JP2541756B2 - Optics and flat panel displays - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical element and a flat panel display (FPD). More specifically, the present invention relates to an optical element utilizing electrostatic attractive force and repulsive force, and a transmissive type in which the optical elements are arranged. The present invention relates to a reflection type FPD.

[0002]

2. Description of the Related Art At present, liquid crystal materials are widely used as FPDs. A liquid crystal display (LCD) is divided into a simple matrix type LCD and an active matrix type LCD depending on the operation method, and generally has a low driving voltage,
It has excellent features such as low power consumption.

As a display device utilizing electrostatic attraction and repulsion, a 7-segment display device using an electrostatic film actuator is proposed in Japanese Patent Laid-Open No. 4-240890. In Japanese Patent Application Laid-Open No. Hei 4-240890, the movable member moves back and forth on the surface of the seven-segment display device due to the action of static electricity generated between the transparent stator and the transparent movable member constituting the seven sections of the seven-segment display device. Alternatively, it has been proposed to use a visual change caused by a change in the overlap between the moving member and the stator when moving left and right as a display principle.

[0004]

Generally, in a simple matrix type LCD using a super twisted nematic effect,
Controlling the gap of the liquid crystal cell in units of 0.1 micron,
High production technology such as aligning the liquid crystal molecular axes at a constant angle to the glass surface of the cell is required. Further, the simple matrix type LCD has a drawback that the viewing angle is narrow. On the other hand, an active matrix type LCD using a thin film transistor element or an MIM element is advantageous for a large screen, high definition, and halftone display, but requires an advanced thin film processing technique, and the yield at the manufacturing stage is poor. . LCD
Although the cost is currently being reduced due to mass production, it cannot be said to be so inexpensive due to the reasons described above and the fact that the liquid crystal material itself is expensive.

Further, in the 7-segment display device using the electrostatic film actuator proposed in Japanese Patent Laid-Open No. 4-240890, the principle of displaying the visual change caused by the moving element moving back and forth or left and right on the surface of the stator is displayed. However, there is a problem that an area twice as large as the display area is required to display one area.

The object of the present invention is not to provide a completely new type of optical element utilizing two light transmitting plates and electrostatic attraction and repulsion, and a transmission type or reflection type FPD in which the optical elements are arranged. Is to

[0007]

In order to achieve the object of the present invention, the following constitution is adopted. That is, the optical element of the present invention comprises two light transmitting plates and at least one of the light transmitting plates.
An optical element comprising a means for rotating a sheet, wherein (1) two light beams generated by rotation of at least one light transmitting plate.
By changing the overlapping of the transmission plates, the two light transmission plates can be transmitted.
Light whose intensity, color, brightness, or saturation changes over time
(2) The rotating part, which is a light-transmitting plate that is a resistor , uses an electrode.
It is supported by a fixed part made of insulators arranged in a radial pattern.
The rotating part and the fixed part when a voltage is applied to the electrode.
The electrostatic attraction and repulsive force generated between the
To meet the requirements of
It

As the light transmitting plate of the present invention, the intensity, the color, the brightness, the saturation, etc. of the transmitted light are changed by the change of the overlapping of the two light transmitting plates due to the rotation of the light transmitting plate which is the rotating portion. Can be used, and the light transmitting plate may be transparent, colored, or provided with some indication. However, it is preferable that at least one of the light transmitting plates is in the form of a film because it is likely to rotate due to electrostatic attraction and repulsion. Further, it is more preferable that both of the light transmitting plates are film-shaped, because the optical element can be made thin and can be made flexible. Further, it is preferable to use a polarizing plate in consideration of the fact that light can be turned on and off and the display area does not change.

The shape of the light transmitting plate is not particularly limited, and may be any shape such as circular or polygonal, but it is circular or polygonal in view of the fact that the shape does not change even when rotated. It is preferably a regular polygon, 90 °
A circular shape or a regular n-sided polygon (n is a multiple of 4) is more preferable in view of having the same shape when rotated.

The polarizing plate used for the light transmitting plate in the optical element of the present invention is not particularly limited as long as it has a function of converting natural light into linearly polarized light, and a polarizing prism such as a Nicol prism or a dichroic crystal is used. It is possible to use a polarizing film or the like, which is aligned with an electric field and scooped up on a substrate. However, at least one of the polarizing plates
The sheet is preferably a polarizing film because the sheet is likely to rotate due to electrostatic attraction and repulsion. Further, it is more preferable that both of the polarizing plates are polarizing films from the viewpoint that the optical element can be made thin and can be made flexible.

