Liquid crystal cells – elements and systems – Particular structure – Having significant detail of cell structure only
Reexamination Certificate
2001-11-16
2004-06-15
Chowdhury, Tarifur R. (Department: 2871)
Liquid crystal cells, elements and systems
Particular structure
Having significant detail of cell structure only
C349S155000, C349S149000, C349S190000
Reexamination Certificate
active
06750937
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to an electro-optical device, such as a liquid crystal device, and a method for manufacturing the electro-optical device, in which an electro-optical substance is sandwiched by a pair of first and second substrates bonded to each other with a sealing material at the periphery of an image display region, and the first and second substrates are provided with a pair of electrodes, respectively, disposed on the faces of the first and second substrates, each opposing the electro-optical substance.
2. Description of Related Art
Currently, an electro-optical device generally includes pixel electrodes, thin-film transistors (TFTs) for switching the pixel electrodes, a TFT-arrayed substrate which is provided with wirings, such as data lines and scan lines connected to the TFTs, for supplying image signals and scan signals, respectively, and an opposing substrate opposing a surface of the TFT-arrayed substrate provided with the wirings and the like. The opposing substrate being provided with an opposing electrode on the entire surface of the opposing substrate, other than color filters, light-shielding films, and the like.
The TFT-arrayed substrate and the opposing substrate are bonded to each other by a sealing material at a sealing region disposed around an image display region. An electro-optical substance such as liquid crystal is sandwiched by the substrates. An electrically conductive vertically-conducting material is sandwiched by the substrates at vertically conducting regions (that is, vertically conductive pads or regions at corners of the opposing substrate) provided on the respective substrates at the outside of the sealing region. A wire provided on the TFT-arrayed substrate for applying potential to an opposing electrode either to be constant or to invert at a given frequency is electrically connected to the opposing electrode via the vertically conducting material. Display is performed by driving the electro-optical substance (for example, by changes of the orientation of the liquid crystal) at a part thereof associated with each pixel electrode corresponding to a pixel by generating driving voltage between the corresponding pixel electrode and the opposing electrode.
Technologies are disclosed in, for example, Japanese Unexamined Patent Application Publication Nos. 62-89024, 11-64874, and 11-202366, in which a sealing material is provided in a sealing region which encloses a liquid crystal layer and is disposed along the four sides of a substrate and a vertically conducting material is provided in vertically conducting regions at the four comers of the substrate. Although the sealing material generally includes a non-conductive photo-curing resin or the like and the vertically conducting material includes a conductive material, the sealing material used in the sealing region and the vertically conducting material used in the vertically conductive regions include a conductive material of the same type in the technology disclosed in above Japanese Unexamined Patent Application Publication No. 62-89024. Therefore, the sealing material and the vertically conducting material can be applied in one process, whereby manufacturing processes can be simplified.
When the above electro-optical device has a large image-display region having a diagonal of, for example, approximately 20 cm or greater, bead-like or fiber-like gap-forming members for controlling a gap between substrates are spread in an electro-optical substance such as liquid crystal which is disposed in the image display region (problems do not occur because the gap-forming members are not shown as images). On the other hand, when the electro-optical device has a small image-display region having a diagonal of, for example, approximately 2 cm or smaller, the gap-forming members for controlling the gap between the substrates are generally mixed in a sealing material (so that the gap-forming members are not shown as images).
SUMMARY OF THE INVENTION
However, since the sealing material used in the technology disclosed in above Japanese Unexamined Patent Application Publication No. 62-89024 is electrically conductive, there is a drawback in that the commercialization is very difficult because short-circuiting often occurs between wirings in the sealing region. When a non-conductive sealing material is used, non-conductive gap-forming members mixed in the sealing material do not cause short-circuits between wirings even when the gap-forming members break an insulation film formed on a TFT-arrayed substrate during being bonded, and are brought into contact with the wirings. However, the gap-forming members are electrically conductive, according to the technology disclosed in the above publication, therefore, short-circuiting between the wirings occurs due to the contact of the gap-forming members.
In the technology disclosed in above Japanese Unexamined Patent Application Publication No. 11-64874, it is described that the vertically conducting material must be disposed at a given distance from an end of a substrate in order to avoid short-circuiting between upper and lower substrates. In the technology disclosed in above Japanese Unexamined Patent Application Publication No. 11-202366, wires along the periphery of an image display region to vertically conducting regions disposed at the four corners of a substrate must be provided on the substrate at the outside of the image display region in order to apply potential evenly to the entire of an opposing electrode which has a relatively high electric resistance. Therefore, according to these publications, there is a problem in that it is fundamentally difficult to reduce the sizes of the substrates or increase the size of the image display region with respect to the sizes of the substrates because the vertically conducting regions must be disposed at the outside of the sealing region.
When the size of the vertically conducting region is reduced so as to reduce the sizes of the substrates or increase the size of the image display region, vertically conductive performance becomes less reliable. When the size of the sealing region is reduced so as to reduce the sizes of the substrates or increase the size of the image display region, bonding performance and control of the gap between the substrates become less reliable.
Accordingly, it is an object of the present invention to provide an electro-optical device and a method for manufacturing an electro-optical device, in which a configuration regarding a sealing material to bond a pair of substrates to each other and a vertically conducting material between the pair of substrates can be made simple, the reliability on vertical conduction can be improved, and the sizes of the substrates can be reduced or the size of an image display region can be increased with respect to the sizes of the substrates.
To these ends, according to an aspect of the present invention, an electro-optical device can include an electro-optical substance sandwiched by a pair of a first substrate and a second substrate, a sealing material disposed between the first substrate and the second substrate for bonding the first substrate and the second substrate to each other at a sealing region along the peripheries, in plan view, of the first substrate and the second substrate, and a plurality of pixel electrodes disposed on the first substrate and in an image display region which is enclosed, in plan view, by the sealing region. The electro-optical device can further include wires provided on the first substrate and extending from the inside of the image display region to the outside of the sealing region, a vertically conducting pad disposed in the sealing region, and an opposing electrode provided on the second substrate and opposing the pixel electrodes, the opposing electrode including a vertical conductor section which opposes the vertically conducting pad. At least one part of the sealing material, which is disposed between the vertically conducting pad and the vertical conductor
Ishii Kenya
Karasawa Kazuki
Chowdhury Tarifur R.
Oliff & Berridg,e PLC
Seiko Epson Corporation
LandOfFree
Electro-optical device, method for manufacturing the same,... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Electro-optical device, method for manufacturing the same,..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electro-optical device, method for manufacturing the same,... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3333761