JPH1026750A - Liquid crystal display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform the inspecting for disconnection and short circuit of a signal line and also to sufficiently perform the static electricity preventing countermeasure of a thin film transistor. SOLUTION: A first common line which is existing along the (y) direction and is to be connected to respective gate signal lines 2 via nonlinear resistance elements D and a second common line which is existing along the (x) direction and is to be connected to respective even-number-th drain signal lines 3 via nonlinear resistance element D and a third common line which is existing along the (x) direction and is to be connected to respective odd-number-th drain signal line via nonlinear resistance elements D are formed on the periphery of a display area formed of a set of pixel areas being on the surface of the liquid crystal side of the transparent substrate of one side. Then, these respective first, second and third common lines are constituted by being electrically separated from each other and respective second and third common lines are electrically connected with the electrically conductive bodies.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal display panel, and more particularly, to a so-called active matrix type liquid crystal display panel.

[0002]

2. Description of the Related Art An active matrix type liquid crystal display panel extends in the x-direction and extends in the y-direction on a liquid crystal side surface of one of a pair of transparent substrates disposed opposite to each other via a liquid crystal. And a drain signal line which is insulated from the gate signal line, extends in the y direction and is arranged in the x direction, and a gate signal line is provided in each pixel region surrounded by these signal lines. The thin film transistor is turned on by the supply of the scanning signal from the line, and the pixel electrode is supplied with the video signal from the drain signal line via the turned on thin film transistor.

Since each of these gate signal lines and drain signal lines is formed by fine processing using a so-called photolithography technique, these signal lines are disconnected in the process of manufacturing a liquid crystal display panel. It is usual to check whether or not the wiring is formed, whether or not a short circuit has occurred between each signal line and the like.

In this case, in order to perform this inspection efficiently, one end of each gate signal line and one end of each drain signal line are connected in common to the transparent substrate surface which is cut and separated later. A connected short-circuit line is formed.

In this case, one test probe is applied to one short-circuit line of the gate signal lines, and the other test probe is applied to the test terminal on the other end side of each gate signal line. It is possible to detect whether or not the signal line is disconnected. The same operation can be performed on the drain signal lines to detect whether or not they are disconnected. Also, one test probe is applied to the short-circuit line of the gate signal line, and the other test probe is applied to the short-circuit line of the drain signal line, and the electric resistance between them is measured. Can be inspected whether or not a short circuit has occurred (hereinafter, a circuit configured as described above may be referred to as a disconnection and short circuit inspection circuit).

On the other hand, the thin film transistor is formed as an MIS transistor in which a part of the gate signal line is used as a gate electrode and a part where the drain signal line is extended is used as a drain electrode. For the purpose of preventing the fluctuation or destruction of the signal lines, measures have been taken to prevent the static electricity from being concentrated on the signal line (for example, see Japanese Patent Application Laid-Open No. 5-27263).

That is, all of the gate signal lines and the drain signal lines are connected to the outer periphery of the display region, which is a region in which the liquid crystal is sealed and formed of the pixel region, via the non-linear resistance element. A common line for protecting the static electricity is formed, and the common line disperses static electricity generated in a part to all of the signal lines. A circuit for protection).

[0008]

However, in a liquid crystal display panel provided with the above-described disconnection and short circuit inspection circuit, when the electrostatic protection circuit is introduced as it is, a gate signal line and a drain signal line are provided. Are connected to each other by a common line via a non-linear resistance element, so that it has been pointed out that the disconnection or short circuit of these signal lines cannot be determined.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a liquid crystal display panel capable of sufficiently inspecting a disconnection or short circuit of a signal line and preventing static electricity of a thin film transistor. To provide.

