JPS61254903A - Liquid crystal color display device - Google Patents

Abstract

PURPOSE:To obtain a clear image by using a specified blue phthalocyanine pigment as a blue coloring material for a color filter in a liq. crystal color display device so as to prevent superposition on transmission spectra from other color filters. CONSTITUTION:A blue phthalocyanine pigment represented by the formula (where X is H, Cl or a substituent) is used as a coloring material for the blue image element filter 33c of a color filter 33 in a TN type liq. crystal cell 21. A coating material prepd. by dispersing the blue pigment in a binder is applied by printing or other method to form the filter 33c. Since the wavelength region of the half-width of the blue pigment does not extend to the green wavelength region, the mixing of colors among the blue image element filter 33c, other red and green image element filters 33a, 33b is not caused. Accordingly, clear and full color image display is carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid crystal color display device using a liquid crystal element as an optical switching element.

Color display devices that apply liquid crystal elements have been attracting attention in recent years because they can be made thinner.
11-240''.

Among liquid crystal color display devices, those using a liquid crystal element as a light shutter are expected.

In this method, pixel color filters of three primary colors, R2O and B, are arranged corresponding to the pixel electrodes of a liquid crystal element, and the light transmitted through the color filters is observed by illuminating with a backside light source.

Color filters used in such devices are required to have high transmittance and clear colors. Furthermore, if the transmission spectrum of a filter of another color overlaps, color mixing occurs and the color tone deteriorates. Therefore, in order to display a clear color image, it is necessary to prevent the half-value widths from overlapping with the transmission spectra of filters of other colors.

Traditionally, color filters have been made by dyeing casein, gelatin, polyvinyl alcohol, synthetic proteins, or by dyeing photoresist.
It was formed into a mosaic shape. In addition, dyes have also been formed by electrodeposition on electrodes.

However, with these methods, there are limits to the selection of dyes, and sufficient color display cannot be achieved.The present invention aims to achieve clear color display in a liquid crystal color display device. purpose.

The liquid crystal color display device of the present invention includes a liquid crystal element that controls the transmission/blocking of electromagnetic waves according to image information, and a pixel-like color filter, and the liquid crystal color display device includes a liquid crystal element that controls the transmission/blocking of electromagnetic waves according to image information, and a pixel-shaped color filter, and converts the transmitted light of the liquid crystal element into the color filter. In a liquid crystal color display device in which am is transmitted through a filter, as a blue coloring material of the color filter,
It is characterized by mainly using a phthalocyanine pigment represented by the general formula (I).

(In the formula, or represents hydrogen or a substituent.) The present invention will be explained in more detail below.

FIG. 1 is a sectional view schematically showing an embodiment of the present invention. a first substrate 15 with transparent electrodes 11, 13 respectively;
and a second substrate 17 are arranged to face each other, and this substrate 15
．． A TN type liquid crystal cell 21 is formed by sealing a TN type liquid crystal substance between the cells 17 and 17 . Reference numeral 19 indicates a sealing material, and the liquid crystal cell 21 has a deflection plate 23 on the tR detection side and a deflection plate 2 on the back side.
A 90'-TN type liquid crystal element 31 is sandwiched between the two. This liquid crystal element can control the transmission and blocking of light from the light source 41 by applying a signal voltage between the electrodes 11 and 13, and functions as a light switching element. The light source 41 includes a phosphor layer 43 and an ultraviolet lamp 45 as an energy source. 47
is a substrate holding a phosphor layer.

On the outer surface of the second substrate 17, a color filter 3 for 5 pixels is provided.
3 is formed. The color filter 33 includes an R pixel filter 33a that selectively transmits red light, a G pixel filter 33b that selectively transmits green light, and a B pixel filter 33c that selectively transmits blue light. A full-color image is displayed by observing the light transmitted through each pixel filter 33a, 33b, and 33c using the liquid crystal element 31 as a light shutter.

As the main coloring material of the B pixel filter 33c.

A phthalocyanine pigment represented by the general formula (I) is used. Particularly preferred phthalocyanine pigments are those in general formula (I) in which X is hydrogen and salt Q. The phthalocyanine pigment of the present invention is
It has spectral characteristics suitable as a coloring material for a blue filter in a liquid crystal color display device, and the half-width wavelength range does not extend to the green light wavelength range, so color mixing can be effectively prevented. - As an example, the spectral transmission spectrum of a filter in which a phthalocyanine pigment in the general formula (r) in which X is hydrogen is dispersed in a resin binder and applied to a thickness of about 3 μm is shown as TR in FIG. The color filter 33 can be formed by dispersing pigment in a resin binder and patterning it by a printing method such as screen printing or a photoetching method using a photoresist. The pigment is preferably fine particles with an average particle size of 2 μm or less. The thickness of the color filter is 1~
Approximately 5 μm is appropriate, and preferably 1 to 5 μm. Moreover, each color filter can also cut unnecessary wavelengths or control color tone using a plurality of color materials.

