METHOD, TOUCH SENSING APPARATUS AND COMPUTER-READABLE RECORDING MEDIUM FOR MINIMIZING NOISE ON TOUCH PANEL

• US 20130257765A1
• Filed: 03/12/2013
• Published: 10/03/2013
• Est. Priority Date: 03/28/2012
• Status: Active Grant

• Current Assignee: HiDeep Inc.
• Original Assignee: HiDeep Inc.
• Inventors: LEE, Hwanhee, Yoon, Sangsic
• Granted Patent: US 9,223,437 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• 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
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: H04M 1/0266 for a display module assembly
• CPC Class Codes: H04M 2250/22 including a touch pad, a touch sensor or a touch detector digitizers for touch screens G06F3/041

Abstract

Disclosed is a method for minimizing noise on a touch panel including a plurality of drive lines and a plurality of sensing lines, wherein the drive lines and the sensing lines cross each other, the method including: performing a dummy scan to sense a signal from the sensing line in a state where a driving signal is not applied to the drive line; and comparing a threshold with a magnitude of a signal obtained through the dummy scan, and estimating noise in a first frequency band, i.e., a frequency of the driving signal.

Claims

1. A method for minimizing noise on a touch panel including a plurality of drive lines and a plurality of sensing lines, wherein the drive lines and the sensing lines cross each other, the method comprising:

performing a dummy scan to sense a signal from the sensing line in a state where a driving signal is not applied to the drive line; and

comparing a threshold with a magnitude of a signal obtained through the dummy scan, and estimating noise in a first frequency band, i.e., a frequency of the driving signal.

2. The method of claim 1, wherein further comprising frequency hopping which changes the frequency of the driving signal when, as a result of the comparison, the magnitude of the signal obtained through the dummy scan is greater than the threshold.

3. The method of claim 2, wherein the frequency hopping comprises:

performing the dummy scan in a second frequency band different from the first frequency band; and

changing the frequency of the driving signal into the second frequency when a magnitude of a signal obtained through the dummy scan in the second frequency band is less than the threshold.

4. The method of claim 2, wherein the frequency hopping comprises:

performing the dummy scan in a second frequency band different from the first frequency band; and

changing the frequency of the driving signal into the second frequency when a magnitude of a signal obtained through the dummy scan in the second frequency band is less than a magnitude of a signal obtained through the dummy scan in the first frequency band.

5. The method of claim 2, wherein the frequency hopping comprises performing the dummy scan in at least one frequency candidate, and changing the frequency of the driving signal into a frequency having a smallest magnitude.

6. The method of claim 1, wherein the dummy scan is performed at every point of time when one cycle ends, during which the touch is sensed by serially inputting the driving signal to a plurality of the drive lines.

7. A method for minimizing noise on a touch panel including a plurality of drive lines and a plurality of sensing lines, wherein the drive lines and the sensing lines cross each other, the method comprising:

performing a first dummy scan which performs, at least one time, a dummy scan in which a signal from the sensing line is sensed in a state where a driving signal is not applied to the drive line;

performing a second dummy scan which performs the dummy scan at least one time when a magnitude of a signal obtained through the first dummy scan is greater than a first threshold; and

comparing a second threshold with a magnitude of a signal obtained through the second dummy scan, and estimating noise in a first frequency band, i.e., a frequency of the driving signal.

8. The method of claim 7, further comprising frequency hopping which changes the frequency of the driving signal when the magnitude of the signal obtained through the second dummy scan is greater than the second threshold.

9. The method of claim 8, wherein the frequency hopping comprises:

performing the dummy scan at least one time in a second frequency band different from the first frequency band; and

changing the frequency of the driving signal into the second frequency when a magnitude of a signal obtained through the dummy scan in the second frequency band is less than the magnitude of the signal obtained through the first or the second dummy scan in the first frequency band.

10. The method of claim 8, wherein the frequency hopping comprises:

performing the dummy scan in a second frequency band different from the first frequency band; and

changing the frequency of the driving signal into the second frequency when the magnitude of the signal obtained through the dummy scan in the second frequency band is equal to or less than the first or the second threshold.

11. The method of claim 10, wherein the frequency hopping further comprises performing the dummy scan at least one time in a third frequency band different from the first and the second frequency bands when the magnitude of the signal obtained through the dummy scan in the second frequency band is greater than the first or the second threshold.

12. The method of claim 8, wherein the frequency hopping comprises performing the dummy scan in at least one frequency candidate, and changing the frequency of the driving signal into a frequency having a smallest magnitude.

13. The method of claim 7, wherein, when the magnitude of the signal obtained through the second dummy scan is equal to or less than the second threshold, the first dummy scan is performed again.

14. The method of claim 13, wherein, when the magnitude of the signal obtained through the second dummy scan is equal to or less than the second threshold, if a number of repetition times of the first dummy scan is equal to or greater than a threshold number, frequency hopping which changes the frequency of the driving signal is performed.

15. A touch sensing apparatus which minimizes noise and includes a touch panel including a plurality of drive lines and a plurality of sensing lines, wherein the drive lines and the sensing lines cross each other, the touch sensing apparatus comprising:

a signal sensor which performs a dummy scan to sense a signal from the sensing line in a state where a driving signal is not applied to the drive line; and

a frequency hopper which compares a threshold with a magnitude of a signal obtained through the dummy scan, and estimates noise in a first frequency band, i.e., a frequency of the driving signal.

16. The touch sensing apparatus of claim 15, wherein, when, as a result of the comparison, the magnitude of the signal obtained through the dummy scan is greater than the threshold, the frequency hopper performs frequency hopping which changes the frequency of the driving signal.

17. The touch sensing apparatus of claim 16, wherein, when the magnitude of the signal obtained by performing the dummy scan in a second frequency band different from the first frequency band is less than the threshold, the frequency hopping comprises changing the frequency of the driving signal into the second frequency.

18. The touch sensing apparatus of claim 16, wherein, when the magnitude of the signal obtained by performing the dummy scan in a second frequency band different from the first frequency band is less than the magnitude of the signal obtained through the dummy scan in the first frequency band, the frequency hopping comprises changing the frequency of the driving signal into the second frequency.

19. The touch sensing apparatus of claim 16, wherein the frequency hopper performs the frequency hopping which performs the dummy scan in at least one frequency candidate, and changes the frequency of the driving signal into a frequency having a smallest magnitude.

20. The touch sensing apparatus of claim 15, wherein the signal sensor performs the dummy scan at every point of time when one cycle ends, during which the touch is sensed by serially inputting the driving signal to a plurality of the drive lines.