JPH0588155A - Color liquid crystal display device - Google Patents

Abstract

PURPOSE:To easily provide a color liquid crystal display device having high resolution. CONSTITUTION:This device is provided with a plate-like cyan layer 1 turned to blue-green by absorbing red, a plate-like magenta layer 2 which is set in a state where it tightly contacts to the layer 1 and which is turned to red-purple by absorbing green, a plate-like yellow layer 3 which is set in a state where it tightly contacts to the layer 2 and which absorbs blue-purple, and a liquid crystal body in which the cyan layer 1, the magenta layer 2 and the yellow layer 3 are combined and whose color is turned by a subtractive color mixture method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color liquid crystal display device used as a display device of a data / image terminal.

[0002]

2. Description of the Related Art Conventionally, a display has been widely used as an output device of a data / image terminal because of its high-speed display and easy rewriting. Displays for processing have become indispensable.

The liquid crystal display LCD (liq
A liquid crystal display is one in which liquid crystal is sealed between transparent electrodes and sandwiched by polarizing plates rotated by 90 °. When no voltage is applied to the electrodes, the liquid crystal is an alignment film (rubbing, oblique vapor deposition, solution coating). The light passes through the polarizing plate due to the 90 ° twist, and when a voltage is applied, the liquid crystal molecules are aligned in a certain direction corresponding to the applied electric field, so that the polarizing plate blocks the light.

As a feature, low power consumption and easy battery drive enable thinness and cost reduction, which contributes to the dramatic development of downsizing of terminals.

The liquid crystal display LCD is a type of digital display in which a normally transparent liquid crystal material is enclosed between two glasses, and tin oxide (tin) is provided on the surface of each glass plate. And a transparent conductive film such as indium oxide is applied. The coating on the viewing side is etched into the shape of letter segments, each segment has a lead to the edge of the display, and when a voltage is applied between the front and back electrodes, the alignment of the molecules is disturbed. , Characters appear due to cloudiness of the liquid, and the characters can be read without emitting light.

The liquid crystal is composed of rod-shaped organic molecules, and is nematic depending on the arrangement of the molecules.
tic), cholesteric (cholesteri)
It is classified into three types, c) and smectic, and each has a regular arrangement, and therefore exhibits anisotropy in electrical, magnetic, optical, and other physical properties. In liquid crystal display LCDs, nematic liquid crystals are mainly used among them, and electrical anisotropy such as dielectric constant and conductivity and optical anisotropy such as refractive index are used. There are various types of LCDs depending on the type of liquid crystal and the optical effect used, but the typical one is the twisted nematic (T
The N: twisted nematic) system is widely used at present, and the molecular orientation is twisted by 90 ° in the off state, so that the incident polarization plane is rotated by 90 ° along the twist and passes through the right polarizer. When voltage is applied to it,
The twist is released, the molecules are rearranged in the direction of the electric field, and the plane of polarization does not rotate, so it cannot pass through the right polarizer. Therefore, the dark state and the bright state can be switched depending on the presence or absence of the voltage. In addition, a ferroelectric liquid crystal (FLC: ferr)
oelectric liquid crystal)
The method is to control the polarization direction of a chiral smectic C liquid crystal exhibiting ferroelectricity by an electric field, and is expected as a next-generation liquid crystal device because of its excellent high-speed response and memory property. At the stage of elucidation of basic physical properties and development of liquid crystal materials, it may be applied as a large-capacity display device or an optoelectronic device.

However, only the ECB system has a multi-color display function in the LCD itself, but in this system, the display color is sensitive to cell gap, temperature, voltage, etc. Hard to apply. On the other hand, red, green, and
A method has been devised that adds a fine blue filter to achieve full color. This is to form a filter in each pixel of a normal matrix LCD or an active matrix LCD by using a photo process, and the color dots of three primary colors can be independently controlled. This method is currently used in color liquid crystal televisions. Although it is applied, back light is required because the light absorption by the polarizer and the color filter is large and the transmittance of the panel is as low as 5 to 7%.