As the polarizing film, a film in which a dichroic dye is adsorbed and stretched and oriented, or a film in which an oriented film of polyvinyl alcohol is adsorbed with iodine can be used.

The polarizing plate has a function of converting natural light into linearly polarized light, and when two polarizing plates are arranged side by side, light can pass through the two polarizing plates if the polarization directions are the same. You can From this state, when one polarizing plate is rotated, the amount of light passing therethrough decreases with the rotation, and the amount of passing light becomes zero after 90 ° rotation. When a polarizing plate is used as the light transmitting plate in the optical element of the present invention, this principle is used for turning on / off the light. Therefore, the polarizing plate has a circular shape or a regular n-gonal shape (n is If it is set to a multiple of 4, the display area of the optical element does not change in the ON state and the OFF state of light, and there is no waste compared to the 7-segment display device proposed in Japanese Patent Laid-Open No. 4-240890. Also,
The optical element of the present invention turns on the light by rotating the light transmitting plate.
Since the color is turned off or the color, the brightness, and the saturation are changed, the state is maintained even if the voltage application is stopped in a certain specific state. That is, the optical element of the present invention,
Unlike LCD, it becomes an optical element having a memory property.

In the rotating means of the light transmitting plate in the optical element of the present invention, the rotating portion is supported by the fixed portion made of an insulator in which the electrodes are arranged radially, and the rotating portion is applied when a voltage is applied to the electrodes. And electrostatic repulsive force generated between the fixing portion and the fixing portion, and this method is a technique known as an electrostatic film actuator.

The electrostatic film actuator is composed of a fixed portion in which electrodes are arranged at regular intervals on an insulating support and a moving portion made of a resistor, and is arranged so that the moving portion and the fixed portion are in contact with each other. Therefore, the moving part is momentarily levitated by the action of static electricity to move the moving part while preventing friction. The operating principle of the light transmitting plate in the optical element of the present invention, which is described in detail in Proceedings of the 6th Annual Conference of the Institute of Electrical Engineers of Japan, 6-191, Nikkei Mechanical 1989, 5, 29, pages 112 to 113, etc. When an electrostatic film actuator is used as the rotating means, if the electrodes are arranged radially in the fixed part, the rotating part composed of a light transmitting plate that is a resistor supported by the fixed part follows the principle of the electrostatic film actuator. It will rotate.

The rotating part of the rotating means of the light transmitting plate in the optical element of the present invention is provided with a resistor layer on at least one surface of the light transmitting plate, preferably a film-like light transmitting plate, and more preferably a polarizing film. The resistor layer is provided by a method such as spray coating of an antistatic agent having a weak antistatic effect.

The fixed portion of the rotating means of the light transmitting plate in the optical element of the present invention is constituted by arranging electrodes radially on an insulator. The fixing part may be transparent or colored as long as it has a light-transmitting property, but in order to increase the contrast or color, brightness, and saturation of the optical element,
It is preferably transparent. Therefore, it is preferable that the fixing portion is formed by arranging transparent electrodes radially on a transparent insulator. As the transparent insulator, a glass plate, polyethylene terephthalate, polystyrene, acrylonitrile-styrene copolymer resin, transparent ABS resin, styrene-butadiene copolymer resin, styrene-maleic acid resin,
Methyl methacrylate-styrene resin, methacrylic resin, polycarbonate, polyarylate, polysulfone, polyether sulfone, polymethylpentene, amorphous polyamide, amorphous polyolefin, transparent fluororesin, fluorinated polyimide, brominated phenoxy resin, Although a film of transparent plastic such as transparent polybutylene terephthalate can be used, it is preferable to use a film from the viewpoint that the optical element can be made thin and can be made flexible.

As the transparent electrode, a transparent metal,
It is preferable to use a metal oxide. Transparent metals include gold, silver, copper, palladium, indium-tin, zinc,
Examples of the transparent metal oxide include indium oxide, indium oxide-tin oxide, zinc oxide, and aluminum oxide.

In the transparent fixing portion, the electrode may be on the surface of the insulator or may be embedded in the insulator.

