LCD device and driving circuit thereof

Abstract

A liquid crystal display device and driving circuit thereof are provided. The liquid crystal display device includes a storage unit, an external gamma reference voltage generator and a source driver IC. The storage unit stores a plurality of digital gamma data each relating to at least one predetermined color. The source driver IC further comprises an internal gamma reference voltage generator and a digital to analog converter module. The internal gamma reference voltage generator generates a plurality of internal gamma reference voltage to the digital to analog converter module according to the digital gamma data supplied by the storage unit. The digital to analog converter module also receives a plurality of external gamma reference voltages supplied by the external gamma reference voltage generator.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating the source driver IC of a conventional LCD.

FIG. 2 is a functional block diagram illustrating a preferred embodiment of the invention.

FIG. 3 is a functional block diagram illustrating a gamma voltage generator according to a preferred embodiment of the invention.

FIG. 4 is a schematic diagram illustrating a preferred embodiment of the invention.

FIG. 5 is a plot illustrating the gamma curve of a source driver IC according to a preferred embodiment of the invention.

Claims

1. A driving circuit for use in a liquid crystal display (LCD) device, comprising: a storage unit for storing a plurality of digital gamma data; anda source driver integrated circuit (IC) electrically connected to the storage unit, wherein the digital gamma data are transmitted from the storage unit to the source driver IC, the source driver IC comprising: a first gamma voltage generator for generating a plurality of sets of first gamma reference voltages according to the plurality of digital gamma data; anda digital analog converter module for receiving the first gamma reference voltages supplied by the first gamma voltage generator, and for receiving a plurality of sets of second gamma reference voltages, wherein the first gamma reference voltages are characteristically related to the gamma curve of a plurality of first determined colors, and the second gamma reference voltages are characteristically related to the gamma curve of a second predetermined color, so that the digital analog converter module converts video data according to the first gamma reference voltages or the second gamma reference voltages.

2. The driving circuit of claim 1, wherein the first gamma voltage generator comprises a deserializer, a positive gamma reference voltage generator, and a negative gamma reference voltage generator, wherein the deserializer is connected to the positive gamma reference voltage generator and the negative gamma reference voltage generator.

3. The driving circuit of claim 2, wherein the deserializer receives the serial digital gamma data supplied by the storage unit, for dividing the serial digital gamma data into a first digital data and a second digital data, and for respectively outputting to the positive gamma reference voltage generator and the negative gamma reference voltage generator.

4. The driving circuit of claim 3, wherein the positive gamma reference voltage generator generates a plurality of positive gamma reference voltages according to the first digital data for outputting to the digital analog converter module, and the negative gamma reference voltage generator generates a plurality of negative gamma reference voltages according to the second digital data for outputting to the digital analog converter module

5. The driving circuit of claim 2, wherein the positive gamma reference voltage generator comprises a first digital analog converter, a first sample-and-hold circuit, and a plurality of first unity-gain buffers, wherein the first digital analog converter is electrically connected to the deserializer and the first sample-and-hold circuit, and the first sample-and-hold circuit is electrically connected to the first unity-gain buffers.

6. The driving circuit of claim 5, wherein the first digital analog converter receives a first digital data and converts the same into one of the gamma reference voltages to be transmitted to one of the unity-gain buffers and output to the digital analog converter module.

7. The driving circuit of claim 2, wherein the negative gamma reference voltage generator comprises a second digital analog converter, a second sample-and-hold circuit, and a plurality of second unity-gain buffers, the second digital analog converter respectively is connected to the deserializer and the second sample-and-hold circuit respectively, and the second sample-and-hold circuit is electrically connected to the second unity-gain buffers.

8. The driving circuit of claim 1, wherein the plurality of digital gamma data is stored in the storage unit in the form of reference tables, and the source driver IC determines the reference tables for use therefrom according to an environmental parameter.

9. The driving circuit of claim 1, wherein the first predetermined colors are red, green, blue, or white.

10. The driving circuit of claim 1, wherein the first predetermined colors are red, green, blue, or yellow.

11. The driving circuit of claim 1, wherein the first predetermined colors are red, green, blue, or cyan.

12. A liquid crystal display (LCD) device, comprising: a display panel;a storage unit for storing a plurality of digital gamma data; andat least one source driver integrated circuit (IC) electrically connected to the display panel and the storage unit, wherein the plurality of digital gamma data are transmitted from the storage unit to the at least one source driver IC, the at least one source driver IC comprising: a first gamma voltage generator for generating a plurality of first gamma reference voltages according to the plurality of digital gamma data; anda digital analog converter module for receiving the first gamma reference voltages supplied by the first gamma voltage generator, and for receiving a plurality of second gamma reference voltages, wherein the first gamma reference voltages are characteristically related to the gamma curve of a plurality of first determined colors, and the second gamma reference voltages are characteristically related to the gamma curve of a second predetermined color, so that the digital analog converter module converts video data according to the first gamma reference voltages or the second gamma reference voltages.

13. The LCD device of claim 12, wherein the first predetermined colors are red, green, blue, or white.

14. The LCD device of claim 12, wherein the first predetermined colors are red, green, blue, or yellow.

15. The LCD device of claim 12, wherein the first predetermined colors are red, green, blue, or cyan.

16. The LCD device of claim 12, wherein the first gamma voltage generator comprises a deserializer, a positive gamma reference voltage generator, and a negative gamma reference voltage generator, wherein the deserializer is electrically connected to the positive gamma reference voltage generator and the negative gamma reference voltage generator.

17. The LCD device of claim 16, wherein the deserializer receives the serial digital gamma data supplied by the storage unit, for dividing the serial digital gamma data into first digital data and second digital data, and for respectively outputting to the positive gamma reference voltage generator and the negative gamma reference voltage generator.

18. The LCD device of claim 17, wherein the positive gamma reference voltage generator generates a plurality of positive gamma reference voltages according to the first digital data for outputting to the digital analog converter module, and the negative gamma reference voltage generator generates a plurality of negative gamma reference voltages according to the second digital data for outputting to the digital analog converter module

19. The LCD device of claim 16, wherein the positive gamma reference voltage generator comprises a first digital analog converter, a first sample-and-hold circuit, and a plurality of first unity-gain buffers, wherein the first digital analog converter is respectively connected to the deserializer and the first sample-and-hold circuit, and the first sample-and-hold circuit is electrically connected to the first unity-gain buffers.

20. The LCD device of claim 19, wherein the first digital analog converter receives a first digital data and converts the same into one of the gamma reference voltages to be transmitted to one of the unity-gain buffers and output to the digital analog converter module.

21. The LCD device of claim 16, wherein the negative gamma reference voltage generator comprises a second digital analog converter, a second sample-and-hold circuit, and a plurality of second unity-gain buffers, wherein the second digital analog converter is respectively connected to the deserializer and the second sample-and-hold circuit, and the second sample-and-hold circuit electrically is connected to the second unity-gain buffers.