JPH0192722A - Transmission type liquid crystal display element - Google Patents

Abstract

PURPOSE:To eliminate the difference of brightness of a display pattern and a background color at the time of non-display and to obviate a skeleton visible phenomenon by forming a white mask layer in a part excluding a display pattern electrode where the upper electrode and the lower electrode are formed so as to be opposed to each other. CONSTITUTION:As for the titled display element, a conventional black mask layer is changed to a white mask 12, and when a voltage is applied between the upper and the lower electrodes 3, 9, a display pattern A is bright and looks like a colored light and a background color B becomes black. Also, when no voltage is applied between the electrodes 3, 9, the arrangement of liquid crystal molecules between a display pattern electrode 3a and the lower electrode 9, and in a part where the upper and the lower electrode 3, 9 are not opposed becomes horizontal, the display pattern A becomes a little bright, but since a light beam from an observer side is reflected by the white mask layer 12, the background part B also becomes a little bright. In such a way, the difference of brightness of the display pattern A and the background part B is eliminated, and a skeleton visible phenomenon occurred up to the present can be prevented.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a transmission type liquid crystal display element.

[Conventional technology]

Figures 3 and 4 are explanatory diagrams of the conventional example. Figure 3 is a cross-sectional view with voltage applied to the upper and lower electrodes (during display), and Figure 4 is a cross-sectional view with no voltage applied. It is a sectional view of a state (when not displayed).

In FIG. 3, reference numeral 1 denotes an upper glass substrate, a polarizing plate 2 is provided on the upper surface of the substrate 1, and an upper electrode 3 is provided on the lower surface. In addition, the display pattern of the pole 3 is placed on the electrodes 3 except for the electrode 3a, and on the glass substrate 1 except for the electrode 3.
A black mask layer 4 is provided. This mask layer 4 is made of ink whose main component is alkyd resin face, and carbon 10 = 20w 1%, or carbon 5~
10wt% and yellow.

It is formed by adding 10 to 15 wt% of red and blue pigments to form a black ink, and applying this to a thickness of 1 to 3 μm. An alignment film 5 is formed under this mask M4. 6
is a lower glass substrate, and a polarizing plate 7 is provided on the lower surface of the substrate 6.
Color filters 8 are sequentially formed, a lower electrode 9 is formed on the upper surface of the substrate 6, an alignment film 13 is formed thereon, and the polarizing plates 2 and 7 have polarization axes parallel to each other;
A liquid crystal 10 is sealed between the two law plates 1°6.

When no voltage is applied between the picture electrodes 3 and 9, the light that has passed through the color filter 8 passes through the polarizing plate 7 and is rotated (twisted) by the liquid crystal molecules 1o. Therefore, both the display pattern A and its background part B have a dark color (black).

Furthermore, when a voltage is applied between the picture electrodes 3 and 9, the optical rotation of the liquid crystal molecules 10 is released, and the light that has passed through the color filter 8 is transmitted to the polarizing plate 7. Colored light is visible in display pattern A through the liquid crystal cell and polarizing plate 2. Note that the background portion B of the display pattern A is shielded from light by the mask layer 4 and appears black.

[Problem that the invention seeks to solve]

However, in the case where no voltage is applied between the picture electrodes 3 and 9, only the display pattern A is displayed because there is a part where the mask layer 4 is formed and a part C where the mask layer 4 is not formed. It is slightly visible and a so-called bone visible phenomenon occurs. In order to prevent this phenomenon, a method has been proposed in which a black dichroic dye is added to the liquid crystal lO to absorb light, but this cannot be completely prevented.

The present invention is an attempt to solve the above-mentioned conventional problems, and the main purpose of the present invention is to provide a transmissive liquid crystal display element that can prevent the visible bone phenomenon.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention forms a white mask layer in a portion other than a display pattern electrode in which an upper electrode and a lower electrode are formed facing each other.

[Effect]

According to the present invention, when no voltage is applied to the upper and lower six electrodes, light from the viewer side is reflected by the white mask layer, eliminating the difference in brightness between the background area and the display pattern area. Therefore, the phenomenon of visible bones in the display pattern is eliminated.

〔Example〕

Hereinafter, the present invention will be explained based on the accompanying drawings.

FIG. 1 is a sectional view of the liquid crystal display element during display, and FIG. 2 is a sectional view of the liquid crystal display element during non-display. Note that the same parts as in the conventional example shown in FIGS. 3 and 4 are given the same reference numerals, and redundant explanation will be omitted.

The difference between the present invention and the conventional example is that the conventional black mask layer 4
The difference is that the mask layer 12 is replaced with a white mask layer 12.

This mask layer 12 is made by adding 5 to 15 wt of titanium oxide (white pigment) to ink whose main component is alkyd resin face.
The offset ink Me White manufactured by Dainippon Ink Co., Ltd. was used as the titanium oxide.

When a voltage is applied between the upper and lower electrodes 3.9 of the liquid crystal display element of the present invention, the display pattern appears bright and colored light, and the background color B becomes black, as in the conventional case.

Also, if no voltage is applied between the electrodes 3.9, the second
As shown in the figure, between the display pattern electrode 3a and the lower electrode 9,
and the liquid crystal molecules 1 in the part where the upper and lower electrodes 3.9 do not face each other.
The array of 0's is horizontal, and the display pattern A becomes slightly brighter, but since the light from the viewer side is reflected by the white mask layer 12, the background portion B also becomes slightly brighter. Therefore, there is no difference in the brightness between the display pattern A and the background portion B (2) 8A, and the bone-visibility phenomenon that has conventionally been observed can be prevented.

This effect is particularly remarkable in LCDs in which no dichroic dye is added to the liquid crystal 10.

〔Effect of the invention〕

According to the present invention, since there is no difference in brightness between the display pattern and the background color when the display is not displayed, the conventional bone visibility phenomenon can be resolved.

[Brief explanation of the drawing]

1 and 2 are explanatory diagrams of the present invention, in which FIG. 1 is a sectional view of the liquid crystal display element during display, FIG. 2 is a sectional view of the liquid crystal display element during non-display, and FIGS. The figure is an explanatory diagram of a conventional example.
FIG. 3 is a sectional view of the liquid crystal display element during display, and FIG. 4 is a sectional view of the liquid crystal display element during non-display. 1... Upper glass substrate, 3... Upper electrode. 3a...Display electrode pattern, 6...Lower glass substrate, 9...Lower electrode, 10...
...Liquid crystal, 12...Mask layer.

Claims (1)

[Claims] 1. A transmissive liquid crystal display element, characterized in that a white mask layer is formed in a portion other than a display pattern electrode in which an upper electrode and a lower electrode are configured to face each other.