[0010]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention basically provides a liquid crystal side of one of a pair of transparent substrates arranged to face each other via a liquid crystal. A gate signal line extending in the x direction and juxtaposed in the y direction and a drain signal line insulated by the gate signal line and extending in the y direction and juxtaposed in the x direction are formed. Each pixel region surrounded by a signal line includes a thin film transistor that is turned on by the supply of a scanning signal from a gate signal line, and a pixel electrode to which a video signal from a drain signal line is supplied via the turned on thin film transistor. ,
A common electrode common to each pixel region is formed on the liquid crystal side surface of the other transparent substrate, and the common electrode is connected to the one transparent substrate through a conductor interposed between the one transparent substrate and the other. In the liquid crystal display panel drawn out, the gate signal lines extending in the y-direction and extending through the non-linear resistance element around the periphery of a display area formed by a set of pixel areas on the liquid crystal side surface of the one transparent substrate And a second common line extending in the x-direction and connected to each of the even-numbered drain signal lines via the non-linear resistance element, and a second common line extending in the x-direction and being non-linear. A third common line connected to each of the odd-numbered drain signal lines via a resistance element is formed, and the first, second, and third common lines are configured to be electrically separated from each other. And the second and third common lines are Through the body and is characterized in that it is electrically connected.

In the liquid crystal display panel configured as described above, for example, when inspecting whether a short circuit has occurred between the gate signal line and the drain signal line, as described above, one of the short-circuit lines of the gate signal line In general, the other probe is applied to the short-circuit line of the drain signal line, and the electric resistance between them is measured.

In this case, as seen in the conventional configuration, the common line in the electrostatic protection circuit includes a common line connected to the gate signal line via a non-linear resistance element,
When the drain signal line and the common line connected via the non-linear resistance element are configured to be connected to each other, from the short-circuit line of the gate signal line to the common line via the non-linear resistance element, Since the current flows to the short-circuit line of the drain signal line via the non-linear element, the above-described inspection cannot be performed.

For this reason, the present invention basically provides a common line commonly connected to a gate signal line via a non-linear resistance element and a common line commonly connected to a drain signal line via a non-linear resistance element. By electrically insulating, the above-mentioned adverse effects can be eliminated.

Further, all other inspections such as inspection for disconnection of the gate signal line or the drain signal line can be performed in the same manner as in the conventional case, and any of them has no effect on the common line for electrostatic protection. A reliable inspection can be performed without being performed.

[0015] Further, the structure of the electrostatic protection circuit comprising the non-linear resistance element and the common line is not restricted by the disconnection or short-circuit detection circuit of each signal line. Measures can be taken.

Therefore, according to the configuration of the present invention, it is possible to sufficiently perform inspection for disconnection or short-circuit of each signal line and antistatic measures for the thin film transistor.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a plan view showing a configuration of a liquid crystal side surface of one glass substrate constituting an envelope of a liquid crystal display panel according to the present invention. The glass substrate is in a state where disconnection or short circuit of each signal line can be inspected.

In FIG. 1, first, there is a glass substrate 1 formed slightly larger than the size of the glass substrate actually constituting the liquid crystal display panel. That is, the glass substrate 1 is cut at a location indicated by a dotted line Q in the drawing in a later step, and the periphery thereof is separated.

Gate signal lines 2 extending in the x direction in the figure and juxtaposed in the y direction are formed on the surface of the glass substrate 1 on the liquid crystal side, and are insulated from these gate signal lines 2. A drain signal line 3 extending in the y direction and juxtaposed in the x direction is formed.

A rectangular area (for example, an area surrounded by a dotted line A in the figure) surrounded by the gate signal line 2 and the drain signal line 3 is a pixel area, and details of this area are shown in FIG. A thin-film transistor TFT that is turned on by a gate signal from the gate signal line 2, and a transparent pixel electrode I to which a drain signal from the drain signal line 3 is supplied via the turned-on thin-film transistor TFT.
It has TO. Further, an additional capacitor Cadd is also provided to allow a long drain signal to be accumulated in the pixel electrode ITO when the thin film transistor TFT is turned off.

As a result, in the pixel region on the gate signal line 2 to which the gate signal is applied, the drain signal (pixel signal) from each drain signal line 3 is applied to the pixel electrode I
The potential difference is generated between the liquid crystal panel and the transparent common electrode formed on the liquid crystal side of the other glass substrate (not shown), and the light transmittance of the liquid crystal is modulated.