As a method of forming the electrode on the insulator, a general method similar to the method of forming a circuit such as an IC can be used. A typical example is described below.
Of course, it is not limited to this. First, a thin film of an electrode material is laminated on the insulator by a sputtering method or a vacuum evaporation method. A resist layer is formed on the surface of this thin film by a bar coater method, a spin coater method, a roll coater method, or the like. Subsequently, exposure and development are performed to form a pattern. An electrode can be formed by etching using this resist pattern and finally removing the resist pattern with a stripping solution. When the electrode is buried in the insulator, a transparent insulating paste may be applied to the surface of the electrode formed as described above.
As the coating method, various coating methods similar to those for forming the resist layer can be used.

The optical element of the present invention comprises a light transmitting plate and
It is composed of a rotating part composed of a single light transmitting plate and a fixed part. However, in the optical element, the light transmitting plate may be the fixed portion, that is, the two light transmitting plates may be the rotating portion and the fixed portion. In this case, 2
It is preferable to use a film-shaped light transmitting plate as a sheet, and it is more preferable to use a polarizing film. When the light transmitting plate is used as the fixing portion, the electrodes are radially formed on the light transmitting plate by the above method.

The optical element of the present invention obtained as described above is inferior to the elements used in LCDs in the on / off speed of light or the change speed of color, brightness tail, and saturation. Since the structure is very simple, it is easy to increase the size, and since it can be manufactured from an inexpensive material, it is advantageous in terms of cost. Also,
The optical element of the present invention can be made flexible and can be used even on a curved surface.

Next, the FPD of the present invention will be described.

The FPD of the present invention is characterized in that a plurality of the optical elements of the present invention described above are arranged. In the FPD, one optical element corresponds to one pixel.

The method of arranging the optical elements in the FPD of the present invention is not particularly limited, but it is preferable that the optical elements are arranged with a certain regularity because a clear image can be displayed. As a concrete arrangement method, an aggregate of one or several optical elements is arranged in parallel with each side when the shape of the FPD is a triangle, a quadrangle or the like, and radially when the shape is a circle, a sphere or an ellipse. , It is good to arrange them at equal intervals. In these cases, the width and accuracy of the interval are appropriately determined according to the size of the FPD and the purpose of use.

Further, the FPD of the present invention is an FPD in which a plurality of light transmitting plates having a rotating means are arranged on one light transmitting plate.
In the rotating means, the rotating portion made of the light transmitting plate which is a resistor is supported by a fixed portion made of an insulator in which electrodes are arranged in a radial pattern, and when a voltage is applied to the electrodes, It is characterized by an electrostatic attraction and a repulsive force generated between the fixing portion. In the FPD, one light transmitting plate having a rotating means corresponds to one pixel.

Here, as the light transmitting plate in the FPD of the present invention, as in the case of the optical element of the present invention, the two light transmitting plates are overlapped by the rotation of the light transmitting plate which is the rotating portion. It is possible to use a material whose intensity, color, brightness, saturation, etc. of the transmitted light changes depending on the change, and whether the light transmitting plate is transparent or colored, and some indication is given. It does not matter if it is done. However, considering that light can be turned on and off, and that the display area does not change, it is preferable to use a polarizing plate as the light transmitting plate. It is more preferable to use a polarizing film as the light transmitting plate from the viewpoint that it is possible and that it is flexible.

In this case, the method of arranging the light transmitting plates having the rotating means is not particularly limited, but it is preferable that the light transmitting plates are arranged with a certain regularity because a clear image can be displayed. As a concrete arrangement method, an assembly of light transmitting plates having one or several rotating means is used as an FPD.
When the shape is a triangle, a quadrangle, etc., it is preferable to arrange them in parallel with each side, and when the shape is a circle, a sphere, an ellipse, etc., they are arranged at equal intervals. In these cases, the width and accuracy of the interval are appropriately determined according to the size of the FPD and the purpose of use.

A light incidence device can be used in the FPD of the present invention. When the light incident device is used, the FPD of the present invention is a transmissive FPD. As the light incident device in the FPD of the present invention, a known device usually called a backlight can be used and is not particularly limited. As an example, a light incident device of a radiation type, a reflection type, a refraction reflection type, or the like can be used. The color of the light source is not particularly limited, and any light such as white light or monochromatic light is used. The number of light sources is also not particularly limited, and may be one, or one pixel or one pixel may be used. Further, it may be used after being split, condensed, polarized, etc. by a prism, a lens or the like. Further, by using a film-shaped light emitting body such as an EL panel, it is possible to make the entire FPD flexible.

