LCD AND BACKLIGHT MODULE DRIVING DEVICE AND METHOD THEREOF

• US 20090262064A1
• Filed: 06/09/2008
• Published: 10/22/2009
• Est. Priority Date: 04/22/2008
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: Hsu, Po-Tang, Ko, Chien-Ming, Li, Yueh-Han, Yu, Ching-Chou
• Granted Patent: US 8,519,939 B2
• Time in Patent Office: Days
• US Class Current: 345/102
• CPC Class Codes: G09G 2310/024 Scrolling of light from the illumination source over the display in combination with the scanning of the display screen
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• 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 2330/06 Handling electromagnetic interferences [EMI], covering emitted as well as received electromagnetic radiation
• CPC Class Codes: G09G 3/342 using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines

Abstract

An LCD and a backlight module driving device and a method thereof are provided. The method is adapted to drive at least one backlight unit in a backlight module. The backlight unit is used for supplying a surface light source to an N^th area pixel of the LCD panel, where N is a positive integer. The method includes the following steps of first calculating a time of the N^th area pixel under a stable state in a frame period and then providing a control signal to drive the backlight unit when the N^th area pixel is under the stable state in the frame period.

Claims

1. A backlight module driving method, adapted to drive at least one backlight unit in a bacldight module, wherein the backlight unit provides a surface light source to an N^th area pixel of a liquid crystal display (LCD) panel, where N is a positive integer, the backlight module driving method comprising:

calculating a total time of the N^th area pixel under a stable state in a frame period so as to obtain a center position of the total time of the N^th area pixel under the stable state in the frame period; and

providing a control signal to drive the backlight unit according to the center position of the total time of the N^th area pixel under the stable state in the frame period.

2. The backlight module driving method according to claim 1, wherein a center position of a turn-on time of the control signal aligns with the center position of the total time of the N^th area pixel under the stable state in the frame period, and the turn-on time of the control signal substantially does not extend into a transition state of the N^th area pixel and an (N+1)^th area pixel of the LCD panel.

3. The backlight module driving method according to claim 2, wherein the control signal is a pulse width modulation (PWM) signal.

4. The backlight module driving method according to claim 1, adapted to drive a plurality of sub backlight units in the backlight unit, further comprising:

providing a plurality of sub control signals to respectively drive the sub backlight units according to the center position of the total time of the N^th area pixel under the stable state in the frame period, wherein an i^th sub backlight unit is used to provide a surface light source to an i^th area pixel in the N^th area pixel, where i is a positive integer.

5. The backlight module driving method according to claim 4, wherein center positions of turn-on times of the sub control signals align with the center position of the total time of the N^th area pixel under the stable state in the frame period, and the turn-on times of the sub control signals substantially do not extend into a transition state of the N^th area pixel and an (N+1)th area pixel of the LCD panel.

6. The backlight module driving method according to claim 4, wherein the sub control signals have different turn-on times and each of the sub control signals is a PWM signal.

7. The backlight module driving method according to claim 1, wherein the backlight module is a light emitting diode (LED) backlight module.

8. A backlight module driving device, adapted to drive at least one backlight unit in a backlight module, wherein the backlight unit provides a surface light source to an N^th area pixel of an LCD panel, where N is a positive integer, the backlight module driving device comprising:

a calculation unit, used to calculate a total time of the N^th area pixel under a stable state in a frame period so as to obtain a center position of the total time of the N^th area pixel under the stable state in the frame period; and

a driving unit, coupled to the calculation unit and the bacldight module, for providing a control signal to drive the backlight unit according to the center position of the total time of the N^th area pixel under the stable state in the frame period.

9. The backlight module driving device according to claim 8, wherein a center position of a turn-on time of the control signal aligns with the center position of the total time of the N^th area pixel under the stable state in the frame period, and the turn-on time of the control signal substantially does not extend into a transition state of the N^th area pixel and an (N+1)^th area pixel of the LCD panel.

10. The backlight module driving device according to claim 9, wherein the control signal is a PWM signal.

11. The backlight module driving device according to claim 8, wherein the backlight unit comprises a plurality of sub backlight units, and an i^th sub bacldight unit is used to provide a surface light source to an i^th area pixel in the N^th area pixel, where i is a positive integer.

12. The backlight module driving device according to claim 11, wherein the driving unit provides a plurality of sub control signals to respectively drive the sub backlight units according to the center position of the total time of the N^th area pixel under the stable state in the frame period.

13. The backlight module driving device according to claim 12, wherein center positions of turn-on times of the sub control signals align with the center position of the total time of the N^th area pixel under the stable state in the frame period, and the turn-on times of the sub control signals substantially do not extend into a transition state of the N^th area pixel and an (N+1)^th area pixel of the LCD panel.

14. The backlight module driving device according to claim 13, wherein the sub control signals have different turn-on times and each of the sub control signals is a PWM signal.

15. The backlight module driving device according to claim 8, wherein the backlight module is an LED backlight module.

16. An LCD, comprising:

a LCD panel;

a backlight module, comprising at least one backlight unit which provides a surface light source to an Nth area pixel of the LCD panel, where N is a positive integer; and

a backlight module driving device, coupled to the backlight module, for providing a control signal to drive the backlight unit according to a center position of a total time of the N^th area pixel under a stable state in the frame period.

17. The LCD according to claim 16, wherein the backlight module driving device comprises:

a calculation unit, used to calculate the total time of the N^th area pixel under the stable state in the frame period so as to obtain the center position of the total time of the N^th area pixel under the stable state in the frame period; and

a driving unit, coupled to the calculation unit and the backlight module, for providing the control signal to drive the backlight unit according to the center position of the total time of the N^th area pixel under the stable state in the frame period.

18. The LCD according to claim 17, wherein the center position of the turn-on time of the control signal aligns with the center position of the total time of the N^th area pixel under the stable state in the frame period, and the turn-on time of the control signal substantially does not extend into a transition state of the Nth area pixel and an (N+1)^th area pixel of the LCD panel.

19. The LCD according to claim 18, wherein the control signal is a PWM signal.

20. The LCD according to claim 17, wherein the backlight unit comprises a plurality of sub backlight units and an i^th sub backlight unit is used to provide a surface light source to an i^th area pixel in the N^th area pixel, where i is a positive integer.

21. The LCD according to claim 20, wherein the driving unit provides a plurality of sub control signals to respectively drive the sub backlight units according to the center position of the total time of the N^th area pixel under the stable state in the frame period.

22. The LCD according to claim 21, wherein center positions of turn-on times of the sub control signals align with the center position of the total time of the N^th area pixel under the stable state in the frame period, and the turn-on times of the sub control signals substantially do not extend into a transition state of the N^th area pixel and an (N+1)^th area pixel of the LCD panel.

23. The LCD according to claim 22, wherein the sub control signals have different turn-on times and each of the sub control signals is a PWM signal.

24. The LCD according to claim 16, wherein the backlight module is an LED backlight module.

25. A backlight module driving method, adapted to drive at least one backlight unit in a backlight module, wherein the backlight unit provides a surface light source to an N^th area pixel of an LCD panel, where N is a positive integer, the backlight module driving method comprising:

calculating a total time of the N^th area pixel under a stable state in a frame period; and

providing a control signal to drive the backlight unit when the N^th area pixel is under the stable state in the frame period.

26. The bacldight module driving method according to claim 25, wherein the control signal substantially does not extend into a transition state of the N^th area pixel and an (N+1)^th area pixel of the LCD panel.