The right end of the gate signal line 2 in FIG. 1 extends to the surface of the glass substrate at a portion to be separated in a later step, and the inspection short-circuit line 2 formed at the portion is separated.
A 'is commonly connected. Each of the gate signal lines 2 is formed to have a relatively large width on one side (left side in the drawing) on which the actual glass substrate 1 after separation is formed, so that the external terminals 2T and the inspection terminals 2t are formed. Have been.

In each of the drain signal lines 3, those corresponding to the even-numbered ones counted from the left side in the figure extend to the portion of the glass substrate which is separated in a later step in the upper part of the figure. Inspection common line 3 formed in the part
A, which is commonly connected to A, and which is equivalent to an odd-numbered one counted from the right side in the figure is extended to and formed on the glass substrate surface in a portion separated in a later step on the lower side in the figure. The common line 3A 'for inspection is commonly connected.

In this case, each drain signal line 3 is formed to have a relatively large width at one side (upper side in the drawing), which is the actual glass substrate 1 after separation, so as to constitute the external terminal 3T. Has become. Further, a single inspection terminal 3t is formed on the other end side (the lower side in the figure) of the drain signal line 3.

Further, on the surface of the glass substrate 1, there is a region between the sealing material 5 formed so as to surround the liquid crystal sealing region and the pixel region and a display region formed by a set of the pixel regions. That is, a so-called common line 10 for electrostatic protection is formed.

The common line 10 for electrostatic protection is insulated from each gate signal line 3, extends in a direction orthogonal to the gate signal line 3, and is connected to the gate signal line 3 via a non-linear resistance element D. Lines 10G, 10G ′ and a common line 10 that extends in a direction orthogonal to each drain signal line 2 while being insulated from each drain signal line 2 and connected to the drain signal lines via a non-linear resistance element D
D, 10D '.

In this case, the common lines 10G and 10G 'are formed on both ends (left and right sides in the figure) of the gate signal line 3, respectively, and they may be electrically insulated from each other. In the embodiment, they are connected to each other via a gate signal line 2 (2J) formed at the lowermost stage in the figure. This effect will be described later.

The common lines 10D and 10D 'are formed on both ends (upper and lower sides in the figure) of the drain signal line 3, respectively. They are configured to be electrically insulated from each other. The reason for this configuration is that if the common lines 10D are connected to each other at the time of inspection for disconnection and short-circuit of each signal line, the inspection cannot be performed.

As shown in FIG. 3 which is an enlarged view, the non-linear resistance element D is connected to the gate signal line 2 on the left side of the external terminal 2T and the common line 10G in each of the gate signal lines 2. Nonlinear resistance element Dg1 connected between
And a non-linear resistance element Dg2 connected between the common line 10G and the gate signal line 2 on the display area side. Similarly, the nonlinear resistance element Dg2 connected between the gate signal line 2 on the right inspection terminal 2t side and the common line 10G ′ in FIG. 1, the common line 10G ′ and the gate signal line 2 on the display area side are connected to each other. Non-linear resistance element Dg connected between
And 2.

In each of the drain signal lines 3, even-numbered drain signal lines 3 counted from the left side in the figure (the drain signal lines 3 connected to the upper short-circuit line 3 A in the figure) are shown in FIG. 3, a non-linear resistance element Dd1 connected between the drain signal line 3 on the upper side of the external terminal 3T in the figure and the common line 10D, and the common line 10D
And a non-linear resistance element Dd2 connected between the drain signal line 3 on the display area side.

As shown in FIG. 1, the odd-numbered drain signal lines 3 (drain signal lines 3 connected to the lower short-circuit line 3A 'in FIG. 1) are counted from the left side in FIG. The drain signal line 3 and the common line 10 on the lower inspection terminal 3t side
D 'and a non-linear resistance element Dd2 connected between the common line 10D' and the drain signal line 3 on the display area side.

