JPS61250696A - Active matrix display element - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an active matrix display element consisting of a liquid crystal and a thin film transistor (hereinafter abbreviated as TPT), and particularly to an active matrix display element that improves display image quality by significantly reducing display defects thereof. This is related to improvement and yield improvement.

[Conventional technology]

FIG. 3 shows a cross section of a pixel of a conventional active matrix display element, in which 1 is a glass substrate, 2 is a P-) electrode made of aluminum, for example, provided on the glass substrate l, and 3 is the upper part of the r-) electrode 2. 4 is a semiconductor layer provided on the dirt insulating film 3, 5 and 6 are f-)
insulation! N3 and a source electrode and a drain electrode provided to cover the upper part of the semiconductor layer 4; 7#:l: a display electrode composed of a transparent conductive film provided above the boot insulating film 3 and the drain electrode 6; FIG. 4 shows an equivalent circuit when an active matrix display element is constructed using pixels configured in this manner. Reference numerals 10 and 11 designate a plurality of scanning lines and signal lines that are provided to intersect with each other, and the P-to and source of the TFT 14 are connected to the intersections thereof. The liquid crystal layer 12 is connected to the drain of the TFT 14,
The TF'T 14 and the liquid crystal layer 12 constitute a pixel circuit. 13 shows the charging current of the pixel circuit.

In the Acti1 matrix display element having the above configuration, 1
When a pixel is selected according to the voltage conditions of the scanning line 10 and the signal +IH1, the TFT 14 is turned on, and a signal voltage is applied to the liquid crystal layer 12 by the charging current 13 at that time, and the pixel is turned on. Operate.

By integrating a large number of pixels, an image can be displayed using an active matrix display element. Furthermore, by switching the plurality of scans @10 and the plurality of signal lines 11 sequentially at different times, a plurality of pixels are sequentially selected and one screen is displayed.

[Problem that the invention seeks to solve]

However, in the active matrix display element as described above, it is necessary to prevent a short circuit from occurring between the scanning illO and the signal line 11. If a short circuit occurs between the scanning line 10 and the signal 1iill, all pixels connected to the shorted scanning line 10 and signal 1j [11] will become inoperable. This will appear as two vertical and horizontal line defects. This short circuit between the scanning line 10 and the signal )i1 is mainly caused by the TFT1
4 r-) Due to pinholes or electrostatic breakdown in the insulating film 3)
This often occurs, and it is extremely difficult to suppress this short circuit to zero in an active matrix display element having tens of thousands or hundreds of thousands of pixels.

The present invention has been made to eliminate the above-mentioned conventional problems, and even if a short circuit occurs between a scanning line and a signal line, it does not cause a line defect on the screen, but only a point defect. Another object of the present invention is to obtain an active matrix display element that can improve image quality and yield.

[Means for solving problems]

The active matrix display element according to the present invention includes TPT
A resistor is provided between the source electrode and the signal line.

[For production]

If a signal line and a scanning line are short-circuited via a TFT, a resistor provided between the source electrode and the signal line prevents the short-circuit. However, the above-mentioned resistance is set to a level that does not inhibit the charging flow of the pixel circuit.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, aluminum, for example, is deposited by sputtering on a glass substrate 1 and patterned to form an r-to-electrode 2. As shown in FIG. Next, f-) The insulating film 3 is made of glass W CV D
After that, a semiconductor layer 4 is deposited by plasma CVD and patterned. Next, aluminum is deposited by sputtering and patterned to form a signal line (source line) 11, a source electrode 5, and a drain electrode 6.

Next, amorphous silicon doped with phosphorus, for example, is deposited by plasma CVD and patterned to form a resistance layer 9 between the signal line 11 and the source electrode 5. Finally, display electrodes 7 are formed using a transparent conductive film.

FIG. 2 shows an equivalent circuit of the above configuration, and of course a resistance layer 9 is provided between the source electrode 5 and the signal line 11 which is a source line. This resistance layer 9 is designed so that when a short circuit is eliminated between the r-to electrode 2 and the source electrode 5 due to a pinhole or the like in the r-to insulating layer 3, this short circuit is caused to occur between the scanning line lO and the signal line 11.
It is necessary to have a resistance value designed to act as a protective resistor to prevent short circuits between the However, since this resistance layer 9 is added to the circuit of the charging current 13 in the on state of the TFT 1 4, it is also necessary to have a value that does not suppress the charging current 13. Therefore, this resistance value is set so as to satisfy both the necessary conditions as a protective resistor and the conditions not to inhibit charging current. As a material for the resistance layer 9, amorphous silicon doped with phosphorus, boron, or other impurities at a relatively low concentration, or other resistance material that can be used as a paper antibody is used.

〔Effect of the invention〕

As described above, according to the present invention, a resistor is provided between the source electrode of the thin film transistor and the signal line! ri, thin j[)
When a short circuit occurs between the r-) electrode and the source electrode of the Lanzoster, the above resistor can prevent the short circuit between the scanning line and the signal line, and prevent line defects from occurring on the screen. can. Therefore, it is possible to improve the image quality and yield of the active matrix display element.

[Brief explanation of drawings]

1 and 2 are a sectional view and an equivalent circuit diagram of a pixel of an active matrix display element according to the present invention, respectively, and FIG.
4 are a cross-sectional view and an equivalent circuit diagram of a pixel of a conventional active matrix display element, respectively. DESCRIPTION OF SYMBOLS 1...Glass substrate, 2...P-) electrode, 3...r
-) Insulating film, 5... Source electrode, 9... Resistance layer, 1
0...Scanning line, 11...Signal line, 12...Liquid crystal layer, 14...Thin film transistor. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] (1) Arrange multiple signal lines and scanning lines so that they intersect,
In an active matrix display element in which a pixel circuit including a thin film transistor whose gate is connected to a scanning line and whose source is connected to a signal line is connected to this intersection, a signal line is connected between the source electrode of the thin film transistor and the signal line. 1. An active matrix display element comprising a resistor having a resistance value that prevents short circuits between scanning lines and does not inhibit charging current of a pixel circuit.