JPS5910924A - Color display device - Google Patents

Abstract

PURPOSE:To display bright and clear colors and to improve the dichroic contrast of display by providing a display body layer capable of controlling a transparent and a scattering mode to a front surface, and providing a dichroic mirror to its rear surface and a scattering and reflecting plate in clear color further on its back. CONSTITUTION:When the dichroic mirror 4 allows only green light to pass and the display body layer 2 is in scattering mode, part of incident light is scattered and reflected by the layer 2 and the remainder is transmitted. The transmitted light has green light transmitted through the dichroic mirror 4 and purplish red light in complementary color is reflected. This reflected purplish red light is emitted out as scattered light after passing through the layer 2 again. The green light transmitted through the mirror 4, on the other hand, is reflected by the scattering and reflecting plate 7 in clear color and emitted out as scattered light, but it is seen nearly in pink on the whole. When the layer 2 is in transparent mode, the scattered green light prevails over the purplish red light if the panel 1 is viewed from the front, and it is seen in bright green on the whole. The layer 2 uses liquid crystal or ferrodielectric transparent ceramic.

Description

[Detailed description of the invention] This invention relates to a color display device.

Conventionally, color display devices that combine twisted nematic liquid crystals and color polarizing plates have been known. Since this display section #l uses a polarizing plate, the amount of light decreases and becomes dark, and since there is nothing that will destroy the complete function as a color polarizing plate, parts other than the color display section will also be colored in similar colors. It had drawbacks such as low visual contrast. Guest-host type liquid crystal display devices are also known, but
The two-color ratio of the pigments is insufficient, resulting in low contrast, and the displayed and non-displayed areas are of the same color, resulting in poor visual contrast.Furthermore, the currently usable pigments are limited, so Yuzu colors are not available. Therefore, there were drawbacks such as the inability to produce clear colors when mixed with pigments.

This invention provides a clear color display device using a tichroic mirror.

Next, examples will be described.

A display body 2 is provided in a cutout of a display panel 1 of a color display device. The display layer 2 must be capable of controlling the transparent mode and the scattering mode. Liquid crystal, ferroelectric transparent ceramic, etc. can be used as the display layer 2.
There is a trick. Liquid crystals include face-change type liquid crystals, which are p-type nematic liquid crystals mixed with chiral materials, electrothermo-optic type liquid crystals, which are pW smectic liquid crystals mixed with chiral materials, and DSM (dynamic liquid crystals), which are n-type nematic liquid crystals mixed with ion dopants. (scattering mode)m, but in short, any material that can control the transparent mode and the scattering mode is sufficient.As a highly conductive transparent ceramic, there is a PLZT ceramic whose optical properties change depending on the applied voltage. It has been known. This display layer 2 is sandwiched between a transparent base 3 at the front and a tichroic mirror 4 at the back, and has a transparent base 3 at the rear. Transparent and scattering mode cutting is performed by B. The tichroic mirror 4 has the function of transmitting only a certain wavelength of light and rejecting other light. Further behind this tichroic mirror 4, a light-colored scattering/reflection plate 7 is arranged. As the light-colored scattering reflector plate 7, white paper or the like may be pasted, or a light-colored paint may be applied to the back surface of the tichroic mirror 4.Next, the display function will be explained. Assume now that the dichroic mirror 4 transmits the green light source and reflects other light. In the state shown in the second figure in which the display layer 2 is in the scattering mode, part of the incident light is scattered and reflected by the display layer 2, and the rest is transmitted. Red-violet light, which is the complementary color of green, is separated. This reflected red-violet light passes through the entire display layer 2 again and comes out as scattered light. - The green light transmitted through the sword-taichroic mirror 4 is reflected by the light-colored scattering reflector 7 and returns to the dichroic mirror.
The reddish-violet light passes through the display layer 2 and exits as scattered light, but since the reddish-violet light is not strong, the overall appearance is bright reddish-purple, almost pink. Display layer 2
When is in the transparent mode as shown in the third figure, the incident light passes through the display body I@2 by one inch, the green light is transmitted by the dichroic mirror 4, and the other light is reflected. The green light is scattered and reflected by the light-colored scattering reflector plate 7 and exits the display panel 1.
When viewed in normal use with the dichroic mirror 4 standing vertically and light entering the center from the diagonal upper blade, most of the reddish-purple light reflected by the dichroic mirror 4 will be reflected by the diagonal lower blade.

Therefore, when viewing panel 1 from the positive polarity, the power of the green scattered light is superior to the source of the reddish-purple color, and the overall color appears bright green. Due to the electrode formation on the display panel 1, when characters, etc. are displayed in segments in the transparent mode part with the scattering mode part as the background part, the characters will be displayed in green on a bright pink or pale reddish-purple background. Become. In the above explanation, we have described the case where the display panel 1 is placed upright and the light enters from the upper blade, but if you turn the display panel 1 to any angle, you will see a reddish-purple reflection from light sources such as the sun or electric lights. There is no problem with the display unless it is placed at an angle where a large amount of light enters the eye, and it is fully usable for practical use.

It has been found that better contrast can be obtained by setting light color scattering anti-Jt=[17 and using a color similar to the wavelength light transmitted by the tychro ink mirror. In the above example, the color of the green display becomes darker, and in the scattering mode, the complementary color of green, reddish-purple, becomes darker, and the color contrast becomes stronger, resulting in a sharper color.

Here, we will discuss the case where another thing is used instead of the light-colored scattering plate in the reference case. In transparent mode, the color becomes a mirror-like dark black, and the color becomes clearer.
/8 Contrast is not expected. Next, in the example using a dark color scattering pattern, it becomes a bright red J#: color in scattering mode, a clear reddish purple in transparent mode, and it is a similar color with no contrast and fc, d, that is, a bright color scattering foul. High-contrast and bright color displays were obtained only when using a machine.

According to the color display device of the present invention having the above configuration, it is possible to output bright and clear colors, and since the two displayed colors are complementary colors, the visual contrast is excellent.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional explanatory diagram of an embodiment of the present invention, and FIGS. 2 and 3 are explanatory diagrams, respectively. 2. Display layer 4. Tychroic mirror 7. Scattering error.

Claims (1)

[Claims] (11) A display layer capable of controlling transparent mode and scattering mode is provided, and a dichroic mirror is placed behind it.
Furthermore, the color display device is unique in that a light-colored scattering reflection 82 is provided behind it. (2) The color display device according to claim 1, wherein the display layer is made of liquid crystal. (31) The color display device according to claim 1, wherein the display layer is made of a ferroelectric transparent ceramic. (4) The scattering light has a similar color to the transmitted wavelength light of the tichroic mirror. A color display device according to claim 1.