Liquid crystal cells – elements and systems – Particular structure – Having significant detail of cell structure only
Reexamination Certificate
2001-12-27
2004-08-10
Nguyen, Dung T. (Department: 2871)
Liquid crystal cells, elements and systems
Particular structure
Having significant detail of cell structure only
C349S063000
Reexamination Certificate
active
06774964
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is related to a reflection type display apparatus for displaying characters and the like by reflecting light entered from a front surface thereof and then controlling this reflection light by every pixel, and also related to a method of manufacturing such a reflection type display apparatus, and an electronic appliance using this reflection type display apparatus.
2. Description of the Related Art
Display apparatus such as liquid crystal display apparatus are mainly subdivided into transmission type display apparatus and reflection type display apparatus. As to a transmission type liquid crystal display apparatus, since a liquid crystal display panel is illuminated by a back light mounted on a rear surface thereof, a display screen becomes bright. However, since the back light must be continuously turned ON while the transmission type liquid crystal display apparatus is used, high power consumption thereof is required. As a result, reflection type liquid crystal display apparatus are preferably employed in portable appliances using batteries, for example, portable telephones.
In a reflection type liquid display apparatus, while a reflection plane is provided on a rear surface of a liquid crystal layer, since a display screen of this reflection type liquid crystal apparatus is illuminated, or lightened in such a manner that external light (namely, light such as directly-entered sunlight and lightening light, which is entered from peripheral portion) which is entered into the display screen of this display apparatus is reflected on the reflection plane under bright peripheral environment, power consumption thereof may be suppressed. Such reflection type liquid crystal display apparatus are further subdivided into a semi-transmission type liquid crystal display apparatus and a full (total) reflection type liquid crystal display apparatus.
A semi-transmission type reflection-mode liquid crystal display apparatus is arranged in such a manner that a large number of very small windows are opened in a reflection plane, and a back light is arranged behind the reflection plane. When the back light is turned ON, since a display screen is lightened by light of the back light, which has passed through very small windows (through holes), a display content of this semi-transmission type reflection-mode liquid crystal display apparatus may be recognized even in a dark place. However, since a large number of windows are opened in the reflection plane in such a semi-transmission type reflection mode liquid crystal display apparatus, an optical reflection efficiency (reflectance factor) at this reflection plane is lowered. As a result, when the semi-transmission type reflection-mode liquid crystal display apparatus is used under external light, there is such a problem that the display screen becomes dark.
In contrast to the above-described semi-transmission type reflection-mode liquid crystal display apparatus, a full reflection type liquid crystal display apparatus is arranged as follows. That is, while a forward lightening (illumination) apparatus is provided on a front surface of a liquid crystal display panel, a display screen of this liquid crystal display panel may be lightened by the forward lightening apparatus from the front surface under such a condition that a peripheral area around this full reflection type liquid crystal display apparatus becomes dark and thus, a display content of the display screen can be hardly observed. As a consequence, since such a large number of windows formed in the semi-transmission type liquid crystal display apparatus are no longer formed in a reflection plane of this full reflection type liquid crystal display apparatus, a light reflection efficiency at this reflection plane is not lowered. Even in such a case that the display screen of this full reflection-type liquid crystal display apparatus is illuminated by external light, the bright display screen may be obtained. In particular, this full reflection type liquid crystal display apparatus may be strongly expected to be employed in portable electronic appliances.
FIG. 1
is a sectional view for schematically indicating a structure of one conventional full (total) reflection type liquid crystal display apparatus
1
. This full reflection type liquid crystal display apparatus
1
is arranged in such a manner that a forward lightening apparatus
3
is positioned on a front surface of a reflection type liquid crystal display panel
2
. This reflection type liquid crystal display panel
2
is constituted by that a liquid crystal material
7
is sandwiched to be sealed between a board
4
and a glass board
6
. A reflection plane
5
is formed on a surface of this board
4
. In this liquid crystal display panel
2
, such a constructual means is provided with each of pixels, by which incident light of this reflection type liquid crystal panel
2
may be reflected by the reflection plane
5
so as to be projected to a forward direction, and incident light may be absorbed not to be projected to the forward direction. The forward lightening apparatus
3
is constructed in such a manner that a light source unit
9
constituted by a cold cathode tube and the like is provided on a side surface of a transparent light conducting plate
8
. It should be understood that light is represented by an arrow in this drawing, and will be similarly denoted in other drawings.
Thus, in accordance with such a full reflection type liquid crystal display apparatus
1
, the forward lightening apparatus
3
is turned OFF in the case that a peripheral area of this full reflection type liquid crystal display apparatus
1
becomes bright. At this time, such external light is reflected on the reflection plane
5
, and thereafter, this reflected external light is projected from the front surface of the full reflection type liquid crystal display apparatus
1
, and then, this projected light is entered into eyes of a viewer. The external light corresponds to directly-entered sunlight, illumination (lightening) light, and the like, which pass through the forward lightening apparatus
3
and then, are entered into the liquid crystal display panel
2
. On the other hand, when a peripheral area of this full reflection type liquid crystal display apparatus
1
becomes dark, the forward lightening apparatus
3
is turned ON. At this time, light projected from the light source unit
9
is entered from a side surface of the light conducting plate
8
into an internal portion of this light conducting plate
8
. Then, while this entered light is fully-reflected between the front surface and the rear surface of the light conducting plate
8
in a repetition manner, this light is propagated within the light conducting plate
8
. While the light is propagated inside the light conducting plate
8
in a half way, the propagation path of this light is bent by an optical pattern
10
which is provided on this light conducting plate
8
. Then, such light which is entered into the rear surface of the light conducting plate
8
at a smaller incident angle then a critical angle of a total reflection of this light conducting plate
8
is projected from this rear surface of the light conducting plate
8
and then, is entered into the liquid crystal display panel
2
. After this incident light is reflected from the reflection plane
5
, the reflected light is projected from the front surface of the full reflection type liquid crystal display apparatus
1
, and then, is entered into the eyes of the viewer.
While a concave/convex-shaped diffusion pattern is formed on the reflection plane
5
, a directivity angle of reflection light may be expanded by this diffusion pattern, so that a visible range of a displayed image may be widened. Also, considering use conditions of such a full reflection type liquid crystal display apparatus
1
, since there are many cases that both the external light and the viewers are positioned along a direction substantially perpendicular to the full reflection
Aoyama Shigeru
Funamoto Akihiro
Ikeda Masaaki
Matsushita Motohiko
Shinohara Masayuki
Duong Thoi V.
Nguyen Dung T.
Omron Corporation
Osha & May L.L.P.
LandOfFree
Reflection type display apparatus, reflection type display... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Reflection type display apparatus, reflection type display..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Reflection type display apparatus, reflection type display... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3348474