In the FPD having the light incident device of the present invention, a color filter can be arranged in front of the FPD. By using the color filter,
The FPD of the present invention is a transmissive full-color FPD.
As the color filter in the FPD of the present invention, known ones used for ordinary color LCDs can be used. If you use a film color filter,
It is possible to make the entire FPD flexible.

In the FPD of the present invention, a black light lamp is used as a light incident device, and a film containing a substance that emits fluorescence by absorbing black light is arranged as a filter on the front surface of the FPD.
Can be used as an FPD that emits very well defined fluorescence.

In the FPD of the present invention, a light reflecting device can be arranged behind the FPD. When the light reflection device is used, the FPD of the present invention is a reflection type FPD. The light reflecting device in the FPD of the present invention is not particularly limited as long as it has a property of reflecting light such as a mirror or a metal. By using a metal foil such as aluminum, a metal-deposited film, a colored film, or paper as the light reflecting device, the entire FPD can be made flexible.

As the light reflecting device in the FPD of the present invention, a device in which 3 or 4 primary colors are arranged in a dot shape can be used. The three primary colors are not particularly limited,
Yellow, cyan and magenta can be used. Also, the four primary colors are not particularly limited, but those obtained by adding black to the above three primary colors can be used. The shape of the dot is not limited to a circle, and may be a triangle, a quadrangle, or a polygon, and may be the same shape as the pixel or a different shape. The size of the dot may be the same size as one pixel of the FPD or may be the same size as a plurality of pixels. When the light reflecting device is used, the FPD of the present invention is
It becomes a reflective color FPD. The material of the light reflecting device is not particularly limited, but the entire FPD can be made flexible by using a film, metal foil, paper, or the like.

Further, in the FPD of the present invention, a film containing a substance that emits fluorescence by absorbing black light is used as a light reflecting device, and the FPD of the present invention is very clear by irradiating it with black light from the front side. It can be used as an FPD that emits various fluorescence.

In the FPD of the present invention, a viewing angle widening device can be arranged on the forefront of the FPD. The viewing angle enlarging device, even when viewing the FPD from an oblique direction,
It is a device that enables reading the display contents, as when viewed from the front. As the device for enlarging the viewing angle of the FPD in the present invention, a convex lens array plate having a convex lens corresponding to each pixel of the FPD can be used. Further, in the FPD of the present invention, the light transmitting plate on the front surface side may have a convex lens structure.

[0035]

Next, examples of the display object of the present invention will be described with reference to the drawings, but the present invention is not limited thereto.

FIG. 1 is a side sectional view of an example of the optical element of the present invention. A transparent fixing part 3 having a transparent radial electrode 2 is attached to a light transmitting plate 1 which is a rotating part, and a transparent insulating paste 4 is provided.
To be in close contact with. A light transmitting plate 6 is placed on this via a spacer 5 of a transparent film. Here, when a polarizing film is used for 1 and 6, positive and negative voltages are sequentially applied to 2 while irradiating light from the rear of 6
When is rotated, the intensity of light observed in front of 1 is increased. Especially, from the state where the maximum light quantity is obtained,
When a voltage for rotating by ° is applied, the amount of light becomes zero and clear contrast is obtained. Further, when the voltage application is cut off in the state where the maximum amount of light or the amount of light is zero, the state is maintained as it is due to the memory property of the optical element. further,
1, 2, 3, 4, 5 and 6 constituting the optical element are
Since all film-like flexible materials can be used, the optical element can be made into a thin film-like flexible material.

FIG. 2 is a side sectional view of another example of the optical element of the present invention. A light transmitting plate 7 which is a fixed part having 2 is attached to 1 with 4 being interposed. Here, when a polarizing film is used for 1 and 7, as in the case of FIG. 1,
When 1 is rotated, a light on / off effect and a memory property are obtained. Further, the optical element can also have a thin film-like flexible structure.

