Computer graphics processing and selective visual display system – Image superposition by optical means – Operator body-mounted heads-up display
Reexamination Certificate
2001-08-17
2004-10-12
Mengistu, Amare (Department: 2673)
Computer graphics processing and selective visual display system
Image superposition by optical means
Operator body-mounted heads-up display
C345S087000, C348S051000
Reexamination Certificate
active
06803886
ABSTRACT:
The present invention relates to active matrix type light valve devices using monocrystalline semiconductor layers as an active region, stereoscopic image display devices capable of observing an image from light valve devices provided on both eyes to obtain stereoscopic vision, and image projectors composed of a light source section, the light valve device, and a projection optical system.
BACKGROUND OF THE INVENTION
Conventionally, the light valve devices of compact type image display devices used in view finders of the 8 mm video cameras are made by depositing polycrystal or amorphous silicon thin films on transparent electrically insulating substrates by vapor depositing or vapor phase epitaxy to form an individual-pixel switching element group and a X-Y electrode driving circuit group for driving such switching element group by the thin film transistors.
First, the conventional active matrix type liquid crystal display device is described referring to
FIG. 40
for its general configuration. In the image display device of this kind, one quartz glass substrate
1001
and the other glass substrate
1012
are oppositely arranged each other and a liquid crystal layer
1016
is sealed between the substrates. On a main surface of the quartz glass substrate
1001
is formed a film of a silicon polycrystal semiconductor layer
1002
P, which constitutes an active region. A pixel array section
1017
and a peripheral circuit section are integrally formed on an inside surface of the quartz glass substrate
1001
. The peripheral circuit section includes an X axis driving circuit
1006
and a Y driving circuit
1008
. Matrix driving electrodes
1005
are formed on the pixel array section
1017
as orthogonally intersecting in the X axis direction and Y axis direction, and pixel electrodes
1010
are formed on intersecting points thereof. Switching elements
1009
are arranged corresponding to individual pixel electrodes
1010
. The switching elements
1009
are composed of the thin film transistors (TFT) having the silicon polycrystal semiconductor layer
1002
P as an active region. Drain electrodes thereof are connected to the corresponding pixel electrodes
1010
, source electrodes thereof are electrically connected to the corresponding X axis matrix driving electrodes
1005
, and gate electrodes thereof are electrically connected to the corresponding Y axis matrix driving electrode
1005
. The Y axis driving circuit
1008
selectively scans the matrix driving electrodes
1005
of the Y axis direction in lineal sequence. The x axis driving circuit
1006
is electrically connected to the matrix driving electrodes
1005
of the X axis direction and feeds display signals to the pixel electrodes
1010
through the selected switching elements
1009
. A polarizer
1011
is bonded on an outer surface of the quartz glass substrate
1001
.
A common electrodes
1014
are entirely formed on an inner surface of the other glass substrate
1012
. A color filter with three original colors RGB is simultaneously formed for color display. A polarizer
1013
is bonded on outer surface of the glass substrate
1012
. The substrate
1012
on the upper side is bonded to the quartz glass substrate
1001
on the down side by seal agent
1015
. The seal agent
1015
is supplied along a seal region
1018
shown by dotted lines. The seal region
1018
is provided to embrace the pixel array section
1017
, the peripheral circuit section composed of the X driving circuit
1006
and Y driving circuit
1008
are positioned outside the seal region
1018
.
These amorphous silicon thin film and polycrystal silicon thin film are easily deposited on the glass substrate by chemical vapor phase epitaxy or like procedures, thus they are suitable for producing a an active matrix type liquid crystal display device having relatively larger display. The transistor elements formed into the amorphous silicon thin film or the polycrystal silicon thin film are generally of a field effect insulating gate type. Displays of approximately 3 inches to 10 inches are included in the active matrix type liquid crystal display devices using the amorphous silicon thin film which are commercially manufactured these days. The amorphous silicon thin film can be formed at a low temperature equal to or less than 350° C. and therefore it is suitable for a large-area liquid crystal panel. The active matrix type liquid crystal display device using the polycrystal silicon thin film is now produced which includes display of a picture size approximately 2 inches in the market.
However, the conventional active matrix type liquid crystal display device using the amorphous silicon thin film or the polycrystal silicon thin film is suitable for direct-view type display devices using relatively larger displays, however it is not always suitable for miniaturizing the devices and high density planning of the pixels. Recently, microminiature type display devices or light valve devices with a microminiature device structure and high density pixel formation are now increasingly in strong demand, other than the direct-view type display device. Such microminiature type light valve device is, for example, used as a primary image forming display of the image projector, and can be applied for the high-definition type television of the projection type. The application of the technique in producing fine semiconductors provides the microminiature type light valve device having a pixel size in the order of 10 &mgr;m and with an entire size of about several centimeters.
Some secondary problems arise in using the active matrix type liquid crystal display device as a light valve device of the projector. The drawbacks in the liquid crystal display device include damage of its light valve function due to temperature rise. In the projector, the light source intensively lights the transmission type liquid crystal display device to project the transmitted light forwardly through an enlargement optical system. Such intensive light from the light source is absorbed in the liquid crystal display device to cause temperature rise, thus if the temperature exceeds a critical point, the liquid crystal phase itself turns to be liquid and not liquid crystal any more.
The use of the active matrix type liquid crystal display device as a light valve device provides a drawback of a relatively lower brightness of the projected image. The pixel image accounts for a relatively too small ratio of space of the entire liquid crystal panel surface to provide a sufficient opening ratio. This prevents a brightness of the projecting image from increasing because of low utilization efficiency of the light. In addition, the polarizer which absorbs light is generally bonded on the liquid crystal panel, therefore the transmitted light amount decreases. Therefore, the use of the liquid crystal panel as a light valve device disadvantageously causes a lower utilization-efficiency of the light.
Conventionally, the light source is used only for lighting the light valve device, and is not intended for other utilizations. The projector requires an intensive light source capable of large amount of energy radiation, however such energy itself is almost lost uselessly. Thus, a problem arises that larger is given the projector power supply.
Using parallax of both eyes has conventionally been proposed to view stereoscopicaly image. For examples, (1) images for the left eye and right eye are separately picked up using two cameras, and projected alternatively on a monitor or a screen by switching from one image to the other, a liquid crystal shutter device is used to alternatively turn ON or OFF the left eye and the right eye in synchronization with the switching period of the projected images, thus the left eye watches the image prepared for the left eye and right eye watches the image prepared for the right eye to view stereoscopically image, and (2) image display elements are arranged separately in front of both eyes to display different images for each of the both eyes, thus a method of stereoscopic view is provided
Kondo Kenichi
Sakurai Atsushi
Takahashi Kunihiro
Takasu Hiroaki
Yamazaki Tsuneo
Adams & Wilks
Mengistu Amare
Seiko Instruments Inc.
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