Liquid crystal cells – elements and systems – Particular structure – Having significant detail of cell structure only
Reexamination Certificate
2000-03-23
2001-06-19
Sikes, William L. (Department: 2871)
Liquid crystal cells, elements and systems
Particular structure
Having significant detail of cell structure only
C257S072000
Reexamination Certificate
active
06249333
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an active matrix liquid crystal display panel which is integral with peripheral driver circuits, as well as to various apparatuses using such a panel.
2. Description of the Related Art
An active matrix liquid crystal display panel is known in which an active matrix circuit and peripheral driver circuits for driving it are integrated on a glass substrate or a quartz substrate. In such an active matrix liquid crystal display panel, various measures have been taken to minimize the area of portions unnecessary for display, i.e., the area occupied by the peripheral driver circuits.
On the other hand, in the liquid crystal display panel, a sealing member is provided in a peripheral portion to hold, i.e., confine a liquid crystal between a pair of substrates. As one measure to minimize the ares of portions unnecessary for display, it is now required to reduce the area occupied by the sealing member.
The active matrix liquid crystal display panel which is integral with the peripheral driver circuits has a problem that failures likely occur in the peripheral driver circuits. This tendency is more remarkable in a configuration in which part of the sealing member is disposed above the peripheral driver circuits.
This problem occurs in the following manner. The sealing member contains a kind of spacer called a filler to maintain the gap between the substrates. In general, the peripheral driver circuits have a very high degree of integration. In these circumstances, pressure is exerted from the filler on thin-film transistors and a wiring of the peripheral driver circuits which are located right under the filler (the pressure is estimated to be very strong locally), so that a line disconnection, a contact failure, and even a disconnection of a semiconductor layer are likely to occur.
Although spherical substrate gap holding means called spacers are also used in the active matrix area, the occurrence of failures in the active matrix area due to the existence of the spacers is not so serious as in the peripheral driver circuits, because the degree of integration is low in the active matrix area.
SUMMARY OF THE INVENTION
An object of the present invention is to minimize the area of portions other than a pixel matrix circuit in an active matrix liquid crystal display panel which is integral with peripheral driver circuits.
Another object of the invention is to prevent destruction of a peripheral driver circuit due to pressure exerted from a sealing member even in the active matrix liquid crystal display panel that attains the above object.
According to a first aspect of the invention, as shown in
FIGS. 1A
to
1
D and
2
in the form of a specific manufacturing process, there is provided a liquid crystal display panel comprising an active matrix circuit (pixel circuit); a peripheral driver circuit, the active matrix circuit and the peripheral driver circuit being integrated on the same substrate
101
; a sealing member (indicated by numeral
206
in FIG.
2
), part of the sealing member being disposed above the peripheral driver circuit; thin-film transistors formed in the peripheral driver circuit; and a protrusion (laminated spacer) formed in the peripheral driver circuit, the protrusion being a lamination of materials that constitute the thin-film transistors, the protrusion being projected (see
FIG. 1D
) from portions where the thin-film transistors are disposed.
According to a second aspect of the invention, as shown in
FIGS. 1A
to
1
D and
2
in the form of a specific manufacturing process, there is provided a liquid crystal display panel comprising an active matrix circuit (pixel circuit); a peripheral driver circuit, the active matrix circuit and the peripheral driver circuit being integrated on the same substrate
101
; a sealing member (indicated by numeral
206
in FIG.
2
), part of the sealing member being disposed above the peripheral driver circuit; thin-film transistors formed in the peripheral driver circuit; and a protrusion (laminated spacer) formed in the peripheral driver circuit in addition to the thin-film transistors, the protrusion being a lamination of materials that constitute the thin-film transistors, the protrusion being higher (see
FIG. 1D
) than portions where the thin-film transistors are disposed.
According to a third aspect of the invention, as shown in
FIGS. 1A
to
1
D and
2
in the form of a specific manufacturing process, there is provided a liquid crystal display panel coming an active matrix circuit (pixel circuit); a peripheral driver circuit, the active matrix circuit and the peripheral driver circuit being integrated on the same substrate
101
; a sealing member (indicated by numeral
206
in FIG.
2
), part of the sealing member being disposed above the peripheral driver circuit; thin-film transistors formed in the peripheral driver circuit; and a protrusion formed in the peripheral driver circuit in addition to the thin-film transistors, the protrusion being a lamination of materials that constitute the thin-film transistors, the protrusion having a function of a spacer.
According to a fourth aspect of the invention, as shown in
FIGS. 1A
to
1
D and
2
in the form of a specific manufacturing process, there is provided a liquid crystal display panel comprising an active matrix circuit (pixel circuit); a peripheral driver circuit, the active matrix circuit and the peripheral driver circuit being integrated on the same substrate
101
; a sealing member (indicated by numeral
206
in FIG.
2
), part of the sealing member being disposed above the peripheral driver circuit; thin-film transistors formed in the peripheral driver circuit; and a laminated portion (laminated spacer) formed in the peripheral driver circuit in addition to the thin-film transistors, the laminated portion having more laminated layers (see
FIG. 1D
) than portions where the thin-film transistors are disposed in the peripheral driver circuit.
As shown in
FIGS. 1A
to
1
D and
2
, the protrusion (laminated spacer) is formed by laminating all the thin films that constitute the pixel circuit and the peripheral driver circuits, the latter circuits having a high degree of integration. With this structure, pressure exerted from spacers
204
in the sealing member
206
is concentrated on the protrusion. As a result, the thin-film transistors and the wiring of the peripheral driver circuits can be prevented from being damaged.
REFERENCES:
patent: 5739549 (1998-04-01), Takemura et al.
patent: 5929948 (1999-07-01), Ohori et al.
patent: 6055034 (2000-04-01), Zhang et al.
patent: 6115097 (2000-09-01), Yamazaki
Teramoto Satoshi
Zhang Hongyong
Fish & Richardson P.C.
Nguyen Dung
Semiconductor Energy Laboratory Co,. Ltd.
Sikes William L.
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