JPS61256376A - Color liquid crystal display unit - Google Patents

Abstract

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

Description

[Detailed Description of the Invention] Technical Field The present invention uses a liquid crystal element as an optical switching element,
The present invention relates to a color liquid crystal display device in which transmitted light from a pixel-shaped back light source is observed.

BACKGROUND OF THE INVENTION Color display devices using liquid crystal panels have excellent properties such as being able to be made thinner, and have been actively developed in recent years. Conventionally, color liquid crystal display devices have been developed by forming pixel-shaped color filter layers of R, G, and B on the electrodes inside the liquid crystal cell, and observing the transmitted light from the illumination light source arranged on the back side. It was displayed in color. However, this method has poor color reproducibility, so the applicant previously proposed a color liquid crystal display device that uses a phosphor that emits fluorescence as a light source and further observes this emission through a color filter (particularly (Gan Sho 59-213175). However, in this display device, it was necessary to form two layers, a colored filter layer and a phosphor layer, and there remained unsatisfactory points in manufacturing, such as poor yield.

The present invention provides a color liquid crystal display device that can display good color with a simple configuration.

The color liquid crystal display device of the present invention includes a liquid crystal element that controls transmission/blocking of light according to image information, and a pixel-shaped colored light emitting device disposed on the back side of the liquid crystal element. Each pixel portion of the colored light-emitting layer includes a light-emitting body that emits colored light and a light-transmitting colored substance that selectively transmits light of the same color.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

FIG. 1 is a sectional view schematically showing an embodiment of the present invention. A first substrate 13 and a second substrate 21 each having a transparent electrode 15.19 are disposed facing each other, and a liquid crystal material 22 is sealed between these substrates 1.3.21.
A type liquid crystal cell 11 is formed. 17 indicates a sealing material. The liquid crystal cell 11 is sandwiched between a polarizing plate 23 on the observation side and a polarizing plate 25 on the back side, and a 90°-TN type liquid crystal element 10
It consists of

This liquid crystal element 10 can control transmission and blocking of light from the light source 37 by applying a signal voltage to the transparent electrodes 15 and 1.9. The light source 37 includes a colored light emitting layer 31 and an ultraviolet lamp 35 as an energy source for emitting light. 33 is a colored light emitting layer 3
This is a substrate for supporting 1.

The colored light emitting layer 31 corresponds to the transparent electrode of the liquid crystal cell 11 in the R pixel portion 31 . a, G pixel section 3]l), B pixel section 31c
In each pixel portion, the pixels are formed in a pixel shape such as a dot I-shape or a stripe shape. The R pixel portion 31a includes a light emitter that emits red light and a red light-transmitting colored material. Similarly, G
The pixel portion 31b includes a light emitter that emits green light and a green light-transmitting colored material, and the B pixel portion 31. c includes a light emitter that emits blue light and a colored material that transmits blue light. As shown in Fig. 3, each of the R, G, and B light emitters and the light-transmitting colored substance are such that the half-width of the spectral emission spectrum of the light-emitting body is included in the half-width of the spectral transmission spectrum 1 to 1 of the light-transmitting colored substance. It is preferable that the The symbols in Figure 3 indicate the following, respectively.

R: Red light emitter R': Red light transmitting colored substance G: Green light emitter G': Green light transmitting colored substance B: Blue light emitter B': Blue light transmitting colored substance Mixture of colored light emitter and light transmitting colored substance The ratio should be set to such an extent that the luminous body absorbs electromagnetic waves and the emission intensity does not decrease significantly, and
The transmittance of the light-transmitting colored substance is set to be at least 50% or more. The mixing ratio of the colored light emitter (P) and the light-transmitting colored substance (T) is 1.0/], although it varies depending on the material.
The range of <P/T<1/IQ is preferable.

Phosphors are usually used as the colored luminescent material, and dyes and pigments are used as the light-transmitting colored substances.

The colored light-emitting layer is produced by, for example, dispersing a phosphor and a dye together with a resin binder in a suitable solvent to form a uniform mixed system, and then using this mixed system to form a mosaic by printing, photolithography, etc. , and can be formed by patterning pixels into stripes.

As shown in FIG. 2, when the colored light emitting layer 31 is irradiated with UV light from the ultraviolet lamp 35, each pixel portion 3]a, 3]b
, 31c emits light. For example, in the G pixel section 31b, a green light emitter emits light, which is mixed additively by the filter effect of the green light-transmitting colored material, resulting in highly pure G light (→
) is incident on the liquid crystal element 10. Similarly, R, G, and B lights are obtained, and full-color image display is possible by using the liquid crystal element 10 as a light shutter.

Furthermore, by arranging a filter that transmits ultraviolet light and cuts visible light between the ultraviolet lamp 35 and the colored light emitting layer 31, the 3Ld between each pixel portion of the colored light emitting layer 31 is made into an apparently blank 1-live. can do. Further, by providing a filter between the colored light emitting layer 31 and the liquid crystal cell 11 that cuts off ultraviolet light and transmits light of 400 nm or more, deterioration of the liquid crystal material can be prevented.

Glass, plastic film, etc. are used as the substrates 13 and 21 of the liquid crystal cell, and by using a plastic film, it is possible to make the device thinner, and it is also possible to prevent color mixing of pixels due to refraction of light.

Any liquid crystal display element that functions as a light shutter can be used.

In addition to the TN type liquid crystal element, for example, a guest host type liquid crystal element, a phase change type liquid crystal element, etc. are used.

Invention - Advantages According to the present invention, a colored luminescent material layer is formed by mixing a colored luminous material and a light-transmitting colored material that selectively transmits light of the same color, thereby producing a colored luminous material layer with a simple structure. Color display with good reproducibility can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an example of the configuration of a color liquid crystal display device of the present invention, and FIG. 2 is an explanatory view showing its color display mechanism. FIG. 3 is a graph showing the spectral spectrum of a colored luminescent material and the spectral transmission spectrum of a light-transmitting colored substance.

Claims (1)

[Claims] 1. It has a liquid crystal element that controls transmission/blocking of light according to image information, and a pixel-shaped colored light emitting layer disposed on the back side of this liquid crystal element, and each pixel part of the colored light emitting layer is A color liquid crystal display device comprising a light emitting body that emits colored light and a light transmitting colored material that selectively transmits light of the same color.