SYSTEM AND METHOD FOR DETECTING LOCATIONS OF TOUCHES ON A PROJECTED CAPACITIVE TOUCH SENSOR

• US 20110279169A1
• Filed: 05/14/2010
• Published: 11/17/2011
• Est. Priority Date: 05/14/2010
• Status: Active Grant

• Current Assignee: Elo Touch Solutions, Inc.
• Original Assignee: Elo Touch Solutions, Inc.
• Inventors: Salaverry, Ricardo R.
• Granted Patent: US 9,727,175 B2
• Time in Patent Office: Days
• US Class Current: 327/517
• CPC Class Codes: G01R 27/2605 Measuring capacitance capacitive sensors G01D5/24
• 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 2203/04105 Pressure sensors for measuring the pressure or force exerted on the touch surface without providing the touch position
• CPC Class Codes: G06F 2203/04107 Shielding in digitiser, i.e. guard or shielding arrangements, mostly for capacitive touchscreens, e.g. driven shields, driven grounds
• CPC Class Codes: G06F 2203/04108 Touchless 2D- 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 without distance measurement in the Z direction
• CPC Class Codes: G06F 2203/04112 Electrode mesh in capacitive digitiser: electrode for touch sensing is formed of a mesh of very fine, normally metallic, interconnected lines that are almost invisible to see. This provides a quite large but transparent electrode surface, without need for ITO or similar transparent conductive material
• CPC Class Codes: G06F 3/04164 Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads
• 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: G06F 3/0448 Details of the electrode shape, e.g. for enhancing the detection of touches, for generating specific electric field shapes, for enhancing display quality

Abstract

A projected capacitive touch sensor includes a substrate and sets of electrodes coupled to corresponding areas of the substrate. The areas are non-overlapping with respect to each other. The sets of electrodes include a horizontal sensing electrode that extends along a height of a first column within the area and vertical sensing electrodes that extend partially along the height of at least one column within the area. The at least one column includes at least two vertical sensing electrodes that are physically separate with respect to each other and electrically connected to each other.

Claims

1. A projected capacitive touch sensor, comprising:

a substrate; and

sets of electrodes coupled to corresponding areas of the substrate, the areas being non-overlapping with respect to each other, the sets of electrodes comprising a horizontal sensing electrode that extends along a height of a first column within the area and vertical sensing electrodes that extend partially along the height of at least one column within the area, the at least one column comprising at least two vertical sensing electrodes that are physically separate with respect to each other and electrically connected to each other.

2. The touch sensor of claim 1, wherein at least one of the vertical sensing electrodes in one of the sets of electrodes is electrically connected to at least one corresponding vertical sensing electrode within a different one of the sets of electrodes.

3. The touch sensor of claim 1, wherein the horizontal sensing electrodes are electrically disconnected with respect to each other and the vertical sensing electrodes.

4. The touch sensor of claim 1, wherein at least one of the sets of electrodes further comprises another horizontal sensing electrode that extends along a height of a second column within the corresponding area, wherein the horizontal sensing electrodes within the corresponding area are adjacent and electrically disconnected with respect to each other.

5. The touch sensor of claim 1, wherein at least one of the sets of electrodes further comprises another horizontal sensing electrode that extends along a height of a second column within the corresponding area, wherein the horizontal sensing electrodes within the corresponding area are electrically disconnected with respect to each other, wherein one of the horizontal sensing electrodes is electrically connected to one horizontal sensing electrode in at least one other area.

6. The touch sensor of claim 1, wherein the vertical sensing electrodes of at least one of the sets of electrodes further comprises:

two vertical sensing electrodes that extend along a second column and are physically separate with respect to each other, the two vertical sensing electrodes being electrically separate with respect to each other and the horizontal and vertical sensing electrodes in other columns within the corresponding area; and

at least three vertical sensing electrodes that extend along a third column and are physically separate with respect to each other, wherein a portion of the at least three vertical sensing electrodes are electrically connected to each other, wherein the at least three vertical sensing electrodes are electrically separate with respect to the horizontal and vertical sensing electrodes in other columns within the corresponding area.

7. The touch sensor of claim 1, wherein the at least two vertical sensing electrodes are physically separated from each other by a gap that is located a distance from a top edge of the corresponding area, and wherein at least one of the vertical and horizontal sensing electrodes in at least one other column within the corresponding area extends through the distance from the top edge of the area.

