor control wiring for controlling on / off of the first transistor and the second transistor; A first transistor scanning terminal and a second transistor for connecting the first transistor control wiring and the second transistor control wiring connected to the first transistor and the second transistor, respectively, and providing a control signal from the outside; A liquid crystal display device comprising: a scanning terminal; 7. The first electrostatic protection wiring, a plurality of first transistors, a first transistor control wiring, and a first transistor scanning terminal; the second electrostatic protection wiring, a plurality of second transistors; The second transistor control wiring and the second transistor scanning terminal are formed on each side of one side on which the pixel signal electrode wiring terminal is formed, and the opposite side parallel to this side and located across the effective display area. The liquid crystal display device according to claim 6, wherein: 8. The liquid crystal display device according to claim 1, wherein said transistor scanning terminal is provided at a position where one of said scanning wiring terminal and said external connection terminal is formed.