Methods and apparatus for detecting user's touch on a touch panel

• US 8,390,576 B2
• Filed: 09/01/2008
• Issued: 03/05/2013
• Est. Priority Date: 09/01/2008
• Status: Active Grant

• Current Assignee: MediaTek, Inc.
• Original Assignee: MediaTek, Inc.
• Inventors: Hong, Hao-Ping, Hsu, Yen-Hsun
• Primary Examiner(s): SHERMAN, STEPHEN G
• Application Number:
  US12/202,337
• Publication Number:
  US 20100053090A1
• Time in Patent Office: 1,646 Days
• Field of Search: 345173-179, 178 1801- 1809, 178/18.11, 341/155
• US Class Current: 345/173
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: H03M 1/1225 using time-division multiplexing

Abstract

A method for detecting a user'"'"'s touch on a touch panel includes: deriving a plurality of geometric differences of a first direction of the touch panel, wherein each of the geometric differences of the first direction represents a difference between respective coupling amounts at two locations of a plurality of locations of the first direction on the touch panel; and analyzing the geometric differences of the first direction to obtain at least one analysis result, wherein the analysis result comprises information representing whether the user touches the touch panel in one or more places.

Claims

1. A method for detecting a user'"'"'s touch on a touch panel, the method comprising:

deriving a plurality of geometric differences of a first direction of the touch panel, wherein each of the geometric differences of the first direction represents a difference between respective coupling amounts at two different locations of a plurality of locations of the first direction on the touch panel, and each of the geometric differences corresponds to a specific location of the locations of the first direction on the touch panel; and

analyzing the geometric differences of the first direction to obtain at least one analysis result by finding polarity changes in the geometric differences, comprising;

determining whether the geometric differences corresponding to two different specific locations of the locations of the first direction on the touch panel have different polarities to find the polarity changes;

wherein the analysis result comprises information representing whether the user touches the touch panel in one or more places.

2. The method of claim 1, wherein the two locations are associated with two neighboring touch sensors of the touch panel.

3. The method of claim 1, wherein the two locations are associated with two adjacent touch sensors of the touch panel.

4. The method of claim 1, wherein the step of deriving the plurality of geometric differences of the first direction of the touch panel further comprises:

differentially performing analog-to-digital conversion on respective coupling amounts at the plurality of locations of the first direction to generate a plurality of digital values, respectively; and

utilizing the digital values as the geometric differences, respectively.

5. The method of claim 4, wherein the step of differentially performing analog-to-digital conversion on the respective coupling amounts at the plurality of locations of the first direction to generate the plurality of digital values further comprises:

utilizing two coupling amounts of the respective coupling amounts at the plurality of locations as differential inputs of an analog-to-digital converter (ADC); and

utilizing the ADC to perform analog-to-digital conversion on the two coupling amounts to generate one of the digital values.

6. The method of claim 1, wherein the step of deriving the plurality of geometric differences of the first direction of the touch panel further comprises:

time-divisionally performing analog-to-digital conversion on respective coupling amounts at the plurality of locations of the first direction to generate a plurality of digital values, respectively; and

calculating differences between the digital values to generate the geometric differences, respectively.

7. The method of claim 6, wherein the step of time-divisionally performing analog-to-digital conversion on the respective coupling amounts at the plurality of locations of the first direction to generate the plurality of digital values further comprises:

selecting at least one of the respective coupling amounts at the plurality of locations of the first direction in turns; and

performing the analog-to-digital conversion on the selected coupling amount to generate one of the digital values.

8. The method of claim 1, wherein the analysis result comprises coordinate value of at least one location within the one or more places of the first direction.

9. The method of claim 1, further comprising:

deriving a plurality of geometric differences of a second direction of the touch panel, wherein each of the geometric differences of the second direction represents a difference between respective coupling amounts at two locations of a plurality of locations of the second direction on the touch panel; and

analyzing the geometric differences of the second direction to obtain the analysis result.

10. The method of claim 9, wherein the analysis result comprises coordinate value of at least one location within the one or more places of the second direction.

11. An apparatus for detecting a user'"'"'s touch on a touch panel, the apparatus comprising:

an analog-to-digital conversion module arranged to perform analog-to-digital conversion on respective coupling amounts at a plurality of locations of a first direction of the touch panel; and

a processing unit arranged to derive a plurality of geometric differences of the first direction and analyze the geometric differences of the first direction to obtain at least one analysis result by finding polarity changes in the geometric differences, wherein each of the geometric differences of the first direction represents a difference between respective coupling amounts at two different locations of the plurality of locations of the first direction on the touch panel, each of the geometric differences corresponds to a specific location of the locations of the first direction on the touch panel, wherein the processing unit determines whether the geometric differences corresponding to two different specific locations of the locations of the first direction on the touch panel have different polarities to find the polarity changes;

wherein the analysis result comprises information representing whether the user touches the touch panel in one or more places.

12. The apparatus of claim 11, wherein the two locations are associated with two neighboring touch sensors of the touch panel.

13. The apparatus of claim 11, wherein the two locations are associated with two adjacent touch sensors of the touch panel.

14. The apparatus of claim 11, wherein the analog-to-digital conversion module comprises:

a plurality of analog-to-digital converters (ADCs) arranged to differentially perform analog-to-digital conversion on the respective coupling amounts at the plurality of locations of the first direction to generate a plurality of digital values, respectively;

wherein the processing unit is arranged to utilize the digital values as the geometric differences, respectively.

15. The apparatus of claim 14, wherein each of the ADCs is arranged to utilize two coupling amounts of the respective coupling amounts at the plurality of locations as differential inputs of the ADC, and perform analog-to-digital conversion on the two coupling amounts to generate one of the digital values.

16. The apparatus of claim 11, wherein the analog-to-digital conversion module comprises:

an ADC arranged to time-divisionally perform analog-to-digital conversion on the respective coupling amounts at the plurality of locations of the first direction to generate a plurality of digital values, respectively;

wherein the processing unit is arranged to calculate differences between the digital values to generate the geometric differences, respectively.

17. The apparatus of claim 16, wherein the analog-to-digital conversion module further comprises:

a multiplexer arranged to select at least one of the respective coupling amounts at the plurality of locations of the first direction in turns;

wherein the ADC is arranged to perform analog-to-digital conversion on the selected coupling amount to generate one of the digital values.

18. The apparatus of claim 11, wherein the analysis result comprises coordinate value of at least one location within the one or more places of the first direction.

19. The apparatus of claim 11, wherein the analog-to-digital conversion module further performs analog-to-digital conversion on respective coupling amounts at a plurality of locations of a second direction of the touch panel;

the processing unit detects the user'"'"'s touch by utilizing the analog-to-digital conversion module, in order to derive a plurality of geometric differences of the second direction; and

each of the geometric differences of the second direction represents a difference between respective coupling amounts at two locations of the plurality of locations of the second direction on the touch panel, and the processing unit analyzes the geometric differences of the second direction to obtain the analysis result.

20. The apparatus of claim 19, wherein the analysis result comprises coordinate value of at least one location within the one or more places of the second direction.