JPS60133423A - Polychromatic display device utilizing liquid crystal - Google Patents

Abstract

PURPOSE:To obtain a bright, easy-to-see polychromatic display device which has the high utilization efficiency of outer circumferential light by providing a guest- host mode liquid crystal display element and such plural kinds of color filters that part of principal transmission wavelength ranges of visual parts are common. CONSTITUTION:Transparent electrodes 4 and 5 which cross each other are provided to a transparent substrate 2 and a diffusion reflecting plate 3 between which liquid crystal 1 in guest mode which allows the control over the transmission of light without using any polarizing plate, and liquid crystal display elements 6 are formed at intersections in a matrix. While the liquid crystal 1 is in black coloration mode, the outer circumferential light 10 is absorbed and seen in black, and while the liquid crystal is in a light transmitting state, the outer circumferential light 10 is transmitted through the liquid crystal, colored by color filters 7C, 7M, and 7Y respectively, and reflected by the diffuse reflecting plate 3 to enter observer's eyes. Colors, i.e. white, red, green, and blue are displayed according to the combinations of light transmission states of three liquid crystal display elements 6 corresponding to the color filters 7C, 7M, and 7Y constituting one picture element 8. In this case, such color filters that part of principal transmission wavelength ranges are common are selected, so a color display is made so that the peak value of the composite color is about two-thirds as large as the outer circumferential light.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color display device, and more particularly to a multicolor display device using liquid crystal.

Several multicolor display devices using liquid crystals have been known in the past, and an example thereof is disclosed in Japanese Unexamined Patent Publication No. 14119/1983. This is a system that performs color synthesis by controlling a liquid crystal display equipped with red, green, and evening 61 wide angle and I-r 3eb filters corresponding to EK-West P-view L filters.
The amount of light of the composite color is 3 depending on the area efficiency even for the brightest white.
1/2 of that amount due to absorption by the polarizing plate I/r-
It becomes 1/1. If this is used as a reflective type, it will be nearly half that, and the efficiency of using outer peripheral light will be 1/12.
It is too dark to be put to practical use. Therefore, a lamp for illumination is required on the back side of the cell, and as a display device that uses batteries as a power source, the battery life is shortened. Another disadvantage is that the volume for the illumination lamp increases, which increases the size of the entire device.

The present invention aims to solve these drawbacks in the prior art.

Next, embodiments of the invention will be described.

In the $1 diagram, guest-host mode liquid crystal 1 is, for example, a nematic liquid crystal to which a dichroic dye and an optically active substance are added, or an n-type nematic liquid crystal to which a dichroic dye and an ionic additive are added. It is a type that can control the transmission of light without using a polarizing plate. This LCD 1
A transparent substrate 2 made of glass or the like is provided on the front side sandwiching the electrodes, and a scattering reflection plate 3 made of white glass, white ceramic or the like is provided on the back side and also serves as an electrode substrate. Band-shaped transparent electrodes 4.5 are provided on each of the transparent substrate 2 and the scattering/reflection plate 3 so as to intersect with each other as shown in the second figure, and liquid crystal display elements 6 are formed in a matrix at the intersecting portions. Corresponding to the liquid crystal display element 6, a plurality of types of color filters 70.7M having a common wavelength range in a part of the main transmission wavelength region in the visible region are disposed on the scattering reflection plate 6;
7Y'i are arranged alternately. This color filter 70
．． 7M.

7Y is made of dyed gelatin film, multilayer dielectric film, etc., and each filter has cyan (C) and magenta (M
), yellow (Y)' and absorbs or reflects other colors, and a part of the main transmission wavelength range is common to both. (Figure 5). The color filters 70.7M and 7Y of the liquid crystal display element 6 are formed at a pitch less than the resolution of the observer's eye, for example, 150 μm. 3
Three types of color filters 70.7M and 7Y are lined up one by one to form one pixel, and one pixel displays a certain color. These color filters are 70.7M.

7Yi, a transparent protective film 9 is formed. On this protective film 9, the above-mentioned transparent electrode VIL5 is formed.

Next, the display effect will be explained.

It is now assumed that a black dichroic dye is mixed into the liquid crystal 1 in the guest self-host mode. When the liquid crystal 1 in this guest-host mode exhibits a black color, the peripheral light 10 is absorbed and appears black. On the contrary, when the liquid crystal 1 transmits light, the peripheral light 10 passes through the liquid crystal, is colored by the color filters 70.7M and 7Y, and is reflected by the scattering reflector 5 to the observer's eyes. enter. 6 corresponding to color filters 70.7M and 7Y that constitute one pixel 8
When all of the liquid crystal display elements 6 are in a light transmitting state, cyan (
C), magenta (Korean), and yellow (Y) are combined to display white (W) as shown in Figure 6. When two liquid crystal display elements 6 transmit light and one blocks light, two colors among cyan, magenta, and yellow are combined to produce a red color (
R'), edge thread (G').

The color of fruits and vegetables (B') is displayed.

Looking at the efficiency of using peripheral light in this display, one pixel is divided into five equal parts by triplets, so the area of one color filter is 5.
The amount of light becomes 1/6, and the amount of light becomes 1/6. However, in the present invention, since color filters are selected whose main transmission wavelength ranges are partially common, the resulting composite color has a peak value that is about two-fifths brighter than the outer peripheral light, as shown in Figure 5. Can be displayed in color. In reality, it is difficult to use a two-sixth display due to reflections at the boundaries of each layer and attenuation of light, but it is possible to change the display to a brighter one without using illumination lamps.

In the above embodiment, the transparent electrodes 4 and 5 for driving the liquid crystal are XY
Although it is provided in a simple matrix, it is not limited to this, and may also be a so-called active matrix type in which a thin film transistor switching element is provided for each display element, or a type in which a non-linear element is combined.

The types and combinations of color filters are not limited to those in the embodiment, and for example, two types of color filters may be used for display.

According to the present invention, it is possible to obtain a bright and easy-to-see multicolor display device that has high efficiency in using peripheral light.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of an embodiment of the present invention, Fig. 2 is a configuration diagram of a liquid crystal driving electrode, and Fig. 3 is a view showing the spectral characteristics of a color filter and a composite color. 1...Guest Φ host mode LCD 3...
...Scattering reflector plate 6...Liquid crystal display element 70.7M, 7Y...Color filter and above Patent applicant Seikosha Co., Ltd. Agent Patent attorney Tsutomu Mogami Figure 3 400 500 600 700 □Length of skin (n m)

Claims (1)

[Claims] A liquid crystal display element is provided in the guest-host mode liquid crystal, and in correspondence with the liquid crystal display element, multiple types of color filters that share a part of the wavelength range of the main transmission wavelength range in the visible region are provided alternately. A multicolor display device using a liquid crystal in which a scattering reflector is provided behind a p-processed color filter.