Liquid crystal cells – elements and systems – Particular excitation of liquid crystal – Electrical excitation of liquid crystal
Patent
1997-12-17
1999-09-07
Sikes, William L.
Liquid crystal cells, elements and systems
Particular excitation of liquid crystal
Electrical excitation of liquid crystal
349 42, G02F 11333, G02F 1136
Patent
active
059495022
DESCRIPTION:
BRIEF SUMMARY
DESCRIPTION
1. Technical Field
The present invention relates to an active matrix liquid crystal display device and, more particularly, to a structure of an active matrix substrate suitable for counter-measures for static electricity.
2. Background Art
In the liquid crystal display element (i.e., the liquid crystal display module) of an active matrix liquid crystal device, for example, on the face, opposed to a liquid crystal layer, of one substrate of two transparent insulating substrates of glass opposed to each other through a liquid crystal layer, there are formed a group of gate lines juxtaposed in a direction Y and a group of drain lines juxtaposed in a direction X, extended in the direction Y and insulated from the gate lines.
These gate lines and drain lines individually define their enclosed regions as pixel regions, in which switching elements such as thin film transistors (TFT) and transparent pixel electrodes are respectively formed.
When scanning signals are fed to the gate lines, the thin film transistors are turned on to feed video signals therethrough from the drain lines to the pixel electrodes.
Not only the individual drain lines group but also the individual gate lines group are extended to the periphery of the transparent insulating substrate to constitute external terminals which are connected with video drive circuits and gate scanning drive circuits, i.e., a plurality of drive ICs (of a semiconductor integrated circuit) externally arranged in the periphery of the transparent insulating substrate. In other words, a plurality of tape carrier packages (TCP) mounted with the individual drive ICs are arranged in the periphery of the substrate.
However, since the transparent insulating substrate is equipped in its periphery with the TCP mounted with drive ICs, the circuits enlarges the area of the region (widely called the picture frame) between the contour of the display region constructed of the intersecting regions of the gate lines and the drain lines of the transparent insulating substrate, and the contour of the outer frame of the transparent insulating substrate. This enlarged area is contrary to the request that the external size of the liquid crystal display module be reduced.
In order to solve this problem, i.e., to increase the density of the liquid crystal display element and to minimize its external size, therefore, there has been proposed a structure in which no TCP part is used but video drive lCs and gate scanning drive ICs are mounted directly on the transparent insulating substrate. This mounting method is termed the flip-chip method or the chip-on glass (COG) method.
The invention can be applied not only to the mounting method using TCP parts but also to the flip-chip mounting.
However, the aforementioned structure of the liquid crystal display element of the prior art is insufficient for the counter-measures for static electricity (dielectric breakage) generated in the manufacture process till the module is completed. Specifically, the static electricity is generated at steps after the film formation by plasma CVD, and at the rubbing step after application of the alignment film because the rubbing cloth comes into contact with the substrate surface. As a defect mode, therefore, the characteristics of the thin film transistors (TFT) or the switching elements extremely weak to the static electricity become deteriorated, causing uneven display on the screen. Further the drain lines may be disconnected, or the insulating layer between the gate lines and the drain lines may be destroyed, causing short-circuit. At the substrate cutting step, moreover, static electricity is produced by the cuffing operation itself, if this operation entails mechanical contact with a diamond cutter, causing asimilar defect. At the step of applying aseal member, at the step of joining the two opposed substrates together or at the step of sealing in a liquid crystal or at the sealing step, static electricity is produced and invade the substrate on the side having the thin film transistors, causin
REFERENCES:
patent: 4807973 (1989-02-01), Kawasaki
patent: 5233448 (1993-08-01), Wu
patent: 5323254 (1994-06-01), Pitt
patent: 5652632 (1997-07-01), Shimizu
patent: 5668032 (1997-09-01), Holmberg et al.
patent: 5691787 (1997-11-01), Shimada et al.
patent: 5748179 (1998-05-01), Ito et al.
Matsunaga Kuniyuki
Ohwada Jun-ichi
Suzuki Masahiko
Tsumura Makoto
Ueda Shiro
Chowdhury Tarifur
Hitachi , Ltd.
Sikes William L.
LandOfFree
Liquid crystal device having resistor elements does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Liquid crystal device having resistor elements, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Liquid crystal device having resistor elements will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1809389