JPS60254122A - Liquid-crystal display element - Google Patents

Abstract

PURPOSE:To improve a maximum scanning line number characteristic and a threshold voltage characteristic by making the angle of orientation of a TN type liquid-crystal element less than 90 deg. and reducing the amount of a Chiral material to be added to a liquid-crystal material. CONSTITUTION:The orientation vector (rubbing direction) of a light-source side substrate 1 is denoted as r1 and the orientation vector (rubbing direction) of an observed value substrate 2 is denoted as r2; and the angle between r1 and r2 is set to 85 deg., and the amount of the added Chiral material is reduced from 1 to 0.5% when the orientation angle is 90 deg.. Consequently, the maximum scanning line characteristic Nmax is improved and a threshold voltage Vth is lowered. A figure (a) shows a clockwise uniform tilt and (b) shows a counterclockwise tilt.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is based on T N
) type liquid crystal display element improvement C: related.

A TN type liquid crystal display element is constructed by disposing a rotating nematic liquid crystal between a light source side substrate and an observation side substrate that face each other. When a voltage is applied to this liquid crystal layer, the liquid crystal molecules line up in the direction of the electric field, so they lose their rotational properties, and return to their original state when the electric field is removed. In this case, either light passes through when it has rotational properties, or light does not pass through the part to which voltage is applied because it does not have rotational properties, and display is performed using this.

[Conventional technology]

In conventional TN type liquid crystal display elements, the orientation angle (the angle formed by the orientation vector (rubbing direction) of one substrate and the orientation vector of the other substrate) is set to 90 degrees, and in this case, the chirality of the liquid crystal material The amount of material added is clockwise for uniform chilled M agent (manufactured by Chisso), C-15 agent (BD
It is customary to add about 1% of each product (manufactured by H). In addition, D.C.
For agent H.1 (manufactured by Dainippon Ink), add about 0.1%.

[Problems to be solved by the present invention]

This chiral amount and the maximum number of scanning lines Nrnax of display characteristics
The relationship between threshold voltage vth and voltage transmittance characteristics is shown in Figure 6 (0.1% addition of DCH 1 agent) and Figure 4 (M agent, C
-15 agent added at 1%).

It is clear from FIGS. 3 and 4 that as the chiral amount increases, the maximum number of scanning lines Nrnax decreases and the threshold voltage vth increases. That is, it can be seen that satisfactory characteristics are not obtained with the conventional chiral amount (0.1% in FIG. 3 and 1% in FIG. 4) when the orientation angle is 90 degrees.

[Means for solving problems]

The present invention aims to provide a liquid crystal display element that can solve the above-mentioned problems, and as a means for that purpose, the orientation angle of the liquid crystal display element is made smaller than 90 degrees and a chiral material is added to the liquid crystal material. I'm reducing the amount.

[Effect]

When the conventional orientation angle is 90 degrees, the standard chiral content of the M agent and C-15 agent is 1%, but in the present invention, as described above, the orientation angle is 90 degrees or less, and the orientation angle is 85 degrees.
For C2, the standard chiral amount is 0.5%. If the amount is less than that, reverse tilt will occur and display quality will be impaired.

〔Example〕

The present invention will now be described in detail with reference to FIGS. 1 and 2.

The relationship between the orientation angle and the amount of chiral added to a nematic liquid crystal material is shown in Figure 1 (=
As shown, when the orientation angle is smaller than 90 degrees, the required amount of addition becomes smaller. The present invention takes advantage of this, and the orientation angle is made smaller than 90 degrees to reduce the amount added. The amount added when the orientation angle is 85 degrees is 0.
．． The standard value is 5%, and if the amount is less than that, reverse tilt will occur and display quality will be impaired. In this way, when the amount of chiral material added decreases, Nmax increases and vth decreases.

Figure 2 shows the twist direction of a TN type liquid crystal display element. Figure 2 (cL) shows uniform tilt in the clockwise direction of rotation, and Figure 2 (b) shows reverse tilt (local reverse twist by applying voltage). Occurrence) & are shown respectively. In the figure, r is the orientation vector (rubbing direction) of the light source side substrate 1, r2 is the orientation vector of the observed value substrate 2, and the double arrow line in FIG. 2 (α) indicates the viewing angle direction.

〔Effect of the invention〕

As described above, according to the present invention (2), the orientation angle is set to 90
By making the threshold voltage Vth smaller than 40%, it is possible to reduce the amount of the chiral material which is an additive of the liquid crystal material, improve the display characteristics Nmax, and reduce the threshold voltage Vth -4-.

[Brief explanation of the drawing]

1 and 2 show examples of liquid crystal display elements according to the present invention. α
l j (A+ is a diagram explaining the twist direction. Figure 6 is a graph showing the relationship between the chiral amount and NmαX, and Figure 4 is a graph showing the relationship between the chiral amount and vth. In the figure, 1 is the light source side substrate , 2 indicates the observation side substrate, and rL+r2 indicates the orientation vector of each substrate.Patent applicant Fujitsu Ltd. agent Patent attorney Gobe Tamamushi (one other person) Figure 1 Orientation angle (degrees) Figure 2 (α )(b)

Claims (1)

[Claims] A TN type liquid crystal display element, characterized in that the alignment angle is smaller than 90 degrees and the amount of chiral material added to the liquid crystal material is reduced.