JPH10104577A - Liquid crystal display - Google Patents

Abstract

(57) [Problem] To provide a liquid crystal display device having improved display uniformity over the entire display section. A plurality of image signal wirings and a plurality of scanning signal wirings are provided to intersect with an insulating film interposed therebetween, and a pixel electrode and a pixel electrode are provided at intersections of the image signal wirings and the scanning signal wirings. A switching thin film transistor 4 for supplying an image signal to S is provided in a matrix, and a liquid crystal material is held between the pixel electrode S and a counter electrode 7 provided to face the pixel electrode S. A liquid crystal display device 1a in which a dummy wiring 9 for an image signal wiring formed at an end of the pixel electrode 8 is connected to a counter electrode 7 of the pixel electrode S by a conductive wire 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal display device, and more particularly to an active matrix type liquid crystal display device using a panel in which a thin film transistor is formed in each pixel (hereinafter, referred to as a TFT array panel).

[0002]

2. Description of the Related Art An active matrix type liquid crystal display device has higher contrast and better multi-gradation display characteristics than a simple matrix type liquid crystal display device. And an image quality equivalent to that of a CRT, and is an excellent method for a color liquid crystal display device.

Hereinafter, a conventional liquid crystal display device will be described with reference to the drawings. FIG. 2 is an equivalent circuit diagram of a TFT array panel in the conventional liquid crystal display device 1, and FIG. 3 is a diagram showing waveforms of terminals shown in FIG. 2 and waveforms of voltages applied to the liquid crystal.

The liquid crystal display device 1 switches the thin film transistor 4 by applying a scan signal VG from the scan signal supply circuit 2 to the gate electrode of the thin film transistor 4 via the scan signal line 3, and switches the image signal from the image signal supply circuit 5. By applying the image signal VS to the pixel electrode S via the wiring 6 and the thin film transistor 4, the pixel electrode S
And a voltage is applied to a liquid crystal material held between the pixel electrode S and a counter electrode 7 provided to face the pixel electrode S to display an image. Reference numeral 8 denotes a display unit connected by the scanning signal wiring 3 and the image signal wiring 6, reference numeral 9 denotes an image signal dummy wiring provided at an end of the display unit 8, and reference numeral 10 denotes a counter electrode signal supply circuit.

In FIG. 3, VG is a scanning signal, V
S is an image signal, VT is a counter electrode signal, VB is an effective voltage applied to the liquid crystal material, and a scanning signal VG is a signal supplied from the scanning signal supply circuit 2 to the gate of the switching thin film transistor 4. And a voltage VGL at which the switching transistor 4 is turned off.

Further, the image signal VS is a signal supplied from the image signal supply circuit 5 to the pixel electrode S via the source / drain of the switching thin film transistor 4, and has a polarity of one scanning period (1 hour (H)). VS + and VS- which are inverted every time, and the center value is VSC.
The counter electrode signal VT is a signal applied to the counter electrode 7.

[0007]

However, according to the liquid crystal display device 1 having the above structure, the dummy wiring 9 for the image signal wiring 6 is formed at the opposite end of the display section 8 as shown in FIG. Since the dummy wiring 9 is electrically open and does not have a structure in which a voltage is supplied from the outside, electric noise or the like is likely to be applied from the outside, so that the voltage fluctuation of the dummy wiring 9 is reduced. There is a problem that adjacent display pixels are affected, and a display abnormality occurs near the end of the display unit 8.

Accordingly, it is an object of the present invention to provide a high-performance liquid crystal display device having improved display uniformity over the entire display section.

[0009]

According to the liquid crystal display device of the present invention, a plurality of image signal lines and a plurality of scanning signal lines are provided so as to intersect with an insulating film interposed therebetween. A pixel electrode and a switching element comprising at least a gate electrode for supplying an image signal to the pixel electrode, the insulating film, the semiconductor film, a source electrode and a drain electrode are provided in a matrix at the intersection of A liquid crystal material is held between a counter electrode provided opposite to the dummy electrode, and a dummy wiring of an image signal wiring formed at an end of a display unit and the counter electrode have the same potential. As described above.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a liquid crystal display device of the present invention will be described with reference to FIG. FIG. 3 is an equivalent circuit diagram of a TFT array panel in the liquid crystal display device 1a according to the present invention. In addition,
The same parts as those of the conventional liquid crystal display device 1 of FIG.

In the liquid crystal display device 1a of the present invention, as compared with the conventional liquid crystal display device 1, the dummy wiring 9 of the image signal wiring 6 formed at the end of the display section 8 has the same potential as the counter electrode 7 for the pixel electrode S. It is characterized by conducting so that In the same figure, the conducting wire for that is indicated by "11".

Further, similarly to the conventional liquid crystal display device 1, a scanning signal VG is applied from the scanning signal supply circuit 2 to the gate electrode of the thin film transistor 4 via the scanning signal wiring 3, and the thin film transistor 4 is switched, so that an image is displayed. By applying an image signal VS to the pixel electrode S from the signal supply circuit 5 via the image signal wiring 6 and the thin film transistor 4, a voltage is applied to the liquid crystal material held between the pixel electrode S and the counter electrode 7. To display an image.

Thus, according to the above configuration, since the counter electrode signal substantially equal to the center voltage of the image signal is applied to the dummy wirings 9 formed at both ends of the display section 8, the dummy wirings 9
An effective voltage equivalent to that of the image signal wiring 6 of the display unit 8 and the pixels connected thereto is applied to the pixels connected thereto, and the display near both ends of the display unit 8 is stabilized.

[0014]

As described above, according to the present invention, since the dummy wiring of the image signal wiring formed at the end of the display section and the counter electrode of the pixel electrode are electrically connected to each other so as to have the same potential, The fluctuation in the voltage of the dummy wiring does not affect the adjacent display pixels, thereby preventing the display portion from being abnormal near the end of the display portion and improving the uniformity of display over the entire display portion. A liquid crystal display device is provided.

[Brief description of the drawings]

FIG. 1 is an equivalent circuit diagram of a TFT array panel in a liquid crystal display device of the present invention.

FIG. 2 is an equivalent circuit diagram of a TFT array panel in a conventional liquid crystal display device.

FIG. 3 is a waveform diagram applied to each terminal or liquid crystal in a conventional liquid crystal display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 1a Liquid crystal display device 2 Scan signal supply circuit 3 Scan signal wiring 4 Thin film transistor 5 Image signal supply circuit 6 Image signal wiring 7 Counter electrode 8 Display part 9 Dummy wiring 10 Counter electrode signal supply circuit 11 Lead wire between dummy electrode and counter electrode S pixel electrode

Claims (1)

[Claims] A plurality of image signal wirings and a plurality of scanning signal wirings are provided so as to intersect with an insulating film interposed therebetween. A pixel electrode is provided at an intersection between the image signal wirings and the scanning signal wirings, and an image is provided on the pixel electrode. A switching element composed of at least a gate electrode for supplying a signal, the insulating film, the semiconductor film, a source electrode and a drain electrode is provided in a matrix, and a switching element is provided between the pixel electrode and a counter electrode provided to face the pixel electrode. Wherein a dummy wiring of an image signal wiring formed at an end of a display unit and the counter electrode are electrically connected to have the same potential.