A large color display having a diagonal length of several meters in which a large number of LCD modules are arranged in a similar manner has been put to practical use.

As another colorization system, there is a method of writing images corresponding to red, green and blue on three liquid crystal cells and projecting the images on one screen through three primary color filters. The active matrix method, the laser writing method, the optical writing method, and the like described above are used for the liquid crystal cell, and is characterized in that a bright display can be obtained on a large screen.

On the other hand, color mixing [color mixtur
e] means that a color different from the original color is produced by superimposing two or more kinds of light, or by superimposing or mixing the absorbing substances, so that the case of superimposing light as in a color television is an additive color mixture. That is, the way of overlapping is the same part of the retina,
Or by irradiating light simultaneously or rapidly alternately in a finely divided form that cannot be visually decomposed. Spectral distribution of colors resulting from additive color mixture and tristimulus values (→ C
The IE color system is represented by weighted addition of the original colors. When superimposing transparent selective absorption films such as color films, it is called subtractive color mixing, and the resulting spectral transmittance is It is represented by the product of color spectral transmittances. In the case of halftone dot printing, subtractive color mixing and additive color mixing are performed at the same time, and mixing of pigments and dyeing of diffusing materials is a case of superimposing diffusible absorbing substances, which is a kind of subtractive color mixing, according to the Kubelka-Munk formula. It is represented.

[0011]

When a high resolution LCD of 1000 * 1000 class is mounted on a laptop computer, it is limited to a monochrome specification or a gradation specification because of structural restrictions. In the present situation, even in the guest-host type LCD, it is presently a single layer, that is, a single color, and it cannot be used as it is for the color display required for computer display. 1000 * 1 because it is necessary to have 3 times (R, G, B) in case of monochrome specification
The 000-class high-resolution LCD has a problem that the screen size is too large to be mounted on a laptop computer.

[0012] The present invention applies a subtractive color mixing method to a guest-host LCD, which combines absorbing materials to produce many colors, and provides a three-layer guest-host LCD, each of which is designed to absorb a different color. It is an object of the present invention to provide a color liquid crystal display device capable of realizing a compact high-resolution LCD without increasing the screen size because each pixel independently expresses a full color on a dot-by-dot basis.

[0013]

According to the present invention, a plate-shaped cyan layer that absorbs red and exhibits a blue-green color and a plate-shaped cyan layer that is installed in close contact with the cyan layer and that absorbs green and exhibits a reddish purple color are provided. A magenta layer, a tabular yellow layer that is installed in close contact with the magenta layer and absorbs blue-violet, a liquid crystal body that combines the cyan layer, the magenta layer, and the yellow layer to exhibit discoloration by the subtractive color mixture method, and this liquid crystal body Transparent electrode plates installed on both sides for applying an AC voltage to the liquid crystal body, polarizing plates installed on both outsides of the transparent electrode plate for rotating an incident polarization plane of the applied voltage by 90 °, and the polarizing plate and the transparent electrode. A color liquid crystal display device comprising a plate and a glass substrate sandwiching and fixing a liquid crystal body.

[0014]

In the color liquid crystal display device according to the present invention,
A cyan layer that absorbs red color to give a blue-green color, a magenta layer that absorbs green color to give a red-purple color, and a yellow layer that absorbs blue-violet color are combined, and a color change due to the subtractive color mixture method occurs, and a liquid crystal is formed by a transparent electrode plate. A polarizing plate for applying an alternating voltage to the body and rotating the incident polarization plane of the applied voltage by 90 ° by the polarizing plate;
The transparent electrode plate and the liquid crystal body are sandwiched and fixed.

