Hosiden Corporation

Hosiden Electronics Co., Ltd.

Nippon Telegraph and Telephone Corporation

Honeywell G.m.b.h.

Tomihisa Sunata

Yasuhiro Ukai

Toshiya Inada

Teizo Yukawa

Takanobu Nakagawa

Shigeo Aoki

Teizou Yukawa

Elias S Haim

Masaru Yasui

Kinya Kato

Tsutomu Wada

Hiroshi Saito

Tadamichi Kawada

Nobuhiko Kakuda

Kazuya Hashimoto

Minori Otsuki

Minoru Shibazaki

Shu Takeuchi

Kiyoshi Taruta

Masamichi Okamura

A transparent insulation film is formed on a glass substrate. Source and drain electrodes are formed on the transparent insulation film with their ends in spaced and opposing relation. The entire face of the substrate is treated with PH.sub.3 plasma to diffuse P atoms to form a doped surface layer. An a-Si semiconductor layer is formed on the doped surface layer so as to span a space between the source and drain electrodes with the opposite end portions of the semiconductor layer overlying those electrodes. A gate insulation film is formed on the semiconductor layer to extend all over the substrate. A gate electrode is formed of metal on the top of the gate insulation film 6 such that the opposite side edges of the gate electrode are recessed inwardly of the edges of the source and drain electrodes. An excimer laser beam is radiated against the face of the substrate with the gate electrode acting as a mask so that the laser-irradiated regions of the semiconductor layer comprise source and drain regions of n.sup.+ poly-Si.

Top gate thin-film transistor

In a gray-scale liquid crystal display panel of the type wherein first and second transparent substrates (1, 5) are disposed in parallel with liquid crystal (7) sealed in a space defined therebetween, the second substrate (5) is coated all over its inside surface with a transparent common electrode (6) and the first substrate (1) has on its inside surface pixels arranged in a matrix form and thin film transistors (8) each provided near one of the pixels, the pixels each include first and second spaced-apart subpixel electrodes (4.sub.1, 4.sub.2) formed on one side of an insulating layer (15) provided on the inside surface of the first substrate and a control capacitor electrode (2) formed on the other side of the insulating layer and covering the gap (GP) and overlapping the first and second subpixel electrodes (4.sub.1, 4.sub.2) over predetermined areas thereof. The first subpixel electrode (4.sub.1), the control capacitor electrode (2) and the second subpixel electrode (4.sub.2) constitute first, second and third liquid crystal capacitors (C.sub.LC1, C.sub.LC2, C.sub.LC3) between them and the common electrode (6) facing them. The first subpixel electrode (4.sub.1) and the control capacitor electrode (2) are coupled via a first control capacitor (C.sub.LC1), and the control capacitor electrode (2) and the second subpixel electrode (4.sub.2) are coupled via a second control capacitor (C.sub.LC2). The drain electrode of the thin film transistor is connected directly to the first subpixel electrode.

Gray scale LCD control capacitors formed between a control capacitor

Liquid crystal is encapsulated between two transparent substrates 16, 17. Pixel electrodes 13 are formed on the inner surface of the transparent substrate 17 in the form of a matrix while a common electrode 12 is formed on the inner surface of the transparent substrate 16. Each pixel electrode 13 is divided into subpixel electrodes 13.sub.1, 13.sub.2. The subpixel electrode 13.sub.1 is connected to the drain of a thin film transistor 21 formed adjacent the subpixel electrode to apply driving voltage to the electrode. The subpixel electrode 13.sub.2 is supplied with capacitance-divided driving voltage through a capacitor comprising the electrode 13.sub.1, and a control capacitor 15 connected thereto with an insulation layer 14 interposed therebetween. Each of the subpixel electrodes 13.sub.1, 13.sub.2 are divided into two domains on which are formed alignment layers 41a, 41b, 42a, 42b, in opposition to alignment layers 43a, 43b, 44a, 44b formed on the common electrode 12. One of the opposed alignment layers is adapted to impart to the liquid crystal a pretilt angle greater than the other alignment layer. One of a pair of adjacent orientating films in the same plane is adapted to impart to the liquid crystal a pretilt angle greater than the other orientating film.

Gray scale multi domain liquid crystal display panel having capacitive

Each pixel electrode of a liquid crystal display device is divided into a plurality of subpixel electrodes, which are separated by a gap from each other, and a control capacitor electrode is provided opposite at least one of the subpixel electrodes through a first insulating film. The control capacitor electrode has a region extending the entire length of the gap so that a drive voltage can be applied to liquid crystal in the gap. The control capacitor electrode forms a control capacitor connected in series with a liquid crystal capacitor formed by the above-said at least one subpixel electrode between it and a common electrode corresponding thereto. An additional capacitor electrode, which is opposite the said at least one subpixel electrode through a second insulating film, is formed, by which is formed an additional capacitor equivalently in parallel to the liquid crystal capacitor.

