Touch Sensing Method and Associated Apparatus

• US 20110012854A1
• Filed: 07/19/2010
• Published: 01/20/2011
• Est. Priority Date: 07/20/2009
• Status: Active Grant

• Current Assignee: Ili Technology Corp. (MediaTek, Inc.)
• Original Assignee: MStar Semiconductor Incorporated (MediaTek, Inc.)
• Inventors: Lin, Chin-Wei, Liu, Chi Kang
• Granted Patent: US 8,638,304 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184

Abstract

A touch screen includes an LCD panel; a display controller for processing a video signal to generate a panel control signal and a sensing control signal, with the panel control signal controlling the LCD panel so that the LCD panel displays images according to the panel control signal; a touch panel, for generating the sensing signal in response to a touch; and a sensing circuit, coupled to the touch panel and the display controller, for receiving the sensing signal and the sensing control signal to generate a position signal with reference to the sensing control signal.

Claims

1. A touch screen, comprising:

an LCD panel;

a display controller, for processing a video signal to generate a panel control signal and a sensing control signal, with the panel control signal controlling the LCD panel so that the LCD panel displays a plurality of images according to the panel control signal;

a touch panel, for generating a sensing signal in response to a touch; and

a sensing circuit, coupled to the touch panel and the display controller, for receiving the sensing signal and the sensing control signal to generate a position signal with reference to the sensing control signal.

2. The touch screen according to claim 1, wherein the sensing circuit determines a plurality of sensing periods according to the sensing control signal and detects the sensing signal within the sensing periods.

3. The touch screen according to claim 1, wherein the touch panel comprises a first sensing layer and a second sensing layer.

4. The touch screen according to claim 1, wherein the video signal comprises a vertical synchronization signal, a horizontal synchronization signal, a red signal, a green signal and a blue signal.

5. The touch screen according to claim 4, wherein the sensing control signal indicates a start time of a frame according to the vertical synchronization signal, the horizontal synchronization signal, the red signal, the green signal or the blue signal.

6. The touch screen according to claim 5, wherein the sensing circuit determines the sensing periods according to the start time of the frame and detects the sensing signal within the sensing periods.

7. The touch screen according to claim 1, wherein the display controller comprises a timing controller, a gate driving circuit and a source driving circuit.

8. The touch screen according to claim 1, wherein the sensing control signal indicates a start time of a frame.

9. The touch screen according to claim 8, wherein the sensing circuit determines the sensing periods according to the start time of the frame and detects the sensing signal within the sensing periods.

10. The touch screen according to claim 1, wherein the sensing control signal is synchronized with a common voltage signal.

11. The touch screen according to claim 1, wherein the sensing circuit comprises a delta-sigma analog-to-digital converter for receiving the sensing signal and performing an in-situ detection on the sensing signal.

12. The touch screen according to claim 2, wherein each sensing period has a guarding period.

13. The touch screen according to claim 2, wherein the sensing periods are within a non-vertical blanking interval.

14. A touch sensing method, for sensing a touch point on a touch panel to output a position signal, comprising:

generating and supplying a sensing control signal to a sensing circuit to determine a plurality of sensing periods; and

detecting a sensing signal by the sensing circuit to output the position signal within the sensing periods.

15. The touch sensing method according to claim 14, wherein the touch panel comprises a first sensing layer and a second sensing layer without a shielding layer.

16. The touch sensing method according to claim 14, wherein the sensing control signal is generated according to a vertical synchronization signal, a horizontal synchronization signal, a red signal, a green signal or the blue signal.

17. The touch sensing method according to claim 14, wherein the sensing control signal indicates a start time of a frame according to a vertical synchronization signal, a horizontal synchronization signal, a red signal, a green signal or a blue signal.

18. The touch sensing method according to claim 17, wherein the sensing circuit determines the sensing periods according to the start time of the frame and detects the sensing signal within the sensing periods.

19. The touch sensing method according to claim 14, wherein the sensing control signal is synchronized with a common voltage signal.

20. The touch sensing method according to claim 14, wherein the sensing control signal is associated with a video synchronization signal.