Touch sensor panel using regional and local electrodes to increase number of sense locations

• US 8,368,657 B2
• Filed: 12/01/2008
• Issued: 02/05/2013
• Est. Priority Date: 12/01/2008
• Status: Expired due to Fees

• Current Assignee: North Star Innovations Inc. (Wi-LAN Inc.)
• Original Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Inventors: Borras, Rodrigo L.
• Primary Examiner(s): Sitta, Grant
• Application Number:
  US12/325,721
• Publication Number:
  US 20100134422A1
• Time in Patent Office: 1,527 Days
• Field of Search: 345173-176, 178/18.01
• US Class Current: 345/173
• CPC Class Codes: G06F 3/03547 Touch pads, in which fingers can move on a surface
• 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

An input sensor for an electronic device which includes a touch sensor panel, multiple electrodes and a sensor circuit. The electrodes include multiple regional electrodes and multiple local electrodes. Each regional electrode covers a corresponding region of the touch sensor panel and each local electrode includes multiple pads including one pad located within each of the regional electrodes. The electrodes are distributed so that a touch anywhere across the touch sensor panel is detected by at least one regional electrode and at least one local electrode. A sensor circuit determines a value for each of the electrodes indicating relative change, and compares relative values of the electrodes to identify a location of a touch of the touch sensor panel. The regional electrodes are used to determine a region of a touch and the local electrodes are used to determine a more specific touch location within the determined region.

Claims

1. An input sensor for an electronic device, comprising:

a touch sensor panel having a first dimension and a second dimension;

a plurality of electrically-isolated electrodes distributed across said touch sensor panel, wherein said plurality of electrodes comprises a plurality of regional electrodes and at least four local electrodes;

wherein each of said plurality of regional electrodes covers a corresponding one of a plurality of regions of said touch sensor panel, wherein each of said plurality of regional electrodes extends no more than half of said first dimension and no more than half of said second dimension, and wherein a touch anywhere along said touch sensor panel is detected by at least one of said plurality of regional electrodes;

wherein each of said at least four local electrodes comprises a plurality of electrically-connected pads distributed within said plurality of regional electrodes so that each of said plurality of regions covered by a regional electrode includes at least one pad of each of said at least four local electrodes, wherein a touch anywhere across said touch sensor panel is detected by at least one of said at least four local electrodes; and

a sensor circuit which determines a value for each of said plurality of electrodes indicating relative change, and which compares relative values of said plurality of electrodes to identify a location of a touch of said touch sensor panel.

2. The input sensor of claim 1, wherein said sensor circuit determines said value comprising a relative capacitive change of each of said plurality of electrodes.

3. The input sensor of claim 1, wherein each of said plurality of regions comprises a rectangular-shaped area with four quadrants, wherein each of said at least four local electrodes comprises a conductive pad located within a corresponding one of said four quadrants of a corresponding one of said plurality of regions, and wherein each of said plurality of regional electrodes comprises a plurality of conductive strips coupled together and surrounding a corresponding four conductive pads of corresponding ones of said at least four local electrodes.

4. The input sensor of claim 3, wherein each of said at least four local electrodes comprises a rectangular-shaped conductive pad located within said corresponding one of said four quadrants of a corresponding one of said plurality of regional electrodes.

5. The input sensor of claim 1, wherein said sensor circuit determines active ones of said plurality of electrodes as those having a value which is greater than a minimum activity threshold.

6. The input sensor of claim 5, wherein said sensor circuit determines that four of said plurality of regional electrodes are active identifying a center touch region between said four regional electrodes, and wherein said sensor circuit weighs relative values of said four regional electrodes to determine a point of gravity within said center touch region.

7. The input sensor of claim 5, wherein said sensor circuit determines that only two of said plurality of regional electrodes are active identifying a border touch region between said two regional electrodes, and wherein said sensor circuit weighs relative values of active local electrodes to determine a point of gravity within said border touch region.

8. The input sensor of claim 5, wherein said sensor circuit determines that only one of said plurality of regional electrodes is active identifying an internal touch region within said only one regional electrode, and wherein said sensor circuit weighs relative values of active local electrodes to determine a point of gravity within said internal touch region.

9. The input sensor of claim 1, wherein said plurality of pads of said at least four local electrodes are sequentially ordered relative to each other to ensure distinction of touches within any of said plurality of regional electrodes from touches between any of said plurality of regional electrodes.

12. The electronic device of claim 1, wherein said sensor circuit determines active ones of said plurality of electrodes comprising a change above a minimum activity threshold.

