Method for warming-up an LCD (liquid crystal display) system

• US 20050227396A1
• Filed: 03/03/2005
• Published: 10/13/2005
• Est. Priority Date: 04/09/2004
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: Chen, Po-Lun, Chang, Ting-Jui
• Granted Patent: US 7,385,578 B2
• Time in Patent Office: Days
• US Class Current: 438/30
• CPC Class Codes: G09G 2300/0491 Use of a bi-refringent liquid crystal, optically controlled bi-refringence [OCB] with bend and splay states, or electrically controlled bi-refringence [ECB] for controlling the color
• CPC Class Codes: G09G 2320/0252 Improving the response speed
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3655 Details of drivers for counter electrodes, e.g. common electrodes for pixel capacitors or supplementary storage capacitors

Abstract

A method for warming-up an LCD system which includes a pixel array having a plurality of pixel units. Each pixel unit includes a pixel electrode, and a TFT (thin film transistor) provide with a source and a gate such that a gate signal inputted into the gate can switch on and switch off the TFT so as to permit transfer of a data signal from the source to the pixel electrode. The method includes the steps: floating the source of the TFT; and applying the gate signal onto the gate which is coupled to the pixel electrode in such a manner that the pixel electrode possesses a voltage level which is substantially equal to that of the gate signal.

Claims

1. A method for warming-up an LCD system, wherein the LCD system includes a pixel array having a plurality of pixel units, each of the pixel units including a pixel electrode, and a TFT (thin film transistor) provided with a source and a gate such that a gate signal inputted into the gate can switch on or switch off the TFT so as to permit transfer of a data signal from the source to the pixel electrode, a common electrode being disposed oppositely to the pixel electrode, a liquid crystal layer being sandwiched between the pixel electrode and the common electrode, the warming-up method comprising the steps:

floating the source of the TFT; and

applying the gate signal onto the gate which is coupled to the pixel electrode in such a manner that the pixel electrode possesses a voltage level which is substantially equal to that of the gate signal.

2. The warming-up method according to claim 1, wherein the LCD system is an OCB (Optically Compensated Bend) mode LCD system, the pixel electrode with the voltage level enabling a quick transition of liquid crystal molecules in the liquid crystal layer from a splay alignment into a bend alignment.

3. The warming-up method according to claim 1, wherein the LCD system includes a data line and a source driver which is coupled to the source of the TFT via the data line, the source driver capable of interrupting the transfer of the data signal so as to cause the floating of the source of the TFT.

4. The warming-up method according to claim 3, wherein the LCD system further includes a plurality of scanning lines and a gate driver coupled to the respective TFTs of the pixel array via a respective one of the scanning lines.

5. The warming-up method according to claim 4, wherein the gate signal is a pulse signal which is formed and inputted into the respective TFTs via the respective one of the scanning lines one by one in accordance with a cycle waveform of a timing reference signal.

6. The warming-up method according to claim 1, wherein the gate signal has a high voltage level and a low voltage level such that application of the gate signal with the high voltage level onto the gate to result in switching on of the TFT.

7. The warming-up method according to claim 6, wherein during a section of the warming-up operation, the gate signal with the high voltage level is applied ceaselessly onto the gate to result in switching on of the TFT.

8. The warming-up method according to claim 6, wherein during a section of the warming-up operation, the gate signal applied onto the gate has a cycle waveform between the high voltage level and the low voltage level.

9. A method for warming-up an OCB mode LCD system, wherein the LCD system includes a pixel array having a plurality of pixel units, each of the pixel units including a pixel electrode, and a TFT (thin film transistor) provide with a source, a drain and a gate such that a gate signal with a high or low voltage level inputted into the gate can switch on or switch off the TFT so as to permit transfer of a data signal from the source to the pixel electrode, a common electrode being disposed oppositely to the pixel electrode, a liquid crystal layer being sandwiched between the pixel electrode and the common electrode, the warming-up method comprising the steps:

(a) floating the source of the TFT during a front section of a warming-up operation, and simultaneously applying the gate signal with the high voltage level onto the gate which is coupled to the pixel electrode in such a manner that the pixel electrode possesses a voltage level which is substantially equal to that of the gate signal, wherein the pixel electrode with the voltage level enables quick transition of liquid crystal molecules in the liquid crystal layer from a splay alignment into a bend alignment; and

(b) restoring the transfer of the data signal inputting the source at a rear section of the warming-up operation, and simultaneously applying the gate signal with the high voltage level onto the gate ceaselessly, thereby permitting the transfer of the data signal from the source to the pixel electrode.

10. The warming-up method according to claim 9, wherein the LCD system includes a data line and a source driver which is coupled to the source of the TFT via the data line, the source driver capable of interrupting the transfer of the data signal to cause the floating action of the source of the TFT.

11. The warming-up method according to claim 10, wherein the source driver is provided with latch up ability in order to interrupt the transfer of the data signal via the data line to the pixel electrode.

12. A method for warming-up an OCB mode LCD system, wherein the LCD system includes a pixel array having a plurality of pixel units, each of the pixel units including a pixel electrode, and a TFT (thin film transistor) provide with a source, a drain and a gate such that a gate signal with a high or low voltage level inputted into the gate can decide switch on and switch off of the TFT so as to permit transfer of a data signal to the pixel electrode via the source and the drain, a common electrode being disposed oppositely to the pixel electrode, a liquid crystal layer being sandwiched between the pixel electrode and the common electrode, the warming-up method comprising the steps:

(a) floating the source of the TFT during a front section of a warming-up operation, and simultaneously applying the gate signal with the high voltage level onto the gate which is coupled to the pixel electrode in such a manner that the pixel electrode possesses a voltage level which is substantially equal to that of the gate signal such that the pixel electrode with the voltage level enables quick transition of liquid crystal molecules in the liquid crystal layer from a splay alignment into a bend alignment; and

(b) restoring the transfer of the data signal inputting the source at a rear section of the warming-up operation, and simultaneously applying the gate signal which is a pulse signal and which is formed and inputted onto the gate following a timing reference signal so as to switch the TFT on, thereby permitting the transfer of the data signal to the pixel electrode via the source and the drain.

13. The warming-up method according to claim 12, wherein the LCD system includes a data line and a source driver which is coupled to the source of the TFT via the data line, the source driver capable of interrupting the transfer of the data signal to cause the floating action of the source of the TFT.

14. The warming-up method according to claim 13, wherein the source driver is provided with latch up ability in order to interrupt the transfer of the data signal via the data line.

15. The warming-up method according to claim 12, wherein the LCD system further includes a plurality of scanning lines and a gate driver coupled to the respective TFTs of the pixel array via a respective one of the scanning lines.

16. The warming-up method according to claim 15, wherein the pulse signal is inputted onto the respective TFTs via the respective one of the scanning lines.