Method and device for analyzing positions

• US 8,400,424 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
• Application Number:
  US13/308,673
• Publication Number:
  US 20120075247A1
• 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 related sensing information from a plurality of sensors corresponding to a touch or approach of at least one external object;

predetermining a first characteristic corresponding to a first type of external object and a second characteristic corresponding to a second type of external object in the touch related sensing information, wherein the first characteristic is opposite to the second characteristic; and

identifying touches or approaches by the first type of external object, the second type of external object or both in the touch related sensing information based on the first and second characteristics.

2. The method of claim 1, wherein one of the first and second characteristics is positive, and the other one of the first and second characteristics is negative.

3. The method of claim 1, wherein the touch related sensing information corresponding to the first type of external object and the second type of external object are an alternating combination of at least a set of one or a plurality of consecutive positive values and at least a set of one or a plurality of consecutive negative values.

4. The method of claim 3, wherein one of the first and second characteristics starts with at least a set of one or a plurality of consecutive positive values, and the other one of the first and second characteristics starts with at least a set of one or a plurality of consecutive negative values.

5. The method of claim 1, wherein one of the first type of external object and the second type of external object is a grounded conductor, and the other one of the first type of external object and the second type of external object is a signal source providing an alternating current signal.

6. The method of claim 1, wherein the first type of external object and the second type of external object are capactively coupled with these sensors.

7. The method of claim 1, wherein the identifying in the touch related sensing information based on the first and second characteristics is based on a positive threshold and a negative threshold.

8. The method of claim 7, wherein at least one touch related sensing information corresponding to the first type of external object is greater than the positive threshold, and at least one touch related sensing information corresponding to the second type of external object is smaller than the negative threshold.

9. The method of claim 7, wherein the identifying in the touch related sensing information based on the first and second characteristics includes:

determining at least a first initial position in the touch related sensing information based on the first threshold;

determining at least a second initial position in the touch related sensing information based on the second threshold;

performing a first zero-crossing position analysis starting from each first initial position in a first range in a first direction; and

performing the first zero-crossing position analysis starting from each second initial position in a second range in a second direction, wherein a zero-crossing analyzed by the first zero-crossing position analysis is a position corresponding to a touch or approach of the first type of external object, and the first range and the second range do not include touch related sensing information corresponding to at least one second external object.

10. The method of claim 9, wherein the identifying in the touch related sensing information based on the first and second characteristics includes:

determining at least a third initial position in the touch related sensing information based on the first threshold;

determining at least a fourth initial position in the touch related sensing information based on the second threshold;

performing a second zero-crossing position analysis starting from each third initial position in a third range in a second direction; and

performing the second zero-crossing position analysis starting from each fourth initial position in a fourth range in a first direction, wherein a zero-crossing analyzed by the second zero-crossing position analysis is a position corresponding to a touch or approach of the second type of external object, and the third range and the fourth range do not include touch related sensing information corresponding to at least one first external object.

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 related sensing information from the plurality of sensors corresponding to a touch or approach of at least one external object;

predetermining a first characteristic corresponding to a first type of external object and a second characteristic corresponding to a second type of external object in the touch related sensing information, wherein the first characteristic is opposite to the second characteristic; and

identifying touches or approaches by the first type of external object, the second type of external object, or both in the touch related sensing information based on the first and second characteristics.

12. The device of claim 11, wherein one of the first and second characteristics is positive, and the other one of the first and second characteristics is negative.

13. The device of claim 11, wherein the touch related sensing information corresponding to the first type of external object and the second type of external object are an alternating combination of at least a set of one or a plurality of consecutive positive values and at least a set of one or a plurality of consecutive negative values.

14. The device of claim 13, wherein one of the first and second characteristics starts with at least a set of one or a plurality of consecutive positive values, and the other one of the first and second characteristics starts with at least a set of one or a plurality of consecutive negative values.

15. The device of claim 11, wherein one of the first type of external object and the second type of external object is a grounded conductor, and the other one of the first type of external object and the second type of external object is a signal source providing an alternating current signal.

16. The device of claim 11, wherein the first type of external object and the second type of external object are capactively coupled with these sensors.

17. The device of claim 11, wherein the identifying in the touch related sensing information based on the first and second characteristics is based on a positive threshold and a negative threshold.

18. The device of claim 17, wherein at least one touch related sensing information corresponding to the first type of external object is greater than the positive threshold, and at least one touch related sensing information corresponding to the second type of external object is smaller than the negative threshold.

19. The device of claim 17, wherein the identifying in the touch related sensing information based on the first and second characteristics includes:

determining at least a first initial position in the touch related sensing information based on the first threshold;

determining at least a second initial position in the touch related sensing information based on the second threshold;

performing a first zero-crossing position analysis starting from each first initial position in a first range in a first direction; and

performing the first zero-crossing position analysis starting from each second initial position in a second range in a second direction, wherein a zero-crossing analyzed by the first zero-crossing position analysis is a position corresponding to a touch or approach of the first type of external object, and the first range and the second range do not include touch related sensing information corresponding to the at least one second external object.

20. The device of claim 19, wherein the identifying in the touch related sensing information based on the first and second characteristics includes:

determining at least a third initial position in the touch related sensing information based on the first threshold;

determining at least a fourth initial position in the touch related sensing information based on the second threshold;

performing a second zero-crossing position analysis starting from each third initial position in a third range in a second direction; and

performing the second zero-crossing position analysis starting from each fourth initial position in a fourth range in a first direction, wherein a zero-crossing analyzed by the second zero-crossing position analysis is a position corresponding to a touch or approach of the second type of external object, and the third range and the fourth range do not include touch related sensing information corresponding to the at least one first external object.