Dual-sensing-mode touch-sensor device
A touch-sensor device is described. The touch sensor-device includes a panel having an array of capacitive sensors arranged to function, in a first direction, as a projected capacitance slider. The array of capacitive sensors is further arranged to function, in a second direction, as a set of independent surface capacitance sensors. A controller is coupled with the panel by an electrical component.
1. A touch-sensor device, comprising:
a panel having an array of capacitive sensors arranged to operate, in a first direction corresponding to a first axis of the panel, as a projected capacitance slider and, in a second direction corresponding to a second axis of the panel, as a set of independent surface capacitance sensors to detect a position of a touch in the second direction, wherein the first axis and the second axis are perpendicular; and
a controller coupled with the panel by an electrical component, wherein the controller is coupled to a first end and a second end of each of the capacitive sensors along the second axis of the panel, the controller to determine a multi-touch result on the panel using additive scanning of the capacitive sensors in the first direction and subtractive scanning of the capacitive sensors in the second direction.
2. The touch-sensor device of claim 1 , wherein the array of capacitive sensors comprises a pattern of interlaced strips of a resistive material.
3. The touch-sensor device of claim 2 , wherein the pattern of interlaced strips of the resistive material comprises an arrangement of continuous wavy strips in a horizontal direction between a pair of vertical edges of the panel, each continuous strip spaced equidistant in a vertical direction between a pair of horizontal edges of the panel.
4. The touch-sensor device of claim 3 , wherein the electrical component is coupled to each continuous wavy strip along the pair of vertical edges of the panel.
5. The touch-sensor device of claim 2 , wherein the pattern of interlaced strips of the resistive material comprises an arrangement of continuous wavy strips in a vertical direction between a pair of horizontal edges of the panel, each continuous strip spaced equidistant in a horizontal direction between a pair of vertical edges of the panel.
6. The touch-sensor device of claim 5 , wherein the electrical component is coupled to each continuous wavy strip along the pair of horizontal edges of the panel.
7. The touch-sensor device of claim 2 , wherein the resistive material is a material selected from the group consisting of indium tin oxide (ITO), a conductive ink, and a graphite trace.
8. The touch-sensor device of claim 1 , wherein the array of capacitive sensors comprises a pattern selected from the group consisting of a pattern of rectangular strips of a resistive material and a pattern of concentric circular strips of a resistive material.
9. The touch-sensor device of claim 1 , wherein the array of capacitive sensors is disposed in a single plane.
10. A method of determining a multi-touch result on a touch-sensor device, comprising:
receiving, on a panel, two or more approximately simultaneous touches in a first direction corresponding to a first axis of the panel;
scanning, in the first direction, an array of capacitive sensors in the panel as a pair of linear sliders;
adding results of the scanning of each of the pair of linear sliders into a single array to determine a first direction component of the multi-touch result; and
determining, by a controller coupled to a first and a second ends of each of the capacitive sensors in a second direction corresponding to a second axis of the panel, a second direction component of the multi-touch result by subtracting the results of scanning each of the pair of linear sliders, wherein the second direction component comprises a position of the touches in the second direction, wherein the first axis and the second axis are perpendicular.
11. The method of claim 10 , wherein adding the results of each of the pair of linear sliders into the single array to determine the first direction component of the multi-touch result comprises calculating a centroid.
12. The method of claim 10 , wherein determining the second direction component of the multi-touch result comprises sequentially grounding portions of the array of capacitive sensors along an axis parallel with the second direction.
13. The method of claim 10 , wherein scanning the array of capacitive sensors comprises scanning a pattern of interlaced strips of a resistive material.
14. The method of claim 13 , wherein scanning the pattern of interlaced strips of the resistive material comprises scanning an arrangement of continuous wavy horizontal strips along a pair of vertical edges of the arrangement.
15. The method of claim 13 , wherein scanning the pattern of interlaced strips of the resistive material comprises scanning an arrangement of continuous wavy vertical strips along a pair of horizontal edges of the arrangement.
16. The method of claim 10 , wherein scanning the array of capacitive sensors comprises scanning a pattern of rectangular strips of a resistive material.
17. The method of claim 16 , wherein scanning the pattern of rectangular strips of the resistive material comprises scanning an arrangement of continuous horizontal strips along a pair of vertical edges of the arrangement.
18. The method of claim 16 , wherein scanning the pattern of rectangular strips of the resistive material comprises scanning an arrangement of continuous vertical strips along a pair of horizontal edges of the arrangement.
19. The method of claim 10 , wherein scanning the array of capacitive sensors comprises scanning a pattern of concentric circular strips of a resistive material.