Each of these non-linear resistance elements is, for example, an MIS transistor formed in substantially the same process as the thin film transistor TFT in the display region, and is formed with its gate electrode and drain electrode connected. It has become something. However, the present invention is not limited to this, and it goes without saying that any element having the same function may be used.

As is clear from the above configuration, y
A common line 10 extending in the direction and connected to each gate signal line 2 via the non-linear resistance element D, and connected to each even-numbered drain signal line extending in the x direction and the non-linear resistance element D And a common line 10D ′ extending in the x direction and connected to each of the odd-numbered drain signal lines via a non-linear resistance element is electrically insulated from each other. I understand.

Further, in this embodiment, in particular, each of the left and right common lines 10G, 10G 'in the figure is connected to the gate signal line 2J at the lower end in the figure. The gate signal line 2J is a so-called dummy signal line, and is a signal line that is not used in actual driving of pixels. That is, the effective use of the gate signal line 2 (2J), which is unnecessary for display, increases the wiring length of the common lines 10G, 10G ', thereby dispersing the static electricity charged. ing.

Similarly, the upper common line 10D in the figure is connected to the drain signal line 3J at the right end in the figure, and the lower common line 10D 'is connected to the drain signal line at the left end in the figure. Connected to line 3J. Each of these drain signal lines is also called a so-called dummy signal line, and is a signal line that is not used in actual use. Similarly, it is for dispersing the static electricity.

Each of the dummy signal lines in the gate signal line and the drain signal line is required as a circuit because the circuit in each pixel region is as shown in FIG. 2, but does not directly contribute to display. It has properties. For this reason, an effective display area in the above-described display area is a portion indicated by oblique lines in the figure.

As described above, each of the common lines 10G, 10G
Even if G ′, 10D, and 10D ′ are connected to the dummy lines, the common lines 10G and 10G ′, the common line 10D, and the common line 10D ′ are not connected to each other and are electrically independent. It has become something.

Further, in this embodiment, the common lines 10D,
One end of each of the 10D ′ is connected to the electrode COM so that when the other glass substrate is assembled, it is connected to the transparent common electrode formed on the liquid crystal side surface of the other glass substrate. , But the common lines 10G, 10G
G ′ is configured so as not to be connected to the common electrode.

The reason for this is that the liquid crystal display panel shown in the figure has a configuration in which a scanning drive circuit is provided on the left side in the figure and a video drive circuit is provided on the upper side in the figure, and the driving load during driving is large. This is to solve the problem.

The glass substrate 1 thus configured is inspected, for example, in the following manner.

(1) Gate signal line 2 and drain signal line 3
Inspection of a short circuit between the short signal line 2A 'on the gate signal line 2 side and the short circuit lines 3A and 3A' on the drain signal line 3 side, and a short circuit line 2A 'and the short line 3A, The current flowing during 3A 'is measured. Based on the measured value, the presence or absence of a short circuit between the gate signal line 2 and the drain signal line 3 can be detected.

In this case, as described above, the common line 10G on the gate signal line 2 side and the common line 10G on the drain signal line 3 side
Since D and D are electrically separated from each other, it is possible to inspect for a short circuit between the gate signal line 2 and the drain signal line 3 without being affected by these common lines 10G and 10D. Become like

(2) Inspection of short between adjacent drain signal lines 2 One of the drain signal lines 3 (upper side in the figure) is a short-circuit line 3A;
The inspection probe is brought into contact with the other short-circuit line 3A '(lower side in the figure) of the drain signal line 3, and the current flowing between them is measured. Based on the measured value, the presence or absence of a short circuit between the adjacent drain signal lines 3 can be detected.

In this case, as described above, each of the drain signal lines 3 has the non-linear resistance element D formed on one side (for example, the upper side in the figure) and the other side (for example, the lower side in the figure). ), The non-linear resistance element is not formed, so that the adjacent drain signal lines 3 are completely electrically insulated from each other (in other words, the adjacent drain signal lines 3 The circuit is not short-circuited by the electrostatic protection circuit). Therefore, a reliable inspection can be performed.

