JPH02186325A - Substrate for active matrix display device - Google Patents

Abstract

PURPOSE:To provide the substrate having simple constitution and to decrease the line defects of gate lines and data lines by connecting the gate lines and data lines of at least either of the adjacent lines of the plural gate lines and data lines at least at >=2 points. CONSTITUTION:Driving signals are impressed from respective driving devices to the gate lines a1, a2, a3... and the data lines b1, b2, b3.... Respective display picture elements 4 are then sampled time-dividedly and are point-sequentially driven. The gate line a1 is formed to a loop shape and, therefore, the signals outputted from the gate driving signals are supplied to all thin-film transistors TFTs 3 connected to the gate line a1 even if, for example, the gate line a1 is disconnected at a point X. The data line b1 is similarly formed to a loop shape and, therefore, the driving signals are supplied to all the TFTs 3 connected to the data line 1b even if the data line b1 is disconnected at a point Y. Namely, the gate lines and data lines are formed to the loop shape and, therefore, the generation of line defects on the display screen is obviated even if the gate lines and the data lines are disconnected at one point.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a substrate for an active matrix display device,
In particular, it relates to reducing line defects in gate lines and data lines.

[Conventional technology]

2. Description of the Related Art Conventionally, a so-called active matrix display is known in which a liquid crystal is directly driven using an array of switching elements arranged in a matrix. According to this display method,
There is no need to worry about the crosstalk effect, which is one of the problems with liquid crystal displays, and very detailed images can be displayed.

[Problem to be solved by the invention]

However, as display screens become larger and more dense,
In a display device substrate, it is an unavoidable problem that a gate line that transmits a signal for switching conduction or non-conduction of a switching element or a data line that transmits a control signal for an electrode of a display pixel is disconnected. If a disconnection occurs in a gate line or a data line, it will appear as a line defect on the display screen, thereby significantly deteriorating the display quality. As a means to solve this problem, for example, Japanese Patent Laid-Open No. 61-411
No. 26 discloses that each gate line and data line are connected to the drive device at two or more locations. However, in order to connect each gate line and data line to the drive device at two or more locations, multiple connection terminals such as wire bonding are required for the number of connection locations, or When connecting both ends of each gate line and data line to a driving device, lIl! , special parts such as an extension boat for the edge sump were required.

The present invention has been made in view of the above points, and has a simple configuration that does not require an increase in the number of connection terminals or special components such as extension boats, and can reduce line defects in gate lines and data lines. An object of the present invention is to provide a substrate for an active matrix display device.

[Means to solve the problem]

In order to achieve the above object, a substrate for an active matrix display device according to the present invention includes a plurality of gate lines and data lines wired in a grid pattern on one surface of a transparent insulating substrate, and one side of the transparent insulating substrate. a plurality of switching elements arranged in a matrix on a surface and connected to the gate line and the data line; and a matrix-shaped switching element connected to the data line via the switching element and whose optical state changes. In the substrate for an active matrix display device, the plurality of gate lines and data lines are connected to only one of the gate lines and data lines adjacent to each other on the one surface of the transparent insulating substrate. The configuration shall be such that it is connected at at least two places.

[Effect]

According to the above configuration, the plurality of gate lines and data lines wired in a grid pattern on the transparent insulating substrate are connected to only one of the adjacent gate lines and data lines at at least two or more locations. Since this connection is made on one side of the transparent insulating substrate, for example, when connecting both ends of a gate line and data line to both ends of an adjacent gate line and data line, special In addition, the number of connection terminals required for connection with the drive device is 1 for 2 data lines and gate lines.
It becomes one.

〔Example〕

Hereinafter, a first embodiment of the present invention will be described based on the drawings.

FIG. 1 is a configuration diagram showing the configuration of a substrate for an active matrix display device.

In FIG. 1, al, a2. a3 is the gate line,
The gate line a1 is formed in a ring shape on the substrate by connecting both ends of the two gate lines 1a and 1b. bl, b2. b3 is a data line, and like the gate line al, the data line bl is formed in a ring shape on the substrate by connecting both ends of the two data lines jJ12a and 2b. 3 is a 7iI film transistor (TPT) as a switching element, 4 is a display pixel, TPT3 is formed in a matrix on the substrate, and its gate electrode is connected to a gate line, and its source electrode is connected to a data line. The drain electrode is connected to the pixel electrode of the display pixel 4.The symbols R, G, and B of the display pixel 4 represent the colors of the color filters provided on each pixel (R→red, G→ 7 indicates a connection terminal between the gate line al and a gate drive device (not shown), and 8 indicates a connection terminal between the data line b1 and a data drive device (not shown).

Further, FIG. 2 is an overall configuration diagram showing the entire configuration including a gate driving device, a data driving device, and a connector.

In FIG. 2, 1la-11C is a gate driving IC constituting a gate driving device, and 12 is a gate driving IC 1l.
It is a printed circuit board on which a to lie are mounted, and 14a to 1
4c is a data driving IC 1 constituting a data driving device.
5 is a printed circuit board on which data driving ICs 14a to 14c are mounted.

These printed circuit boards 12.15 are connected to a liquid crystal display 17 by flexible connectors 13.16.

In the above configuration, the operation of this embodiment will be explained.

