Method, touch sensing apparatus and computer-readable recording medium for minimizing noise on touch panel

• US 9,223,437 B2
• Filed: 03/12/2013
• Issued: 12/29/2015
• Est. Priority Date: 03/28/2012
• Status: Active Grant

• Current Assignee: HiDeep Inc.
• Original Assignee: HiDeep Inc.
• Inventors: Yoon, Sangsic, Lee, Hwanhee
• Primary Examiner(s): MERCEDES, DISMERY E
• Application Number:
  US13/797,202
• Publication Number:
  US 20130257765A1
• Time in Patent Office: 1,022 Days
• Field of Search: None
• US Class Current: 1/1
• 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

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

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

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

when the magnitude of the signal obtained through the second dummy scan is less than or equal to the second threshold, performing the first dummy scan again; and

when the magnitude of the signal obtained through the second dummy scan is less than or equal to the second threshold and a number of repetition times of the first dummy scan is greater than or equal to a threshold number, performing frequency hopping which changes a frequency of a driving signal.

2. The method of claim 1, further comprising:

performing 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.

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

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

determining whether a magnitude of a signal obtained through the another 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; and

changing the frequency of the driving signal into the second frequency when it is determined that the magnitude of a signal obtained through the another 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.

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

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

determining whether a magnitude of the signal obtained through the another dummy scan in the second frequency band is less than or equal to the first or the second threshold; and

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

5. The method of claim 4, wherein the performing of frequency hopping further comprises performing a further 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 another dummy scan in the second frequency band is greater than the first or the second threshold.

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