JPS6385587A - Color display device - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a color display device using an LED as a light source, and in particular to a color display device that has a more peaceful display surface and a faster display response speed than a CRT display. It is related to the device.

[Conventional technology]

Conventionally, CRT (shadow@
wire tubes) are mainly used. In particular, most television receiver displays and computer terminals are CRT. This is because CRTs are low cost and highly reliable, but recently, even higher resolution technology has been developed, and their uses are expanding more and more.

However, since CRTs have the disadvantage of not only being deep but also consuming large amounts of power, development of flat displays with low power consumption is progressing rapidly. A typical example of such a display is a liquid crystal display, but one that is the same size as a CRT, has excellent image quality, and is capable of color display is still under development. These recent technological trends are described in "Display Devices,""Japanese Science and Technology J, 1984.
It is explained in detail in the September 1 issue, pp9-jO.

For detailed technical information on color liquid crystal displays, please refer to "Componentized LCD Pocket Color Television" [Nikkei Electronics J, September 10, 1984 issue, No. 351°pp, 211-240] "Full-color 4-inch LCD displays are coming one after another"
, "Nikkei Electronics J, November 19, 1984 issue, No. 356.pp, 209-214. Here, a fine filter was developed for colorization, and it was also used as a switching element for liquid crystal cells. TF
It is stated that a switching transistor called T (thin film transistor) was developed.Furthermore, as a new color display technology, I!: urodi
Ph1lip B announced at spray no 84
os, Thomas Buzak, Roof Vat
ne et al.'s 7-9 "4A Full-ColorF
ield-8equential Co1or Dis
There is pla7J (1984/9/1B-20). This document describes a full-color display means that uses a monochrome CRT'i as a light source and image display means, and is characterized by changing the display color over time using a high-speed liquid crystal called "bicell." . However, in this literature,
In the above displays, the light transmittance decreases because many polarizing plates and liquid crystal cells are installed in front of the CRT, and as a result, the CRT
The brightness on the RT was 720 fL (foot-lambert), but on the display surface it was 40 fL, which was 5.0 fL (foot-lambert) compared to the brightness on the CRT. ．． It is shown that the number drops to 696.

[Problem that the invention seeks to solve]

In view of the above-mentioned problems, the present invention is currently being studied with the aim of developing a flat color display with excellent responsiveness. The present invention was completed as a result of studies aimed at developing a flat color display device using iD.

[Means for solving problems]

The color television device according to the present invention includes a display surface made of a light modulator and an LKD light source for irradiating the display surface with light of different colors, and sequentially irradiates the light with different colors. By irradiating the modulator and driving the light modulator in synchronization with the irradiation of the light, the light transmittance of the light modulator is changed, thereby producing a multicolor display. t-Characteristics.

The optical modulator used in the present invention needs to be able to change the amount of transmitted light at high speed. The maximum level that humans can see without flickering is 50 Hf.
M, so the modulation speed of this optical modulator is at least 10
It is necessary that the frequency is higher than Hz. Here, responsiveness is required depending on the number of colors of light to be illuminated, but in the case of full-color display, it is necessary to sequentially irradiate light of three or more colors. In case 30 Hz ~ 9
Responsiveness of 0 Hz or higher is required. However, the color range that can be expressed is limited, or two types of colored lights may be used, or conversely, to widen the expressed color range, colored light of 4 m or more may be used.

As such a fast response optical modulator, AT7P↓P
N. A. hys, Left 4.36.899 (1980).

It is also possible to use the ferroelectric liquid crystal proposed by 01ark et al., and it is also possible to use a dual frequency drive type liquid crystal panel.

Furthermore, it is also possible to improve the contrast and the like by using a liquid crystal panel in which a large number of thin film transistors and thin film diodes are fabricated on a transparent substrate.

