DRIVING METHOD OF TOUCH DISPLAY MODULE

• US 20110090174A1
• Filed: 10/18/2010
• Published: 04/21/2011
• Est. Priority Date: 10/16/2009
• Status: Abandoned Application

• Current Assignee: Aussmak Optoelectronics Corp.
• Original Assignee: Aussmak Optoelectronics Corp.
• Inventors: LIN, Chung-Jyh
• Application Number:
  US12/906,833
• Publication Number:
  US 20110090174A1
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06F 3/0447 Position sensing using the local deformation of sensor cells
• CPC Class Codes: G09G 2310/06 Details of flat display driving waveforms
• 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 driving method of a touch display module is disclosed. The driving method includes the steps of writing a liquid crystal (LC) calibration signal to the data line by a calibration signal writing circuit during a blanking time between at least a data line writes the data signals to its corresponding pixel, so that the data line has a specific root mean square (RMS) voltage; and sensing a first sensing signal corresponding to the LC capacitance of the data line and sensing a second sensing signal corresponding to the LC capacitance of at least one scan line. An LC calibration signal is input to the data line during a blanking time between at least a data line writes the data signals to its corresponding pixel to achieve the same background capacitance so as to enhance the accuracy and the efficiency of touch sensing.

Claims

1. A driving method of a touch display module, wherein the touch display module comprises a liquid crystal display (LCD) panel, a calibration signal writing circuit, and a sensing circuit, the LCD panel has an effective display area correspondingly configured with a plurality of scan lines, a plurality of data lines, and a plurality of pixels, each of the pixels has at least one charging switch, a pixel electrode, and a common electrode, the charging switches are electrically connected with the scan lines and the data lines respectively, the scan lines transmit scan signals in sequence to turn on the charging switches, so that the data lines write data signals into the pixel electrodes of the pixels, and corresponding liquid crystal molecules of each of the pixels is operated according to the voltage difference between the pixel electrode and the common electrode, the driving method comprising steps of:

writing a liquid crystal (LC) calibration signal to at least one of the data lines by the calibration signal writing circuit during a blanking time between the data line writes the data signals to the corresponding pixel, so that the data line has a specific root mean square (RMS) voltage; and

when the data line has the specific RMS voltage, sensing a first sensing signal corresponding to an LC capacitance of the data line and sensing a second sensing signal corresponding to an LC capacitance of at least one scan line by the sensing circuit.

2. The driving method of claim 1, further comprising a step of:

comparing first sensing signals retrieved by sensing the data line at different time.

3. The driving method of claim 1, further comprising:

comparing first sensing signals of at least two of the data lines.

4. The driving method of claim 1, further comprising:

comparing the first sensing signal with a first preset reference.

5. The driving method of claim 1, wherein the calibration signal writing circuit writes the LC calibration signal to the data line, so that the liquid crystal molecules corresponding to the data line are in vertical, horizontal, or a specific angle.

6. The driving method of claim 1, wherein the LC calibration signal controls the RMS voltage of the data line to be less than, equal to, or greater than an LC saturate voltage.

7. The driving method of claim 1, wherein the LC calibration signal is obtained by calculation depending on the data signal of the data line.

8. The driving method of claim 1, wherein the LC calibration signal has a high level, which is between scan signals transmitted through two adjacent scan lines, before a scan signal transmitted through a first scan line of the scan lines, or after a scan signal transmitted through a latest scan line of the scan lines.

9. The driving method of claim 1, wherein the LC calibration signal is a DC signal or an AC signal.

10. The driving method of claim 1, wherein the LC calibration signal comprises a high-frequency signal.

11. The driving method of claim 1, wherein the calibration signal writing circuit writes LC calibration signals into the data lines respectively, so that the data lines have substantially the same RMS voltage.

12. The driving method of claim 11, wherein the amplitudes of the LC calibration signals are different.

13. The driving method of claim 1, wherein the calibration signal writing circuit writes LC calibration signals into the data lines respectively, so that the RMS voltages of the data lines are greater than an LC saturate voltage.

14. The driving method of claim 13, wherein the amplitudes of the LC calibration signals are the same.

15. The driving method of claim 1, wherein the calibration signal writing circuit writes LC calibration signals into the data lines respectively, so that each of the LC calibration signals has a first high level, each of the scan signals has a second high level, and the first high levels and the second high levels are interlaced.

16. The driving method of claim 1, wherein the scan signal comprises a high-frequency signal.

17. The driving method of claim 1, wherein the sensing circuit is electrically connected with the common electrode.

18. The driving method of claim 1, further comprising a step of:

filtering and/or amplifying the first sensing signal by the sensing circuit.

19. The driving method of claim 1, wherein the sensing circuit comprises an inductance element electrically connected with the common electrode and a common power source.