Method and device for analyzing positions

• US 8,400,423 B2
• Filed: 12/01/2011
• Issued: 03/19/2013
• Est. Priority Date: 10/09/2009
• Status: Active Grant

• Current Assignee: eGalax_eMPIA Technology Inc.
• Original Assignee: eGalax_eMPIA Technology Inc.
• Inventors: Chang, Chin-Fu, Lee, Cheng-Han, Tang, Chi-Hao, Ho, Shun-Lung
• Primary Examiner(s): Osorio, Ricardo L
• Application Number:
  US13/308,638
• Publication Number:
  US 20120075246A1
• Time in Patent Office: 474 Days
• Field of Search: 345173-175, 178 1801- 1807, 178 1901- 1905
• US Class Current: 345/174
• CPC Class Codes: G01R 27/2605 Measuring capacitance capacitive sensors G01D5/24
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/04182 Filtering of noise external to the device and not generated by digitiser components
• 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
• CPC Class Codes: G06F 3/047 using sets of wires, e.g. crossed wires

Abstract

A method and device for analyzing positions are disclosed. In sensing information, at least one position is determined according to a first characteristic of a touch related sensing information. The sensing information also has a touch related sensing information with a second characteristic, which is opposite to the first characteristic. The touch related sensing information with the second characteristic is neglected or filtered. In addition, another method and device for analyzing positions are disclosed. An AC signal is provided through a pen, and a first characteristic of a touch related sensing information corresponding to a finger is opposite to the second characteristic of the touch related sensing information corresponding to the pen. The first characteristic and the second characteristic can be used to distinguish the touch of the finger from the touch of the pen or for palm rejection.

Claims

1. A method for analyzing positions, comprising:

obtaining a touch sensitive information from a plurality of sensors corresponding to at least one first external object touching or approaching a signal source, wherein the at least one first external object electrically coupled with at least one second external object, and the touch sensitive information corresponds to signals of these sensors mutual-capacitively coupled to the signal source, the at least one first external object and the at least one second external object;

determining at least a first initial position in the touch sensitive information based on a first threshold; and

performing a zero-crossing position analysis from each first initial position in a first range in a first direction, wherein the first range does not include touch sensitive information corresponding to the at least one second external object.

2. The method of claim 1, wherein the first range is from the first initial position to a value just before a zero-crossing, a zero-crossing, or a value just after a zero-crossing.

3. The method of claim 1, wherein the first threshold determines a first initial range, and each first initial position is at a single value with no other adjacent value, or the peak value, the first value or the last value in a plurality of consecutive values in the first initial range.

4. The method of claim 1, wherein the first threshold is positive or negative and the first direction is forward or backward.

5. The method of claim 1, wherein the zero-crossing position analysis includes analyzing the zero-crossing position based on values before and after the zero-crossing.

6. The method of claim 1, further comprising:

determining at least a second initial position in the touch sensitive information based on a second threshold; and

performing a zero-crossing position analysis from each second initial position in a second range in a second direction, wherein the second range does not include touch sensitive information corresponding to the at least one first external object.

7. The method of claim 1, wherein the second threshold determines a second initial range, and each second initial position is at a single value with no other adjacent value or the peak value, the first value or the last value in a plurality of consecutive values in the second initial range.

8. The method of claim 1, wherein one of the first and second thresholds is positive, and the other one of the first and second thresholds is negative, wherein the second direction is opposite to the first direction.

9. The method of claim 1, further comprising:

determining at least one ending position in the touch sensitive information based on a second threshold; and

pairing the at least first initial position with the at least one ending position to determine the first range corresponding to each first initial position.

10. The method of claim 1, wherein the touch sensitive information corresponding to the at least one second external object includes at least one zero-crossing.

11. A device for analyzing positions, comprising:

a sensing device including a plurality of sensors; and

a controller for performing at least the following operations;

obtaining a touch sensitive information from the plurality of sensors corresponding to at least one first external object touching or approaching a signal source, wherein the at least one first external object electrically coupled with at least one second external object, and the touch sensitive information corresponds to signals of these sensors mutual-capacitively coupled to the signal source, the at least one first external object and the at least one second external object;

determining at least a first initial position in the touch sensitive information based on a first threshold; and

performing a zero-crossing position analysis from each first initial position in a first range in a first direction, wherein the first range does not include touch sensitive information corresponding to the at least one second external object.

12. The device of claim 11, wherein the first range is from the first initial position to a value just before a zero-crossing, a zero-crossing, or a value just after a zero-crossing.

13. The device of claim 11, wherein the first threshold determines a first initial range, and each first initial position being at a single value with no other adjacent value, or the peak value, the first value or the last value in a plurality of consecutive values in the first initial range.

14. The device of claim 11, wherein the first threshold is positive or negative and the first direction is forward or backward.

15. The device of claim 11, wherein the zero-crossing position analysis includes analyzing the zero-crossing position based on values before and after the zero-crossing.

16. The device of claim 11, wherein the controller further includes performing the following operations:

determining at least a second initial position in the touch sensitive information based on a second threshold; and

performing a zero-crossing position analysis from each second initial position in a second range in a second direction, wherein the second range does not include touch sensitive information corresponding to the at least one first external object.

17. The device of claim 11, wherein the second threshold determines a second initial range, and each second initial position being at a single value with no other adjacent value or the peak value, the first value or the last value in a plurality of consecutive values in the second initial range.

18. The device of claim 11, wherein one of the first and second thresholds is positive, and the other one of the first and second thresholds is negative, wherein the second direction is opposite to the first direction.

19. The device of claim 11, wherein the controller further includes performing the following operations:

determining at least one ending position in the touch sensitive information based on a second threshold; and

pairing the at least first initial position with the at least one ending position to determine the first range corresponding to each first initial position.

20. The device of claim 11, wherein the touch sensitive information corresponding to the at least one second external object includes at least one zero-crossing.