JPS63296017A - Liquid crystal display panel - Google Patents

Abstract

PURPOSE:To improve the display quality at the time of no-electric field, and to obtain a black and satisfactory contrast when an electric field is applied, by enclosing a substance having a high absorbance in long wavelength and short wavelength, into a nematic liquid crystal which contains a chiral substance and whose angle of torsion is 180-270 deg.. CONSTITUTION:Between glass substrates 2, a nematic liquid crystal which contains a chiral substance, and also, whose angle of torsion is 180-270 deg. is enclosed. If a variance exists in a gap between these glass substrates, when the gap is large, a reddish color is assumed, and when the gap is small, a bluish color is assumed. Therefore, a substance having a high absorbance in long wavelength and short wavelength areas as shown in the figure is enclosed. As a result, at the time of no-electric field, the reddish color due to the variance of the gap is softened and the display quality is improved. Also, when an electric field is applied, a satisfactory contrast by a black display can be shown.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a liquid crystal display panel.

BACKGROUND OF THE INVENTION Conventionally, a liquid crystal panel of this type has a structure as shown in FIG. In the figure, 1 is a polarizing plate, 2 is a glass plate with a transparent electrode, and 3 contains a chiral substance and has a twist angle of 180° to 2.
7oO nematic liquid crystal, 4 is sealing resin. Incidentally, the spectral characteristics of the polarizing plate 1 used here are approximately 9th.
It looked like the picture.

In such a conventional configuration, when an electric field is applied, 18
As a phenomenon peculiar to a liquid crystal display panel twisted by 0 to 270 degrees, the spectral characteristics change as shown in FIG. That is, A when there is no electric field, B when there is an intermediate electric field, and C when there is a high electric field.

Problems to be Solved by the Invention Since this type of liquid crystal display panel is normally dynamically driven, it cannot be used in characteristic C in FIG. 10 because crosstalk is strong.

Generally, spectral characteristics shown by characteristics A and B are used.

In the case of characteristic B, light on the short wavelength side was transmitted, the display area was blue, and good contrast could not be obtained.

In addition, in the case of characteristic A, since the birefringence effect is utilized, color unevenness occurs due to slight variations in the cell gap, which is a factor that deteriorates display quality and process yield.

The present invention aims to provide a liquid crystal display panel that can solve the above-mentioned drawbacks.

Means for Solving the Problems The liquid crystal display panel of the present invention is a liquid crystal in which a nematic liquid crystal with a twist angle of 180° to 2700 and a chiral substance is sealed between glass substrates. A substance with high absorbance is encapsulated.

Operation With the above configuration, when no electric field is applied, the reddish color that appears due to variations in the cell gap is alleviated, the display quality is improved, and the process yield can be improved. Furthermore, when an electric field is applied, it is possible to produce a panel that displays black and exhibits good contrast.

Embodiment [Embodiment 1] FIG. 1 is a sectional view of a liquid crystal display panel according to an embodiment of the present invention. In this figure, the same numbers as in FIG. 8 indicate the same parts, and 6 is a filter.

As described in the conventional example, for example, if there is variation in the gap between the glass plates 2, a large gap will give a reddish color, and a small gap will give a bluish color. This reddish color has a long wavelength, and if this portion is cut, color unevenness caused by gap variations will be alleviated. Therefore, in this embodiment, a substance exhibiting the absorbance shown in FIG. 2 is sealed in a liquid crystal.

As a result, the spectral characteristics when no electric field is applied and when an electric field is applied are as shown in FIG. As is clear from the figure, when no electric field is applied (A), the long wavelength side is attenuated, and when an electric field is applied (B), the short wavelength side is attenuated compared to the conventional case, and the color unevenness is alleviated.

A panel with a black color and a good display of con)9 strokes is obtained.

A comparison between the contrast obtained in this example and the conventional configuration is shown in the table below.

[Example 2] FIG. 4 shows a cross-sectional view of a liquid crystal display panel having an alignment film 6. In this embodiment, this alignment film 6 has a second
A material having the light absorption characteristics shown in the figure is enclosed, and the same characteristics as in Example 1 can be obtained.

[Embodiment 3] FIG. 6 shows a configuration according to another embodiment of the present invention, in which the upper filter 6a in the figure has the spectral characteristics shown in FIG. As the side filter 6b, a filter having the spectral characteristics shown in FIG. 6(b), that is, a long wavelength cut filter is used. The spectral characteristics of the liquid crystal display panel obtained in this example are as shown in FIG. In the figure, A is a characteristic diagram when no electric field is applied, and B is a characteristic diagram when an electric field is applied.

Effects of the Invention As described above, according to the present invention, when an electric field is applied, the short wavelength side remaining in the conventional configuration is cut off, making it possible to display black with good contrast. In addition, when there is no electric field, the long wavelength side is also cut, making it possible to alleviate color changes due to gap fluctuations and improve display quality.

Process yield can be improved. As described above, according to the present invention, a black display with good contrast can be obtained when an electric field is applied, and the display quality when no electric field is applied is improved, and at the same time, it is possible to improve the process yield.

[Brief explanation of the drawing]

Figure 1, Minoh Alley; Figures 4 and 6 are cross-sectional views of a liquid crystal display panel according to an example of the present invention; Figure 2 is a characteristic diagram of the absorbance of the substance used in this example; Figure 3; , FIG. 7 is a spectral characteristic diagram of this example, and FIG. 6(a). (G) is a filter characteristic diagram used in the embodiment shown in FIG. 6, FIG. 8 is a sectional view of a liquid crystal display panel according to the conventional example, and FIG.
The figure is a spectral characteristic diagram of the polarizing plate, and FIG. 10 is the spectral characteristic diagram of FIG. 8. 3...Liquid crystal, 5a...Short wavelength cut filter, 6b...Long wavelength cut filter, 6
...Alignment film. Name of agent: Patent attorney Toshio Nakao and one other person
Polarization loss l Figure 2 included Figure 3 Figure 6 Figure 7 included 4005f) 061) IJ70u (nm) Figure 8 Light amount Figure 10 Light amount

Claims (2)

[Claims] (1) The twist angle between the glass substrates is 180° to 270°
A liquid crystal display panel, which is a liquid crystal in which a nematic liquid crystal and a chiral substance are sealed, and a substance having high absorbance at long and short wavelengths is sealed in the liquid crystal or alignment film. (2) The twist angle between the glass substrates is 180° to 270°
A liquid crystal display panel comprising a nematic liquid crystal and a liquid crystal sealed with a chiral substance, and a filter for blocking long wavelength and short wavelength light is provided on a glass substrate of the liquid crystal.