In addition to the above-mentioned liquid crystal panel, Ba
rnhard Hllll, Klaus-Peter
8chmidt is Kuroaisplay '84
Hlgh-Rescription Magne announced at
to-Optic Line Display Par
OFT Engineering CALPR Engineering NT Engineering NG (High resolution magneto-optical line display for optical printers) (1!1u
rodisplay' 84゜191-193) (19
84/9) and the same (Eurodisp'la
E announced at y+ 84.

Lueder, GoMoersch, T., Ka.
llfass, K., Koger's 885, T.
he Addressing of light va
lves in printer by Hlg
h Voltage TFT's AND
Re5is-tors with A Large 1
(1984
It is also possible to use an optical modulator array that utilizes the electro-optic effect produced by applying an electric field to PI and Z'f', such as in /9). Both of these two optical modulator arrays were developed as single-purpose switches, but the play-type array, which is the object of the present invention, is suitable for use as a light modulator in a matrix-type color display device. Of course it is also possible.

There are other examples of special optical switches, but the same (1
Rayma in nuroaiaplay 84
nd Vuilleumier, Andre-Kti
enne Perret, Francis Porr
et, 1 2 N published by Paulweiss et al.
ove1glec+;romechanical Mi
crosshutter DisplayDθviCθ“
Even a minute mechanical optical switch like the one shown in FIG. 1 can be used because it has a response speed of 2 m5ec and satisfies the high-speed response 't' required in the present invention.

In the present invention, a light source capable of emitting different colors is installed on the back or rear blade of such a fast-responsive optical modulator. The light modulator is sequentially irradiated with light of different colors emitted from this light source, and in order to achieve color mixing by sequential additive color mixing,
Like a light modulator, it is necessary to irradiate at high speed and with different colors of light over time.

Here, the terminology of additive color mixing will be explained.

First, to explain color mixing, as is often said, there are two types of color mixing: additive color mixing and subtractive color mixing.

Additive color mixture is when two or more colors of light enter the eye and mix on the retina, resulting in the appearance of different colors. Subtractive color mixture is when light of two or more colors enters the eye and mixes on the retina, resulting in the appearance of different colors. Subtractive color mixture is when light of two or more colors enters the eye and is mixed on the retina, resulting in the appearance of different colors. This is the phenomenon of color mixing when mixed light reaches the eye and appears as different colors.

The sequential additive color mixture is a type of the above-mentioned additive color mixture, and is a case where light of different colors enters the eye over time and mixes the colors.

A well-known example is the phenomenon where a top painted red and blue appears purple when rotated. Note that the method described in the prior art, in which a filter is placed in front of a monochrome CRT and colors are mixed over time, also utilizes the same phenomenon.

However, in general displays, juxtaposed additive color mixing is used, and displays using the above-mentioned sequential additive color mixing are hardly known other than the above-mentioned points. Here, the juxtaposed additive color mixture is a phenomenon in which, for example, when small color dots of yellow and red are closely arranged, it appears orange, and most conventional color displays use this method. Color CRT, color liquid crystal, and multicolor printing are typical examples. In addition to the above-mentioned sequential additive color mixing and juxtaposed additive color mixing, there is also a method called simultaneous additive color mixing, and a projection type color CRT projector is an example of this method.

Now, in the color display device using sequential additive color mixing according to the present invention, an LBD is used as a light source to emit red, green, and blue light sequentially, and this light is irradiated onto a light control device.

EXAMPLE Hereinafter, an example of a color display device according to the present invention will be explained based on the drawings.

As shown in FIG. 1, in the color display device according to this embodiment, a light modulator 1 having a dot matrix structure
Three LEDs capable of emitting light of different colors are placed at a predetermined distance from this light modulator 1 on one side of the
Light sources 2a to 2C are provided, and these light sources 2a to 2
c can irradiate light onto the optical modulator 1.

In the color display device according to this embodiment configured as described above, a predetermined drive circuit (not shown) is activated in synchronization with the irradiation of LBD light by each of the light sources 2a to 2C.
By driving the optical modulator 1, the transmittance of light passing through the optical modulator 1 is changed, thereby realizing a sequential additive color mixture to perform color display.

