Two Dimensional Position Sensor

• US 20140111223A1
• Filed: 12/30/2013
• Published: 04/24/2014
• Est. Priority Date: 05/31/2006
• Status: Active Grant

• Current Assignee: Neodrón Limited (Atlantic IP Services Limited)
• Original Assignee: Atmel Corporation (Microchip Technology Incorporated)
• Inventors: Philipp, Harald, Hristov, Luben
• Granted Patent: US 9,927,476 B2
• Time in Patent Office: Days
• US Class Current: 324/658
• CPC Class Codes: G01R 27/2605 Measuring capacitance capacitive sensors G01D5/24
• 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 two-dimensional position sensor comprising a substrate with a sensitive area defined by a pattern of electrodes including electrodes for determining x-position and electrodes for determining y-position. The x-electrodes and y-electrodes generally extend in the x-direction and are interleaved in the y-direction. The x-electrodes comprise at least first, second and third groups of elements shaped such that adjacent ones of the elements of the different x-electrode groups co-extend in the x-direction so that the x-electrodes provide ratiometric capacitive signals, thereby providing quasi-continuous x-position sensing across the sensitive area. In addition, the y-electrodes may be resistively connected or arranged in ratiometric pairs to provide quasi-continuous y-position sensing. Alternatively, the x-electrode groups may be interdigitated to form pairs of x-adjacent blocks of differing area to provide stepwise x-position sensing in combination with stepwise y-position sensing provided by the y-electrodes.

Claims

1. A two-dimensional position sensor comprising a substrate with a sensitive area defined by a pattern of electrodes including electrodes for determining x-position and electrodes for determining y-position, wherein the x-electrodes and y-electrodes generally extend in the x-direction and are interleaved in the y-direction, and wherein the x-electrodes comprise first, second and third groups of elements shaped such that adjacent ones of the elements of the first and second groups co-extend in the x-direction over one portion of the sensitive area and adjacent ones of the elements of the second and third groups co-extend in the x-direction over another portion of the sensitive area so that the x-electrodes provide respective ratiometric capacitive signals spanning the sensitive area in the x-direction.

2. The sensor of claim 1, wherein the x-electrodes further comprise a fourth group of elements and adjacent ones of the elements of the third and fourth groups co-extend over a still further portion of the sensitive area so that the x-electrodes provide respective ratiometric capacitive signals spanning the sensitive area in the x-direction.

3. The sensor of claim 2, further comprising a plurality of external electrical lines connecting to the electrodes in the periphery of the sensitive area, including:

respective electrical lines connected to the elements of each of the groups of x-electrodes; and

a plurality of electrical lines connected to the y-electrodes.

4. The sensor of claim 1, further comprising a central spine extending from the periphery of the sensitive area in the y-direction to interconnect the elements of the third group of x-electrodes, which extend from both sides of the central spine, thereby allowing the elements of the third group of x-electrodes to be externally contacted from the periphery of the sensitive area.

5. The sensor of claim 4, further comprising a plurality of external electrical lines connecting to the electrodes in the periphery of the sensitive area, including:

an electrical line connected to the central spine thereby contacting the third group of x-electrodes, the central spine notionally dividing the sensitive area into left and right sides;

an electrical line connected to the elements of the first group of x-electrodes on the left side of the central spine;

an electrical line connected to the elements of the first group of x-electrodes on the right side of the central spine;

an electrical line connected to the elements of the second group of x-electrodes on the left side of the central spine;

an electrical line connected to the elements of the second group of x-electrodes on the right side of the central spine; and

a plurality of electrical lines connected to the y-electrodes.

6. The sensor of claim 1, wherein the elements of respective groups of x-electrodes which co-extend have complementary tapers over their distance of co-extension to provide the ratiometric capacitive signals.

7. The sensor of claim 1, wherein the elements of respective groups of x-electrodes which co-extend have adjacent blocks of varying area over their distance of co-extension in the x-direction to provide the ratiometric capacitive signals.

8. The sensor of claim 1, wherein the y-electrodes are connected individually and/or in groups to respective external electrical lines, thereby providing position information in the y-direction.

9. The sensor of claim 1, wherein the y-electrodes are interconnected by resistive elements so that ratiometric capacitive signals are output through external electrical lines connected to a subset of the y-electrodes, thereby providing position information in the y-direction.

10. The sensor of claim 1, wherein the y-electrodes are arranged in vertically adjacent groups of at least two y-electrodes, with the y-electrodes of each group having differing vertical extents so that ratiometric capacitive signals are output through external electrical lines connected to the different y-electrodes of each group, thereby providing position information in the y-direction.

11. The sensor of claim 1, wherein the electrodes are made of a transparent material.

12. The sensor of claim 1, wherein the substrate is made of a transparent material.