ORTHOGONAL MULTI-ROW TOUCH PANEL STIMULATION

• US 20130176271A1
• Filed: 03/08/2012
• Published: 07/11/2013
• Est. Priority Date: 01/09/2012
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Sobel, David A., Ranganathan, Sumant, Walley, John S.
• Granted Patent: US 8,937,606 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• 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 3/04182 Filtering of noise external to the device and not generated by digitiser components
• 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

Control circuitry for a touch panel includes a touch panel interface, a memory comprising scanning logic, and a controller in communication with the memory and the touch panel interface. The controller is operable, when the scanning logic is executed, to energize a first and a second row in the touch panel simultaneously, a first time; obtain a first signal measurement along a column intersecting the first and second rows; energize the first and the second row in the touch panel simultaneously, a second time; obtain a second signal measurement along the column; and determine a first pixel value and a second pixel value along the column from the first signal measurement and the second signal measurement.

Claims

1. A method for scanning a touch panel, the method comprising:

energizing a first and a second row in the touch panel simultaneously, a first time;

obtaining a first signal measurement along a column intersecting the first and second rows;

energizing the first and the second row in the touch panel simultaneously, a second time;

obtaining a second signal measurement along the column; and

determining a first pixel value and a second pixel value along the column from the first signal measurement and the second signal measurement.

2. The method of claim 1, where energizing the first and second row comprise:

energizing with signals modulated by a real or complex valued Hadamard sequence.

3. The method of claim 1, where energizing the first time and the second time comprise energizing with orthogonal signals.

4. The method of claim 1, further comprising obtaining first additional signal measurements along additional columns intersecting the first and second rows after energizing the first time.

5. The method of claim 4, further comprising obtaining second additional signal measurements along the additional columns intersecting the first and second rows after energizing the second time.

6. The method of claim 5, further comprising determining additional first and second pixel values along the additional columns from the first and second additional signal measurements.

7. The method of claim 1, where energizing occurs in response to an instruction to increase signal-to-noise ratio.

8. Control circuitry for a touch panel, the control circuitry comprising:

a touch panel interface;

a memory comprising scanning logic; and

a controller in communication with the memory and the touch panel interface, the controller operable, when the scanning logic is executed, to;

energize a first and a second row in the touch panel simultaneously, a first time;

obtain a first signal measurement along a column intersecting the first and second rows;

energize the first and the second row in the touch panel simultaneously, a second time;

obtain a second signal measurement along the column; and

determine a first pixel value and a second pixel value along the column from the first signal measurement and the second signal measurement.

9. The control circuitry of claim 8, where the first and second rows are energized with signals modulated by a Hadamard sequence.

10. The control circuitry of claim 8, where the scanning logic causes the controller to energize the first time and the second time with orthogonal signals.

11. The control circuitry of claim 8, where the scanning logic causes the controller to obtain first additional signal measurements along additional columns intersecting the first and second rows after energizing the first time.

12. The control circuitry of claim 11, where the scanning logic causes the controller to obtain second additional signal measurements along the additional columns intersecting the first and second rows after energizing the second time.

13. The control circuitry of claim 12, where the scanning logic causes the controller to determine additional first and second pixel values along the additional columns from the first and second additional signal measurements.

14. The control circuitry of claim 8, where the controller is operable to energize in response to an instruction to increase signal-to-noise ratio.

15. A product comprising:

a computer readable medium; and

scanning logic stored on the medium and operable to, when executed by a controller;

energize a first and a second row in a touch panel simultaneously, a first time;

obtain a first signal measurement along a column intersecting the first and second rows;

energize the first and the second row in the touch panel simultaneously, a second time;

obtain a second signal measurement along the column; and

determine a first pixel value and a second pixel value along the column from the first signal measurement and the second signal measurement.

16. The product of claim 15, where the scanning logic causes the controller to energize the first time and the second time with orthogonal signals obtained using a real or complex valued Hadamard sequence.

17. The product of claim 15, where the scanning logic causes the controller to obtain first additional signal measurements along additional columns intersecting the first and second rows after energizing the first time.

18. The product of claim 17, where the scanning logic causes the controller to obtain second additional signal measurements along the additional columns intersecting the first and second rows after energizing the second time.

19. The product of claim 18, where the scanning logic causes the controller to determine additional first and second pixel values along the additional columns from the first and second additional signal measurements.

20. The product of claim 15, where the scanning logic is operable to energize in response to an instruction to increase signal-to-noise ratio.