LIQUID CRYSTAL DISPLAY

• US 20150035869A1
• Filed: 02/13/2013
• Published: 02/05/2015
• Est. Priority Date: 02/15/2012
• Status: Abandoned Application

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Mori, Tomohiko, Tomizawa, Kazunari, Hasegawa, Makoto, Yoshida, Yuichi
• Application Number:
  US14/378,188
• Publication Number:
  US 20150035869A1
• Time in Patent Office: Days
• US Class Current: 345/690
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/0247 Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes
• CPC Class Codes: G09G 2320/0271 Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping
• CPC Class Codes: G09G 2320/028 by changing the viewing angle properties, e.g. widening the viewing angle, adapting the viewing angle to the view direction
• CPC Class Codes: G09G 2320/068 for control of viewing angle adjustment
• CPC Class Codes: G09G 3/2007 Display of intermediate tones
• CPC Class Codes: G09G 3/36 using liquid crystals

Abstract

In a display apparatus having a liquid crystal panel, a change in luminance of the entire display frame when overshoot driving is performed is suppressed, while improving a viewing angle of the liquid crystal panel. A processing unit performs a high gradation display displaying a gradation higher than a gradation of an input image at one of two adjacent pixels, performs a low gradation display displaying a gradation lower than a gradation of an input image at the other of the two adjacent pixels, and switches between the high gradation display and the low gradation display for each pixel every display frame. A correction unit corrects a gradation of a pixel located adjacent to a pixel displayed with a gradation for which predetermined overshoot driving is difficult in the next display frame to a gradation for which overshoot driving stronger than the predetermined overshoot driving is possible.

Claims

1. A liquid crystal display apparatus comprising:

a liquid crystal panel having a plurality of pixels disposed in a matrix pattern; and

a viewing angle improvement unit that performs a process of improving a viewing angle of the liquid crystal panel,

wherein the viewing angle improvement unit includes;

a processing unit that performs a high gradation display displaying a gradation higher than a gradation of an input image at one of two adjacent pixels, performs a low gradation display displaying a gradation lower than a gradation of an input image at the other of the two adjacent pixels, and switches between the high gradation display and the low gradation display for each pixel every display frame; and

a correction unit that corrects a gradation of a pixel located adjacent to a pixel displayed with a gradation for which predetermined overshoot driving is difficult in the next display frame to a gradation for which overshoot driving stronger than the predetermined overshoot driving is possible, and

wherein, when there is the pixel displayed with a gradation for which predetermined overshoot driving is difficult, the processing unit displays a pixel located adjacent to the pixel displayed with a gradation for which predetermined overshoot driving is difficult, with the gradation corrected by the correction unit.

2. The liquid crystal display apparatus according to claim 1,

wherein, when the gradation of an input image is lower than a threshold gradation, after performing the high gradation display with an intermediate gradation higher than a minimum gradation and lower than a maximum gradation, the processing unit performs the low gradation display with the minimum gradation,

wherein, when the gradation of an input image is higher than the threshold gradation, after performing the high gradation display with the maximum gradation, the processing unit performs the low gradation display with the intermediate gradation.

3. The liquid crystal display apparatus according to claim 2,

wherein the correction unit corrects a gradation of a pixel located adjacent to a pixel switched from the low gradation display when the gradation of an input image is lower than the threshold gradation to the high gradation display when the gradation of an input image is higher than the threshold gradation, to a gradation for which overshoot driving stronger than the predetermined overshoot driving is possible.

4. The liquid crystal display apparatus according to claim 2,

wherein the correction unit corrects a gradation of a pixel located adjacent to a pixel switched from the low gradation display when the gradation of an input image is higher than the threshold gradation to the high gradation display when the gradation of an input image is higher than the threshold gradation, to a gradation for which overshoot driving stronger than the predetermined overshoot driving is possible.

5. The liquid crystal display apparatus according to claim 2,

wherein the gradation for which predetermined overshoot driving is difficult is a gradation in a predetermined range including the maximum gradation.

6. The liquid crystal display apparatus according to claim 1,

wherein, when the gradation of an input image is lower than a predetermined threshold gradation, after performing the low gradation display with the minimum gradation, the processing unit performs the high gradation display with an intermediate gradation higher than the minimum gradation and lower than the maximum gradation,

wherein, when the gradation of an input image is higher than the threshold gradation, after performing the low gradation display with the intermediate gradation, the processing unit performs the high gradation display with the maximum gradation.

7. The liquid crystal display apparatus according to claim 6,

wherein the correction unit corrects a gradation of a pixel located adjacent to a pixel switched from the high gradation display when the gradation of an input image is lower than the threshold gradation to the low gradation display when the gradation of an input image is lower than the threshold gradation, to a gradation for which overshoot driving stronger than the predetermined overshoot driving is possible.

8. The liquid crystal display apparatus according to claim 6,

wherein the correction unit corrects a gradation of a pixel located adjacent to a pixel switched from the high gradation display when the gradation of an input image is higher than the threshold gradation to the low gradation display when the gradation of an input image is lower than the threshold gradation, to a gradation for which overshoot driving stronger than the predetermined overshoot driving is possible.

9. The liquid crystal display apparatus according to claim 6,

wherein the gradation for which predetermined overshoot driving is difficult is a gradation in a predetermined range including the minimum gradation.