Next, color display by this sequential additive color mixture will be explained in detail based on FIG. 2. In this figure 2, A, B,
C, M, . . . indicate display patterns of the optical modulator 1.

First, the optical modulator 1 is driven so that the display butter y of A is obtained, and then the LED light source 2a is turned on.

Next, after turning off the LED light source 2a, the optical modulator 1 is driven so as to display pattern B, and then the LED light source 2b'i is turned on. Next, after turning off the LED light source 2b,
The optical modulator 1 is driven so as to display a pattern C, and then the L5LD light source 2C is turned on. After this, the LID light source 2C is briefly turned off, and then the display pattern of the optical modulator 1 is changed to A, and the same operation as described above is repeated.

Note that a series of steps from displaying the display pattern A on the optical modulator 1 to finishing displaying the display pattern C on the optical modulator 1 constitutes one frame. In order to prevent flicker from appearing to the human eye, 1-frame is at least 17
It is configured to finish in 30 seconds to 1710 seconds.

- As an example, if the LED light source 2a emits red, the LED light source 2b emits green, and the LED light source 2c emits blue, the light modulator 1 is always open when these light sources 2a to 2C are lit. It appears white when the light source 2a,
If the light modulator 1 is open only when LED light sources 2'b and 2c are lit, it will appear yellow, and if the light modulator 1 is open only when LED light sources 2'b and 2c are lit, it will appear light blue. Naturally, when only the light source 2a is lit, it appears red, and when only the light source 2c is lit, it appears blue, and when the transmittance of each color of light is analog modulated, each All the colors in the X-Y chromaticity diagram shown in a single color can be expressed. There are various possible ways to arrange the LF and D light sources, but for example,
As shown in the figure (by stacking LED arrays, flattening and full color can be easily achieved.The first layer (3a) has a red LED array, the second layer (3b) has a green LED array, and the third layer (3N) has a red LED array. 3c) Arrange the blue LED array as closely as possible.The dots a, b, and c are arranged in an equilateral triangle shape as shown in Figure 4 when viewed from the upper blade. The units (4A) are arranged so that 4A becomes the densest light beam.

In this way, high resolution of pixels can be achieved.

〔Effect of the invention〕

According to the image color ray device according to the present invention, color display can be performed not by a spatial color mixing method (juxtaposed additive color mixing) but by a temporal color mixing method, which is a sequential additive color mixing method, so that the resolution of the display surface can be improved. As it is, the resolution of the f image is υ,
Therefore, it is possible to provide a high resolution color display device. In addition, since LID is used as a light source, the entire device can be made flat and smaller compared to those using CRT'i, and its response speed can be extremely high. Since the structure of the color display device is simplified because there is no need for a filter, and it is extremely difficult to change the color tone with the conventional one-type microfilter, according to the present invention, it is possible to change the color tone of each color. By adjusting the light irradiation conditions in terms of power and time, the color tone can be changed extremely easily.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a color display device according to an embodiment of the present invention, FIG. 2 is a waveform diagram showing the timing of successive driving of three types of light sources in the color display device shown in FIG. Figure 3 is a stacking diagram of an LED array. FIG. 4 is a diagram showing the dot structure of each color in the LKD array. In addition, in the symbols used in the drawings, 1...... Optical modulators 2a, 2b
, 2c...=L RD light source 3a, 5'b, 3c
m--L Fi D array 4A...---Pot/LED dot constituent unit Patent applicant: Mitsubishi Rayon Co., Ltd. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. A display screen comprising a light modulator, and an LED light source for irradiating display light of different colors onto the display surface, and the light from the LED light source is sequentially emitted. A color display characterized in that the light transmittance of the light modulator is changed by irradiating the light modulator and driving the light modulator in synchronization with the irradiation of the light to perform display. display device. 2. The color display device according to claim 1, wherein the light modulator is a liquid crystal panel.