Computer graphics processing and selective visual display system – Plural physical display element control system – Display elements arranged in matrix
Reexamination Certificate
1998-07-21
2001-05-29
Shalwala, Bipin (Department: 2673)
Computer graphics processing and selective visual display system
Plural physical display element control system
Display elements arranged in matrix
C359S227000
Reexamination Certificate
active
06239777
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to a display device for displaying an image or the like by use of electrostatic force.
At present, a large-scale image display device has received much attention.
FIG. 1
shows various types of conventional large-scale display devices for comparison. In
FIG. 1
, the expandability indicates whether or not a large screen can be easily formed by combining small displays.
Next, individual displays are explained. A CRT (Cathode Ray Tube) is a most widely used display device, but it is technically difficult to form a thin type and large display device of 40 inches or more. Further, since a large display device becomes relatively heavy, it becomes difficult to handle. Further, there is provided a display technique for combining small CRTs, but it is difficult to completely eliminate the boundary lines.
A PDP (Plasma Display Panel) has received much attention as a thin type display of 40-inch size, but it has problems that the maximum luminance thereof is lower than that of the CRT, the power consumption is large and the manufacturing cost is high and hard to be even 70 U.S. dollars for one inch. Further, when a display of larger size is formed, the manufacturing cost will be at least doubled. This is because the manufacturing line is constructed in accordance with the display size which will become most popularized. When a display of 40 inches or more is formed by combining small displays, the boundary lines become noticeable since the PDP is of a low-pressure gas-filed type and the peripheral wall cannot be made small.
A PALC (Plasma Addressing Liquid Crystal) is a combination of a liquid crystal cell and plasma generation electrodes. That is, a plasma generation cell is formed separately from the liquid crystal cell and the two cells are stacked together. The plasma cell has a function of selecting one or some of the pixels in the liquid crystal cell to which the potential is applied. It is said that the display of a large area can be attained at a low cost in comparison with the selecting system using the conventional TFTs (Thin Film Transistors). However, in this type of display, since the manufacturing line is constructed in accordance with a specified size (for example, 40 inches) as in the case of PDP, the manufacturing cost is abruptly raised if the display size is increased. Further, like the PDP, the boundary lines become noticeable when it is formed by combining small displays.
In the case of LCD (Liquid Crystal Display), the maximum size thereof is 20 inches at present and is 30 inches even if the combination technique is used. Further, the manufacturing cost will be made high if it is made large since TFTs are used.
An FED (Field Emission Display) is a system in which fine cold cathodes for emitting electrons are arranged on a silicon substrate or glass substrate and electrons emitted from the cold cathodes are applied to a fluorescent material for display. It is said that the maximum luminance which is almost equal to that of the CRT can be attained in this system, but it is difficult to uniformly form the cold cathodes on the large substrate and it is difficult to form a large screen display.
An LED (Light Emitting Diode) display is a large display formed by arranging a large number of light emitting diodes. It is most widely used as a large and thin type display of 40 inches or more. However, the power consumption is large and the manufacturing cost is high. Further, since the light emitting diodes are used, the maximum luminance is not so high.
That is, in the conventional large and thin type display, a display which has high expandability and which can be formed at a low cost is not present.
Further, a movable film type display device in which an electric field is applied to a conductive plastic foil or metal foil to move the same as a shutter for display is provided (Jpn. Pat. Appln. KOKAI Publication No. 1-72195, Jpn. Pat. Appln. KOKAI Publication No. 1-72196, Jpn. Pat. Appln. KOKAI Publication No. 1-108598 and Jpn. Pat. Appln. KOKAI Publication No. 4-12391).
In the above display device, a light source such as an LED or electric lamp is inserted into a cylinder whose surface is coated with a transparent electrode and a conductive movable film is set to cover and conceal the cylinder. Then, a potential difference is applied between the cylinder and the movable film to displace the movable film so as to change the amount of light emitted from the cylinder.
It is considered that a thin type display device of low cost can be formed by use of the above display method. However, a concrete method for constructing a large display by use of the movable film type display device has not been provided.
BRIEF SUMMARY OF THE INVENTION
An object of this invention is to provide a display device which can attain large screen display by use of a movable film type display device and can be manufactured at a low cost.
In order to attain the above object, a display device according to a first aspect of this invention comprises a light guiding fixed electrode portion formed of a transparent material for guiding light incident from an exterior to a surface portion having a transparent conductive layer and then emitting the light; a flexible conductive light shielding plate arranged to face the transparent conductive layer of the light guiding fixed electrode portion and having one end fixed to pass the emitted light therethrough; and electrostatic force generating means for applying a potential difference between the conductive light shielding plate and the transparent conductive layer to generate electrostatic force between the transparent conductive layer and the conductive light shielding plate; wherein the conductive light shielding plate is displaced according to the electrostatic force with one end set as an axis to shield the surface portion of the light guiding fixed electrode portion when the potential difference is applied between the conductive light shielding plate and the transparent conductive layer.
The conductive light shielding plate includes a plurality of conductive light shielding plates arranged in rows and columns, the light guiding fixed electrode portion includes a plurality of light guiding fixed electrode portions respectively having a plurality of transparent conductive layers formed by arranging the transparent conductive layer in rows and columns, and the electrostatic force generating means can include means for applying an independent potential difference between each of the plurality of conductive light shielding plates and a corresponding one of the plurality of transparent conductive layers.
It is preferable to integrally form the plurality of light guiding fixed electrode portions arranged on the same row.
It is preferable to electrically connect the plurality of transparent conductive layers of the plurality of transparent light guiding fixed electrode portions arranged on the same row.
It is preferable that the surface portion of the transparent light guiding fixed electrode portion is curved.
It is preferable to form a light shielding frame on a periphery of the transparent conductive layer of the light guiding fixed electrode portion.
According to the display device of the first aspect of this invention, the conductive light shielding plate is displaced with the supporting point set as an axis by the electrostatic force caused when the potential difference is applied between the conductive light shielding plate and the transparent conductive layer. The area of the transparent conductive layer which is covered with the conductive light shielding plate varies according to the displacement amount of the conductive light shielding plate. Therefore, the amount of light emitted from the transparent conductive layer is changed and desired gray scale display can be attained by controlling the area of the transparent conductive layer which is covered with the conductive light shielding plate, that is, controlling the electrostatic force acting between the conductive light shielding plate and the transpar
Okumura Haruhiko
Sugahara Atsushi
Sunohara Kazuyuki
Finnegan Henderson Farabow Garrett & Dunner L.L.P.
Kabushiki Kaisha Toshiba
Piziali Jeff
Shalwala Bipin
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