Liquid crystal display device

• US 20070139341A1
• Filed: 12/06/2006
• Published: 06/21/2007
• Est. Priority Date: 12/20/2005
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Original Assignee: Hitachi Displays Limited (Japan Display Incorporated)
• Inventors: Kubo, Chikae, Tokuda, Naoki
• Granted Patent: US 7,961,162 B2
• Time in Patent Office: Days
• US Class Current: 345/98
• CPC Class Codes: G09G 2310/0245 Clearing or presetting the whole screen independently of waveforms, e.g. on power-on G09G2310/063 takes precedence
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 2320/0242 Compensation of deficiencies in the appearance of colours
• CPC Class Codes: G09G 2320/0261 in the context of movement of objects on the screen or movement of the observer relative to the screen
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

In a liquid crystal display device, both of the brightness characteristic and the chromaticity characteristic are set to optimum values. In the liquid crystal display device which includes a liquid crystal display panel, a data driver, a scanning driver and a display control circuit, the display control circuit includes a first circuit which generates and insertion display data which differs from the image display data and inserts the display data into the data driver, and a second circuit which sets a first time at which the scanning signal for displaying the display data and a second time at which the scanning signal for displaying the insertion display data are outputted. The first circuit generates display data of one chromatic color and, at the same time, sets gradations of chromatic color for every frame period.

Claims

1. A liquid crystal display device comprising:

a liquid crystal display panel in which a plurality of data signal lines and a plurality of scanning signal lines are arranged in a matrix array and which forms a region surrounded by two neighboring data signal lines and two neighboring scanning signal lines into one pixel region;

a data driver which outputs a display signal to the data signal lines;

a scanning driver which outputs a scanning signal to the scanning signal lines; and

a display control circuit which transmits a control signal for controlling outputting of the display signal of the data driver and the display signal to the data driver and, at the same time, a control signal which controls the outputting of the scanning signal of the scanning driver to the scanning driver, wherein

the display control circuit includes

a first circuit which divides image display data inputted from an external device for every 1 frame period and generates insertion display data which differs from the image display data in the image display data of each frame period and transmits the insertion display data to the data driver by insertion, and

a second circuit which sets a first time at which the scanning signal for displaying the display data is outputted to the respective scanning signal lines and a second time at which the scanning signal for displaying the insertion display data is outputted to the respective scanning signal lines, and

the first circuit generates display data of one chromatic color and, at the same time, sets gradations of chromatic color for every frame period.

2. A liquid crystal display device according to claim 1, wherein the circuit which sets the gradations of chromatic color sets the gradations based on an average gradation of the image display data which is displayed in every frame period.

3. A liquid crystal display device according to claim 2, wherein the circuit which sets the gradations of chromatic color increases the gradations of the insertion display data when the average gradation is high, and decreases the gradation of the insertion display data when the average gradation is low.

7. A liquid crystal display device according to claim 1, wherein the first circuit generates and inserts blue insertion display data between the image display data for every frame period.

4. A liquid crystal display device comprising:

a liquid crystal display panel in which a plurality of data signal lines and a plurality of scanning signal lines are arranged in a matrix array and which forms a region surrounded by two neighboring data signal lines and two neighboring scanning signal lines into one pixel region;

a data driver which outputs a display signal to the data signal lines;

a scanning driver which outputs a scanning signal to the scanning signal lines; and

a display control circuit which transmits a control signal for controlling outputting of the display signal of the data driver and the display signal to the data driver and, at the same time, a control signal which controls the outputting of the scanning signal of the scanning driver to the scanning driver, wherein

the display control circuit includes

a first circuit which divides image display data inputted from an external device for every 1 frame period and generates insertion display data which differs from the image display data in the image display data of each frame period and transmits the insertion display data to the data driver by insertion, and

a second circuit which sets a first time at which the scanning signal for displaying the display data is outputted to the respective scanning signal lines and a second time at which the scanning signal for displaying the insertion display data is outputted to the respective scanning signal lines, and the first circuit generates display data of one chromatic color, and

the second circuit sets an interval between the first time and the second time for every frame period.

5. A liquid crystal display device according to claim 4, wherein the circuit which sets the interval between the first time and the second time sets the interval based on an average gradation of the image display data displayed in every frame period.

6. A liquid crystal display device according to claim 5, wherein the circuit which sets the interval between the first time and the second time is prolonged when the average gradation is high and shortens the interval when the average gradation is low.

8. A liquid crystal display device according to claim 4, wherein the first circuit generates and inserts blue insertion display data between the image display data for every frame period.