CLOSED-LOOP SENSOR ON A SOLID-STATE OBJECT POSITION DETECTOR

• US 20080042976A1
• Filed: 10/26/2007
• Published: 02/21/2008
• Est. Priority Date: 04/11/2002
• Status: Active Grant

• Current Assignee: Wacom Co Limited (Wacom)
• Original Assignee: Synaptics Incorporated
• Inventors: Huie, Mark, GILLESPIE, David, SHAW, Scott, TRENT, Raymond, HEINY, Christopher
• Granted Patent: US 7,710,407 B2
• Time in Patent Office: Days
• US Class Current: 345/157
• CPC Class Codes: G06F 2203/0339 Touch strips, e.g. orthogonal touch strips to control cursor movement or scrolling; single touch strip to adjust parameter or to implement a row of soft keys
• CPC Class Codes: G06F 3/03547 Touch pads, in which fingers can move on a surface
• 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

The present disclosure discloses an object position detector. The object position detector comprises a touch sensor formed as a closed loop and having a physical constraint formed on an upper surface of the touch sensor and coextensive with the closed loop. The touch sensor is configured to sense motion of an object proximate to the closed loop. The object position detector also comprises a processor coupled to the touch sensor and is programmed to generate an action in response to the motion on the touch sensor.

Claims

1. An object position detector, comprising:

a plurality of sensor electrodes configured to sense an object proximate to a substantially closed loop, wherein the plurality of sensor electrodes are disposed in the substantially closed loop, and wherein at least one of the plurality of sensor electrodes is interdigitated with an adjacent one of the plurality of sensor electrodes; and

a processor coupled to the plurality of sensor electrodes, the processor configured to provide positional information about the object proximate to the substantially closed loop.

2. The object position detector of claim 1, wherein a shape of the at least one of the plurality of sensor electrodes is selected from the group consisting of a lightning bolt shape and a spiral shape.

3. The object position detector of claim 1, wherein each of the plurality of sensor electrodes is interdigitated with an adjacent one of the plurality of sensor electrodes.

4. The object position detector of claim 3, wherein more than one interdigitation occurs between each adjacent sensor electrode in the plurality of sensor electrodes.

5. The object position detector of claim 1, wherein a shape of the at least one of the plurality of sensor electrodes comprises a self-interpolating shape, and wherein the positional information includes radial position information.

6. The object position detector of claim 5, wherein the plurality of sensor electrodes is disposed in a region having an inner edge and an outer edge, and wherein the plurality of sensor electrodes are configured such that each of a first subset of the plurality of sensor electrodes are narrower toward the inner edge and wider toward the outer edge, and each of a second subset of the plurality of sensor electrodes are wider toward the inner edge and narrower toward the outer edge.

7. The object position detector of claim 6, wherein sensor electrodes of the first subset alternate with sensor electrodes of the second subset along the substantially closed loop.

8. The object position detector of claim 6, wherein the processor is configured to determine the radial position information by comparing capacitance sensed by the first subset of the plurality of sensor electrodes with the capacitance sensed by the second subset of the plurality of sensor electrodes.

9. The object position detector of claim 1, wherein at least two of the plurality of sensor electrodes are ohmically coupled to each other and to a single sensor input.

10. The object position detector of claim 1, wherein sensor electrodes of a first subset of the plurality of sensor electrodes are ohmically coupled to each other and share a first sensor input, sensor electrodes of a second subset of the plurality of sensor electrodes are ohmically coupled to each other and share a second sensor input, and sensor electrodes of a third subset of the plurality sensor electrodes are ohmically coupled to each other and share a third sensor input.

11. An object position detector, comprising:

a plurality of sensor electrodes disposed in a substantially closed loop, the plurality of sensor electrodes configured to sense an object proximate to the substantially closed loop, wherein at least one of the plurality of sensor electrodes has a shape adapted to provide self-interpolation; and

a processor coupled to the plurality of sensor electrodes, the processor configured to determine positional information about the object both radial to and along the substantially closed loop.

12. The object position detector of claim 11, wherein the plurality of sensor electrodes includes a first subset of sensor electrodes and a second subset of sensor electrodes, and wherein the processor is configured to determine positional information about the object radial to the substantially closed loop by comparing capacitance sensed by the first subset of the plurality of sensor electrodes with capacitance sensed by the second subset of the plurality of sensor electrodes.

13. An object position detector, comprising:

a touch sensor having a plurality of sensor electrodes disposed in a substantially closed loop, the touch sensor configured to sense an object proximate to the substantially closed loop, wherein each of the plurality of sensor electrodes are configured with a lighting-bolt shape and configured so that each of the plurality sensor electrodes is interdigitated with an adjacent one of the plurality of sensor electrodes; and

a processor coupled to the touch sensor, the processor configured to provide positional information about the object proximate to the substantially closed loop.

14. The object position detector of claim 13, wherein the substantially closed loop comprises a generally circular shape, and wherein the information indicating position along the substantially closed loop comprises angular position information.

15. A method of providing an object position detector, comprising:

providing a plurality of sensor electrodes configured to sense an object proximate to a substantially closed loop, the providing comprising disposing the plurality of sensor electrodes in the substantially closed loop, wherein at least one of the plurality of sensor electrodes is interdigitated with an adjacent one of the plurality of sensor electrodes; and

providing a processor coupled to the plurality of sensor electrodes, the processor configured to provide positional information about the object proximate to the substantially closed loop.

16. The method of claim 15, wherein disposing the plurality of sensor electrodes in the substantially closed loop comprises disposing a sensor electrode having a lightning bolt shape.

17. The method of claim 15, wherein disposing the plurality of sensor electrodes in the substantially closed loop comprises shaping each of the plurality of sensor electrodes such that each of the plurality of sensor electrodes is interdigitated with an adjacent one of the plurality of sensor electrodes.

18. The method of claim 15, wherein disposing the plurality of sensor electrodes in the substantially closed loop comprises shaping each of the plurality of sensor electrodes such that each of the plurality of sensor electrodes has more than one interdigitation with an adjacent sensor electrode in the plurality of sensor electrodes.

19. The method of claim 15, wherein disposing the plurality of sensor electrodes in the substantially closed loop comprises ohmically coupling at least two of the plurality of sensor electrodes are to each other and to a single sensor input.