JPS6015045B2 - LCD color display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color display device using liquid crystal.

Display devices using liquid crystals are currently in practical use only for black and white display.

There is a strong demand for color displays, and although several principles of liquid crystal color display have been proposed, they have not yet been put to practical use. A nematic liquid crystal is sealed between two substrates on which transparent electrodes are formed, and a voltage is applied between those electrodes to create turbulence in the nematic liquid crystal and scatter light (DSM state). A method has been proposed in which color display is achieved by combining a dichroic mirror and a diffuser plate that transmit wavelengths of light and reflect the remaining wavelengths. To explain the technical details thereof, as shown in FIG. 1, a transparent electrode pattern 2 is formed on a glass substrate 1. A dichroic mirror 5 and a transparent electrode pattern 2 are formed on a glass substrate 3. A liquid crystal 4 is sealed between two glass substrates 1 and 3.

A diffusion plate 6 is installed behind the substrate 3. two transparent electrodes 2
When a voltage is applied between them and a current flows through the liquid crystal, turbulent flow occurs in the liquid crystal, and when the incident light 8 passes through the portion 7 where the turbulent flow occurs, it is scattered and becomes milky white. Then, only the colors corresponding to the reflection characteristics 12 of the dichroic mirror 5 shown in FIG. 2 are selectively reflected. Moreover, since the reflected light is diffused, the direction component of the eye 11 is 10
, and a traffic light color is created. On the other hand, the incident light 8' that has passed through the field-free portion reaches the dichroic mirror 5 without being diffused, where it is partially selectively reflected, but there is no component toward the eye. On the other hand, the selectively transmitted wavelength range 13 is reflected by the colored diffuser plate 6 by the color 14 of the diffuser plate, and has an eye direction component 9 due to the diffusion, thereby creating a background color. In this way, the pattern can be displayed. In a device that displays information in combination with a dichroic mirror and a diffusion plate, opposing electrodes are arranged along one plane on at least one substrate, and a voltage is applied between the electrodes to display information. It is characterized by Next, the principle and embodiments of the present invention will be explained in detail with reference to the drawings. FIG. 3 is an embodiment of the present invention and is a sectional view of a cell. 1 and 3 are glass substrates.

A dichroic mirror 5 and transparent electrodes 7-1 to 7-n and 8-1 to 8-n are provided on a glass substrate 3. The transparent electrodes 7-1 to 7-n and 8-1 to 8-n are comb-shaped electrodes inserted between each other as shown in FIG. 4, and the longitudinal direction of the comb-shaped electrodes is shown in FIG. The direction is perpendicular to the paper. The surface of the glass substrate is subjected to alignment treatment to align the liquid crystal molecules 10 parallel to the substrate surface as shown in FIG. 6 is a diffusion plate.

Reference numerals 91a, 9-b, . . . , 91h shown in FIG. 4 are extraction electrodes. Electrodes 91a and 9-b, 91c,...
. . , 9-h, an electric field is generated between the desired opposing electrodes. The long axis of the liquid crystal molecules 10 in FIG. 3 is rotated by an electric field. Due to the anisotropy of the refractive index of liquid crystal molecules, the refractive index changes periodically, causing light to be scattered, producing an effect similar to that of the scattering portion 7 in FIG. Then, based on the same principle as explained in FIG. 1, the electrode portion (display portion) and the background portion become different colors, and a desired pattern can be displayed. The case where the liquid crystal molecules 10 are aligned parallel to the substrate surface has been described, but if the liquid crystal molecules are aligned perpendicular to the substrate surface, or perpendicular to one substrate surface and parallel to the other substrate surface, the liquid crystal molecules 10 are aligned parallel to the substrate surface. Displays similar to those described above are possible in both cases of orientation in which the molecular long axes are parallel and rotated by 90 degrees.

Further, in FIG. 3, a similar display can be obtained by forming comb-shaped electrodes on the substrate 1 so as to face the comb-shaped electrodes on the substrate 3, and applying voltages to both simultaneously. In the present invention, light is scattered by applying an electric field and rotating the liquid crystal molecules to create a periodic refractive index distribution, so compared to the conventional method of creating turbulence by current injection and scattering light, it consumes less light. The current is reduced to about 1/100.

As a result, when used in battery-powered portable products, the battery life can be dramatically extended. Furthermore, since almost no current flows through the liquid crystal, deterioration of the liquid crystal molecules can be prevented. Furthermore, since the transparent electrodes are formed only on one substrate, one transparent electrode is removed, and there is no need to align the two transparent electrodes with each other during the assembly process of the liquid crystal cell, which reduces the cost of the liquid crystal cell. can be measured. Furthermore, since the extraction electrode of the liquid crystal cell is formed on one substrate, connection with an external circuit is facilitated, and the reliability of the connection is also improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the configuration of a conventional display device, FIG. 2 is a view showing the optical characteristics of a dichroic mirror, FIG. 3 is a sectional view showing an embodiment of the device of the invention, and FIG. 4 FIG. 2 is a plan view showing an example of electrodes arranged along one plane. 1, 3...Substrate, 4...Liquid crystal, 2...Transparent electrode, 5...Dichroic mirror, 7, 8...Comb tooth electrode. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. A liquid crystal display device in which a liquid crystal is sealed between two transparent substrates that have been subjected to alignment treatment, and a dichroic mirror is disposed on the upper surface of one of the transparent substrates, and a diffuser plate is disposed on the lower surface of the transparent substrate. interdigitated comb-shaped electrodes are formed on one side of the mirror, and a voltage is selectively applied between the mutually inserted comb-shaped electrodes to form a periodic pattern corresponding to the mutually inserted comb-shaped electrode pattern. 1. A liquid crystal color display device that displays information by scattering light by producing a periodic refractive index distribution due to a molecular arrangement.