Touch and hover sensor compensation

• US 8,982,060 B2
• Filed: 09/30/2010
• Issued: 03/17/2015
• 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
• Primary Examiner(s): Lao, Lun-Yi
• Assistant Examiner(s): Siddiqui, Md Saiful A
• Application Number:
  US12/895,600
• Publication Number:
  US 20120050209A1
• Time in Patent Office: 1,629 Days
• Field of Search: 345173-179, 327/517, 455/566, 178 1801- 1809, 463/37
• US Class Current: 345/173
• 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; and

a touch and hover control system configured to;

drive the sensor lines with a voltage for sensing the object,

when the object is closer than a threshold distance from the device, adjustably configure the sensor lines by ganging at least two of the sensor lines together with a ganging circuitry, the ganged sensor lines having a first resistance, and

when the object is further than the threshold distance from the device, adjustably configure the sensor lines by declining to gang the at least two sensor lines together, each of the at least two sensor lines having a second resistance, greater than the first resistance.

2. 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.

3. The device of claim 2, wherein the different directions are opposite directions.

4. The device of claim 2, 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.

5. 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;

when the object is closer than a threshold distance from the sensing panel, selectively configuring the sensors by ganging at least two of the sensors together with a gaging circuitry, the ganged sensors having a first resistance; and

when the object is further than the threshold distance from the sensing panel, selectively configuring the sensors by separating the at least two of the sensors, each of the at least two sensors having a second resistance, greater than the first resistance.

6. The method of claim 5, 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.

7. The method of claim 5, wherein configuring the sensors comprises selectively ganging adjacent rows of sensors.

8. A touch and hover sensing method, comprising:

driving configurable sensor lines with a voltage for sensing a proximate object;

when the object is closer than a threshold distance, adjustably configuring the sensor lines by ganging at least two of the sensor lines together with a ganging circuitry, the ganged sensor lines having a first resistance; and

when the object is further than the threshold distance, adjustably configuring the sensor lines by declining to gang the at least two sensor lines together, each of the at least two sensor lines having a second resistance, greater than the first resistance.

9. The method of claim 8, further comprising applying the voltage to each sensor line from different directions at the same time, wherein the application from different directions substantially reduces effects of the resistance.

10. The method of claim 8, further comprising partitioning a touch and hover sensing device including the sensor lines, each partition having separate portions of the sensor lines, and driving the voltage separately to the portions of the sensor lines in each partition.