LIQUID CRYSTAL DISPLAY DEVICE AND LIQUID CRYSTAL DRIVER

Abstract

In order to prevent the reproducibility of a display image from degrading due to the characteristic of a liquid crystal, a liquid crystal display device includes: a liquid crystal panel; a gray scale value generation unit which generates, based on a first gray scale value, a second gray scale value with a gray scale number smaller than the gray scale number of the first gray scale value; and a brightness control unit which sequentially controls the brightness of a corresponding liquid crystal pixel based on the second gray scale value generated by the gray scale value generation unit in a case where the first gray scale value is within a predetermined range, and which controls the brightness of the corresponding liquid crystal pixel based on the first gray scale value in a case where the first gray scale value is out of the predetermined range.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing a schematic configuration of a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a voltage applied to a liquid crystal, and the brightness.

FIG. 3 shows correspondences between 8-bit gray scale values D and gray scale values in 65 gray scales.

FIG. 4 is a diagram explaining operations by Frame Rate Control.

FIG. 5 is a diagram for the purpose of explaining a method of controlling the brightness.

FIGS. 6A, 613, 6C, and 6D are diagrams showing gray scale values for each frame in ¼ FRC.

FIGS. 7A, 7B, 7C, and 7D are diagrams showing gray scale values obtained for each frame in a case where “0” is added to all the gray scale values d0.

FIGS. 8A, 8B, 8C, and 8D are diagrams showing gray scale values for each frame in 2/4 FRC.

FIGS. 9A, 9B, 9C, and 9D are diagrams showing gray scale values for each frame in ¾ FRC.

FIG. 10 is a diagram showing the difference between the brightness obtained in a case where the applied voltage is controlled corresponding to the 8-bit gray scale value D, and the brightness obtained in the case where the applied voltage is controlled corresponding to the gray scale value in 65 gray scales.

Claims

1. A liquid crystal display device, comprising: a liquid crystal panel in which a plurality of liquid crystal pixels are arranged;a gray scale value generation unit which generates, based on a first gray scale value for determining the brightness of a liquid crystal pixel, at least one second gray scale value with a gray scale number smaller than the gray scale number of the first gray scale value; anda brightness control unit which sequentially controls the brightness of a liquid crystal pixel corresponding to the first gray scale value based on the second gray scale value generated by the gray scale value generation unit in a case where the first gray scale value is larger than a lower threshold value and smaller than an upper threshold value, and which controls the brightness of the liquid crystal pixel corresponding to the first gray scale value based on the first gray scale value in a case where the first gray scale value is not larger than the lower threshold value or is not smaller than the upper threshold value.

2. A liquid crystal display device, comprising: a liquid crystal panel in which a plurality of liquid crystal pixels are arranged;a gray scale value generation unit which generates, based on a first gray scale value for determining the brightness of a plurality of liquid crystal pixels, a plurality of second gray scale values with a gray scale number smaller than the gray scale number of the first gray scale value; anda brightness control unit which sequentially controls the brightness of each of the plurality of liquid crystal pixels corresponding to the first gray scale value based on the plurality of second gray scale values generated by the gray scale value generation unit in a case where the first gray scale value is larger than a lower threshold value and smaller than an upper threshold value, and which controls the brightness of the plurality of liquid crystal pixels corresponding to the first gray scale value based on the first gray scale value in a case where the first gray scale value is not larger than the lower threshold value or is not smaller than the upper threshold value.

3. A liquid crystal driver, comprising: a gray scale value generation unit which generates, based on a first gray scale value for determining the brightness of a liquid crystal pixel arranged in a liquid crystal panel, at least one second gray scale value with a gray scale number smaller than the gray scale number of the first gray scale value; anda brightness control unit which sequentially controls the brightness of a liquid crystal pixel corresponding to the first gray scale value based on the second gray scale value generated by the gray scale value generation unit in a case where the first gray scale value is larger than a lower threshold value and smaller than an upper threshold value, and which controls the brightness of the liquid crystal pixel corresponding to the first gray scale value based on the first gray scale value in a case where the first gray scale value is not larger than the lower threshold value or is not smaller than the upper threshold value.

4. A liquid crystal driver, comprising: a gray scale value generation unit which generates, based on a first gray scale value for determining the brightness of a plurality of liquid crystal pixels arranged in a liquid crystal panel, a plurality of second gray scale values with a gray scale number smaller than the gray scale number of the first gray scale value; anda brightness control unit which sequentially controls the brightness of each of the plurality of liquid crystal pixels corresponding to the first gray scale value based on the plurality of second gray scale values generated by the gray scale value generation unit in a case where the first gray scale value is larger than a lower threshold value and smaller than an upper threshold value, and which controls the brightness of the plurality of liquid crystal pixels corresponding to the first gray scale value based on the first gray scale value in a case where the first gray scale value is not larger than the lower threshold value or is not smaller than the upper threshold value.

5. The liquid crystal driver according to any one of claims 3 and 4, wherein the brightness control unit controls, based on the first gray scale value or second gray scale value, a voltage of a signal line which determines a voltage applied to a liquid crystal of each of liquid crystal pixels.