Liquid crystal display device with control capacitor for gray scale

A multigap liquid crystal color display having RED, GREEN and BLUE pixels with TFT activating transistors and with the pixels being constructed and arranged so that the offset voltages at the RED, GREEN and BLUE pixels induced by the gate pulses applied to the TFTs are equalized. In one embodiment, the pixel storage capacitors are customized to equalize the offset voltages. In a second embodiment, the pixel areas are adjusted so as to provide the offset voltage equalization.

Multigap liquid crystal color display with reduced image retention and

Each pixel electrode of a liquid crystal display device is divided into a plurality of subpixel electrodes, which are separated by a gap from each other, and a control capacitor electrode is provided opposite at least one of the subpixel electrodes through a first insulating film. The control capacitor electrode has a region extending the entire length of the gap so that a drive voltage can be applied to liquid crystal in the gap. The control capacitor electrode forms a control capacitor connected in series with a liquid crystal capacitor formed by the at least one subpixel electrode between it and a common electrode corresponding thereto. An additional capacitor electrode, which is opposite the at least one subpixel electrode through a second insulating film, is formed, by which is formed an additional capacitor equivalently in parallel to the liquid crystal capacitor.

Liquid crystal display device with control capacitors for gray scale

Each pixel electrode of a liquid crystal display device is divided into a plurality of subpixel electrodes, which are separated by a gap from each other, and a control capacitor electrode is provided opposite at least one of the subpixel electrodes through a first insulating film. The control capacitor electrode has a region extending the entire length of the gap so that a drive voltage can be applied to liquid crystal in the gap. The control capacitor electrode forms a control capacitor connected in series with a liquid crystal capacitor formed by the above-mentioned least one subpixel electrode between it and a common electrode corresponding thereto. An additional capacitor electrode, which is opposite the at least one subpixel electrode through a second insulating film, is formed, by which is formed an additional capacitor equivalently in parallel to the liquid crystal capacitor.

Liquid crystal display device with control capacitors for gray-scale

On the inside surface of one of a pair of opposed transparent substrates forming an active liquid crystal substrate there are formed first and second insulating layers. Between the insulating layers there are provided transparent pixel electrodes arranged in a matrix form and source lines corresponding to respective columns of the pixel electrodes. A short-circuit metal layer is formed on the substrate, the opposite ends of the metal layer underlying a marginal portion of each pixel electrode and the source line adjacent thereto, respectively, but separated therefrom by the first insulating layer. In these overlapping regions welding metal pads are formed on the pixel electrode and the source line. Other welding metal pads of a ductile metal are formed on the second insulating layer right above the first-mentioned welding metal pads, respectively. In the case of a white-defect pixel, laser beams are applied to the two overlapping regions to destroy the first and second insulating layers and fuse metals of three layers together, by which the pixel electrode of the defective pixel is short-circuited to the corresponding source line.

Active liquid crystal display panel having a short-circuit metal layer

In an active matrix structure for liquid crystal display elements which includes pixel electrodes arranged in a matrix form on a glass base plate, thin film transistors having their drains connected to the pixel electrodes, respectively, data lines each connected to sources of the thin film transistors of one column and gate lines connected to gates of the thin film transistors of one row, there are provided in the same plane a light blocking layer disposed opposite each of the thin film transistors across an insulating layer, a storage capacitance electrode disposed partly opposite each of the pixel electrodes across the insulating layer and storage capacitance lines for interconnecting the capacitance electrodes. The light blocking layers, the storage capacitance electrodes and the storage capacitance lines are formed of the same material and at the same time.

Active matrix structure for liquid crystal display elements wherein each

In an active liquid crystal display element which operates in a normally white mode, there is formed a shorting metal layer which overlaps each pixel electrode and a source bus adjacent thereto. In those portions of the pixel electrode and the source bus overlapping the shorting metal layer there are formed weld metal layers. The pixel electrode of a defective pixel is connected to the corresponding source bus by welding the weld metal layers and the shorting metal layer through irradiation with laser beams to the above-mentioned overlapping portions. As a result of this, the defective pixel becomes a black defect when the liquid crystal display element operates.

Liquid crystal display element and method for treating defective pixels

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

In an active matrix liquid crystal display device an internal short circuiting bus is formed across source and gate buses outside of a display region where thin film transistors and pixel electrodes are respectively arranged in a matrix form and inside of arrays of source and gate bus terminals. At intersections of the internal short circuiting bus with the source bus and the gate bus coupling elements of a high resistance material are provided for connecting the internal short circuiting bus to the source bus and the gate bus, respectively.

Active matrix liquid crystal display device having improved

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.

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Miki, Japan

Tomihisa Sunata