Touchscreen with Z-velocity enhancement

• US 8,711,110 B2
• Filed: 09/08/2010
• Issued: 04/29/2014
• Est. Priority Date: 09/08/2009
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Barras, Lawrence Scott, Albanowski, Kenneth James, Hughes, Thomas David
• Primary Examiner(s): PATEL, PREMAL R
• Application Number:
  US12/877,776
• Publication Number:
  US 20110059778A1
• Time in Patent Office: 1,329 Days
• Field of Search: 345173-176, 178 1801- 1809
• 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 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 a movement of an object relative to a region of a touch-sensitive screen of a computing device, the region comprising a plurality of cells, the method performed by one or more processors and comprising:

detecting a movement of the object relative to the region the touch-sensitive screen by, for one or more of the plurality of cells, (i) determining a first signal value corresponding to a first position of the object relative to the cell at a first time, and (ii) determining a second signal value corresponding to a second position of the object relative to the cell at a second time;

calculating a velocity of the movement of the object based on the first signal value at the first time and the second signal value at the second time, the velocity having a magnitude and a direction; and

classifying the movement of the object as either approaching or moving away from the region of the touch-sensitive screen based on at least the magnitude and direction associated with the velocity.

2. The method of claim 1, further comprising:

responsive to the magnitude equaling zero and the first signal value exceeding a threshold, determining that the object is physically contacting the touch-sensitive screen.

3. The method of claim 1, further comprising:

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

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

4. The method of claim 1, wherein the second signal value is previously stored in a memory, and wherein determining the second signal value further comprises retrieving the previously stored second signal value from the memory.

5. The method of claim 1, wherein the first signal value comprises a value that depends on a distance of the object from the touch-sensitive screen.

6. The method of claim 1, wherein the magnitude includes a first magnitude, the direction includes a first direction, the velocity of the movement of the object includes a first velocity of the movement, and classifying the movement of the object as either approaching or moving away from the touch-sensitive screen based on at least the magnitude and the direction associated with the velocity of the movement comprises:

detecting a third signal value corresponding to a third position of the object relative to the region of the touch-sensitive screen at a third time;

determining a fourth signal value corresponding to a fourth position of the object relative to the region of the touch-sensitive screen at a fourth time;

calculating a second velocity of the movement by subtracting the fourth signal value from the third signal value, the second velocity associated with a second magnitude and a second direction;

calculating an acceleration of the movement by subtracting the second velocity of the movement from the first velocity of the movement; and

classifying the movement using the acceleration, the second magnitude and the second direction.

7. The method of claim 1, wherein each of the cells comprises an element of a two-dimensional array of electrodes.

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:

detect a movement of an object relative to a region of a touch-sensitive screen, the region comprising a plurality of cells, by, for one or more of the plurality of cells (i) determining a first signal value corresponding to a first position of an object relative to the cell at a first time and (ii) determine a second signal value corresponding to a second position of the object relative to the cell at a second time;

calculate a velocity of the movement based on the first signal value at the first time and the second signal value at the second time, the velocity having a magnitude and a direction;

classify the movement using the magnitude and the direction associated with the velocity, wherein classifying the movement using the magnitude and the direction associated with the velocity comprises;

determine that the direction is a positive direction or a negative direction;

in response to determining that the direction is the positive direction, classify the movement of the object approaching the region of the touch-sensitive screen; and

in response to determining that the direction is the negative value, classify the movement of the object moving away from the region of the touch-sensitive screen.

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

in response to the magnitude equaling zero and the first signal value exceeding a threshold, determine that the object is physically contacting the touch-sensitive screen.

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

perform a first action in response to the magnitude associated with the velocity of the movement exceeding a threshold; and

perform a second action in response to the magnitude associated with the velocity of the movement not exceeding the threshold.

11. The non-transitory computer readable storage medium of claim 8, wherein the first signal value comprises a value which depends on a distance of the object from the touch-sensitive screen.

12. The non-transitory computer readable storage medium of claim 8, wherein the second signal value is previously stored in a memory, and wherein the instructions further cause the at least one processor to determine the second signal value by retrieving the previously stored second signal value from the memory.

13. The non-transitory computer readable storage medium of claim 8, wherein the magnitude includes a first magnitude, the direction includes a first direction, the velocity of the movement includes a first velocity, and wherein the instructions further cause the at least one processor to classify the movement by:

detecting a third signal value corresponding to a third position of the object relative to the region of the touch-sensitive screen at a third time interval;

determining a fourth signal value corresponding to a fourth position of the object relative to the region of the touch-sensitive screen at a fourth time interval;

calculating a second velocity of the movement by subtracting the fourth signal value from the third signal value, the second velocity associated with a second magnitude and a second direction;

calculating an acceleration of the movement by subtracting the second velocity of the movement from the first velocity of the movement; and

classifying the movement using the acceleration, the second magnitude and the second direction.

14. A mobile computing device comprising:

a touch-sensitive screen configured to display information and to detect a movement of an object relative to the touch-sensitive screen, the touch-sensitive screen comprising a region comprising a plurality of cells;

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;

detecting a movement of the object relative to the region of the touch-sensitive screen by, for one or more of the plurality of cells, (i) determining a first signal value corresponding to a first position of the object relative to the cell at a first time, and (ii) determining a second signal value corresponding to a second position of the object relative to the region of the touch-sensitive screen at a second time;

calculating a velocity of the movement based on the first signal value at the first time and the second signal value at the second time, the velocity having with a magnitude and a direction, classifying the movement using the magnitude and the direction associated with the velocity, wherein classifying the movement using the magnitude and the direction associated with the velocity comprises;

determining that the direction is a positive direction or a negative direction;

in response to determining that the direction is the positive direction, classifying the movement of the object approaching the region of the touch-sensitive screen; and

in response to determining that the direction is the negative value, classifying the movement of the object moving away from the region of the touch-sensitive screen.

15. The mobile computing device of claim 14, wherein the memory further includes instructions that cause the processor to, responsive to the magnitude equaling zero and the first signal value exceeding a threshold, determine that the object is physically contacting the touch-sensitive screen.

16. The mobile computing device of claim 14, wherein the memory further includes instructions that cause the processor to perform steps comprising:

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

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

17. The mobile computing device of claim 14, wherein the first signal value comprises a value which depends on a distance from the object to the touch-sensitive screen.

18. The mobile computing device of claim 14, wherein the magnitude includes a first magnitude, the direction includes a first direction, the velocity of the movement includes a first velocity, and wherein the memory further includes instructions that cause the processor to classify the movement using the magnitude and the direction associated with the velocity of the movement by:

detecting a third signal value corresponding to a third position of the object relative to the region of the touch-sensitive screen at a third time interval;

determining a fourth signal value corresponding to a fourth position of the object relative to the region of the touch-sensitive screen at a fourth time;

calculating a second velocity of the movement by subtracting the fourth signal value from the third signal value, the second velocity associated with a second magnitude and a second direction;

calculating an acceleration of the movement by subtracting the second velocity of the movement from the first velocity of the movement; and

classifying the movement using the acceleration, the second magnitude and the second direction.