Method and device for determining a touch or touches

• US 8,842,079 B2
• Filed: 10/08/2010
• Issued: 09/23/2014
• 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): ABDIN, SHAHEDA A
• Application Number:
  US12/923,806
• Publication Number:
  US 20110084927A1
• Time in Patent Office: 1,446 Days
• Field of Search: 345173-174, 345/156, 345/179, 178/18.01, 715/701, 715/863, 715/702
• US Class Current: 345/173
• CPC Class Codes: G01R 27/2605 Measuring capacitance capacitive sensors G01D5/24
• CPC Class Codes: G06F 2203/04101 2.5D-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 and also measures the distance of the input means within a short range in the Z direction, possibly with a separate measurement setup
• CPC Class Codes: G06F 2203/04102 Flexible digitiser, i.e. constructional details for allowing the whole digitising part of a device to be flexed or rolled like a sheet of paper
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 2203/04104 Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
• CPC Class Codes: G06F 2203/04106 Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection
• CPC Class Codes: G06F 2203/04111 Cross over in capacitive digitiser, i.e. details of structures for connecting electrodes of the sensing pattern where the connections cross each other, e.g. bridge structures comprising an insulating layer, or vias through substrate
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• 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 3/04182 Filtering of noise external to the device and not generated by digitiser components
• CPC Class Codes: G06F 3/04184 Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• 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 determining a single touch or multiple touches is disclosed. A touch related sensing information with a single zero-crossing is used for determining a pair of values, and the locations of a pair of centroids are calculated depending on the pair of values. The distance between the locations of the pair of centroids can be used to determine whether the number of touches is one or more.

Claims

1. A method for determining a touch or touches, comprising:

obtaining a sensing information;

determining each touch related sensing information in the sensing information; and

analyzing each touch related sensing information having a single zero-crossing, the analyzing includes;

determining a pair of values based on each touch related sensing information having a single zero-crossing;

calculating the locations of a pair of centroids based on the pair of values of each touch related sensing information having a single zero-crossing; and

determining whether there is a touch or touches based on the distance between the locations of the pair of centroids of each touch related sensing information having a single zero-crossing.

2. The method of claim 1, wherein the determining of the pair of values includes:

determining one of the pair of values based on a positive threshold; and

determining the other one of the pair of values based on a negative threshold.

3. The method of claim 2, wherein the determining of the one of the pair of values includes:

determining at least one positive value greater than the positive threshold based on the positive threshold; and

determining the one of the pair of values based on the first value, the maximum value, the last value, the value adjacent to the first value, the value adjacent to the maximum value, and the value adjacent to the last value of the at least one positive value.

4. The method of claim 2, wherein the determining of the other one of the pair of values includes:

determining at least one negative value smaller than the negative threshold based on the negative threshold; and

determining the other one of the pair of values based on the first value, the minimum value, the last value, the value adjacent to the first value, the value adjacent to the minimum value, and the value adjacent to the last value of the at least one negative value.

5. The method of claim 1, wherein the calculating of the locations of a pair of centroids based on the pair of values of each touch related sensing information having a single zero-crossing includes:

determining a pair of ranges in the sensing information based on the pair of values of each touch related sensing information having a single zero-crossing; and

calculating the locations of the pair of centroids based on the pair of ranges of each touch related sensing information having a single zero-crossing.

6. The method of claim 1, wherein the calculating of the locations of a pair of centroids based on the pair of values of each touch related sensing information having a single zero-crossing includes:

determining a pair of ranges in another sensing information based on the pair of values of each touch related sensing information having a single zero-crossing; and

calculating the locations of the pair of centroids based on the pair of ranges of each touch related sensing information having a single zero-crossing.

7. The method of claim 6, wherein the sensing information is generated based on the another sensing information.

8. The method of claim 6, wherein the another sensing information is generated based on the sensing information.

9. The method of claim 6, wherein the another sensing information including a plurality of signal values, a plurality of differences, or a plurality of dual differences.

10. A device for determining a touch or touches, comprising a controller or a host for performing the following operations:

obtaining a sensing information;

determining each touch related sensing information in the sensing information; and

analyzing each touch related sensing information having a single zero-crossing, the analyzing includes;

determining a pair of values based on each touch related sensing information having a single zero-crossing;

calculating the locations of a pair of centroids based on the pair of values of each touch related sensing information having a single zero-crossing; and

determining whether there is a touch or touches based on the distance between the locations of the pair of centroids of each touch related sensing information having a single zero-crossing.

11. The device of claim 10, wherein the determining of the pair of values includes:

determining one of the pair of values based on a positive threshold; and

determining the other one of the pair of values based on a negative threshold.

12. The device of claim 11, wherein the determining of the one of the pair of values includes:

determining at least one positive value greater than the positive threshold based on the positive threshold; and

determining the one of the pair of values based on the first value, the maximum value, the last value, the value adjacent to the first value, the value adjacent to the maximum value, and the value adjacent to the last value of the at least one positive value.

13. The device of claim 11, wherein the determining of the other one of the pair of values includes:

determining at least one negative value smaller than the negative threshold based on the negative threshold; and

determining the other one of the pair of values based on the first value, the minimum value, the last value, the value adjacent to the first value, the value adjacent to the minimum value, and the value adjacent to the last value of the at least one negative value.

14. The device of claim 10, wherein the calculating of the locations of a pair of centroids based on the pair of values of each touch related sensing information having a single zero-crossing includes:

determining a pair of ranges in the sensing information based on the pair of values of each touch related sensing information having a single zero-crossing; and

calculating the locations of the pair of centroids based on the pair of ranges of each touch related sensing information having a single zero-crossing.

15. The device of claim 10, wherein the calculating of the locations of a pair of centroids based on the pair of values of each touch related sensing information having a single zero-crossing includes:

determining a pair of ranges in another sensing information based on the pair of values of each touch related sensing information having a single zero-crossing; and

calculating the locations of the pair of centroids based on the pair of ranges of each touch related sensing information having a single zero-crossing.

16. The device of claim 15, wherein the sensing information is generated based on the another sensing information.

17. The device of claim 15, wherein the another sensing information is generated based on the sensing information.

18. The device of claim 15, wherein the another sensing information including a plurality of signal values, a plurality of differences, or a plurality of dual differences.

19. The device of claim 10, wherein the sensing information is obtained from a plurality of dual-differential values that each dual-differential value is based on the signals of three sensors of a plurality of sensors separately, wherein the three sensors are adjacent or non-adjacent.