Fault tolerant active matrix display device

• US 5,469,025 A
• Filed: 03/22/1995
• Issued: 11/21/1995
• Est. Priority Date: 09/27/1990
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Marumoto, Hideji, Kato, Hiroaki, Okamoto, Masaya, Katayama, Mikio, Fujihara, Toshiaki, Mitsumoto, Kazuyori, Nakazawa, Kiyoshi, Fujiki, Hiroshi, Kanemori, Yuzuru, Irie, Katsumi, Kondo, Naofumi, Otsu, Kumiko, Yano, Kozo, Negoto, Hidenori
• Primary Examiner(s): Pascal, Robert J.
• Assistant Examiner(s): Shingleton, Michael B.
• Application Number:
  US08/408,183
• Time in Patent Office: 244 Days
• Field of Search: 359/55, 359/59, 359/87, 313/583, 340/784 BI, 340/784 CI, 315/169.3, 315/169.4
• US Class Current: 315/169.3
• CPC Class Codes: G02F 1/1362 Active matrix addressed cells G02F1/134336, G02F1/134363 take precedence
• CPC Class Codes: G02F 1/136259 Repairing; Defects
• CPC Class Codes: G02F 1/136268 Switch defects

Abstract

An active matrix display device which includes a first and a second insulating substrates, a gate bus an adjacent gate bus, and a source bus arranged on the first substrate, a pixel electrode in a segment enclosed by the gate and the source buses, a switching element connected to the pixel electrode, the gate bus and the source bus, wherein the source bus comprises a projection extending toward the pixel electrode so as to be electrically disconnected therefrom, and the adjacent gate bus comprises a projection extending toward the pixel electrode, the source bus being overlaid on the adjacent gate bus projection with an insulating layer sandwiched therebetween, the adjacent gate bus projection being provided with an electroconductive member at the top thereof with an insulating layer sandwiched therebetween, the electroconductive member being electrically connected to the pixel electrode, and electrically disconnected from the source bus projection.

Claims

1. An active matrix display device comprising:

a first insulating substrate and a second insulating substrate;

a gate bus having a branch formed thereon and an adjacent gate bus having a projection formed thereon and a source bus having a first projection formed thereon and a second projection formed thereon, the gate bus, the adjacent gate bus, and the source bus being arranged on the first insulating substrate;

a pixel electrode bordered by the gate bus, the adjacent gate bus, and the source bus;

a switching element which is connected to the pixel electrode, to the branch of the gate bus, and to the first projection of the source bus;

wherein the second projection of the source bus extends toward the pixel electrode, and the projection of the adjacent gate bus extends toward the pixel electrode, the second projection of the source bus being overlaid on the projection of the adjacent gate bus with the insulating layer sandwiched therebetween, the projection of the adjacent gate bus being provided with an electroconductive member at a top end thereof with the insulating layer sandwiched therebetween, the electroconductive member being electrically connected to the pixel electrode; and

the display device further comprising a protective layer overlaid at least on the second projection of the source bus and the electroconductive member for containing a release of molten molecules therefrom, wherein the electroconductive member is fused to the projection of the adjacent gate bus through said insulating layer and the second projection of the source bus is fused to the projection of the adjacent gate bus through said insulating layer; and

wherein direct electrical communication of the source bus and the pixel electrode is attained, regardless of a voltage on the gate bus, through the fused electroconductive member and the fused second projection of the source bus.

3. An active matrix display device as defined in claim 1, wherein the switching element is a thin film transistor.

2. An active matrix display device comprising:

a first insulating substrate and a second insulating substrate;

a gate bus, an adjacent gate bus, and a source bus arranged on the first insulating substrate;

a pixel electrode bordered by the gate bus, the adjacent gate bus, and the source bus;

a switching element connected to the pixel electrode, a part of the pixel electrode being overlaid on the adjacent gate bus so as to form an additive capacitance together with the adjacent gate bus with an insulating layer sandwiched therebetween;

wherein the source bus is provided with a projection extending toward the pixel electrode, and the adjacent gate bus being provided with a projection extending toward the pixel electrode, and the projection of the source bus being overlaid on the adjacent gate bus projection with the insulating layer therebetween, the adjacent gate bus projection being provided with an electroconductive member with the insulating layer sandwiched therebetween, the electroconductive member being electrically connected to the pixel electrode;

the display device further comprising protective layer overlaid on the projection of the source bus and the electroconductive member for containing a release of molten molecules therefrom, wherein the projection of the source bus is fused to the projection of the adjacent gate bus and the electroconductive member is fused to the projection of the adjacent gate bus through said insulating layer; and

wherein direct electrical communication of the source bus and the pixel electrode is attained, regardless of a voltage on the gate bus, through the fused electroconductive member and the fused second projection of the source bus.