Touch and hover sensing

• US 10,268,303 B2
• Filed: 03/28/2016
• Issued: 04/23/2019
• Est. Priority Date: 07/10/2009
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Bernstein, Jeffrey Traer, Amm, David T., Leung, Omar S., Mullens, Christopher Tenzin, King, Brian Michael, Land, Brian Richards, Cutler, Reese T.
• Primary Examiner(s): Khoo, Stacy
• Application Number:
  US15/083,102
• Publication Number:
  US 20160209982A1
• Time in Patent Office: 1,121 Days
• Field of Search: 345173-179, 178 1801- 1809
• 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 2203/04107 Shielding in digitiser, i.e. guard or shielding arrangements, mostly for capacitive touchscreens, e.g. driven shields, driven grounds
• 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
• CPC Class Codes: G06F 3/04817 using icons graphical or visual programming using iconic symbols G06F8/34
• CPC Class Codes: G06F 3/04845 for image manipulation, e.g. dragging, rotation, expansion or change of colour
• CPC Class Codes: G06F 3/0486 Drag-and-drop

Abstract

Improved capacitive touch and hover sensing with a sensor array is provided. An AC ground shield positioned behind the sensor array and stimulated with signals of the same waveform as the signals driving the sensor array may concentrate the electric field extending from the sensor array and enhance hover sensing capability. The hover position and/or height of an object that is nearby, but not directly above, a touch surface of the sensor array, e.g., in the border area at the end of a touch screen, may be determined using capacitive measurements of sensors near the end of the sensor array by fitting the measurements to a model. Other improvements relate to the joint operation of touch and hover sensing, such as determining when and how to perform touch sensing, hover sensing, both touch and hover sensing, or neither.

Claims

1. A capacitive sensing apparatus comprising:

a sensor array comprising;

a first set of multiple conductive lines configured to perform a self-capacitance measurement; and

a second set of multiple conductive lines configured to perform a mutual capacitance measurement based on a coupling between one or more lines of the first set of multiple conductive lines and one or more lines of the second set of multiple conductive lines; and

a sensor control system configured to;

transmit a combined alternating current (AC) signal to a first line of the first set of multiple conductive lines, wherein the combined AC signal includes a first alternating current (AC) signal component and a second alternating current (AC) signal component, and

concurrently measure;

a self capacitance based on the combined AC signal at the first line of the first set of multiple conductive lines, and

a mutual capacitance based on the combined AC signal.

2. The capacitive sensing apparatus of claim 1, wherein the sensor control system is further configured to combine the first AC signal component and the second AC signal using component frequency multiplexing before transmitting the combined signal to the sensor array.

3. The capacitive sensing apparatus of claim 1, wherein the sensor control system is further configured to combine the first AC signal component and the second AC signal component using code division multiplexing before transmitting the combined signal to the sensor array.

4. The capacitive sensing apparatus of claim 1, wherein the first AC signal component has a first frequency, and the second AC signal component has a second frequency, the second frequency being different than the first frequency.

5. The capacitive sensing apparatus of claim 1, wherein the sensor control system is capable of concurrently measuring the self capacitance of the sensor array and the mutual capacitance of the sensor array at a first portion of the sensor array that includes the first line of the first set of multiple conductive lines.

6. The capacitive sensing apparatus of claim 5, wherein the first portion of the sensor array is a region of the sensor array that includes the first line of the first set of multiple conductive lines.

7. The capacitive sensing apparatus of claim 1, wherein the sensor control system is capable of concurrently measuring:

the self capacitance of the sensor array at a first portion of the sensor array, and

the mutual capacitance of the sensor array at a second portion of the sensor array, different from the first portion of the sensor array.

8. The capacitive sensing apparatus of claim 1, wherein the sensor array includes common circuitry for measuring the self capacitance of the sensor array and measuring the mutual capacitance of the sensor array.

9. The capacitive sensing apparatus of claim 1, wherein the sensor control system is further configured to selectively:

measure a self capacitance of the sensor array,

measure a mutual capacitance of the sensor array, and

concurrently measure the self capacitance of the sensor array and the mutual capacitance of the sensor array.

