Handling of electromagnetic interference in an electronic apparatus

• US 9,274,649 B2
• Filed: 11/06/2014
• Issued: 03/01/2016
• Est. Priority Date: 11/06/2013
• Status: Active Grant

• Current Assignee: Apex Material Technology Corp., Imagination Broadway Ltd.
• Original Assignee: Apex Material Technology Corp., Imagination Broadway Ltd.
• Inventors: Liao, Zong-Bin, Qiu, Zhong-peng, Ding, Ke-hao, Lee, Shang-Li
• Primary Examiner(s): PATEL, PREMAL R
• Application Number:
  US14/534,743
• Publication Number:
  US 20150123950A1
• Time in Patent Office: 481 Days
• US Class Current: 1/1
• CPC Class Codes: G06F 2203/04108 Touchless 2D- digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface without distance measurement in the Z direction
• CPC Class Codes: G06F 3/04186 Touch location disambiguation
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

The present invention provides a touch-sensitive apparatus and a method for determining a coordinate position in response to a proximity detection for the touch-sensitive apparatus. The method comprises the steps of: evaluating a plurality of designed measurement modes by measuring noise over a plurality of measurement cycles when a proximity event on the touch-sensitive apparatus has been detected; selecting an optimal measurement mode from the plurality of designed measurement modes; assigning the optimal measurement mode to be a working measurement mode; performing the proximity detection for the touch-sensitive apparatus in use of the working measurement mode; and calculating the coordinates of the touched position based on results obtained with the working measurement mode.

Claims

1. A method for determining a coordinate position in response to a proximity detection for a touch-sensitive apparatus, wherein the touch-sensitive apparatus comprises a touch-sensitive module having a plurality of first electrodes and a plurality of second electrodes that intersect in multiple regions of the touch sensitive module, said method comprising the steps of:

evaluating a plurality of designed measurement modes when a proximity event on the touch-sensitive apparatus has been detected, wherein the touch sensitive module is configured to measure noise over a plurality of measurement cycles;

selecting an optimal measurement mode from the plurality of designed measurement modes;

assigning the optimal measurement mode to be a working measurement mode;

performing the proximity detection for the touch-sensitive apparatus in use of the working measurement mode; and

calculating the coordinates of the touched position based on results obtained with the working measurement mode.

2. The method according to claim 1, wherein the proximity event on the touch-sensitive apparatus has been detected prior to the step of evaluating the plurality of designed measurement modes.

3. The method according to claim 2, wherein further comprising a step of determining whether the touch-sensitive apparatus is operating at a default operating frequency before the step of evaluating the proximity event on the touch-sensitive apparatus, and further comprising a counter implemented for maintaining stability of the touch-sensitive apparatus when the touch-sensitive apparatus is not operating at the default operating frequency.

4. The method according to claim 3, wherein the touch-sensitive apparatus is set to the default operating frequency when the touch-sensitive apparatus is not operating at the default operating frequency and the value of the counter has reached a predetermined value.

5. The method according to claim 3, wherein the value of the counter is increased when the touch-sensitive apparatus is not operating at the default operating frequency and the value of the counter has not reached the predetermined value.

6. The method according to claim 1, wherein each of the plurality of designed measurement modes corresponds to a combination of a plurality of forward operations and a plurality of reverse operations.

7. The method according to claim 1, wherein further comprising a step of acquiring a plurality of voltage values of noise before the step of evaluating the plurality of designed measurement modes, the step of acquiring a plurality of voltage values of noise comprising:

disconnecting the first electrodes from a driving voltage source; and

measuring a plurality of voltage signals associated with the second electrodes over a plurality of measurement cycles during the first electrodes without a driving voltage.

8. The method according to claim 7, wherein further comprising a step of connecting the second electrodes to a voltage at the beginning of each of the measurement cycles in order to receive charges from noise and then the plurality of voltage values of noise are read out over each of the plurality of measurement cycles.

9. The method according to claim 7, wherein further comprising a step of calculating respectively a plurality of evaluations of noise in a one-by-one correspondence with each of the designed measurement modes according to the plurality of voltage values of noise.

10. The method according to claim 9, wherein further comprising a step of comparing the evaluations of noise with a threshold value and check whether at least one evaluation of noise corresponding with the designed measurement modes is below a threshold value.

11. The method according to claim 10, wherein further comprising a step of determining one of the measurement modes with a minimum evaluation of noise as the optimal measurement mode when at least one evaluation of noise corresponding with the designed measurement modes is below a threshold value.

12. The method according to claim 11, wherein further comprising a step of checking whether the optimal measurement mode is the same as the working measurement mode, wherein the method goes back to redo all steps from the step of evaluating the designed measurement modes if the optimal measurement mode is not the same as the working measurement mode, until the number of redoing iterations is equaling to P times, or until the optimal measurement mode is not the same as the working measurement mode but the optimal measurement mode is the same one in consecutive redoing iterations for the number of redoing iterations equaling to Q times, where P and Q are positive integers and 1<

Q<

P.

13. The method according to claim 10, further comprising iterative steps of modifying an operating frequency which the touch-sensitive apparatus is operating at present and then evaluating the designed measurement modes at the modified operating frequency when none of the evaluation of noise corresponding with the designed measurement modes is below a threshold value.

14. The method according to claim 13, wherein the post-modified operating frequency is lower than the pre-modified operating frequency.

15. The method according to claim 14, wherein the post-modified operating frequency is directly set to a lowest operating frequency when the post-modified operating frequency is lower than the lowest operating frequency.

16. The method according to claim 14, wherein the post-modified operating frequency is reduced to 1/N times of the pre-modified operating frequency where N is positive integer and N>

1.

17. The method according to claim 16, wherein N is a predetermined positive integer or a positive integer which is related to how high or how low the pre-modified operating frequency is.