JPH05281524A - Liquid crystal electro-optical element and manufacture thereof - Google Patents

Abstract

PURPOSE:To perform color display capable of providing good appearance and bright display having the same electro-optical characteristics as that of a high polymer dispersion type liquid crystal electro-optical element in which a dichroism dystuff is not contained, by dispersing and orientating the dichroism dystuff at the high polymer side. CONSTITUTION:A transparent electrode ITO 12 and a transparent electrode ITO 15 are formed on a substrate 11 and a substrate 16, and a mixture of a liquid crystal 13, a high polymer 14 and a dichroism dystuff 18 is held between the substrates to form a cell. The most part of the dichroism 18 exists on the high polymer side and the dichroism dystuff 18 is dispersed and orientated on the high polymer side, thereby switching the state of absorbing light and the state of transmitting light. Thus, the dystuff is orientated within a high polymer, thereby causing the light absorption effect on the orientated dystuff due to the light dispersion effect of a liquid crystal and a high polymer without the dystuff being contained in the liquid crystal, so that the element shows the corresponding color to the dystuff. In the liquid crystal drive with an electrical field, the liquid crystal does not have any influence of the dystuff.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal panel using a liquid crystal electro-optical element such as a liquid crystal display.

[0002]

2. Description of the Related Art A dichroic dye type of a polymer-dispersed liquid crystal electro-optical element is a special type in which a dye 18 is dispersed in a liquid crystal 13 as shown in FIG. It is a display body. This polymer-dispersed liquid crystal electro-optical element containing a dichroic dye (hereinafter referred to as GH-PDLC) changes from a light absorbing state to a light transmitting state with application of a voltage. Utilizing this property, application as a light valve of a projection type liquid crystal projector or a display is also under study.

When the GH-PDLC is used as a liquid crystal display, the polarizing plate required in the conventional liquid crystal electro-optical element becomes unnecessary, and in combination with a color filter, an aperture for preventing scattered light in the optical system is not necessary. Therefore, a bright display element with good contrast may be obtained.

[0004]

[Problems to be Solved by the Invention] Conventional GH-PDLC
In, the dichroic dye was dispersed in the liquid crystal droplets or liquid crystal domains. Therefore, the threshold voltage, which is an electro-optical characteristic of the device, is increased, and there is a problem that a new driving IC driver is made for driving. Further, in some cases, a voltage of several tens of V or higher is required, and its use as an electronic device is limited.

The present invention has been made in order to solve such a difficulty, and its object is to have the same electro-optical characteristics as a polymer dispersion type liquid crystal electro-optical element which does not contain a dichroic dye. The aim is to provide a colored display that can be displayed brightly with good appearance.

[0006]

The liquid crystal electro-optical element and the method for producing the same according to the present invention are as follows: In the liquid crystal electro-optical element including the formed electrode substrate, most of the dichroic dye is present on the polymer side.

(2) It is characterized in that the dichroic dye is oriented perpendicular to the substrate.

(3) The polymer is characterized by being a polymer having a dye molecule introduced into the side chain of the polymer.

(4) The invention is characterized in that a force for orienting the dichroic dye is applied from the outside when the liquid crystal, the polymer and the dichroic dye are phase-separated and fixed.

(5) An electric field is a force for orienting the dichroic dye,
It is characterized by being a magnetic field.

[0011]

The liquid crystal electro-optical device of the present invention is a polymer-dispersed liquid crystal display device in which a dichroic dye is dispersed and oriented on the polymer side to switch between light absorption and light transmission. .. In the conventional method, since the dye is dispersed in the liquid crystal, the dielectric constant anisotropy of the dye and the difference in the alignment order with the liquid crystal tend to cause the threshold value and the steepness to be worse than those without the dye. .. However, by orienting the dye in the polymer, the dye is not contained in the liquid crystal, and the light scattering effect of the liquid crystal / polymer induces the light absorption effect of the oriented dye. Excuse me. Therefore, the element exhibits a color corresponding to the dye. Further, when the liquid crystal is driven by an electric field, the liquid crystal is not affected by the dye at all. Further, when the liquid crystal is aligned in the direction of the electric field, the dye does not have any influence on the light incident direction, so that the light transmitting state is realized.

