Hosiden Electronics Co., Ltd.

Hosiden Corporation

Teizo Yukawa

Yasuhiro Ukai

Tomihisa Sunata

Masaru Yasui

In an active matrix liquid crystal display device in which source and gate buses are arranged in a matrix form, thin film transistors are provided at intersections of the source and gate buses and display electrodes are driven by applying voltage thereto via the thin film transistors, source and gate bus repair conductive layers are provided which extend along the source buses in opposing relation thereto across an insulating layer. When any one of the source or gate buses is broken, the repair conductive layer and the broken bus can be connected at both side of the broken portion by laser welding.

Liquid crystal display device having metallic bus repair layer

One end portion of each pixel electrode is extended under a gate insulating film underlying the neighboring gate bus and defines an additional capacitance region. The extended portion of the pixel electrode is divided into a plurality of comb-tooth-like electrodes, each defining divided additional capacitors. One of the comb-tooth-like electrodes is separated by a gap from the pixel electrode, and first and second electrodes for laser welding use are formed on the comb-tooth-like electrode and the pixel electrode facing each other across the gap. The first and second electrodes form series-connected first and second capacitances for laser welding use between them and a third electrode for laser welding use formed above them with a gate insulating film interposed therebetween. When one of the divided additional capacitors connected to the pixel electrode is bad in insulation, the defective one of the divided additional capacitors is cut off and the first and second capacitances are caused to short by welding, whereby the total additional capacitance can be held substantially constant.

Active matrix display device having divided additional capacitors

Liquid crystal is sealed in between a pair of opposed first and second transparent substrates, picture element electrodes, gate buses, and source buses are formed on the first transparent substrate, and thin film transistors are each disposed at one of the intersections of the source and gate buses, thereby constituting an active matrix liquid crystal display element. On the first transparent substrate there are provided capacitive electrodes respectively opposite the source buses, with an insulating layer interposed therebetween, and the capacitive electrodes are connected to a common potential point.

Growing community of inventors

Kobe, Japan

Teizo Yukawa