Touchscreen with Z-Velocity Enhancement

• US 20110059778A1
• Filed: 09/08/2010
• Published: 03/10/2011
• Est. Priority Date: 09/08/2009
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Palm, Inc. (TCL Technology Group Corp.)
• Inventors: Barras, Lawrence Scott, Hughes, Thomas David, Albanowski, Kenneth James
• Granted Patent: US 8,711,110 B2
• Time in Patent Office: Days
• US Class Current: 455/566
• 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 3/04883 for inputting data by handwriting, e.g. gesture or text
• CPC Class Codes: H04M 2250/22 including a touch pad, a touch sensor or a touch detector

Abstract

A system and a method are disclosed for detecting an interaction, such as physical contact, with a touch-sensitive screen. The screen comprises a plurality of cells each associated with a signal value, such as a capacitance, that is modified based on the proximity of an object to the screen. During a first time interval, a first signal value associated with a cell is captured and during a second time interval a second signal value associated with the cell is captured. A difference is computed by subtracting the second signal value from the first signal value. The difference is used to classify the proximity of the object to the screen. For example, the object is classified as approaching the screen if the difference is positive and non-zero or the object is classified as moving away from the screen if the difference is negative and non-zero.

Claims

1. A method for classifying an interaction of an object with a region having at least one cell of a touch-sensitive screen comprising:

capturing a first signal value associated with the region during a first time interval;

determining a second signal value associated with the region during a second time interval;

calculating a velocity by subtracting the second signal value of the second time interval from a first signal value in the first set of signal values of the first time interval; and

classifying the interaction using a magnitude and a direction associated with the velocity.

2. The method of claim 1, wherein classifying the interaction using the magnitude associated with the velocity comprises:

determining whether the direction is a positive value or a negative value;

responsive to determining the direction is a positive value, classifying the interaction as an object approaching the touch-sensitive screen; and

responsive to determining the direction is a negative value, classifying the interaction as an object moving away from the touch-sensitive screen.

3. The method of claim 1, wherein classifying the interaction using the magnitude and the direction associated with the velocity comprises:

responsive to the magnitude equaling zero and the first signal value exceeding a threshold, classifying the interaction as an object physically contacting the touch-sensitive screen.

4. The method of claim 1, further comprising:

responsive to the magnitude associated with the velocity exceeding a threshold, performing a first action; and

responsive to the magnitude associated with the velocity not exceeding the threshold, performing a second action.

5. The method of claim 1, wherein determining further comprises retrieving a previously stored signal value from the second time interval.

6. The method of claim 1, wherein the signal value comprises a value that depends on a proximity of the object to the touch-screen.

7. The method of claim 1, wherein classifying the interaction using the magnitude and the direction associated with the velocity comprises:

capturing a third signal value associated with the region during a third time interval;

determining a fourth signal value associated with the region during a fourth time interval;

calculating a second velocity by subtracting the fourth signal value from the third signal value;

calculating an acceleration by subtracting the second velocity from the velocity;

classifying the interaction using the acceleration, a magnitude and a direction associated with the fourth velocity.

8. A non-transitory computer readable storage medium storing instructions, the instructions when executed by at least one processor cause the at least one processor to:

capture a first signal value associated with the region during a first time interval;

determine a second signal value associated with the region during a second time interval;

calculate a velocity by subtracting the second signal value of the second time interval from a first signal value in the first set of signal values of the first time interval; and

classify the interaction using a magnitude and a direction associated with the velocity.

9. The non-transitory computer readable storage medium of claim 8, wherein the instructions that cause the at least one processor to classify the interaction using the magnitude associated with the velocity further comprises instructions that cause the at least one processor to:

determine whether the direction is a positive value or a negative value;

classify the interaction as an object approaching the touch-sensitive screen in response to a determination of the direction being a positive value; and

classify the interaction as an object moving away from the touch-sensitive screen in response to a determination of the direction being a negative value.

10. The non-transitory computer readable storage medium of claim 8, instructions that cause the at least one processor to classify the interaction using the magnitude associated with the velocity further comprises instructions that cause the at least one processor to:

classify the interaction as an object physically contacting the touch-sensitive screen, in response to the magnitude equaling zero and the first signal value exceeding a threshold.

11. The non-transitory computer readable storage medium of claim 8, further comprising instructions that cause the at least one processor to:

perform a first action in responsive to the magnitude associated with the velocity exceeding a threshold; and

perform a second action in responsive to the magnitude associated with the velocity not exceeding the threshold.

12. The non-transitory computer readable storage medium of claim 8, wherein the signal value comprises a value which depends on a proximity of the object to the touch-screen.

13. The non-transitory computer readable storage medium of claim 8, wherein the instructions that cause the at least one processor to determine further comprises instructions that cause the at least one processor to retrieve a previously stored signal value from the second time interval.

14. The non-transitory computer readable storage medium of claim 8, wherein the instructions that cause the at least one processor to classify the interaction using the magnitude and the direction associated with the velocity further comprises instructions that cause the at least one processor to:

capture a third signal value associated with the region during a third time interval;

determine a fourth signal value associated with the region during a fourth time interval;

calculate a second velocity by subtracting the fourth signal value from the third signal value;

calculate an acceleration by subtracting the second velocity from the velocity; and

classify the interaction using the acceleration, a magnitude and a direction associated with the fourth velocity.

15. A mobile computing device comprising:

a touch-sensitive screen configured to display information and to receive an input;

a processor coupled to the touch-sensitive screen;

a memory including instructions to be executed by the processor, the instructions when executed by the processor cause the processor to perform a computer-implemented method comprising;

capturing a first signal value associated with the region during a first time interval;

determining a second signal value associated with the region during a second time interval;

calculating a velocity by subtracting the second signal value from the first signal value; and

classifying the interaction using a magnitude and a direction associated with the velocity.

16. The mobile computing device of claim 15, wherein classifying the interaction using the magnitude associated with the velocity comprises:

determining whether the direction is a positive value or a negative value;

responsive to determining the direction is a positive value, classifying the interaction as an object approaching the touch-sensitive screen; and

responsive to determining the direction is a negative value, classifying the interaction as an object moving away from the touch-sensitive screen.

17. The mobile computing device of claim 15, wherein classifying the interaction using the magnitude and the direction associated with the velocity comprises:

responsive to the magnitude equaling zero and the first signal value exceeding a threshold, classifying the interaction as an object physically contacting the touch-sensitive screen.

18. The mobile computing device of claim 15, wherein the memory further includes instructions to be executed by the processor, the instructions when executed by the processor cause the processor to perform steps comprising:

responsive to the magnitude associated with the velocity exceeding a threshold, performing a first action; and

responsive to the magnitude associated with the velocity not exceeding the threshold, performing a second action.

19. The mobile computing device of claim 15, wherein the signal value comprises a value which depends on a proximity of the object to the touch-screen.

20. The mobile computing device of claim 15, wherein classifying the interaction using the magnitude and the direction associated with the velocity comprises:

capturing a third signal value associated with the region during a third time interval;

determining a fourth signal value associated with the region during a fourth time interval;

calculating a second velocity by subtracting the fourth signal value from the third signal value;

calculating an acceleration by subtracting the second velocity from the velocity;

classifying the interaction using the acceleration, a magnitude and a direction associated with the fourth velocity.