JPH09105914A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display device having a wide visual angle by providing a command part for commanding the number of times of a voltage applied within a write time of once in the same pixel of a liquid crystal and an application part for applying a prescribed voltage to the same pixel according to the number of commanded times from the command part. SOLUTION: The liquid crystal display of the liquid crystal display device 10 is the display of a normally white type TN cells, that is, the one where the polarization directions of two sheets of polarizers are made orthogonally crossed, and an interruption state of light is made its on-state. The display is constituted so that the liquid crystal 113 is oriented twisting by 90 deg. by a pair of oriented plates 114, 115 with minute grooves between a pair of transparent electrodes 111, 112 at an interval of several μm to 10μm extent, and a pair of polarizing plates 118, 119 are arranged twisting by 90 deg. through a pair of glass substrates 116, 117 on the outside of the oriented plates. Further, the drive part 12 of the liquid crystal display device 10 is constituted so that a voltage application part 121 applies the voltage from a power source 122 between the transparent electrodes 111, 112 according to the number of applied times of the voltage from a number of applied times command part 123.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device using liquid crystal used in, for example, a television or a CRT of a computer terminal.

[0002]

2. Description of the Related Art The liquid crystal display (LCD) of the above-mentioned liquid crystal display device has recently been attracting attention because it can be thinned and lightened and has low power consumption. When an external field such as an electric field or heat is applied to the LCD, an alignment state or a phase change of liquid crystal molecules occurs due to an electric field, a current, or a temperature rise, and light interference, scattering, diffraction, optical rotation in the liquid crystal state,
The operating principle is that the optical properties such as selective scattering and absorption change. Therefore, the operation mode of the LCD is classified according to the external field, the type of optical change, the phase of the liquid crystal constituting the device, the dielectric anisotropy, the orientation state, and the like. As one of LCD operation modes, TN (twisted nemati)
c: twist nematic) mode, which is a low voltage,
It is the most widely used among various operation modes because it is possible to manufacture an LCD having features such as low power consumption and long life.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention TN LCD described above
Has a high viewing angle dependency, and therefore has a drawback that the display is unclear depending on the viewing direction and the visibility is deteriorated. As a means for improving such deterioration of visibility, a TN type LCD
It is proposed that the alignment film of (1) has a plurality of patterns. However, in such a TN type LCD, when liquid crystal molecules rise, they are energetically equivalent to each other in right and left directions, so that a disclination called a tilt domain occurs when a voltage is applied. Therefore, there is a problem that the area of the black mask increases and the characteristics such as a decrease in aperture ratio deteriorate.

The present invention has been made to solve the above problems, and an object thereof is to provide a liquid crystal display device having a wide viewing angle.

[0005]

According to the present invention, there is provided a liquid crystal display device for displaying characters, figures, etc. using a liquid crystal, wherein the liquid crystal is applied within one writing time in the same pixel. This is achieved by including a command unit that commands the number of times of the voltage to be applied, and an application unit that applies a predetermined voltage to the same pixel according to the command number from the command unit.

According to the above arrangement, since halftone display is performed mainly by turning on and off a voltage having a relatively wide viewing angle, it is possible to improve the visibility.

[0007]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Although the embodiments described below are preferred specific examples of the present invention, various technically preferable limitations are given. However, the scope of the present invention is not limited to the following description. It is not limited to these forms unless otherwise stated.

FIG. 1 is a diagram showing an embodiment of a liquid crystal display device of the present invention. A liquid crystal display (LCD) 11 of the liquid crystal display device 10 is a normally white TN cell, that is, one in which the polarization directions of two polarizers are made orthogonal to each other, and an ON state is a light blocking state. is there. Several μ
A pair of transparent electrodes 111, 11 with an interval of about m to 10 μm
The liquid crystal 113 between the two is a pair of alignment plates 11 having fine grooves.
4 and 115 are twisted and oriented by 90 °, and a pair of deflection plates 118 and 119 are arranged on the outer side thereof with a pair of glass substrates 116 and 117 offset by 90 °.

The drive unit 12 of the liquid crystal display device 10 is
The voltage application unit 121 is configured to apply the voltage from the power source 122 between the transparent electrodes 111 and 112 according to the number of times the voltage is applied from the application number command unit 123.

An example of the display operation in such a configuration will be described. When performing normal black and white display, the voltage application unit 121 turns on / off a predetermined voltage between the transparent electrodes 111 and 112. That is, when no voltage is applied between the transparent electrodes 111 and 112, as shown in FIG. 1, the light passing through the deflecting plate 118 is rotated 90 ° by the layer of the liquid crystal 113 twisted by 90 ° and the other deflecting plate is rotated. Pass 119.

When a voltage is applied between the transparent electrodes 111 and 112, as shown in FIG. 2, the molecules of the liquid crystal 113 become parallel to the electric field, and the light passing through the deflection plate 118 remains as it is. However, the other deflector 119 blocks the light. In this way, the liquid crystal 113 serves as a switch that allows or blocks light to be displayed, thereby displaying characters and images.

On the other hand, in the case of gray display, the voltage applying section 121 follows the number of times the voltage is applied from the application number commanding section 123 and the transparent electrode within one writing (one frame) time in the same pixel of the liquid crystal 113. A predetermined voltage is turned on / off between 111 and 112. For example, when performing gray display at the 50% transmittance level, the number of times the voltage is applied is instructed from the application number instruction unit 123 to be “2”, so that one frame time is divided into two as shown in FIG. , A predetermined voltage is applied for ½ frame time, and the remaining ½ frame time is not applied. As described above, by alternately displaying the on / off states having low viewing angle dependence, it is possible to artificially perform gray display at the intermediate level of the transmittance of 50%. Therefore, it is possible to improve the viewing angle dependence of the intermediate level. In addition, flicker due to voltage change within one frame can be realized at a level of 60 Hz, which is almost invisible to the eye.

The voltage applied when divided within one frame time is divided and converted according to the display level. The conversion method is set so that n-1 is either on or off when divided into n. As a result, display with low viewing angle dependency can be performed. For example, the transparent electrodes 111, 1
In an atmosphere of 60 ° C. with a distance between 12 of 2.7 μm, on was 4 ms and off was 12 ms.

[0014]

As described above, according to the present invention, the influence of variations in device characteristics is small, multi-gradation display is easy, low voltage driving is possible, and the structure is simple and the manufacture is easy. Therefore, an inexpensive liquid crystal display device can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing one mode of a liquid crystal display device of the present invention.

FIG. 2 is a diagram for explaining the operation of the liquid crystal display device shown in FIG.

3 is a diagram showing an example of a drive voltage of the liquid crystal display device shown in FIG.

[Explanation of symbols]

 10 liquid crystal display device 11 liquid crystal display 12 drive unit 111, 112 transparent electrode 113 liquid crystal 114, 115 alignment plate 116, 117 glass substrate 118, 119 polarizing plate 121 voltage application unit 122 power supply 123 application frequency command unit

Claims (3)

[Claims] 1. A liquid crystal display device for displaying characters, figures, etc. using liquid crystal, and a command section for commanding the number of times of a voltage to be applied within one writing time in the same pixel of the liquid crystal, and the command section The liquid crystal display device, comprising: an applying unit that applies a predetermined voltage to the same pixel in accordance with the number of times of the instruction. 2. The liquid crystal display device according to claim 1, wherein the application section applies voltage-on or voltage-off n-1 times to the command number n (n is a positive integer). 3. The liquid crystal display device according to claim 1, wherein the liquid crystal is a twisted nematic type.