TOUCH AND HOVER SENSOR COMPENSATION

• US 20120050209A1
• Filed: 09/30/2010
• Published: 03/01/2012
• Est. Priority Date: 08/27/2010
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: KING, Brian Michael, Leung, Omar, Puskarich, Paul G., Bernstein, Jeffrey Traer, Mucignat, Andrea, Cieplinski, Avi E., Choudry, Muhammad U., Subramani, Praveen R., Piche, Marc J., Amm, David T., Kerr, Duncan Robert
• Granted Patent: US 8,982,060 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G06F 2203/04101 2.5D-digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface and also measures the distance of the input means within a short range in the Z direction, possibly with a separate measurement setup
• CPC Class Codes: G06F 2203/04106 Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection
• CPC Class Codes: G06F 2203/04108 Touchless 2D- digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface without distance measurement in the Z direction
• CPC Class Codes: G06F 2203/04111 Cross over in capacitive digitiser, i.e. details of structures for connecting electrodes of the sensing pattern where the connections cross each other, e.g. bridge structures comprising an insulating layer, or vias through substrate
• CPC Class Codes: G06F 3/04166 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 Class Codes: G06F 3/041662 using alternate mutual and self-capacitive scanning
• 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

Abstract

Compensation for sensors in a touch and hover sensing device is disclosed. Compensation can be for sensor resistance and/or sensor sensitivity variation that can adversely affect touch and hover measurements at the sensors. To compensate for sensor resistance, the device can gang adjacent sensors together so as to reduce the overall resistance of the sensors. In addition or alternatively, the device can drive the sensors with voltages from multiple directions so as to reduce the effects of the sensors'"'"' resistance. To compensate for sensor sensitivity variation (generally at issue for hover measurements), the device can apply a gain factor to the measurements, where the gain factor is a function of the sensor location, so as to reduce the sensitivity variation at different sensor locations on the device.

Claims

1. A touch and hover sensing device comprising:

configurable sensor lines for sensing an object proximate thereto, the sensor lines having a resistance; and

a touch and hover control system configured to drive the sensor lines with a voltage for sensing the object and to adjustably configure the sensor lines for substantially reducing the resistance when driving the lines.

2. The device of claim 1, wherein the control system gangs at least two of the sensor lines together for substantially reducing the resistance.

3. The device of claim 1, wherein the control system gangs at least two of the sensor lines together when the object is close to the device and declines to gang the sensor lines together when the object is distant from the device.

4. The device of claim 1, wherein the control system applies the voltage to each sensor line from different directions at the same time, and wherein the application from different directions substantially reduces effects of the resistance.

5. The device of claim 4, wherein the different directions are opposite directions.

6. The device of claim 4, wherein the device is partitioned, each partition having separate portions of the sensor lines, and wherein the control system drives the voltage separately to the portions of the sensor lines in each partition.

7. A method of compensating for sensors of a sensing panel, the method comprising:

measuring capacitance associated with an object proximate to the sensing panel;

determining the relative proximity of the object to the sensing panel; and

based on the determined relative proximity, selectively configuring the sensors for substantially reducing a resistance of the sensors.

8. The method of claim 7, wherein configuring the sensors comprises selectively ganging the sensors together when the object is in close proximity to the panel and selectively separating the sensors when the object is farther away from the panel.

9. The method of claim 8, wherein selectively ganging the sensors together substantially reduces the resistance of the sensors.

10. The method of claim 7, wherein selectively configuring the sensors adjusts resolution of the sensors, the configuring comprising selectively ganging the sensors together to substantially decrease the resolution of the sensors.

11. The method of claim 7, wherein configuring the sensors comprises selectively ganging adjacent rows of sensors.

12. A method of compensating for sensors of a sensing panel, the method comprising:

measuring capacitance at the sensors, the capacitance being indicative of an object hovering over the sensing panel;

determining a sensor location having the measurement of the hovering object; and

adjusting the measurement based on the determined sensor location so as to compensate for sensitivity variation in the sensors.

13. The method of claim 12, wherein adjusting the measurement comprises applying a gain factor to the measurement, the gain factor being a function of a minimum capacitance determined at an edge sensor location and a maximum capacitance determined at a center sensor location.

14. The method of claim 13, wherein the gain factor varies based on sensor location.

15. The method of claim 12, wherein the sensor sensitivity is at a minimum at edge sensor locations, at a maximum at center sensor locations, and increases therebetween from the edge sensor locations to the center sensor locations.

16. The method of claim 12, wherein adjusting the measurement comprises providing a substantially uniform sensitivity across the sensors.

17. A touch and hover sensing device comprising:

a sensing panel having multiple sensors at locations of the panel, the sensors having varying sensitivities as a function of sensor location; and

a touch and hover control system configured to compensate for the sensitivity variation by adjusting capacitance measurements from the sensors according to the sensor locations, the capacitance measurements being caused by the proximate object.

18. The device of claim 17, wherein the control system applies a gain factor to the capacitance measurements to compensate for the sensitivity variation, the gain factor being a function of sensor location.

19. The device of claim 17, wherein the control system adjusts the capacitance measurements according to the sensor locations relative to a center sensor location.

20. The device of claim 17, wherein the proximate object is a hovering object.

21. A touch and hover sensing device comprising:

a touch and hover sensing panel having multiple sensors configured to detect one or more objects proximate to the panel, wherein the objects touch the panel to cause a touch event, hover over the panel to cause a hover event, or touch and hover concurrently to cause touch and hover events; and

a touch and hover control system configured to measure capacitance associated with the proximate objects and to at least one of configure the panel or adjust the capacitance measurement so as to compensate for sensor effects on the touch and hover events.

22. The device of claim 21, wherein the sensor effects comprise at least one of sensor resistance or sensor sensitivity variation.

23. The device of claim 22, wherein the control system is configured to gang the sensors of the panel so as to compensate for the sensor resistance, and wherein the control system is configured to increase the capacitance measurement as a function of sensor location so as to compensate for the sensor sensitivity variation.

24. The device of claim 21, further comprising a display configured to display graphical information to select in response to the touch and hover events.

25. The device of claim 21 incorporated into at least one of a mobile phone, a digital media player, or a computer.