JPS58223118A - Liquid crystal display element - Google Patents

Abstract

PURPOSE:To make the effective visual angle of a TN type liquid crystal display having a large number of time divisions wide and easy to see, by disposing two liquid crystal display parts having the same display font on the same substrate so as to have complementary visual angle directions of the max. contrast. CONSTITUTION:A display having the same display font (a set of types having the same type and size) is manufactured by placing a pair of glass substrates 1 provided respectively with transparent electrodes 2 and coated with oriented layers 3-1, 3-2 on the electrodes 2 so as to face to each other, sealing a TN type liquid crystal material 4 between the same, disposing a pair of polarization plates 5 on the front and rear surfaces in parallel Nicols or crossed Nicols, orienting initially the layers 3-1, 3-2 of display parts A, B to the states differing respectively in liquid crystal molecules, and adjusting the max. contrast after application of voltage so as to differ in the visual angles thereof. The element is thus driven time-dividedly with the same electric signal, and the liquid crystal display element having a wide region of the effective visual angle even if the number of time divisions is increased is obtd. For example, the rubbing directions of the front substrate are made as shown by solid lines in the parts A, B, and the directions on the rear substrate are made as shown by dotted lines, whereby the element is made easily visible by plural persons.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid crystal display element, and particularly to improvement of viewing angle characteristics thereof.

In recent years, the practical use of liquid crystal display elements (abbreviated as LCD) has been remarkable, especially the TN type (Twisted Nematic).
With the advent of type LCD, low voltage and low power consumption.

It became possible to obtain displays with long lifespans, and made a dramatic advance into the field of displays for watches, calculators, etc. Recently, with the improvement of liquid crystal materials, the duty ratio of time-division driving has become larger, making it easier to display characters, numbers, symbols, etc. using matrix electrodes, and attempts have also been made to apply them to terminals, etc. There is. However, there is a drawback that the larger the number of time divisions, the narrower the range of viewing angles. Generally based on time division drive <TN
In the display of a type LCD, the display contrast has a strong viewing angle dependence, and as shown in the example in FIG. 1, there is a maximum contrast viewing angle direction, and as the number of time divisions increases, the effective viewing angle area becomes narrower. As shown in Figure 1 (bl), the duty ratio is 1.
/8, the effective viewing angle area significantly decreases to about 40 degrees in the θ direction, making it impossible to follow even the slightest movement of the line of sight. Furthermore, the angle between the maximum contrast direction and the panel normal increases, making it difficult to see from the front.

The present invention eliminates the above drawbacks and provides a liquid crystal display element with a wide effective viewing angle area.

According to the present invention, in the liquid crystal display element in which a first liquid crystal display part and a second liquid crystal display part having the same font as the sealing part are formed on the same substrate, the first liquid crystal display part and the second liquid crystal display part are formed on the same substrate. A liquid crystal display element is obtained in which the liquid crystal display portions have different maximum contrast viewing angle directions. DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the liquid crystal display element according to the present invention will be described below with reference to the drawings.

FIG. 2 is a structural sectional view showing an example of a liquid crystal display element according to the present invention. The transparent electrode 2tl is set up by arranging a pair of glass substrates 1 on which the transparent electrodes are coated with alignment treatment layers 3-1 and 3-2, and hermetically sealing the periphery of the substrates with a sealing material 4, so that the space between the substrates is A pair of polarizing plates 5 are arranged in a parallel Nicols or crossed Nicols state on the front and back surfaces of a liquid crystal panel formed by filling a liquid crystal material 4 into a liquid crystal panel. The orientation treatment layer 3-1 of the display section and the orientation treatment layer 3-2 of the display section B indicated by arrow A are formed so that the liquid crystal molecules are initially oriented in different states, and the maximum contrast after voltage application is The viewing angle directions are 1l11i different between the display section and the display section B.

Further, the electrodes are arranged so that the display section A and the display section B have the same display font. When the display parts A and B of such a liquid crystal display element are time-divisionally driven with the same electrical signal and the same display is performed, the maximum contrast is adjusted so that the effective viewing angle areas of the image display parts are complementary. By determining the viewing angle direction, the conventional drawbacks can be eliminated and a liquid crystal display element with a wide viewing angle can be obtained. A specific example of this is shown below.

FIG. 3 shows a specific embodiment of the display element according to the present invention. FIGS. 3(a-1) and 3(b-1) are plan views showing the direction of lagging of the alignment treatment layer, and A and B show each display area. The solid line arrow in the figure indicates the direction of rubbing of the front glass substrate (see-through), and the broken line arrow indicates the direction of rubbing of the rear glass substrate (direct view) 1r. The direction of the maximum contrast viewing angle in the case where such alignment treatment by rubbing is performed and a counterclockwise liquid crystal material is used is as shown in the front views of FIGS. 3(a-2) and 3(b-2). Case (a-2) is suitable for display to a large number of people, and case (b-2) is suitable for - people to observe the display from the front of the display element. By arranging the maximum contrast viewing angle direction in a complementary manner in this manner, the problem of narrow viewing angle, which is a drawback of TN type LCDs with a large number of time divisions, can be solved.

As described above, the maximum contrast viewing angle direction is specified by 0° ψ, but θ is determined by the pretilt angle and drive voltage (depending on the number of effective voltage 2 time divisions) at the time of initial alignment of the liquid crystal material.
ψ is determined by the direction of loving and the direction of rotation of the liquid crystal material. Therefore, by appropriately selecting the material of the alignment layer, the direction of lagging, the liquid crystal material, the driving voltage, etc., the maximum contrast viewing angle can be set in any direction, making it possible to have a wide range of applications for various purposes. Become.

In order to confirm the viewing angle compensation effect based on the present invention, an alignment treatment layer was formed using polyimide, a rubbing treatment was performed as shown in Figure 3 (a-1), and Np liquid crystal ROTN-653 manufactured by RO-CHF was used as a liquid crystal material. Counterclockwise Kairam material C-15 (BDH
When a dot matrix LCD with a time division number of 8 is operated using a 1/4 bias voltage averaging method with a driving voltage of 5 V, the maximum contrast viewing angle direction of each of display sections A and B is as follows. θ=25°, effective viewing angle area is 3
It was 0゛.

As described above, according to the present invention, the drawbacks of the TN type LCD with a large number of time divisions can be eliminated, and a liquid crystal display element with a wide effective viewing angle area can be obtained.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the maximum contrast viewing angle direction and effective viewing angle area of a TN type LCD. 2 and 3 show an embodiment of the present invention. 1...Glass substrate, 2...Transparent electrode,
3...Alignment treatment layer, 4...Liquid crystal material, 5
······Polarizer. (a) (Shi2 Bud 1 Open13 A ¥2 Diagram

Claims (1)

[Claims] In a liquid crystal display element in which a first liquid crystal display part and a second liquid crystal display part having the same display font as the display part are formed on the same substrate, the maximum of the first liquid crystal display part and the second liquid crystal display part is A liquid crystal display element characterized by having different contrast viewing angle directions.