According to the invention, a bright liquid crystal electro-optical element can be obtained because a color display of PDLC can be performed without causing deterioration of electro-optical characteristics due to a dye and a polarizing plate is unnecessary.

[0013]

【Example】

(Embodiment 1) In this embodiment, as a liquid crystal panel, a PDL having a display area of 5 mm × 5 mm in a 1 × 1 inch cell.
An example using the C element is shown. FIG. 1 is a cross-sectional view of a display element showing one configuration of the present invention. A cell in which the transparent electrode ITO 12 and the transparent electrode ITO 15 are formed on the substrate 11 and the substrate 16 and the mixture of the liquid crystal 13, the polymer 14, and the dichroic dye 18 is sandwiched between these substrates is shown. As the liquid crystal, MJ90657 manufactured by Merck was used. The liquid crystal is not limited to this embodiment and may be any type of liquid crystal such as cholesteric, smectic, nematic. As for the polymer and the dichroic dye, the side chain of the polymer was a dichroic dye as shown below.

[0014]

[Chemical 1]

X and Y were adjusted to be 1 and 15, respectively. This polymer and liquid crystal are 35:65 by weight, respectively.
The mixture was mixed so that the temperature was raised to 130 ° C., and the mixture was sealed in a cell. The cell was cooled slowly from 100 ° C. to 50 ° C. while an alternating current of 60 Hertz 100 V was continuously applied to the cell.
When the cell was returned to room temperature, the cell exhibited a light cyan color when no voltage was applied, and became transparent when an electric field of 50 V-60 Hz was applied. The cell thickness was 15 μm.

(Example 2) In this example, the same material as in Example 1 was used. After mixing and enclosing the cells, at 140 ℃, 10
0V-60 hertz was applied for about 2 hours, and immediately after 2 hours, it was cooled to room temperature. The applied voltage remained unchanged. With no voltage applied, the cell shows a light cyan color at room temperature, and 60V-
It became transparent when an electric field of 60 Hz was applied.

Comparative Example In a comparative example, 35% by weight of polyethylene oxide was used as the polymer and the following was used as the dichroic dye.

[0018]

[Chemical 2]

2% by weight of liquid crystal was used. The liquid crystal was the same as in the example. This cell exhibited a cyan color at room temperature.
It became transparent when a voltage of 100 V-60 Hz was applied.

[0020]

As described above, according to the present invention, by dispersively orienting dichroic dye molecules on the polymer side, color display of PDLC can be performed without deteriorating the electro-optical characteristics, and the contrast can be improved. It has become possible to provide a high-quality, bright display element.

[Brief description of drawings]

FIG. 1 is a drawing showing the concept of the present invention.

[Explanation of symbols]

 11 --- Glass Substrate 12 --- Transparent Electrode 13 --- Liquid Crystal 14 --- Polymer Matrix 15 --- Transparent Electrode 16 --- Glass Substrate 17 --- Device of the Present Invention 18 --- Dual Color Sex dye

Claims (5)

[Claims] 1. A liquid crystal electro-optical element comprising a liquid crystal polymer composite comprising a polymer, a liquid crystal and a dichroic dye, and electrode substrates arranged on both sides of the liquid crystal polymer composite, and most of the dichroic dye is Liquid crystal electro-optical element characterized by being present on the polymer side. 2. A liquid crystal electro-optical device characterized in that the dichroic dye is aligned perpendicular to a substrate. 3. A liquid crystal electro-optical element, wherein the polymer is a polymer in which a dye molecule is introduced into a side chain of the polymer. 4. A method of manufacturing a liquid crystal electro-optical element, wherein a force for orienting the dichroic dye is applied from the outside when the liquid crystal, the polymer and the dichroic dye are phase-separated and fixed. 5. A force for orienting the dichroic dye is an electric field,
A method of manufacturing a liquid crystal electro-optical element characterized by being a magnetic field.