FIG. 3 is a side view of an example of the FPD of the present invention. The FPD 8 is configured by using the optical element 9 of the present invention as a pixel and arranging a plurality of 9 elements. The image control unit 10 controls the rotation state of the rotating unit of 9 forming 8 for each pixel, whereby an arbitrary display on 8 can be obtained. Further, even if the voltage application is cut off, the display of 8 is retained due to the memory property of 9. Since 8 is composed of a thin film and flexible 9, 8 itself also has a thin film and flexible structure. In addition, the simple structure makes it lightweight.
The size can be easily increased, and the manufacturing cost is low.

FIG. 4 is a side view of another example of the FPD of the present invention. The FPD 11 includes a light transmitting plate 12 having a rotating means.
Are arranged on the large-sized light-transmitting plate 13. The display control is the same as in the case of FIG.
It is possible to do so by controlling the 12 rotation states. Further, 11 has a thin film-like and flexible structure similar to 8, and since it has a simple structure, it is lightweight and easy to be upsized, and the manufacturing cost is low.

FIG. 5 is a side view of another example of the FPD of the present invention. The FPD 14 is composed of a display section in which a plurality of 9 pixels are arranged and a light incident device 15 arranged on the back surface of the display section, and is a transmissive FPD.

FIG. 6 is a side view of another example of the FPD of the present invention. The FPD 16 is composed of a display section in which a plurality of 9 pixels are arranged, 15 arranged on the rear surface of the display section, and a color filter 17 arranged on the front surface of the display section, and is a transmissive full-color FPD.

FIG. 7 is a side view of another example of the FPD of the present invention. The FPD 18 includes a display section in which a plurality of 9 pixels are arranged, and a light reflection device 19 arranged on the back surface of the display section, and is a reflection type FPD.

FIG. 8 is a side view of another example of the FPD of the present invention. The FPD 20 is a transmissive FPD, and is composed of a display section in which a plurality of 9 pixels are arranged, a 15 arranged on the back surface of the display section, and a viewing angle expansion device 21 arranged on the front surface of the display section. Moreover, the display content can be read even when viewed from an oblique direction.

15, 17, 1 in FIGS. 5, 6, 7 and 8.
Since it is possible to use film-shaped ones for both 9 and 21, the FPDs 14, 16, 18, and 20 are
All can have a thin film-like flexible structure. Further, since these FPDs have a simple structure, they are lightweight, can be easily increased in size, and are inexpensive to manufacture.

[0045]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. That is, those who have learned the technical idea of the present invention can easily change to a more efficient one.

Example 1 A transparent conductive layer of indium oxide-tin oxide was formed on a disc-shaped polyethylene terephthalate film by a sputtering method. A resist film was applied thereto, and the resist film was exposed using a mask capable of obtaining a radial electrode. Next, after removing the exposed portion, etching was performed, and the remaining resist was completely removed. A commercially available polarizing film, which is a rotating part sprayed with an antistatic agent, was brought into close contact with the fixed part having the obtained radial electrodes. Here, the polarizing film having the same size as the fixing portion was used. Further, a commercially available polarizing film was arranged with a spacer sandwiched on the surface of the fixed portion on the side without the rotating portion. When positive and negative voltages were applied to the optical element thus obtained, the rotating part was rotated, and the intensity of light observed on the front surface of the rotating part was increased. Further, when a voltage for rotating the polarizing plate by 90 ° was applied from the state where the maximum light quantity was obtained, the light quantity became zero, and clear contrast was obtained. Furthermore, when the voltage application was cut off in the state where the maximum light amount or the light amount was zero, the state was maintained as it was, and the memorability of the optical element was confirmed. In addition, in the material forming the optical element,
Since all of the film-shaped flexible elements were used, the optical element was a thin-film-shaped flexible element.

[0047]

As described above, the present invention is a completely new type optical element utilizing two light transmitting plates and electrostatic attraction and repulsion, and a transmission type or reflection type FPD in which the optical elements are arranged. Can be obtained.

The optical element obtained by the present invention has the following features.

(1) When a polarizing plate is used as the light transmitting plate, a clear light on / off effect can be obtained by rotating the polarizing plate.

(2) Since all the constituent materials can be film-shaped, a thin-film optical element can be obtained.

(3) Since all the constituent materials can be film-shaped, a flexible optical element can be obtained.

