Liquid crystal cells – elements and systems – Particular structure – Having significant detail of cell structure only
Reexamination Certificate
2002-11-06
2004-01-20
Ton, Toan (Department: 2871)
Liquid crystal cells, elements and systems
Particular structure
Having significant detail of cell structure only
C349S106000, C349S151000, C349S153000, C349S158000
Reexamination Certificate
active
06680764
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to an integrated liquid crystal display apparatus having a function of an image sensor, and particularly it relates to the constitution of an image sensor part.
BACKGROUND OF THE INVENTION
A liquid crystal panel, in which a liquid crystal is oriented by applying a voltage to a liquid crystal layer from pixel electrodes, to form an image on a display part, has been known.
A constitution of a conventional liquid crystal panel is briefly described below.
An element substrate comprises an insulating substrate having thereon a display part comprising thin film transistors and a peripheral circuit. The element substrate and a counter substrate are adhered by a sealing material with ensuring a gap between the substrates by a spacer. A liquid crystal is contained between the element substrate and the counter substrate.
The liquid crystal is sandwiched by the pair of substrates and surrounded by the sealing part.
As shown in
FIG. 2
, the sealing part of the panel is arranged to surround the display part or the display part and the peripheral driver circuit.
In the conventional constitution, the element substrate means a substrate in which an active matrix circuit and the peripheral circuit are provided. The counter substrate arranged as facing the element substrate, in which a counter electrode and a color filter are provided.
In the conventional constitution, a resin for sealing having an ultraviolet setting property or a thermosetting property is used as the sealing material.
An image sensor, on the other hand, has been widely used as an optical sensor converting an image to an electric signal in a copying machine, a digital still camera, a video camera and a facsimile machine.
Recently, a miniature system for incorporating an image and displaying the image is demanded. As a constitution meeting such a demand, a liquid crystal display device with which a sensor module such as a CCD is integrated is considered, but there are problems in consumption power (about 5 W), production cost and size.
The inventors of the invention intend to produce a liquid crystal panel and an image sensor on one substrate by using a MOS thin film transistor.
By using such a constitution, the apparatus can be miniaturized and of a low consumption power (about 50 mW) and low cost.
In the case where a liquid crystal panel and an image sensor are produced on one substrate, the arrangement of the panel and the image sensor and the constitution of the seal become important issue.
An object of the invention is to provide a liquid crystal display panel having a display part and an image sensor on one substrate, which has high reliability and an image sensor of low cost.
SUMMARY OF THE INVENTION
The structure of the liquid crystal panel shown in
FIG. 1B
corresponds to those shown in
FIGS. 4A and 4B
.
The invention relates to, as a first aspect, a liquid crystal display apparatus comprising a liquid crystal display part comprising an active matrix circuit, a peripheral driver circuit for driving the active matrix circuit, and a sensor part, integrated on one substrate, wherein the sensor part
120
has a sealed space
307
sealed by a sealing part
104
and a counter substrate
302
. By employing such a constitution, the sealed space is completely shielded from an external atmosphere by the substrates and the sealing part, as shown in
FIGS. 8A and 8B
.
Furthermore, the counter substrate may be adhered in an inert gas atmosphere to fill the sealed space with an inert gas (such as Ar and N
2
), so as to prevent deterioration of the sensor part due to a reaction with oxygen contained in the air.
By sealing the sensor part with the sealing part and the counter substrate, an effect is obtained in that inclusion of the liquid crystal and dusts into the sensor part and a damage such as a flaw of the sensor part occurring on an injection step of the liquid crystal can be prevented.
The invention relates to, as a second aspect shown in
FIG. 1A
, a liquid crystal display apparatus comprising a liquid crystal display part comprising an active matrix circuit, a peripheral driver circuit
111
for driving the active matrix circuit, and a sensor part
120
, integrated on one substrate,
wherein the sensor part
120
is surrounded by at least one sealing part
104
, and
a sealing part
103
provided between the liquid crystal display part and the sensor part seals the liquid crystal and protects the sensor part.
By employing such a constitution, inclusion of the liquid crystal and dusts, generation of static charge, and an external impact can be prevented in the sensor part after the adhering step.
Alternatively, as shown in
FIGS. 1B
,
4
A and
4
B, the sensor part may be doubly surrounded by plural sealing parts. The outer sealing part functions as a dummy seal. By employing such a constitution, the sensor part
120
can be further prevented from dusts, static charge and external pressures, and the distance between the substrates can be sufficiently maintained. The sensor part may further be surrounded by plural sealing parts in three times, four times or more, or plural sealing parts may be arranged as a dummy seal outside the sealing part of the sensor part.
The invention relates to, as a third aspect, a liquid crystal display apparatus comprising a liquid crystal display part comprising an active matrix circuit, a peripheral driver circuit for driving the active matrix circuit, and a sensor part, integrated on one substrate, wherein a spacer
306
is not present in the sensor part. When the number of the spacers in the sensor part is larger than that in the liquid crystal part, they becomes obstacles upon incorporating an image. Thus, as shown in
FIG. 4B
, it is preferred that no spacer is present between a receptor of the sensor part and the counter substrate. By employing such a constitution, an image can be incorporated with good quality while uniformly maintaining the distance between the substrates.
Since the sensor part is an element that reacts against external heat, it is preferred that the sensor part is arranged with a sufficient distance to a heat generating circuit such as the peripheral driver circuit, i.e., at a position that is less affected by heat.
By employing such a constitution, the sensor part can be protected from external electrical influence, thermal influence and other physical influence.
In the image sensor of the invention, as shown in
FIG. 3A
, photo carriers are generated by an amorphous silicon layer
352
having a large light absorption coefficient to visible lights, and the readout of the signals is controlled with a polycrystalline silicon TFT having a large mobility as a switching element.
In the invention, an image sensor formed by the thin film technique and the thin film transistors constituting the display part are formed on one substrate, and an apparatus is obtained at low cost.
The display apparatus of direct vision type containing an image sensor is becoming large scale in future. The substrate is also becoming large scale due to a multi-panels substrate for reducing the production cost.
On the other hand, the sensor part, which is demanded to have a large number of pixels and a miniaturized optical system, is being miniaturized to have a reduced pixel area, and therefore the difference in pixel area between the sensor part and the display part becomes large.
The invention relates to, as a fourth aspect, a liquid crystal display apparatus comprising a liquid crystal display part comprising an active matrix circuit, a peripheral driver circuit for driving the active matrix circuit, and a sensor part, integrated on one substrate, wherein a color filter formed on a counter substrate of the sensor part has a cell size that is smaller than that formed on a counter substrate of the display part.
By employing such a constitution, a liquid crystal display panel can be obtained at low cost, in which the sensor part that has a small pixel area and can incorporate an image with good quality is formed on the same substrate as the liquid
Sakakura Masayuki
Zhang Hongyong
Cook Alex McFarron Manzo Cummings & Mehler, Ltd.
Duong Tai
Semiconductor Energy Laboratory Co,. Ltd.
Ton Toan
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