Display system and driving method thereof

• US 20040196244A1
• Filed: 06/17/2003
• Published: 10/07/2004
• Est. Priority Date: 04/04/2003
• Status: Abandoned Application

• Current Assignee: VIA Technologies Incorporated (VIA Technologies)
• Original Assignee: VIA Technologies Incorporated (VIA Technologies)
• Inventors: Lin, Jiing
• Application Number:
  US10/462,651
• Publication Number:
  US 20040196244A1
• Time in Patent Office: Days
• US Class Current: 345/98
• CPC Class Codes: G09G 2310/04 Partial updating of the display screen
• CPC Class Codes: G09G 2360/18 Use of a frame buffer in a display terminal, inclusive of the display panel
• CPC Class Codes: G09G 5/393 Arrangements for updating the contents of the bit-mapped memory
• CPC Class Codes: G09G 5/399 using two or more bit-mapped memories, the operations of which are switched in time, e.g. ping-pong buffers

Abstract

A display system and a driving method thereof. The display system has a display panel, a storage device, a frame buffer, a display controller, a driving circuit, and a digital-to-analog converter. The storage device is used to store display data corresponding to a plurality of pixels of the display panel. The display controller generates the display data and stores the display data in the frame buffer. When data stored in a second memory unit of the frame buffer are different from data stored in a first memory unit of the storage device, the display controller transmits data stored in the second memory unit toward the driving circuit for using the driving circuit to update data stored in the first memory unit. In addition, the digital-to-analog converter then immediately drives a corresponding pixel according to the updated data of the first memory unit.

Claims

1. A display device comprising:

a display panel for displaying an image, the display panel comprising a plurality of pixels arranged according to a matrix format;

a storage device electrically connected to the display panel, the storage device comprising a plurality of memory units, each of the memory units respectively corresponding to a pixel disposed on the display panel;

a driving circuit electrically connected to the storage device for updating data stored in the memory units according to address data and display data; and

a digital-to-analog converter (DAC) electrically connected between the storage device and the display panel for converting data of the memory units into corresponding driving voltages to drive the pixels associated with the memory units.

2. The display device of claim 1 wherein the DAC comprises a plurality of DAC units, and each of the DAC units is respectively connected to a memory unit of the storage device.

3. The display device of claim 1 wherein the storage device is a volatile memory, and the display device further comprises a refresh circuit for periodically refreshing data stored in each of the memory units of the storage device.

4. The display device of claim 3 wherein the volatile memory is a dynamic random access memory (DRAM).

5. The display device of claim 1 wherein the storage device is a non-volatile memory.

6. The display device of claim 5 wherein the non-volatile memory is a flash memory.

7. A display system comprising:

a display panel for displaying an image, the display panel comprising a plurality of pixels arranged according to a matrix format;

a storage device electrically connected to the display panel, the storage device comprising a plurality of first memory units for storing data corresponding to the pixels of the display panel;

a frame buffer comprising a plurality of second memory units respectively corresponding to the first memory units;

a display controller for outputting data of a second memory unit when data of the second memory unit is different from data of a first memory unit corresponding to the second memory unit;

a driving circuit electrically connected between the display controller and the storage device for updating data of the first memory unit according to data of the corresponding second memory unit received from the display controller; and

a digital-to-analog converter (DAC) electrically connected between the storage device and the display panel for converting data of the first memory units into corresponding driving voltages to drive pixels corresponding to the first memory units.

8. The display system of claim 7 wherein the storage device is a volatile memory, and the display system further comprises a refresh circuit for periodically refreshing data stored in each of the first memory units.

9. The display system of claim 8 wherein the volatile memory is a dynamic random access memory (DRAM).

10. The display system of claim 7 wherein the storage device is a non-volatile memory.

11. The display system of claim 10 wherein the non-volatile memory is a flash memory.

12. The display system of claim 7 wherein the display controller is a graphics chip.

13. The display system of claim 12 wherein the graphics chip is disposed on a graphics card.

14. The display system of claim 13 wherein the frame buffer is disposed on the graphics card.

15. The display system of claim 12 wherein the graphics chip is disposed within a north bridge circuit.

16. The display system of claim 7 wherein the display panel is a liquid crystal display (LCD) panel.

17. The display system of claim 7 wherein the display controller comprises:

a status register comprising a plurality of status bits respectively corresponding to the first memory units and the second memory units for indicating whether data stored in the first memory units are identical to data stored in the corresponding second memory units; and

an update controller electrically connected to the status register and the driving circuit for selectively transmitting data of a second memory unit to the driving circuit according to data stored in a register bit corresponding to the second memory unit.

18. The display system of claim 17 wherein the status register is a static random access memory (SRAM).

19. A method for driving a display system, the display system comprising a display device and a computer host, the display device comprising a display panel and a plurality of first memory units, the first memory units storing data used to drive the display panel, the computer host comprising a plurality of second memory units respectively corresponding to the first memory units for receiving and storing display data, the method comprising:

(a) holding data stored in a first memory unit and utilizing data stored in the first memory unit to successively drive the display panel to display a plurality of image frames; and

(b) if display data stored in a second memory unit is different from data stored in the first memory unit, utilizing the display data stored in the second memory unit to update data stored in the first memory unit.

20. The method of claim 19 wherein step (a) further comprises refreshing the first memory unit periodically for holding data stored in the first memory unit.