In FIG. 1, gate lines al, a2 . a3... and data mbl, b2. A drive signal (pulse voltage) is applied from each drive device to b3..., and each display pixel 4 is time-divisionally sampled and driven point-sequentially. Here, for example, even if the gate line al is broken at the point X shown in the figure, since the gate line a1 is formed in an annular shape,
A signal output from the gate drive device is supplied to all TPTs connected to gate line a1. Similarly, when data line bt is disconnected at point Y shown in the figure, data line b
A drive signal is supplied to all TPTs connected to 1. In other words, even if the gate line and data line are broken at a few places, line defects will not occur on both display surfaces because the gate line and data line are formed in an annular shape.

Further, in this embodiment, for example, four display pixels R+, R*, Ri, and Rn surrounded by a broken line 9 are connected to the same gate line a2 and data line b2. Therefore, these four display pixels R and -R4 all operate in the same way. Therefore, although there are four display pixels R2 to R4, it is displayed on the display screen as if only one display pixel exists there. In this way, in this embodiment, one display pixel is composed of the four display pixels R8 to R4, so unless the pattern of the four display pixels R1 to R4 is defective, a complete pixel defect will not occur. do not have. That is, according to this embodiment, it is possible to extremely reduce the occurrence of complete pixel defects.

Next, a second embodiment of the present invention will be described.

In the first embodiment described above, the broken lines 9, 1.0° 11 in FIG.
As shown, one display pixel was constructed from four display pixels, and the TPT 3 and the display pixels were connected so that the display pixels having color filters of respective colors were arranged in a triangular arrangement. On the other hand, in the second embodiment, as shown by broken lines 9, 10, and 11 in FIG. ), the TPT 3 and display pixels are connected. According to this wiring method, it is also possible to create a horizontal stripe or diagonal mosaic pattern by changing the arrangement of display pixels having color filters of respective colors.

Next, a third embodiment of the present invention will be described.

The above 1. In the second embodiment, four display pixels were connected to the same gate line and data line, and one display pixel was constructed from these four display pixels.

On the other hand, in the third embodiment, as shown in FIG. 4, the same gate lines al, a2. a3... and data lines b1, b2
．． Only one display pixel is connected to the gates L'Aa1, .b3, . a2. a3... and data Ib1. b2. The connection between the b3 river and the display pixel 4 is made at two places. According to this, although there is only one display pixel 4, this display pixel 4 has two connection paths, so the first. Similarly to the second embodiment, pixel defects due to TFT defects and the like can be reduced. Note that, as shown in FIG. 5, two TPTs are provided for one display pixel.
It goes without saying that display can be performed even with only one 3.3'.

Next, a fourth embodiment of the present invention will be described.

As shown in FIG. 5, gate lines al, a2. a3...
and data lines bl, b2 . b3... is formed into a ring shape,
In addition, if only one display pixel is connected to the same gate line and data line, twice the number of wiring is required compared to the wiring of a conventional display device. Correspondingly, the aperture ratio (full pixel area) decreases, and the transmittance decreases. In order to deal with this problem, if the pixel area is increased, there is a possibility that the gate line of al and the gate line of a2 will be short-circuited. Therefore,
In this embodiment, each gate line and data line are wired in two layers to prevent short circuits and to obtain a substrate with a large open area ratio.

Figure 6 is a cross-sectional view taken along the line ■-■' in Figure 5.
There is an insulation layer 1fI of SjO, Si3N, etc. between a and the data line 1b! 27 is formed.

Note that 21 is a gate insulating film, 22 is a semiconductor film, 23 is a train electrode, 24 is a pixel electrode (rTOI), 25 is a protective film, and 26 is a source electrode.

Also, games with two layers of wiring) 1. The Sl and data lines are connected through contact holes 20, as shown in the cross-sectional and plan views of FIGS. 7(a) and 7(b).

Note that in the first embodiment described above, the gate and data driving f
c and the liquid crystal display were connected using a flexible connector, but as shown in Figure 8, each drive IC
I! a to llc and 14a to 14c may be directly soldered to the wiring on the glass substrate 30.

(Effects of the Invention) As explained above, according to the present invention, an active matrix display that does not require an increase in the number of connection terminals or special components such as an extension board, and can reduce line defects in gate lines and data lines. A device substrate can be provided.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the structure of the active matrix display device substrate of the first embodiment, FIG. 2 is an overall configuration diagram showing the entire structure of the first embodiment, and FIG. 3 is a schematic diagram showing the structure of the active matrix display device substrate of the first embodiment. FIG. 4 is a schematic diagram showing the configuration of the display device substrate of the third embodiment. FIG. 5 is a schematic diagram showing the configuration of the display device substrate of the fourth embodiment. , FIG. 6 shows a cross-sectional state of the display device substrate of the fourth embodiment 8! Formula diagram, 7th
Figures (a) and (b) are a sectional view and a plan view showing the structure of a contact hole, and Fig. 8 is an overall configuration diagram showing the overall configuration of another embodiment. a1. a2. a 3-...Gate line,
bl, b2. b3...Data line, 3...
Thin film transistor, 4... display pixel, 7, 8... connection terminal. lI z Color No. 13 b2 No. ■

Claims (1)

[Scope of Claims] A plurality of gate lines and data lines arranged in a grid pattern on one surface of the transparent insulating substrate, and a plurality of gate lines and data lines arranged in a matrix pattern on the one surface of the transparent insulating substrate, an active matrix display device comprising: a plurality of switching elements connected to a line and the data line; and display pixels arranged in a matrix that are connected to the data line via the switching element and whose optical states change. In the substrate, the plurality of gate lines and data lines are connected to only one of the adjacent gate lines and data lines on the one surface of the transparent insulating substrate at at least two places. Active matrix display device substrate.