Input device with optimized capacitive sensing

Patent metadata

Field	Value
Publication number	US-9354751-B2
Application number	US-56084609-A
Country	US
Kind code	B2
Filing date	Sep 16, 2009
Priority date	May 15, 2009
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

An input device is disclosed that can improve input detection associated with sensor elements that exhibit a weaker response at the lower end of their dynamic range than their counterparts. This can be advantageous when implementing input reporting rules that rely on a sufficient response at the lower end of a sensor element's dynamic range. The input device can compensate for a weak sensor element at the low end of its dynamic range by increasing its sensitivity in certain situations, such as when an adjacent sensor provides a strong input signal, or after the weak sensor element provides a signal level exceeding a noise threshold for example. The sensitivity of the weak sensor element can be increased in a variety of ways, such as by reducing a noise threshold associated with the sensor element or boosting a signal level associated with the sensor element for example.

First claim

What is claimed is:

1. An input device comprising:
multiple touch sensor elements comprising a first touch sensor element adjacent to a second touch sensor element; and
a controller configured to scan at least the second touch sensor element, determine if a touch input threshold associated with the second touch sensor element is exceeded, and increase a sensitivity associated with the first touch sensor element in response to the touch input threshold associated with the second touch sensor element being exceeded.

2. The input device of claim 1 , wherein the controller is configured to increase the sensitivity by reducing a noise threshold associated with the first touch sensor element.

3. The input device of claim 1 , wherein the controller is configured to increase the sensitivity by boosting a signal level associated with the first touch sensor element.

4. The input device of claim 1 , wherein the controller is configured to increase the sensitivity based on a signal level associated with the second touch sensor element.

5. The input device of claim 1 , wherein the controller is configured to increase the sensitivity based on an ambient temperature associated with the input device.

6. The input device of claim 1 wherein the touch input threshold comprises a predetermined signal level above which a signal level from the second touch sensor element indicates a touch input to the input device.

7. The input device of claim 1 wherein increasing sensitivity of the sensor element comprises at least one of reducing a noise threshold associated with the sensor element and boosting a signal level associated with the sensor element.

8. A method comprising:
scanning multiple touch sensor elements,
capturing scan data associated with multiple individual sensor elements;
implementing an input reporting rule comprising
reporting an input in response to the scan data indicating (1) a first input signal greater than a first predetermined threshold and associated with a first sensor element and (2) at least a second input signal less than a second predetermined threshold and associated with a second sensor element adjacent to the first sensor element, wherein the second predetermined threshold is less than the first predetermined threshold,
reporting an input in response to the scan data indicating a single input signal greater than the first predetermined threshold when an input has been reported in a preceding scan cycle, and
not reporting an input in response to the scan data indicating (1) an input signal greater than the first predetermined threshold and associated with a third sensor element, and (2) no second input signal less than the second predetermined threshold and associated with a fourth sensor element adjacent to the third sensor element and (3) no input having been reported in a preceding scan cycle.

9. The method of claim 8 , wherein the input associated with the preceding scan cycle is reported in a location adjacent to a location of the input associated with the single input signal greater than the first predetermined threshold.

10. The method of claim 8 , wherein the input associated with the single input signal greater than the first predetermined threshold is reported at a location comprising a centroid of the multiple sensor element associated with the single input signal greater than the first predetermined threshold.

11. The method of claim 8 wherein the first sensor element and the third sensor element are the same and wherein the second sensor element and the fourth sensor element are same.

12. An input device comprising:
multiple touch sensor elements; and
a controller configured to scan the multiple touch sensor elements, determine if an input threshold associated with any of the multiple touch sensor elements is exceeded, and increase a sensitivity associated with each of the multiple touch sensor elements in response to an input threshold associated with any of the multiple touch sensor elements being exceeded.

13. The input device of claim 12 , wherein the controller is configured to increase the sensitivity by reducing a noise threshold associated with each of the multiple touch sensor elements.

14. The input device of claim 12 , wherein the controller is configured to increase the sensitivity by boosting a signal level associated with each of the multiple touch sensor elements.

15. The input device of claim 12 , wherein the controller is configured to increase the sensitivity based on a signal level associated with any of the multiple touch sensor elements associated with the exceeded input thresholds.

16. The input device of claim 12 , wherein the controller is configured to increase the sensitivity based on an ambient temperature associated with the input device.

17. The input device of claim 12 wherein the touch input threshold comprises a predetermined signal level above which a signal level from the second touch sensor element indicates a touch input to the input device.

18. The input device of claim 12 wherein increasing sensitivity of the sensor element comprises at least one of reducing a noise threshold associated with the sensor element and boosting a signal level associated with the sensor element.

19. An input device comprising:
multiple touch sensor elements; and
a controller configured to scan the multiple touch sensor elements, determine if an input threshold associated with any of the multiple touch sensor elements is exceeded, and increase a sensitivity associated with one of the multiple touch sensor elements in response to a noise threshold associated with the one touch sensor element being exceeded.

20. The input device of claim 19 , wherein the controller is configured to restore the sensitivity when a signal level associated with the one touch sensor element meets or falls below the noise threshold.

21. The input device of claim 19 wherein the touch input threshold comprises a predetermined signal level above which a signal level from the second touch sensor element indicates a touch input to the input device.

22. The input device of claim 19 wherein increasing sensitivity of the sensor element comprises at least one of reducing a noise threshold associated with the sensor element and boosting a signal level associated with the sensor element.

23. An input device comprising:
multiple touch sensor elements comprising a first touch sensor element and a second touch sensor element; and
a controller configured to scan the multiple touch sensor elements and detect an input by performing a sensing operation associated with each of the multiple touch sensor elements, the sensing operation associated with the first touch sensor element being normalized based on a first scale factor and the sensing operation associated with the second touch sensor element being normalized based on a second scale factor.

24. The input device of claim 23 , wherein the first scale factor is associated with a noise threshold associated with the first touch sensor element, and the second scale factor is associated with a noise threshold associated with the second touch sensor element.

25. An electronic device comprising:
an input device comprising multiple touch sensor elements comprising two adjacent touch sensor elements;
a surface covering the multiple touch sensor elements, the surface comprising a curvature; and
a controller configured to scan the multiple touch sensor elements, determ

Assignees

• Fisher Joseph
• Kocalar Erturk
• Hotelling Steven
• Gutierrez David
• Apple Inc

Inventors

• Fisher Joseph
• Kocalar Erturk
• Hotelling Steven
• Gutierrez David

Classifications

• G06F3/044 Primary

  by capacitive means · CPC title

• G06F3/0416

  Control or interface arrangements specially adapted for digitisers · CPC title

• G06F3/04166

  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 title