Touch sensor having a single sensor layer

• US 9,478,189 B2
• Filed: 10/30/2014
• Issued: 10/25/2016
• Est. Priority Date: 10/30/2014
• Status: Expired due to Fees

• Current Assignee: Atmel Corporation (Microchip Technology Incorporated)
• Original Assignee: Atmel Corporation (Microchip Technology Incorporated)
• Inventors: Lewis, Lowry D.
• Primary Examiner(s): Spar, Ilana
• Assistant Examiner(s): HERMANN, KIRK W
• Application Number:
  US14/528,249
• Publication Number:
  US 20160124554A1
• Time in Patent Office: 726 Days
• Field of Search: None
• US Class Current: 1/1
• 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 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 5/003 Details of a display terminal, the details relating to the control arrangement of the display terminal and to the interfaces thereto specific for a CRT G09G1/165; for a flat panel G09G3/2092
• CPC Class Codes: H03K 17/962 Capacitive touch switches
• CPC Class Codes: H03K 17/9622 using a plurality of detectors, e.g. keyboard
• CPC Class Codes: H03K 2017/9604 characterised by the number of electrodes

Abstract

In one aspect, a touch sensor includes a dielectric surface layer; drive electrodes disposed on the dielectric surface layer and arranged radially about a center, the drive electrodes defining a perimeter about the center, and a sense electrode disposed on the dielectric surface layer and arranged between two of the drive electrodes. Each drive electrode can include: an outer radial section extending radially along the perimeter; a central section extending from the outer radial section towards the center; and an inner radial section comprising a first section extending radially away from the central section in a first radial direction and a second section, shorter than the first section, extending radially away from the central section in a second radial direction.

Claims

1. A touch sensor comprising:

a dielectric surface layer;

a plurality of drive electrodes disposed on the dielectric surface layer and arranged radially about a center, the drive electrodes defining a perimeter about the center, wherein each drive electrode comprises;

an outer radial section extending radially along the perimeter;

a central section extending from the outer radial section towards the center; and

an inner radial section comprising a first section extending radially away from the central section in a first radial direction and a second section, shorter than the first section, extending radially away from the central section in a second radial direction; and

a sense electrode disposed on the dielectric surface layer and arranged between two of the drive electrodes, wherein a distance between the sense electrode and the outer radial section of each of the two of the drive electrodes is associated with a thickness of each section of the drive electrode.

2. The touch sensor of claim 1, wherein the sense electrode comprises:

a first central section extending, between first and second drive electrodes, from the perimeter towards the center;

a first radial section extending radially from an inner end of the first central section towards the first and second drive electrodes; and

a second central section extending, between a first long section of a first inner radial section of the first drive electrode and a first short section of a second inner radial section of the second drive electrode, from the first radial section towards the center.

3. The touch sensor of claim 2, wherein each section of the drive electrodes has a thickness T, and wherein a distance between the first radial section of each sense electrode and the outer radial section of each drive electrode is T/2.

4. The touch sensor of claim 1, wherein each section of the drive electrodes has a thickness T, and wherein a distance between a first long section of a first drive electrode and a first short section of a second drive electrode is T/2.

5. The touch sensor of claim 1, wherein each section of the drive electrodes has a thickness T, and wherein a gap between a first outer radial section of a first drive electrode and a first central section of an adjacent sense electrode spans a distance of T/2.

6. The touch sensor of claim 1, wherein the drive electrodes and the sense electrode are arranged on a single layer.

7. The touch sensor of claim 1, comprising a plurality of sense electrodes, wherein each sense electrode is electrically connected to a common sense electrode.

8. The touch sensor of claim 1, comprising a touch sensor controller configured to pulse each of the drive electrodes at different times and to measure a response from each of the sense electrodes.

12. The touch sensor of claim 1, wherein each section of the drive electrodes has a thickness T, and wherein a distance between a first long section of a first drive electrode and a first short section of a second drive electrode is T/2.

13. The touch sensor of claim 1, wherein each section of the drive electrodes has a thickness T, and wherein a gap between a top horizontal section of a first drive electrode and a first vertical section of a first adjacent sense electrode spans a distance of T/2.

14. The touch sensor of claim 1, wherein the drive electrodes and the sense electrode are arranged on a single layer.

15. The touch sensor of claim 1, comprising a plurality of sense electrodes, wherein each sense electrode is electrically connected to a common sense electrode.

16. The touch sensor of claim 1, comprising a touch sensor controller configured to pulse each of the drive electrodes at different times and to measure a response from each of the sense electrodes.

9. A touch sensor comprising:

a dielectric surface layer;

a plurality of drive electrodes disposed on the dielectric surface layer and collectively arranged in a rectangular pattern, wherein each drive electrode comprises;

a first horizontal section extending along a horizontal direction;

a vertical section extending along a vertical direction; and

a second horizontal section extending along the horizontal direction from the vertical section towards an adjacent drive electrode; and

a third horizontal section, shorter than the second horizontal section, extending along the horizontal direction from the vertical section towards the adjacent drive electrode; and

a sense electrode disposed on the dielectric surface layer and arranged between two of the drive electrodes, wherein a distance between the sense electrode and the first horizontal section of each of the two of the drive electrodes is associated with a thickness of each section of the drive electrode.

10. The touch sensor of claim 9, wherein the sense electrode comprises:

a first vertical section extending along the vertical direction between first and second drive electrodes;

a first horizontal section extending along the horizontal direction from a bottom of the first vertical section; and

a second vertical section extending along the vertical direction from the first horizontal section and between the first and second drive electrodes; and

a second horizontal section extending along the horizontal direction from a bottom of the second vertical section.

11. The touch sensor of claim 10, wherein each section of the drive electrodes has a thickness T, and wherein a distance between the first vertical section of each sense electrode and the top horizontal section of the drive electrode is T/2.

17. A method performed by a touch sensor controller, the method comprising:

sequentially applying multiple pulses to each drive electrode of a plurality of drive electrodes arranged radially about a center of a touch sensor, the drive electrodes defining a perimeter about the center, wherein each drive electrode comprises;

an outer radial section extending radially along the perimeter;

a central section extending from the outer radial section towards the center; and

an inner radial section comprising a long section extending radially away from the central section in a first direction and a short section, shorter than the long section, extending radially away from the central section in a second direction;

for each drive electrode, measuring a response from a plurality of sense electrodes to the pulse applied to the drive electrode; and

determining a location on a surface of the touch sensor based on the measured responses,

wherein one of the plurality of sense electrodes is arranged between two of the drive electrodes, and a distance between the sense electrode and the outer radial section of each of the two of the drive electrodes is associated with a thickness of each section of the drive electrode.

18. The method of claim 17, wherein the sense electrodes are arranged in an alternating fashion between the drive electrodes.

19. The method of claim 18, wherein each sense electrode comprises:

a first central section extending, between first and second drive electrodes, from the perimeter towards the center;

a first radial section extending radially from an inner end of the first central section towards the first and second drive electrodes; and

a second central section extending, between a first long section of a first inner radial section of the first drive electrode and a first short section of a second inner radial section of the second drive electrode, from the first radial section towards the center.

20. The method of claim 17, wherein the drive electrodes and the sense electrodes are arranged on a single layer, and wherein each sense electrode is connected to a common sense electrode.