CAPACITIVE POSITION SENSOR

• US 20100141277A1
• Filed: 02/10/2010
• Published: 06/10/2010
• Est. Priority Date: 10/20/2006
• Status: Active Grant

• Current Assignee: Neodrón Limited (Atlantic IP Services Limited)
• Original Assignee: Atmel Corporation (Microchip Technology Incorporated)
• Inventors: Philipp, Harald
• Granted Patent: US 7,952,367 B2
• Time in Patent Office: Days
• US Class Current: 324/686
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06F 3/04847 Interaction techniques to control parameter settings, e.g. interaction with sliders or dials
• CPC Class Codes: H03K 17/962 Capacitive touch switches

Abstract

Methods and apparatus related to a sensor are discussed herein. The sensor can include a sensing element having a sensing path, the sensing element coupled to a sensing channel, and a processor configured to interpret a signal generated by the sensing channel indicative of a capacitance between the sensing path and a system ground. The processor can have a first mode configured to set a parameter to a desired value. The desired value can be related to a first position of an object sensed along the sensing path and a range of parameter values mapped to a length of the sensing path. A second mode can adjust the parameter based on a displacement of the object along the sensing path.

Claims

1. A sensor comprising:

a sensing element comprising a sensing path having a length;

at least one sensing channel coupled to the sensing element, the sensing channel operable to generate a signal indicative of capacitance between the sensing path and a system ground;

a processor having a first mode and a second mode, the processor configured to determine a first position of an object along the sensing path using the signal and to set a parameter to an initial value in the first mode, wherein the initial value is related to the first position along the sensing path and to a range of parameter values associated with the length of the sensing path, the processor further configured to adjust the parameter in a second mode in response to a displacement of the object along the sensing path from the first position, wherein the processor is configured to switch from the first mode to the second mode when the signal indicates displacement of the object, proximate the sensing element, along the sensing path.

2. The sensor of claim 1, wherein the sensing path is formed as a closed loop.

3. The sensor of claim 1, wherein the processor is configured to change from the first mode to the second mode when the displacement of the object exceeds a minimum threshold displacement.

4. The sensor of claim 3, wherein the minimum threshold value is predetermined and the processor is configurable to set the minimum threshold value at different values depending on a sensitivity setting and the parameter.

5. The sensor of claim 1, wherein, in the second mode, the processor effects an incremental change in the parameter value when it is sensed that the object has moved along the sensing path by a pre-determined threshold displacement.

6. The sensor of claim 1, wherein, in the second mode, the processor changes the parameter value by a number of units based on the number of times the displacement of the object along the sensing path is sensed to have exceeded the pre-determined threshold displacement.

7. The sensor of claim 1, wherein, in the second mode, the processor maps a narrower sub-range of parameter values onto the sensing path around the initial value set in the first mode.

8. The sensor of claim 1, wherein the processor is further configured such that if a release of touch from the sensing element in the second mode followed by a subsequent re-touching of the sensing element is sensed, then the first mode is activated.

9. The sensor of claim 1, wherein the parameter set using the capacitive position sensor is selected from the group consisting of temperature, volume, contrast, brightness, and frequency.

10. The sensor of claim 1, wherein the processor is configured to allow selection of the parameter prior to use of the capacitive position sensor.

11. A control panel of an electronic appliance incorporating a capacitive position sensor according to claim 1.

12. An electronic appliance having a control panel incorporating a capacitive position sensor according to claim 1.

13. The electronic appliance of claim 12 selected from the group consisting of a cooking oven, microwave oven, television, washing machine, MP3 player, mobile phone, and multimedia device.

14. A method comprising:

detecting an object proximate a first position along a sensing path of a capacitive position sensor;

activating a first mode of the capacitive position sensor;

setting a parameter to an initial value related to the first position;

sensing a displacement of the object from the first position, the object proximate a sensing element along the sensing path of the capacitive position sensor;

initiating a change in mode of the sensor from the first mode to a second mode using the sensed displacement of the object along the sensing path; and

incrementally adjusting the parameter from the initial value using a magnitude of the displacement.

15. The method of claim 14, including mapping a range of values along a length of the sensing path.

16. The method of claim 14, wherein the sensing path is formed as a closed loop.

17. The method of claim 14 wherein the sensing a displacement includes sensing a displacement having a magnitude that exceeds a minimum threshold displacement in order to initiate a change in mode of the sensor from the first mode to the second mode.

18. The method of claim 17, including setting a minimum threshold displacement using a sensitivity setting and the parameter.

19. The method of claim 14, wherein the incrementally adjusting the parameter includes incrementally adjusting the parameter after sensing the object has moved along the sensing path by a minimum threshold displacement.

20. The method of claim 14, wherein the incrementally adjusting the parameter includes incrementally adjusting the parameter by a number of units based on the number of times the displacement of the object along the sensing path exceeds a minimum threshold displacement.

21. The method of claim 14, including mapping a narrower sub-range of parameter values onto the sensing path in the second mode, wherein the narrower sub-range of parameter values includes the initial value set in the first mode.

22. The method of claim 14, including switching from the second mode to the first mode upon sensing the first position of the object.

23. The method of claim 14, including receiving information to select the parameter from the group consisting of temperature, volume, contrast, brightness, and frequency.

24. The method of claim 23, wherein the receiving information to select the parameter includes receiving information to select the parameter prior to use of the capacitive position sensor.