JPS59208577A - Color display - 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 The present invention relates to a color display device using a liquid crystal or the like using a backlight source.

Thin, low power consumption LCD panels used to be capable of only monochrome displays, but recently it has finally become possible to display full color LCD panels.

FIG. 1 shows a principle diagram of a full-color display using this liquid crystal. By sealing the liquid crystal 2 between the glasses 1 and 3 to form a liquid crystal panel, the amount of light passing through each pixel 5 can be controlled as desired. By distributing color filters 4 to each pixel, any hue can be formed. For example, as in this specific example, R (red), G (green), B (
Perform additive color mixing using six primary colors (blue). -For example,
The liquid crystal 5 of the pixel corresponding to the simple filter 6 transmits light,
Furthermore, if the liquid crystal of pixels 7.9 corresponding to G8 and B10 is controlled so that no light is transmitted through the liquid crystal, the entire display becomes red. By controlling the liquid crystal display in this way, any hue can be reproduced. Usually, the color filter 4 used here uses dyes or pigments as the material, but these dyes and pigments usually do not have sufficient color saturation.

FIG. 2 shows the wavelength characteristics of each color of the color filter, and as can be seen from this example, each color has fairly broad characteristics with respect to wavelength. As a result, the color density is reduced and vivid colors cannot be reproduced. In addition, if you select a reliable dye with good light resistance and heat resistance, the hue will be less saturated and you will only be able to reproduce dull colors. It is susceptible to variations and reduces manufacturing yield.

Therefore, the present invention aims to completely improve these drawbacks.
The purpose of the present invention is to provide a method that reproduces vivid colors even when using pigments that are easy to produce, highly reliable, and have broad spectral characteristics.

The basic idea of the present invention is to improve saturation by sharpening the characteristics of the rear light source while keeping the spectral characteristics of the color filter broad. Conventionally, in this method, the backlight source was a white light source with nearly flat spectral characteristics, but in the present invention, each color element constituting the filter (for example, utosl) is a white light source with almost the same peak wavelength and a smaller half-width. The purpose is to use a light source with sharp spectral characteristics.

FIG. 3 is an example of the spectral characteristics of the light source used in the present invention. A light source having sharper peaks of Rp, Gp, and Bp is used for each dye of the filter consisting of R, G, and B. This light source is Bp so that it appears white.
and Gp and Rp i are adjusted. For example, in the case of G, by setting the half-width B of the light source smaller than the half-width A of the filter, even if the saturation of each color element of the color filter is not the same, the characteristics of the light source are reflected and the saturation is improved. Direction
It will be a hit. Therefore, by replacing the conventional white light source with a flat spectrum with a white light source having peak characteristics matched to each dye in the filter, dramatically vivid colors can be reproduced.

FIG. 4 shows an example of the configuration of such a light source. Planar light source 14
is made up of a part that emits red light, namely R10, a part G12 that emits green light, and a part B11 that emits blue light. The diffuser plate 13 mixes the colors of this light well and emits it as white light. The light source for emitting R2O and B used here can be, for example, a light emitting diode as shown in this figure, or a phosphor or electroluminescence that emits light when hit by an accelerated electron beam or ultraviolet rays. This is what I did.

FIG. 5 shows C which is another embodiment of the light source used in the present invention.
(A) is a plan view, (B) is a cross-sectional view, and shows the R light source 21.
G light source 22. Light emitted from the light emitting source 24 consisting of the B light source 25 enters from the entrance of the light guide @20 and emits white light to the upper side of the light guide plate. The light source used here may be a light emitting diode, a fluorescent display tube, or a cathode ray tube that emits light using an electron beam, or a phosphor light source that emits light using ultraviolet light such as a plasma display tube, or an electroluminescent light source (EI, ) is used. Especially in the case of phosphors and KL, R and G are displayed on a plane.

Of course it is possible to place B, but %' R, G.

If you blend the substances that develop color B in advance, you can get the three wavelength peaks of light from the entire surface without having to arrange them on a plane, making it easier to mix colors.Part 6 shows the light source 24 in Figure 5. This is a specific example, where (A) is a cross-sectional view and (D
) is a longitudinal sectional view. The inside of the glass tube 30 is depressurized and a part of it is red.

Firefly is a blend of 5 types of fluorophores that emit green and blue light = 5
- A light body layer 51 is formed, and a cathode/heater 32 is provided inside it.
and an anode, 33. When the heater is heated and a voltage of several tens of V is applied between the anode and the cand, the small hole thermionic electrons from the copper rod 2 are accelerated toward the anode 36, and the phosphor 3
Hit 1 to emit white light forward.

As described above, the present invention provides a display device that obtains full color by transmitting light from a rear white light source through a color filter, which has substantially the same peak characteristics corresponding to each color element of the color filter, and which has substantially the same peak characteristics in the spectral characteristics. By using a light source with peak characteristics whose half-width is smaller than each color element of the color filter, color filters can use dyes with reliable broad spectral characteristics, and the spectral characteristics of the filter can tolerate large variations. It will be easier to create within the range.

The result is a low-cost, highly reliable, and highly saturated color display.

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[Brief explanation of the drawing]

FIG. 1 shows an example of the configuration of a color display using a backlight source used in the present invention. 1.2.3...Liquid crystal panel 4...Color filter Figure 2 shows an example of the spectral characteristics of a color filter consisting of R, G, and B. Figure Fg3 shows the spectral characteristics of the backlight source of the present invention. FIG. 4, FIG. 5, and FIG. 6 are configuration examples of a backlight source according to the present invention. Applicant: Suwa Seikodai Co., Ltd. Agent: Patent Attorney Tsutomu Mogami 7- Figure 2

Claims (1)

[Claims] (1) In a color display device that performs color display by controlling the amount of light emitted from a white backlight source and transmitted through a color filter consisting of multiple color elements, approximately 1. A color display device characterized by using a white backlight source having the same beak characteristics and having spectral characteristics smaller than the half-width of each color element of a half-width S color filter.