[0015]

EXAMPLE An example of the present invention will be described below. FIG. 1 shows a plate-shaped cyan layer 1 that absorbs red and exhibits a blue-green color, a plate-shaped magenta layer 2 that is installed in close contact with the cyan layer 1 and that absorbs green, and exhibits a reddish-purple color, and a magenta layer 2. A plate-shaped yellow layer 3 that is closely attached and absorbs blue-violet, a liquid crystal body that combines the cyan layer 1, the magenta layer 2, and the yellow layer 3 to cause discoloration by the subtractive color mixture method, and is installed on both sides of the liquid crystal body. Transparent electrode plates 4 and 4a for applying an alternating voltage to the liquid crystal body,
Polarizing plates 5 and 5a which are installed on both outer sides of the transparent electrode plates 4 and 4a and rotate the incident polarization plane of the applied voltage by 90 °, and the polarizing plates 5 and 5a, the transparent electrode plates 4 and 4a, and the liquid crystal body are sandwiched therebetween. 1 illustrates a color liquid crystal display device including a glass substrate to be fixed.

That is, 1 is a cyan layer, 2 is a magenta layer, 3 is a yellow layer, and many colors are created by the subtractive color mixing effect.

Reference numerals 5 and 5a denote polarizing plates, which are filters for converting circularly polarized white light, which serves as a light source, into linearly polarized light.

Reference numeral 7 is a dye molecule (dichroic pigment), and a dye of a required color is mixed in each of the cyan layer 1, the magenta layer and the yellow layer.

6 is a liquid crystal molecule, and when an electric field is applied,
With the property of aligning the major axis in the direction of application, three layers of monochromatic guest-host LCDs that currently consist of one layer are laminated, and cyan, magenta, and yellow dyes are mixed in each, and the voltage applied to the electrodes of each layer By controlling the size of each pixel, full color display can be realized by the effect of subtractive color mixing for each pixel on a dot-by-dot basis.

FIG. 2 shows the case where no electric field is applied (V = 0) to all three layers. When no electric field is applied to all three layers, the flow crystal molecules 6 and the dichroic dye 7 mixed in each layer are polarized. Since it is parallel to the direction, the light linearly polarized by the polarizing plate 5a is absorbed by the dichroic dye 7 and colored.

Next, as shown in FIG. 3, when an electric field is applied to all three layers, the liquid crystal molecules 6 are aligned with their direct axes in the direction of the applied electric field. The dichroic dye 7, which is mixed so as to be attracted thereto, also follows the direction of the electric field application.

The above is the basic operation of the guest-host type liquid crystal, but if the electric field application to each layer is controlled separately, the light absorption can also be changed, so full color can be realized by the subtractive color mixture method.

Since only one dot is required to obtain a color display of 7 pixels, a full color panel for a laptop computer which has a high resolution and is compact can be easily realized.

As another application example, the present invention is used in general laptop computers which have a high resolution and require a color LCD which is required to be compact.

As described above, the present invention is a guest host type L
In addition to using a CD, it is not necessary to use a color filter, and since the three laminated layers act on the color development by the subtractive color mixture method, the number of electrodes in the lateral direction is increased as seen in a CRT or a current color LCD. It is not necessary to make it three times as large as the monochrome specification, and this has an effect that a compact color LCD can be mounted on a laptop computer while having a high resolution.

[0026]

According to the present invention, a high-resolution color display device can be easily provided.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a color liquid crystal display device showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing the operation of FIG.

FIG. 3 is an explanatory diagram showing the operation of FIG.

[Explanation of symbols]

 1 ... Cyan layer 2 ... Magenta layer 3 ... Yellow layer 4 ... Transparent electrode plate 5 ... Polarizing plate

Claims (1)

[Claims] 1. A plate-shaped cyan layer that absorbs red and exhibits a blue-green color, a plate-shaped magenta layer that is installed in close contact with the cyan layer and that absorbs green and exhibits a reddish-purple color, and a magenta layer. A plate-shaped yellow layer that is closely attached and absorbs blue-violet, a liquid crystal body that changes color by subtractive color mixing by combining the cyan layer, the magenta layer, and the yellow layer, and is installed on both sides of this liquid crystal body. A transparent electrode plate for applying an AC voltage to the liquid crystal body, a polarizing plate installed on both outer sides of the transparent electrode plate for rotating an incident polarization plane of the applied voltage by 90 °, the polarizing plate, the transparent electrode plate, and A color liquid crystal display device comprising a glass substrate which is sandwiched and fixed with a liquid crystal body.