JPH02296213A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To obtain a full-color liq. crystal display device without using a color filter by fitting a means of separating light into its spectral components to the light source side of a position corresponding to each image element of a liq. crystal display. CONSTITUTION:A liq. crystal display device is composed of a liq. crystal display 3 and a light source 1 for illuminating the display 3 and a means 2 of separating light into its spectral components is fitted to the light source side of a position corresponding to each image element of the display 3. Part 11 of light emitted from the light source 1 is separated into its spectral components through a fine diffraction grating 22 and voltage impressed between segment electrodes 4-6 placed opposite to red, green and blue components R, G, B and a common electrode 7 is made variable to vary the intensities of the components R, G, B. A full-color display is obtd. without using a color filter.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a liquid crystal display device. In particular, the present invention relates to a liquid crystal display device capable of full color display.

[Conventional technology]

Conventional full-color liquid crystal display devices have R (red), G (green), and B (blue) color filters arranged on the outer or inner surface of the liquid crystal display element, and the light emitted from the light source passes through the color filters. The three primary colors of RGB were created using the technology, and the intensity of these three primary colors was varied using the light valve effect of the liquid crystal display element to provide a full-color display. Its structure is shown in FIGS. 6 and 7. 1 is a light source, 3 is a liquid crystal display element, and 9 is a color filter.

In particular, when forming color filters on the inner surface of liquid crystal display elements, dyeing methods and electrodeposition methods have been proposed, but the manufacturing methods for color filters are complicated, and the various chemicals used in the manufacturing process of liquid crystal display elements There were various problems, such as color filters deteriorating due to heat energy applied.

Furthermore, when color filters are placed on the outer surface of a liquid crystal display element, there are various problems such as difficulty in accurately aligning them with display pixels, and color filters peeling off due to moisture when used for a long period of time. there were. Furthermore, there are other problems in general that the color purity of RGB produced by color filters is low and that the color filters themselves are degraded by the light energy irradiated from the light source.

[Problem to be solved by the invention]

Conventional full-color liquid crystal display devices use RGBO color filters, so there are problems with the manufacturing process for forming the color filters as described above, as well as problems with the color filters themselves, making it difficult to commercialize full-color liquid crystal display devices. It was a hindrance.

Therefore, the present invention is intended to solve these problems, and its purpose is to provide a full-color liquid crystal display device that does not use color filters.

[Means to solve the problem]

The liquid crystal display device of the present invention comprises a liquid crystal display element and a light source for illuminating the liquid crystal display element, and includes a spectroscopic means on the light source side at a position corresponding to each pixel of the liquid crystal display element. It is characterized by

〔Example〕

FIG. 1 is a sectional view schematically showing the structure of a liquid crystal display device according to the present invention. In the figure, 1 is a light source, 2 is a device having a spectroscopic function, and 3 is a liquid crystal display element used as a light valve.

FIG. 2 is an enlarged view of one pixel of the liquid crystal display device shown in FIG. In FIG. 2, a portion 11 of the light emitted from the light source 1 is separated into spectra by passing through a minute diffraction grating 22. Here, for example, R (600nm to 750n
m), G (490nm to 560nm), B (
The intensity of RGB is changed by arranging segment electrodes 4, 5, 6 corresponding to the positions (430 nm to 480 nm) and varying the voltage applied between them and the common electrode 7. In other words, in one pixel 33, a liquid crystal display element that can vary the intensity of KGB is formed at a position corresponding to the separated RGB. Structure 1 as described above
By arranging a large number of pixels as one unit, a full-color display like that on a television can be constructed.

[Example 1] A halogen bulb was used as a light source, a diffraction grating was used as a device having a spectroscopic function, and a black guest-host mode having voltage-transmittance characteristics as shown in FIG. 3 was used as a liquid crystal display element. By varying the voltage applied to the liquid crystal display element between 0 and 15V, the transmittance was changed and 64 gradations were achieved.

[Example 2] A 3-wavelength fluorescent lamp was used as a light source, a diffraction grating was used as a device having a spectroscopic function, and a voltage source as shown in Fig. 4 was used as a liquid crystal display element.
Combined twisted nematic mode with transmittance characteristics. By varying the voltage applied to the liquid crystal display element between O and 5V, the transmittance was changed and 16 gradations were achieved.

[Example 3] Combining a halogen bulb as a light source and a black guest-host mode having the characteristics as shown in Fig. 3 as a liquid crystal display element,
A diffraction grating was formed on the outer surface of the substrate on the light source side of the liquid crystal display element.

〔Effect of the invention〕

As described above, according to the present invention, a full color display can be obtained without using color filters, and various problems associated with forming color filters are therefore eliminated, reducing the cost and improving the reliability of color liquid crystal display devices. can be achieved. Furthermore, since the separated colors are directly used as RGB light sources, a color liquid crystal display device with high color purity can be provided.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the structure of a liquid crystal display device according to the present invention. FIG. 2 is a diagram showing the structure of one pixel of a liquid crystal display device according to the present invention. FIGS. 3 and 4 are diagrams showing voltage-transmittance characteristics of a liquid crystal display element used in an example of the present invention. FIG. 5 is a diagram showing a structure in which a diffraction grating is formed on the outer surface of a substrate constituting a liquid crystal display element. 6 and 7 are diagrams showing the structure of a color liquid crystal display device according to the prior art. ...Light source...Spectroscopic plate...Liquid crystal display element 6φ/Segment electrode...Common electrode 1 ・ ・ 2 ・ ・ 3 ・ ・ 4.5. 7th ・ 8 ・ 9 ・ 11 ・ 22 ・ 33 ・ Substrate color filter on the light source side of a liquid crystal display element Part of the light irradiated from the light source A minute diffraction grating for one pixel or more of a liquid crystal display device Applicant Seiko Epson Corporation Agent: Patent attorney Kisanbe Suzuki (and 1 other person) Figure 3↑

Claims (1)

[Claims] A liquid crystal display device comprising a liquid crystal display element and a light source for illuminating the liquid crystal display element, characterized in that a spectroscopic means is provided on the light source side at a position corresponding to each pixel of the liquid crystal display element.