The coloring materials used for the G pixel filter 33b and the R pixel filter 33a are appropriately selected so that the half widths of their transmission spectra do not overlap, and examples thereof include phthalocyanine green and quinacridone red pigments. Preferred G pixel filter-like pigments include phthalocyanine pigments represented by the following general formulas (II), (m), or (TV).

(y, )nz (y 4) n.

(In the formula, Yl, Y,, Y,, Y4 represent C1 or Br, and n1r nxt na+ n* represents 1 to 4.) (In the formula, z,, z,, z,, z4 represent C1. 1m1゜m2.m, , m indicates 1 to 4) (In the formula, Y, , Y, , Y, , Y is H or COON
Fig. 3 shows the spectral transmission spectrum of a phthalocyanine pigment containing 15 to 16 CIs in the general formula (II) in which X is CI.

In FIG. 1, the phosphor layer 43 can be formed by dispersing and coating phosphor particles that emit light in R, G, and B in a binder. Further, the phosphor can be formed in the shape of R, G, and B pixels corresponding to each of the R2O and B pixel filter sections.

The light emitted from the phosphor is additively mixed by a color filter, and a brighter and better color image can be obtained. Here, the relationship between the emission spectrum of the phosphor and the transmission spectrum of the color filter is important, but the phthalocyanine-based blue pigment of the present invention has a transmission spectrum suitable as a coloring material for the B filter, so it can be used for good color display. It can be realized. FIG. 2 shows an example of the phosphor emission spectrum as EB.

The position of the color filter is not limited to that shown in FIG. 1, and can be formed, for example, on the transparent electrode, on the first substrate surface, or on the polarizing plate 25, on another separate substrate, etc. It can also be provided in

The main feature of the present invention is to use a phthalocyanine-based blue pigment in a color filter of a liquid crystal color display device, and other components may be appropriately selected.

For example, electroluminescence (E
L) A light emitter, a fluorescent lamp, a white lamp, etc. can be used, and as for the liquid crystal element, any liquid crystal element can be used as long as it functions as a light shutter, such as a guest-host type.

According to the present invention, a clear color image display can be realized by using a phthalocyanine blue pigment represented by the general formula (I) as a blue coloring material of a color filter in a liquid crystal color display device. .

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of a liquid crystal color display device according to the present invention. FIG. 2 is a graph showing an example of the spectral transmission spectrum of the phthalocyanine-based blue pigment used in the present invention and the emission spectrum of the phosphor. FIG. 3 is a graph showing the spectral transmission spectrum of a green pigment. 11.13...Transparent electrode 15...First substrate 1
7... Second substrate 21... Liquid crystal cell 31...
・Liquid crystal element 33...Color filter 41...
・Light source 43... Phosphor layer 45... Ultraviolet lamp city 1 (2) Flame 20 Procedural amendment June 27, 1985 Manabu Shiga, Commissioner of the Patent Office 1, Indication of case 1985 Patent Application No. 95544 No. 2, Name of the invention Liquid crystal color display device 3, Relationship to the amended case Patent applicant 1-3-6 Nakamagome, Ota-ku, Tokyo (674) Ricoh Co., Ltd. Representative Hama 1) Hiro 4 , Agent 5, Ichibancho Phoenix Building, 15-1 Ichibancho, Chiyoda-ku, Tokyo, Subject of amendment (I) Column 6 of "Detailed Description of the Invention" of the specification, Contents of amendment (I) Specification No. On page 8, line 4, after rclJ, insert ``or BrJl.''

Claims (1)

[Claims] 1. It has a liquid crystal element that controls transmission/blocking of electromagnetic waves according to image information and a pixel-shaped color filter, and the light transmitted through the liquid crystal element is observed through the color filter. In the liquid crystal color display device, the blue coloring material of the color filter is mainly represented by the general formula (I) ▲ mathematical formula, chemical formula, table, etc. ▼ (wherein, X represents hydrogen or a substituent). A liquid crystal color display device characterized by using a phthalocyanine pigment.