CONCURRENT SIGNAL DETECTION FOR TOUCH AND HOVER SENSING

• US 20120050211A1
• 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 9,098,138 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

Detecting a signal from a touch and hover sensing device, in which the signal can be indicative of concurrent touch events and/or hover events, is disclosed. A touch event can indicate an object touching the device. A hover event can indicate an object hovering over the device. The touch and hover sensing device can ensure that a desired hover event is not masked by an incidental touch event, e.g., a hand holding the device, by compensating for the touch event in the detected signal that represents both events. Conversely, when both a hover event and a touch event are desired, the touch and hover sensing device can ensure that both events are detected by adjusting the device sensors and/or the detected signal. The touch and hover sensing device can also detect concurrent hover events by identifying multiple peaks in the detected signal, each peak corresponding to a position of a hovering object.

Claims

1. A touch and hover sensing device comprising:

multiple sensors configured to detect a first object touching the device and a second object hovering over the device concurrently; and

a touch and hover control system configured to measure capacitance at one or more of the sensors associated with the touching object and the hovering object and to compensate the measurement for the touching object by discarding from the measurement a portion caused by the touching object.

2. The device of claim 1, wherein the sensors are partitioned to provide at least one partition for detecting the touching object and at least another partition for detecting the hovering object, and

wherein the control system discards the measurement portion in the partition detecting the touching object.

3. The device of claim 1, wherein the touching object is near a border of the device, the device further comprising a grounding shield at the border and configured to shield the touching object from the sensors.

4. A method of detecting a signal indicative of a hovering object and a touching object at a sensing panel, the method comprising:

obtaining a set of capacitance measurements of multiple sensors of the sensing panel, the capacitance measurements forming the detected signal;

identifying the capacitance measurements indicative of the hovering object and the capacitance measurements indicative of the touching object; and

adjusting the detected signal to retain the capacitance measurements indicative of the hovering object and to discard the capacitance measurements indicative of the touching object.

5. The method of claim 4, wherein identifying the capacitance measurements comprises:

comparing the capacitance measurements to a predetermined threshold;

identifying the capacitance measurements less than the threshold as being indicative of the hovering object; and

identifying the capacitance measurements greater than the threshold as being indicative of the touching object.

6. The method of claim 4, wherein obtaining the set of capacitance measurements comprises:

driving the sensors at a specific voltage so as to saturate the sensors detecting the touching object; and

obtaining the set of capacitance measurements having saturated values caused by the touching object and unsaturated values caused by the hovering object.

7. The method of claim 4, wherein obtaining the set of capacitance measurements comprises:

driving the sensors with a high frequency voltage;

obtaining a first set of capacitance measurements based on the high frequency voltage;

driving the sensors with a low frequency voltage; and

obtaining a second set of capacitance measurements based on the low frequency voltage.

8. The method of claim 7, wherein identifying the capacitance measurements comprises:

identifying the first set of capacitance measurements as indicative of the touching object; and

identifying the second set of capacitance measurements as indicative of both the touching object and the hovering object.

9. The method of claim 7, wherein adjusting the detected signal comprises subtracting the first set of capacitance measurements from the second set of capacitance measurements to discard the capacitance measurements associated with the touching object.

10. The method of claim 4, wherein the sensors are formed in lines in the sensing panel, and wherein obtaining the set of capacitance measurements comprises:

driving alternate sensor lines from opposite directions;

obtaining a first set of capacitance measurements of the sensors driven from one direction; and

obtaining a second set of capacitance measurements of the sensors driven from the opposite direction.

11. The method of claim 10, wherein identifying the set of capacitance measurements comprises:

identifying the first set of capacitance measurements as being indicative of the touching object; and

identifying the second set of capacitance measurements as being indicative of the hovering object.

12. The method of claim 10, wherein adjusting the detected signal comprises:

discarding the first set of capacitance measurements as being associated with the touching object; and

retaining the second set of capacitance measurements as being associated with the hovering object.

13. A touch and hover sensing device comprising:

multiple sensors configured to detect a first object touching the device and a second object hovering over the device concurrently; and

a touch and hover control system configured to measure capacitance at one or more of the sensors associated with the touching object and the hovering object and to determine a touch location of the touching object and a hover location of the hovering object based on the measurements.

14. The device of claim 13, wherein the sensors are partitioned to provide at least one partition for detecting the touching object and at least another partition for detecting the hovering object, and

wherein the control system determines the touch location based on a portion of the measurement in the partition for detecting the touching object and the hover location based on a portion of the measurement in the partition for detecting the hovering object.

15. The device of claim 14, wherein each partition includes at least one edge of the device.

16. A method of detecting a signal indicative of a hover position of a first object and a touch position of a second object at multiple sensors of a sensing panel, the method comprising:

partitioning the multiple sensors into one or more touch partitions and hover partitions;

measuring capacitance at the sensors in each of the partitions; and

identifying the hover position corresponding to the measurement in a hover partition and the touch position corresponding to the measurement in a touch partition.

17. The method of claim 16, wherein the touch partitions include sensors likely to receive a touching object.

18. The method of claim 16, wherein the hover partitions include sensors likely to receive a hovering object.

19. The method of claim 16, further comprising partitioning the multiple sensors into one or more dual partitions, wherein the dual partitions include sensors likely to receive either a touching object or a hovering object.

20. The method of claim 16, wherein the sensors are based on mutual capacitance.

21. A method of detecting a concurrent touch signal and hover signal at a sensing panel, the method comprising:

recalibrating the sensing panel to detect an unsaturated touch signal;

measuring capacitance at the sensing panel; and

identifying the touch signal having an unsaturated value and the hover signal having a lesser value based on the measurement.

22. The method of claim 21, further comprising:

measuring capacitance at the sensing panel to determine a saturated touch signal, the capacitance being caused by a touch at the panel, wherein recalibrating the sensing panel comprises using the saturated touch signal in the recalibration.

23. A touch and hover sensing device comprising:

a sensing panel having multiple sensors configured to detect multiple objects concurrently hovering over the panel; and

a touch and hover control system configured to measure capacitance associated with the hovering objects and to determine a first hover location of one of the hovering objects and a second hover location of another of the hovering objects based on the measurement.

24. The device of claim 23, wherein the capacitance measurement is a mutual capacitance measurement.

25. The device of claim 23, wherein the sensing panel is partitioned, each partition configured to detect multiple objects therein.

26. A method of detecting a signal indicative of concurrent hover positions of objects at multiple sensors of a sensing panel, the method comprising:

measuring capacitance at the multiple sensors;

identifying multiple peaks in the measurement; and

determining the hover positions of the objects corresponding to the identified peaks.

27. The method of claim 26, wherein identifying the multiple peaks comprises identifying sensor locations in the sensing panel corresponding to the peaks.

28. The method of claim 26, wherein measuring the capacitance comprises measuring mutual capacitance at the multiple sensors.

29. A touch and hover sensing device comprising:

a touch and hover sensing panel having multiple sensors configured to detect multiple objects proximate to the panel, wherein the objects touch the panel to cause concurrent touch events, hover over the panel to cause concurrent hover events, 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, in accordance with at least one of the concurrent touch events, concurrent hover events, or concurrent touch and hover events.

30. The device of claim 29, wherein the control system configures the panel into multiple partitions, each partition configured to detect at least one of a touch event or a hover event.

31. The device of claim 29, wherein the control system adjusts the capacitance measurement to distinguish between concurrent touch and/or hover events.

32. The device of claim 29, further comprising a display configured to display graphical information to select in response to the touch and hover events.

33. The device of claim 29 incorporated into at least one of a mobile phone, a digital media player, or a computer.