METHOD FOR IMPROVING SCAN TIME AND SENSITIVITY IN TOUCH SENSITIVE USER INTERFACE DEVICE

• US 20140077827A1
• Filed: 08/13/2013
• Published: 03/20/2014
• Est. Priority Date: 07/03/2007
• Status: Active Grant

• Current Assignee: Parade Technologies, Ltd.
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: Seguine, Ryan D.
• Granted Patent: US 9,482,559 B2
• Time in Patent Office: Days
• US Class Current: 324/686
• CPC Class Codes: G01D 5/24 by varying capacitance

Abstract

System and method for optimizing the consumption of power while maintaining performance in capacitive sensor arrays. A limited sensing area is used to improve the update rate and sensitivity of a row/column array of capacitive sensors. According to one embodiment, a method is provided for scanning a plurality of capacitive sensors by: detecting a stimulus in the field of capacitive sensors, scanning the field of capacitive sensors to determine the position of the stimulus. Once the position of the stimulus is determined, a subsection of the field comprising window corresponding to the position of the stimulus remains activated while the remaining sensors in the field are deactivated.

Claims

1-20. -20. (canceled)

21. A method for scanning a plurality of capacitive sense elements, the method comprising:

scanning a first set of capacitive sense elements at a first sensitivity level to detect a stimulus;

determining a location of the stimulus detected during the scanning of the first set;

after the determining the location, selecting a second set of capacitive sense elements based on the location of the stimulus detected during the scanning of the first set; and

scanning the second set of capacitive sense elements at a second sensitivity level.

22. The method of claim 21, wherein the second sensitivity level is lower than the first sensitivity level.

23. The method of claim 21, wherein the second set of capacitive sense elements comprises a subset of the first set of capacitive sense elements.

24. The method of claim 21, wherein the selecting the second set of capacitive sense elements comprises selecting the second set of capacitive sense elements according to proximity of the second set of capacitive sense elements to the location of the stimulus detected during the scanning of the first set.

25. The method of claim 21, wherein the stimulus is provided by a finger.

26. The method of claim 21, wherein the second set of capacitive sense elements comprising capacitive sense elements that are not included in the first set of capacitive sense elements.

27. The method of claim 21, wherein the determining the location of the stimulus comprises determining the location according to a centroid positioning algorithm of activated capacitive sense elements.

28. The method of claim 21, wherein the scanning the second set of capacitive sense elements is continued to be performed while the stimulus is detected in the location.

29. The method of claim 21, further comprising:

determining a motion of the stimulus based on the location of the stimulus detected during the scanning of the first set; and

adjusting the scanning of the second set according to the motion of the stimulus.

30. The method of claim 29, wherein the motion of the stimulus comprises a displacement of the stimulus from one or more previous locations to the location of the stimulus detected during the scanning of the first set.

31. The method of claim 29, wherein the second set of capacitive sense elements comprises at least one of the first set of capacitive sense elements that is activated during the scanning of the first set and a capacitive sense element corresponding to an expected subsequent location of the stimulus.

32. An apparatus comprising:

a controller coupled to a capacitive sense element array comprising a plurality of capacitive sense elements, wherein the controller is to;

scan a first set of the plurality of capacitive sense elements at a first sensitivity level to detect a stimulus;

determine a location of the stimulus detected during the scan of the first set;

after the location is determined, select a second set of the plurality of capacitive sense elements based on the location of the stimulus detected during the scan of the first set; and

scan the second set of the plurality of capacitive sense elements at a second sensitivity level.

33. The apparatus of claim 32, wherein the second sensitivity level is lower than the first sensitivity level.

34. The apparatus of claim 32, wherein the second set of the plurality of capacitive sense elements comprises a subset of the first set of the plurality of capacitive sense elements.

35. The apparatus of claim 32, wherein the controller is to select the second set of the plurality of capacitive sense elements according to proximity of the second set of the plurality of capacitive sense elements to the location of the stimulus detected during the scan the first set.

36. The apparatus of claim 32, wherein the stimulus is provided by a finger.

37. The apparatus of claim 32, wherein the second set of the plurality of capacitive sense elements comprising capacitive sense elements that are not included in the first set of the plurality of capacitive sense elements.

38. A system comprising:

a controller; and

an array of capacitive sense elements, wherein the controller is to;

scan a first set of capacitive sense elements of the array at a first sensitivity level to detect a stimulus;

determine a location of the stimulus detected during the scan of the first set;

after the location is determined, select a second set of capacitive sense elements of the array based on the location of the stimulus detected during the scan of the first set; and

scan the second set of capacitive sense elements at a second sensitivity level.

39. The system of claim 38, wherein the second sensitivity level is lower than the first sensitivity level.

40. The system of claim 38, wherein the second set of capacitive sense elements comprises a subset of the first set of capacitive sense elements, wherein the controller is to select the second set of capacitive sense elements according to proximity of the second set of capacitive sense elements to the location of the stimulus detected during the scan of the first set.

41. The system of claim 38, wherein at least one of the capacitive sense elements comprises:

a conductive pad;

surrounding ground; and

a connection coupling the at least one capacitive sense element to the controller,