(3) Inspection of disconnection of each signal line Common terminal (2A or 3A, 3A) of the signal line to be inspected
A ′) and an inspection probe are brought into contact between the common terminal of the signal line and the terminal (2t or 3t, 3T) placed at the opposite end, and the current flowing between them is measured.

Thus, by configuring the electrostatic protection circuit as described above, it is possible to efficiently and reliably inspect for disconnection or short-circuit of each signal line.

In this manner, the glass substrate 1 in which the disconnection or short-circuit of each signal line is not found can be obtained as shown in FIG.
As shown in FIG. 1, a liquid crystal display panel is configured together with the other glass substrate 10 different from the glass substrate 1. Here, the other glass substrate 10 has a transparent common electrode already common to each pixel region on its liquid crystal side surface,
If the liquid crystal display panel is for color display, a color filter or the like is formed.

Here, as described above, the transparent common electrode on the glass substrate 10 side can be drawn out to the glass substrate 1 side by the conductor 12 arranged on the terminal COM of the glass substrate 1. I have.

In this manner, the envelope of the liquid crystal display panel is formed, and the liquid crystal is provided in advance (not shown) on the sealing member 5 between the glass substrates 1 and 10. It is to be sealed and sealed from the sealing hole.
Needless to say, the sealing hole provided in the sealing material 5 is completely sealed after the liquid crystal is sealed.

As is clear from the embodiment described above,
For example, when checking whether a short circuit has occurred between the gate signal line and the drain signal line, as described above, apply one probe to the short circuit line of the gate signal line and apply the other probe to the short circuit line of the drain signal line. It is usual to measure the electrical resistance between them.

In this case, as shown in the conventional configuration, the common line in the electrostatic protection circuit includes a common line connected to the gate signal line via the non-linear resistance element,
When the drain signal line and the common line connected via the non-linear resistance element are configured to be connected to each other, from the short-circuit line of the gate signal line to the common line via the non-linear resistance element, Since the current flows to the short-circuit line of the drain signal line via the non-linear element, the above-described inspection cannot be performed.

Therefore, in this embodiment, basically, a common line commonly connected to the gate signal line via the non-linear resistance element and a common line commonly connected to the drain signal line via the non-linear resistance element are used. Is electrically insulated, the above-mentioned adverse effects can be eliminated.

Further, all other inspections such as inspection for disconnection of the gate signal line or the drain signal line can be performed in the same manner as in the conventional case, and any of them has no effect on the common line for electrostatic protection. A reliable inspection can be performed without being performed.

Also, in the electrostatic protection circuit composed of the non-linear resistance element and the common line, the structure is not restricted by the disconnection or short circuit detection circuit of each signal line. Will be able to

Therefore, according to the configuration of the present invention, it is possible to sufficiently perform inspection for disconnection or short-circuit of each signal line and antistatic measures for the thin film transistor.

The common lines 10G, 10G ', 10D,
10D ′ has a configuration that can sufficiently disperse the charged static electricity since the line length is substantially increased by using the dummy lines. Therefore, there is an effect that sufficient measures can be taken for electrostatic protection.

In this case, each common line 10
Although dummy lines are used to increase the line lengths of G, 10G'10D, and 10D ', it goes without saying that a new line may be formed and connected to this line. However, when a dummy line is used, there is an effect that it is not necessary to provide an extra area on the glass substrate 1.

In the above-described embodiment, the gate signal is supplied from one side of the gate signal line 2 and the drain signal is supplied from one side of the drain signal line 3. Of course, the present invention is not limited to this. In each of the drain signal lines 3, a drain signal is supplied from one side to every other drain signal line 3 and a drain signal is supplied to the other drain signal lines 3 from the other side. Because it can be applied.

FIG. 5 is a schematic circuit diagram in this case, and portions corresponding to FIG. 1 are denoted by the same reference numerals. Also in this case, basically, a common line 10G (10G ′) extending in the y-direction and connected to each gate signal line 2 via the nonlinear resistance element D is connected to a common line 10G (10G ′) extending in the x-direction. A common line 10D connected to each even-numbered drain signal line via the element D, and a common line 10D 'extending in the x direction and connected to each odd-numbered drain signal line via the non-linear resistance element. Are electrically insulated from each other.