(4) The on / off speed of light or the changing speed of color, brightness, and saturation is slower than that of a liquid crystal cell, but it has a memory property for voltage application.

(5) Since it does not require a strict structure such as a liquid crystal cell, it is easy to manufacture. (6) Since it is easy to manufacture and the material used is inexpensive, it can be supplied at a much lower cost than LCD.

Further, the FPD obtained by the present invention has the following features.

(1) Transmissive and reflective FPDs can be obtained.

(2) Monochromatic and color FPDs are obtained.

(3) A thin film FPD is obtained.

(4) A sheet-like flexible FPD that can be bent and rolled can be obtained.

(5) Although the display rewriting speed is slower than that of the LCD, the display content can be retained even if the voltage application is cut off.

(6) Since the structure of the optical element is simple, it is possible to increase the size of the FPD at a low manufacturing cost.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an example of an optical element of the present invention.

FIG. 2 is a side sectional view showing an example of the optical element of the present invention.

FIG. 3 is a side view showing an example of the FPD of the present invention.

FIG. 4 is a side view showing an example of the FPD of the present invention.

FIG. 5 is a side view showing an example of the FPD of the present invention.

FIG. 6 is a side view showing an example of the FPD of the present invention.

FIG. 7 is a side view showing an example of the FPD of the present invention.

FIG. 8 is a side view showing an example of the FPD of the present invention.

[Explanation of symbols]

 1: Light transmitting plate which is a rotating part 2: Radial electrode 3: Fixed part 4: Insulating paste 5: Spacer 6: Light transmitting plate 7: Light transmitting plate which is a fixed part 8, 11, 14, 16, 18, 20: FPD 9: Optical element 10: Image control unit 12: Light transmission plate having rotating means 13: Large light transmission plate 15: Light incident device 17: Color filter 19: Light reflection device 21: Viewing angle expansion device

Claims (13)

(57) [Claims] 1. An optical element comprising two light transmitting plates and means for rotating at least one of the light transmitting plates,
An optical element satisfying the following requirements. (1) Two light beams generated by rotation of at least one light transmitting plate
By changing the overlapping of the transmission plates, the two light transmission plates can be transmitted.
Light whose intensity, color, brightness, or saturation changes over time
Use a transparent plate. (2) The rotating part made of a light transmitting plate which is a resistor serves as an electrode.
It is supported by a fixed part made of insulators arranged in a radial pattern.
The rotating part and the fixed part when a voltage is applied to the electrode.
The electrostatic attraction and repulsive force generated between the
To do. 2. The optical element according to claim 1, wherein the two light transmitting plates are polarizing plates. 3. The optical element according to claim 1, wherein the two light transmitting plates are polarizing films. 4. The optical element according to claim 1, 2 or 3, wherein the two light transmitting plates are a rotating portion and a fixed portion. 5. A flat panel display comprising a plurality of the optical elements according to claim 1, 2, 3 or 4. 6. A flat panel display in which a plurality of light transmitting plates B having rotating means are arranged on one light transmitting plate A , and the following requirements are satisfied.
Panel display. (1) By rotating the light transmitting plate B, the two light transmitting plates A and B are
Light that passes through two light-transmitting plates due to changes in overlap
A light-transmitting plate whose intensity, color, brightness, or saturation changes
To use. (2) The rotating part composed of the light transmitting plate B which is a resistor is an electrode.
Are supported by a fixed part made of an insulator in which the
The rotating part and the fixed part when a voltage is applied to the electrode.
The electrostatic attraction and repulsive force generated between the
To do. 7. The flat panel display according to claim 6, wherein the light transmitting plate is a polarizing plate. 8. The flat panel display according to claim 6, wherein the light transmitting plate is a polarizing film. 9. The flat panel display according to claim 5, 6, 7 or 8, wherein a light incident device is arranged behind the flat panel display. 10. The flat panel display according to claim 9, wherein a color filter is arranged in front of the flat panel display. 11. The flat panel display according to claim 5, 6, 7 or 8, wherein a light reflecting device is arranged behind the flat panel display. 12. The flat panel display according to claim 11, wherein the light reflecting device is one in which three or four primary colors are arranged in a dot shape. 13. The method of claim 5, 6, 7, 8, 9, 10, 1
13. The flat panel display according to 1 or 12, wherein a viewing angle expanding device is arranged on the forefront of the flat panel display.