Liquid crystal cells – elements and systems – Particular structure – Holder – support – frame – or housing
Reissue Patent
2001-08-14
2004-05-18
Ngo, Julie (Department: 2871)
Liquid crystal cells, elements and systems
Particular structure
Holder, support, frame, or housing
C349S059000, C349S060000, C349S149000, C349S158000, C349S070000, C349S062000
Reissue Patent
active
RE038516
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of Industrial Application
The present invention relates to a liquid crystal display device comprising a back light including a liquid crystal display panel having a liquid crystal sealed between two superposed insulating substrates, a light guide plate arranged below the liquid crystal display panel, and a fluorescent tube arranged in the vicinity of the side of the light guide plate, and, more particularly, to a data processing device having said liquid crystal display device assembled as a display unit.
2. Prior Art
In a liquid crystal display device of active matrix type, nonlinear devices (e.g., switching devices) are disposed in a manner to correspond to a plurality of pixel electrodes arranged in matrix, respectively. The liquid crystal in each pixel is always drive, in principle, (at a duty ratio of 1.0). In comparison with the so-called “simple matrix type” which employs a time division driving system, therefore, the active system has better contrast and has become an indispensable technique particularly in a color liquid crystal display device. A typical example of the switching devices is a thin film transistor (TFT).
The liquid crystal display device is constructed to comprise: a liquid crystal display panel (or liquid crystal display element) prepared by superposing two transparent glass substrates at a predetermined gap such that their surfaces each having display pixel electrodes of a transparent conductive film and an orientation film laminated thereon are opposed to each other, by adhering the two substrates to each other by a seal member applied in a frame shape to the edge portion between the two substrates, by filling and sealing a liquid crystal from a liquid crystal sealing entrance formed in a portion of the seal member into the seal member between the two substrates, and by mounting or adhering a polarizing plate to the outer sides of the two substrates; a circuit substrate arranged outside of the outer peripheral portion of the liquid crystal display panel; an intermediate frame molded for holding the aforementioned individual members; a metallic shield casing formed with a liquid crystal display window for accommodating those individual members; and a back light arranged below the liquid crystal display panel for supplying a light to the liquid crystal display panel.
Here, the liquid crystal display device of active matrix type using the thin film transistors is known in Japanese Patent Laid-Open No. 309921/1988 or on pp. 193 to 210 of Nikkei Electronics entitled “Active Matrix Type Color Liquid Crystal Display of 12.5 Type Adopting Redundant Construction” and issued on Dec. 15, 1986 NIKKEI McGRAW-HILL for example.
SUMMARY OF THE INVENTION
Problems to Be Solved by the Invention
The liquid crystal display device of the prior art is constructed such that vide signal lines are alternately extracted to the two opposed longer sides of the liquid crystal display panel and such that video signal line driving circuit substrates are individually arranged outside of the longer sides. As a result, the periphery of the display unit, i.e., the so-called “frame portion” cannot have its area reduced to raise a problem in which the liquid crystal display device or a data processing device such as a personal computer or word processor having the liquid crystal display device assembled therein as the display unit has its external size enlarged to have a heavy weight.
A first target the present invention is to solve the above-specified problem.
In the liquid crystal display device, on the other hand, in order that the liquid crystal display panel having the liquid crystal sealed between the two superposed transparent glass substrates may be fixed in that device, both the two transparent substrates are pushed through rubber cushions. As a result, the two transparent glass substrates are so severely pushed that the gap of the liquid crystal between the two transparent glass substrates is changed to raise a problem of a display unevenness. As a result, the liquid crystal display panel cannot be so firmly held that a sufficient mechanical strength cannot be retained.
A second target the present invention is to solve the above-specified problem.
In the liquid crystal display device of the prior art having the back light composed of a fluorescent tube and a light guide plate, on the other hand, a sufficient consideration has not been taken into the place for arranging the fluorescent tube or the like so that said device is not sufficiently small-sized and light-weighted yet. In accordance with the development of recent years in the computerized society, it is desired that the data processing device such as a personal computer or word processor be progressed to a portable one having the size of a notebook, and that the liquid crystal display device assembled as the display unit and mainly determining the shape, size and weight of the data processing device be small-sized and light-weighted.
A third target the present invention is to solve the above-specified problem.
In the prior art, on the other hand, in order that the light guide plate of the back light and the liquid crystal display panel may be firmly held in said device, there arises a problem that the device has its external size enlarged.
A fourth target the present invention is to solve the above-specified problem.
In the prior art, on the other hand, when two lamp cables, with which are individually connected the one-side ends of the fluorescent tube constituting the back light, are to be extracted in one direction, there is no space for threading the lamp cables to allow these cables to bulging out of the liquid crystal display device. Thus, a large space for accommodating the lamp cables to make it difficult to reduce the size and weight of the device. On the other hand, the rubber bushes of the prior art for holding the fluorescent tube are active to hold only the fluorescent tube.
A fifth target the present invention is to solve the above-specified problem.
On the other hand, the light guide plate of the back light of the prior art has many spare areas for holding the light guide plate in said device so that it is made far larger than an effective light emitting portion. As a result, there is a problem that the device is large-sized and heavy-weighted.
A sixth target the present invention is to solve the above-specified problem.
In the prior art, on the other hand, after the liquid crystal display device has been assembled, there is a problem that the monolithic mold casing (or frame body) has its bottom face caused to bulge by the downward force which is exerted upon the bottom face by the weight of the liquid crystal display panel, the light guide plane and so on. In order to suppress this bulge, the mold casing has to be thickened to disable the liquid crystal display device to be thinned and light-weighted.
A seventh target the present invention is to solve the above-specified problem.
In the liquid crystal display device of the prior art, on the other hand, the cables of the fluorescent tube of the back light extend along the outer side of said device so that said cables and an inverter to be connected wit the leading ends of the former bulge out of the device. Thus, there arises a problem that the external size is substantially enlarged.
An eighth target the present invention is to solve the above-specified problem.
In recent years, on the other hand, the liquid crystal display device of active matrix type using thin film transistors as its switching elements is demanded to have the multi-gradation and the single power source so that its performance and facility may be improved. However, the circuit for realizing those demands consumes much power. If, moreover, the circuit means is packaged in compact, the highly dense packaging results to raise a problem in the hear liberation in the parts packaged on the circuit substrate.
A ninth target the present invention is to solve the above-specified problem.
On the other hand, in case the number of electronic parts constituting
Hasegawa Kaoru
Imajo Yoshihiro
Kobayashi Naoto
Kondo Hironori
Suzuki Masahiko
Antonelli Terry Stout & Kraus LLP
Ngo Julie
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