In the configuration shown in FIG. 5, the length of each of the common lines 10G (10G '), 10D and 10D' is substantially increased while ensuring the configuration electrically insulated from each other. Needless to say, this may be done.

[0061]

As is apparent from the above description,
ADVANTAGE OF THE INVENTION According to the liquid crystal display panel by this invention, the disconnection or short circuit of a signal line and the antistatic measures of a thin film transistor can also be fully performed.

[Brief description of the drawings]

FIG. 1 is a plan view showing a configuration of a liquid crystal side surface of one glass substrate of a liquid crystal display panel according to the present invention.

FIG. 2 is an equivalent circuit diagram showing details of a pixel region of one glass substrate of the liquid crystal display panel according to the present invention.

FIG. 3 is a partially enlarged view of FIG. 1;

FIG. 4 is a partially cutaway view showing a plane of a liquid crystal display panel according to the present invention.

FIG. 5 is an equivalent circuit diagram showing another embodiment of the liquid crystal display panel according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Glass substrate, 2 ... Gate signal line, 3 ... Drain signal line, 2A, 2A'3A, 3A '... Short circuit line, 10
G, 10G ', 10D, 10D' ... common line, D ... non-linear resistance element.

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[Procedure amendment]

[Submission date] September 19, 1996

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 4

[Correction method] Change

[Correction contents]

FIG. 4

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takashi Isoda 3681 Hayano Mobara City, Chiba Prefecture Hitachi Device Engineering Co., Ltd. (72) Inventor Tsutomu Sato 3300 Hayano Mobara City Chiba Prefecture Hitachi Electronics Co., Ltd. 72) Inventor Yoshihiko Nakahara 3300 Hayano, Mobara-shi, Chiba Pref.Electronic Device Division, Hitachi, Ltd. (72) Inventor Takeshi Tanaka 3300, Hayano, Mobara-shi, Chiba Pref. Electronic Device Division, Hitachi, Ltd. 3300 Hayano Mobara-shi, Chiba Pref.Electronic Device Division, Hitachi, Ltd.

Claims (3)

[Claims] 1. A liquid crystal-side surface of one of a pair of transparent substrates disposed opposite to each other with a liquid crystal interposed therebetween, x
A gate signal line extending in the direction and juxtaposed in the y direction and a drain signal line insulated by the gate signal line and extending in the y direction and juxtaposed in the x direction are formed and surrounded by these signal lines. Each pixel region includes a thin film transistor that is turned on by supply of a scanning signal from a gate signal line, and a pixel electrode to which a video signal from a drain signal line is supplied via the turned on thin film transistor. A common electrode common to each pixel region is formed on the liquid crystal side surface of
In the liquid crystal display panel, the common electrode is drawn out to the one transparent substrate side through a conductor interposed between the one transparent substrate and a set of pixel regions on a liquid crystal side surface of the one transparent substrate. A first common line extending in the y-direction and connected to each gate signal line through the non-linear resistance element, and a first common line extending in the x-direction and interposing the non-linear resistance element A second common line connected to each even-numbered drain signal line and a third common line extending in the x-direction and connected to each odd-numbered drain signal line via a non-linear resistance element. The first, second, and third common lines are formed so as to be electrically separated from each other, and the second and third common lines are electrically connected via the conductor. A liquid crystal display panel, wherein the liquid crystal display panel is connected to a liquid crystal display panel. 2. A first common line connected to each gate signal line via a non-linear resistance element is provided two with a display area therebetween, and each of these first common lines is used for driving an actual pixel. 2. The liquid crystal display panel according to claim 1, wherein the liquid crystal display panels are connected to each other via an unused gate signal line. 3. A first common line connected to each gate signal line via a non-linear resistance element is connected to a common electrode formed on a liquid crystal side surface of another transparent substrate opposed to the liquid crystal via a liquid crystal. 2. The liquid crystal display panel according to claim 1, wherein the liquid crystal display panel is not connected.