10. A touch sensing device incorporating the capacitive sensing apparatus of claim 1.

11. The device of claim 10, further comprising a display configured to display graphical information for selection based on at least one of the self capacitance of the sensor array and the mutual capacitance of the sensor array.

12. The device of claim 10 incorporated into at least one of a mobile phone, a digital media player, or a computer.

13. A method for controlling a capacitive sensor array, the method comprising:

transmitting a combined alternating current (AC) signal to a first line of a first set of multiple conductive lines, wherein the combined AC signal includes a first alternating current (AC) signal component and a second alternating current (AC) signal component; and

concurrently measuring;

a self capacitance based on the combined AC signal at the first line of the first set of multiple conductive lines, and

a mutual capacitance based on the combined AC signal;

wherein the first set of multiple conductive lines is configured to perform self-capacitance measurements; and

a second set of multiple conductive lines is configured to perform mutual capacitance measurements based on a coupling between one or more lines of the first set of multiple conductive lines and one or more lines of the second set of multiple conductive lines.

14. The method of claim 13, further comprising combining the first AC signal component and the second AC signal component using frequency multiplexing before transmitting the combined AC signal to the first line of the first set of multiple conductive lines.

15. The method of claim 13, further comprising combining the first AC signal component and the second AC signal component using code division multiplexing before transmitting the combined signal to the sensor array.

16. The method of claim 13, wherein the first AC signal component has a first frequency, and the second AC signal component has a second frequency, the second frequency being different than the first frequency.

17. The method of claim 13, further comprising concurrently measuring the self capacitance of the sensor array and the mutual capacitance of the sensor array at a first portion of the sensor array that includes the first line of the first set of multiple conductive lines.

18. The method of claim 17, wherein the first portion of the sensor array comprises the first line of the first set of multiple conductive lines and a second line of the second set of multiple conductive lines.

19. The method of claim 13, further comprising:

concurrently measuring;

the self capacitance of the sensor array at a first portion of the sensor array, and

the mutual capacitance of the sensor array at a second portion of the sensor array, different from the first portion of the sensor array.

20. The method of claim 13, further comprising selectively:

measuring a self capacitance of the sensor array,

measuring a mutual capacitance of the sensor array, and

concurrently measuring the self capacitance of the sensor array and the mutual capacitance of the sensor array.

21. A non-transitory computer-readable storage medium having stored therein instructions, which when executed by a processor cause the processor to perform a method for controlling a capacitive sensor array, the method comprising:

transmitting a combined alternating current (AC) signal to a first line of a first set of multiple conductive lines, wherein the combined AC signal includes a first alternating current (AC) signal component and a second alternating current (AC) signal component; and

concurrently measuring;

a self capacitance based on the combined AC signal at the first line of the first set of multiple conductive lines, and

a mutual capacitance based on the combined AC signal;

wherein the first set of multiple conductive lines is configured to perform self-capacitance measurements; and

a second set of multiple conductive lines is configured to perform mutual capacitance measurements based on a coupling between one or more lines of the first set of multiple conductive lines and one or more lines of the second set of multiple conductive lines.

22. The non-transitory computer-readable storage medium of claim 21, the method further comprising:

combining the first AC signal component and the second AC signal component using frequency multiplexing before transmitting the combined AC signal to the first line of the first set of multiple conductive lines.

23. The non-transitory computer-readable storage medium of claim 21, wherein the first AC signal component has a first frequency, and the second AC signal component has a second frequency, the second frequency being different than the first frequency.

24. The non-transitory computer-readable storage medium of claim 21, further comprising selectively:

measuring a self capacitance of the sensor array,

measuring a mutual capacitance of the sensor array, and

concurrently measuring the self capacitance of the sensor array and the mutual capacitance of the sensor array.

25. The non-transitory computer-readable storage medium of claim 21, the method further comprising:

concurrently measuring;

the self capacitance of the sensor array at a first portion of the sensor array, and

the mutual capacitance of the sensor array at a second portion of the sensor array, different from the first portion of the sensor array.