Integrated normal sensing and proximity sensing on a multi-dimensional sensor array

• US 8,878,811 B1
• Filed: 06/11/2009
• Issued: 11/04/2014
• Est. Priority Date: 04/05/2007
• Status: Expired due to Fees

• Current Assignee: Monterey Research, LLC (Vector Capital Corporation)
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: Baumbach, Jason G.
• Primary Examiner(s): OLSON, JASON C
• Application Number:
  US12/483,181
• Time in Patent Office: 1,972 Days
• Field of Search: None
• US Class Current: 345/174
• CPC Class Codes: G06F 3/03547 Touch pads, in which fingers can move on a surface
• CPC Class Codes: G06F 3/0442 using active external devices, e.g. active pens, for transmitting changes in electrical potential to be received by the digitiser
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• CPC Class Codes: H03K 17/955 using a capacitive detector
• CPC Class Codes: H03K 17/962 Capacitive touch switches
• CPC Class Codes: H03K 17/9622 using a plurality of detectors, e.g. keyboard
• CPC Class Codes: H03K 2217/94026 Automatic threshold calibration; e.g. threshold automatically adapts to ambient conditions or follows variation of input

Abstract

Apparatuses and methods for coupling a group of sensor elements together in one mode to collectively measure a capacitance on the group of sensor elements, in addition to individually measuring a capacitance on each of the sensor elements in another mode. The apparatus may include a processing device, and a plurality of sensor elements that are individually coupled in a first mode for normal sensing and collectively coupled in a second mode for proximity sensing.

Claims

1. A method, comprising:

detecting a presence of a conductive object on a surface of a device having a multi-dimensional sensory array by individually measuring a capacitance for each of a plurality of sensor elements of the multi-dimensional array;

coupling a group of sensor elements of the plurality of sensor elements together;

conductively coupling to the group of sensor elements another conductor substantially surrounding at least one of the plurality of sensor elements; and

detecting a presence of the conductive object in proximity to the surface of the device by applying a signal to the group of coupled sensor elements to measure a single collective capacitance for the group of coupled sensor elements while the group of coupled sensor elements is conductively coupled to the another conductor substantially surrounding the at least one of the plurality of sensor elements.

2. The method of claim 1, wherein the multi-dimensional sensor array comprises a plurality of rows of sensor elements and a plurality of columns of sensor elements, wherein:

detecting the presence of the conductive object on the surface of the device comprises;

measuring capacitances of the plurality of rows; and

measuring capacitances on the plurality of columns;

detecting the presence of the conductive object in proximity to the surface of the device comprises;

coupling the plurality of rows or columns together into the group of sensor elements; and

measuring the single collective capacitance for the coupled group of sensor elements.

3. The method of claim 2, further comprising:

determining a proximity event when the conductive object is detected in proximity to surface of the device; and

determining a position of the conductive object using the measured capacitances on the plurality of rows and columns when the conductive object is detected on the surface of the device.

4. The method of claim 1, wherein detecting the presence of the conductive object on the surface of the device by individually measuring the capacitance is performed in a first mode and detecting the presence of the conductive object in proximity to the surface of the device by measuring the single collective capacitance is performed in a second mode, and wherein the first mode is a normal scanning mode and a second mode is a proximity scanning mode.

5. The method of claim 4, further comprising transitioning from the second mode to the first mode when the presence of the conductive object is detected in proximity to the surface device in the first mode.

6. The method of claim 5, further comprising transitioning from the first mode to the second mode when the presence of the conductive object is not detected on the surface of the device for a period of time.

7. The method of claim 1, wherein coupling the group of sensor elements comprises at least one of coupling all of the plurality of sensor elements together as the group of sensor elements or coupling a fraction of the plurality of sensor elements together as the group of sensor elements.

8. The method of claim 1, wherein coupling the group of sensor elements comprises coupling the group of sensor elements as a first group of coupled sensor elements in a first zone of the device, and wherein the method further comprises:

coupling a second group of sensor elements of the plurality of sensor elements together in a second zone of the device;

measuring a first single collective capacitance for the first group of coupled sensor elements and a second single collective capacitance for the second group of coupled sensor elements;

determining a first proximity event when the conductive object is detected in proximity to the first zone of the device using the first single collective capacitance on the first group of coupled sensor elements; and

determining a second proximity event when the conductive object is detected in proximity to the second zone of the device using the second single collective capacitance on the second group of coupled sensor elements.

9. The method of claim 8, further comprising:

performing a first operation upon determining the first proximity event;

and performing a second operation upon determining the second proximity event.

10. The method of claim 9, wherein performing the first operation comprises activating a first portion of a display, and wherein performing the second operation comprises activating a second portion of the display.

11. An apparatus, comprising:

a plurality of sensor elements disposed in a multi-dimensional sensor array; and

a processing device coupled to the plurality of sensor elements in a first mode and coupled to a group of sensor elements of the plurality of sensor elements that is additionally conductively coupled to a conductor substantially surrounding at least one of the plurality of sensor elements in a second mode, wherein the processing device is configured to measure a capacitance for each of the plurality of sensor elements individually to detect a presence of a conductive object on a surface of the apparatus in the first mode and apply a signal to the group of sensor elements to measure a single collective capacitance for the group of sensor elements while the group of sensor elements is conductively coupled to the conductor to detect a presence of the conductive object in proximity to the surface of the apparatus in the second mode.

12. The apparatus of claim 11, further comprising a circuit coupled between the processing device and each of the plurality of sensor elements to individually couple the plurality of sensor elements to the processing device in the first mode, and to collectively couple the group of sensor elements to the processing device in the second mode.

13. The apparatus of claim 11, wherein the processing device is configured to measure a plurality of capacitances of the plurality of sensor elements in the first mode, and to measure the single collective capacitance of the group of sensor elements in the second mode.

14. The apparatus of claim 11, wherein the processing device is configured to perform a single capacitance measurement for the group of sensor elements during each sensing interval when in the second mode, and wherein the processing device is configured to perform a plurality of capacitance measurements for the plurality of sensor elements during each sensing interval when in the first mode.

15. The apparatus of claim 11, wherein the group of sensor elements comprises all of the plurality of sensor elements or a fraction of all of the plurality of sensor elements.

16. The apparatus of claim 11, wherein the processing device is configured to transition from the second mode to the first mode when the presence of the conductive object is detected in proximity to the surface of the apparatus, and to transition from the first mode to the second mode when the presence of the conductive object is not detected on the surface of the apparatus for a period of time.

17. The apparatus of claim 11, wherein the apparatus is a touchpad device comprising the processing device and the plurality of sensor elements.

18. The apparatus of claim 11, wherein the apparatus is a touchscreen device comprising the processing device and the plurality of sensor elements.

19. An apparatus, comprising:

a device having a touch-sensitive surface and a plurality of sensor elements of a multi-dimensional sensor array;

means for coupling a group of sensor elements of the plurality of sensor elements together in a first mode;

means for conductively coupling the group of sensor elements to a conductor that substantially surrounds at least one of the plurality of sensor elements;

means for applying a signal to the group of sensor elements to measure a single collective capacitance for the group of sensor elements to detect a first presence of a conductive object in proximity to the touch-sensing surface while the group of sensor elements are coupled together and conductively coupled to the conductor that substantially surrounds the at least one of the plurality of sensor elements in the first mode; and

means for measuring a capacitance for each of the plurality of sensor element individually to detect a second presence of the conductive object on the touch-sensing surface while the group of sensor elements are not coupled together in the a second mode.

20. The apparatus of claim 19, further comprising means for reducing power consumption of the apparatus.