8. The touch sensor of claim 1, wherein the at least two vertical sensing electrodes are physically separated from each other by a gap that is located a distance from a top edge of the corresponding area, and wherein other columns within the corresponding area have a vertical sensing electrode or a horizontal sensing electrode that extends through the distance from the top edge of the area.

9. The touch sensor of claim 1, further comprising:

the set of electrodes in a first area further comprising at least first and second vertical sensing electrodes in a column that are physically and electrically separate with respect to each other; and

the set of electrodes in a second area that is adjacent to the first area further comprising at least third and fourth vertical sensing electrodes in a column that are physically and electrically separate with respect to each other, wherein the first vertical sensing electrode is electrically connected to the corresponding vertical sensing electrode in a third area that is adjacent to the first area and electrically separate with respect to the corresponding vertical sensing electrode in the second area, and wherein the second vertical sensing electrode is electrically connected to the corresponding vertical sensing electrodes in the second area and the third area.

10. The touch sensor of claim 1, further comprising:

the set of electrodes in a first area further comprising at least first and second vertical sensing electrodes in a column that are physically separate with respect to each other; and

the set of electrodes in a second area that is adjacent to the first area further comprising at least third and fourth vertical sensing electrodes in a column that are physically separate with respect to each other, wherein the first, second, third and fourth vertical sensing electrodes are electrically disconnected with respect to each other, wherein the first and second vertical sensing electrodes are electrically connected to corresponding vertical sensing electrodes in a third area that is adjacent to the first area, and the third and fourth vertical sensing electrodes are electrically connected to the corresponding vertical sensing electrodes in a fourth area that is adjacent to the second area.

11. A projected capacitive touch sensor system, comprising:

a substrate;

sets of electrodes coupled to corresponding areas of the substrate, the areas being non-overlapping with respect to each other, the sets of electrodes comprising a horizontal sensing electrode that extends along a height of a first column within the area and vertical sensing electrodes that extend partially along the height of at least one column within the area, the at least one column comprising at least two vertical sensing electrodes that are physically separate with respect to each other and electrically connected to each other; and

a controller configured to detect signal levels associated with at least one touch on the substrate from the sets of electrodes, the signal levels associated with the horizontal sensing electrodes being used to determine the corresponding areas of the at least one touch and the signal levels associated with the vertical sensing electrodes being used to determine vertical locations within the corresponding areas of the at least one touch.

12. The touch sensor system of claim 11, wherein the controller further comprises electronic channels, the horizontal sensing electrodes connected to different ones of the electronic channels.

13. The touch sensor system of claim 11, wherein at least one of the sets of electrodes further comprises another horizontal sensing electrode that extends along a height of a second column within the corresponding area, the horizontal sensing electrodes within the corresponding area being adjacent and electrically disconnected with respect to each other, and wherein the controller is further configured to determine the corresponding areas of the at least one touch based on the signal levels associated with the horizontal sensing electrodes within the first and second columns.

14. The touch sensor system of claim 11, wherein the controller further comprises electronic channels, wherein at least one of the sets of electrodes further comprises another horizontal sensing electrode that extends along a height of a second column within the corresponding area, the horizontal sensing electrodes within the corresponding area being adjacent and electrically disconnected with respect to each other, wherein one of the horizontal sensing electrodes is electrically connected to one of the horizontal sensing electrodes in a different area, and wherein the controller is further configured to determine the corresponding areas of the at least one touch based on the signal levels associated with the horizontal sensing electrodes.

15. The touch sensor system of claim 11, wherein at least one of the vertical sensing electrodes within one of the areas is electrically connected to at least one of the vertical sensing electrodes within another one of the areas.

16. The touch sensor system of claim 11, wherein the at least two vertical sensing electrodes are electrically connected to at least one of the vertical sensing electrodes within another one of the areas.

17. The touch sensor system of claim 11, wherein the vertical locations are further determined based on ratios of the signal levels associated with the vertical sensing electrodes.

18. The touch sensor system of claim 11, wherein the corresponding areas of the at least one touch are further determined based on greatest signal levels associated with at least one of the horizontal sensing electrodes.

19. The touch sensor system of claim 11, wherein the vertical locations are further determined based on a size of the at least one touch.

20. The touch sensor system of claim 11, wherein the vertical locations are further determined based on interpolation.