13. The electronic device of claim 12, wherein said sensor circuit determines that four of said plurality of regional electrodes are active identifying a center touch region between said four regional electrodes, and wherein said sensor circuit weighs relative changes of said four regional electrodes to determine a point of gravity within said center touch region.

14. The electronic device of claim 12, wherein said sensor circuit determines that two of said plurality of regional electrodes are active identifying a border touch region between said two regional electrodes, and wherein said sensor circuit weighs relative changes of active local electrodes to determine a point of gravity within said border touch region.

15. The electronic device of claim 12, wherein said sensor circuit determines that only one of said plurality of regional electrodes is active identifying an internal touch region within said only one regional electrode, and wherein said sensor circuit weighs relative changes of active local electrodes to determine a point of gravity within said internal touch region.

20. The input sensor of claim 1, wherein said plurality of regional electrodes comprises six regional electrodes distributed in a two-by-three array of regional electrodes in which said first dimension comprises a length of three regional electrodes and in which said second dimension comprises a length of two regional electrodes, and wherein each of said at least four local electrodes comprises six pads in which one of said six pads is located in a corresponding one of said plurality of regional electrodes.

10. An electronic device, comprising:

a touch sensor panel having a first dimension and a second dimension, comprising;

a plurality of electrically-isolated regional electrodes distributed across said touch sensor panel for distinguishing a touch within or between each of a plurality of regions of said touch sensor panel, wherein each of said plurality of regional electrodes extends no more than half of said first dimension and no more than half of said second dimension; and

at least four electrically-isolated local electrodes distributed across said touch sensor panel, each comprising a plurality of electrically-connected pads distributed within said plurality of regional electrodes so that each of said plurality of regions covered by a regional electrode includes at least one pad of each of said at least four local electrodes, wherein a touch anywhere across said touch sensor panel is detected by at least one of said at least four local electrodes; and

a sensor circuit which senses changes of any of said plurality of electrodes, and which compares relative changes of said plurality of electrodes to identify a corresponding touch location of said touch sensor panel.

11. The electronic device of claim 10, wherein said touch sensor panel comprises a capacitive-type touch sensor panel.

21. The electronic device of claim 10, wherein said plurality of regional electrodes comprises six regional electrodes distributed in a two-by-three array of regional electrodes in which said first dimension comprises a length of three regional electrodes and in which said second dimension comprises a length of two regional electrodes, and wherein each of said at least four local electrodes comprises six pads in which one of said six pads is located in a corresponding one of said plurality of regional electrodes.

16. A method of determining a touch location along a touch area of a touch sensor panel having a first dimension and a second dimension, comprising:

providing a plurality of electrically-isolated electrodes comprising a plurality of regional electrodes and at least four local electrodes;

locating each of the plurality of regional electrodes within a corresponding one of a plurality of regions of the touch area wherein each region includes one regional electrode, wherein each regional electrode extends no more than half of the first dimension and no more than half of the first dimension, and wherein a touch anywhere along the touch area is detected by at least one of the plurality of regional electrodes;

dividing each of the at least four local electrodes into a plurality of electrically-coupled touch pads;

distributing the plurality of touch pads of each of the at least four local electrodes within the plurality of regional electrodes so that each of said plurality of regions covered by a regional electrode includes a touch pad of each local electrode, and so that a touch anywhere along the touch area is detected by at least one of the at least four local electrodes; and

determining the touch location by determining which of the regional electrodes are changed above a minimum activity threshold and by weighing relative changes of the plurality of electrodes.

17. The method of claim 16, further comprising:

detecting four active regional electrodes; and

weighing relative changes of the four active regional electrodes to determine a point of gravity within a center touch region between the four active regional electrodes.

18. The method of claim 16, further comprising:

detecting only two active regional electrodes; and

weighing relative changes of the local electrodes to determine a point of gravity within a border touch region between the two active regional electrodes.

19. The method of claim 16, further comprising:

detecting only one active regional electrode; and

weighing relative changes of the local electrodes to determine a point of gravity within the active regional electrode.

22. The method of claim 16, wherein said plurality of regional electrodes comprises six regional electrodes distributed in a two-by-three array of regional electrodes in which said first dimension comprises a length of three regional electrodes and in which said second dimension comprises a length of two regional electrodes, and wherein each of said at least four local electrodes comprises six pads in which one of said six pads is located in a corresponding one of said plurality of regional electrodes.