Auto-calibration of a touch screen

• US 8,004,503 B2
• Filed: 02/21/2006
• Issued: 08/23/2011
• Est. Priority Date: 02/21/2006
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Zotov, Alexander, Townsend, Reed, Shariff, Sameer, Dodge, Steve
• Primary Examiner(s): Nguyen; Kevin M
• Assistant Examiner(s): Bray; Stephen A
• Application Number:
  US11/358,816
• Publication Number:
  US 20070195067A1
• Time in Patent Office: 2,009 Days
• Field of Search: 345173-179, 178 1801- 2004
• US Class Current: 345/178
• CPC Class Codes: G06F 3/04186 Touch location disambiguation
• CPC Class Codes: G06F 3/04883 for inputting data by handwriting, e.g. gesture or text

Abstract

Methods and systems are provided for automatically calibrating a pointing device, such as a stylus, with a writing surface, such as a touch screen. In one example, an automated method is implemented to calibrate the writing surface based user inputs attempting to use the computer for functions other than calibration of the writing surface. The user inputs may be, for example, a user selecting a button within a non-calibration software application. The automated method may generate a miscalibration vector based upon where the user input was received and where the user input was expected. In yet another example, a bias field may be generated for the writing surface from the collected user inputs. In yet other examples, a computing device may comprise computer-executable instructions for performing one or methods of calibrating the writing surface.

Claims

1. A computer-implemented method of automatically calibrating a writing surface respective to a pointing device during normal operation of the writing surface, the method comprising:

displaying data on a display device having a writing surface thereon, the display device being in operative communication with a computing device;

receiving at least one operational user input on at least one actual location on or proximate to a user-selectable element of a graphical user interface upon the writing surface during usage of the computing device, wherein the user input is indicative of attempting at least one function other than calibration, the function related to the user-selectable element;

determining a type of input from among recognized user input types including a single tap motion, a double tap motion, and a dragging motion for each operational user input;

determining an expected location on the writing surface for each operational user input;

determining a miscalibration vector between the location on the writing surface of the at least one user input and at least one expected location on the writing surface of the at least one user input;

recalibrating the writing surface with respect to at least one axis to interpret subsequent operational user input;

detecting a modification in a configuration parameter of the computing device, wherein the configuration parameter is related to a configuration of hardware components of the computing device relative to one another and the modification comprising changing the computing device from a direct current (DC) power to alternating current (AC) power, changing a location of a battery or power source, or changing a use of a hard-disk drive; and

executing a scheme to automatically adjust the calibration of the writing surface, wherein the adjustment is determined by the plurality of operational user inputs previously received prior to the modification.

2. The computer-implemented method of claim 1, wherein the user-selectable element is selected from the group consisting of a button, hyperlink, task bar, edges of a boundary, and combinations thereof.

3. The computer-implemented method of claim 1, wherein the expected location of the at least one operational user input is determined according to the proximity of the actual location of the at least one operational user input relative to a user-selectable element.

4. The computer-implemented method of claim 1, wherein the expected location of the at least one operational user input is determined according to the type of actual operational user input received upon the writing surface.

5. The computer-implemented method of claim 1, wherein the at least one expected location on the writing surface comprises a plurality of locations located on different portions of the writing surface.

6. The computer-implemented method of claim 5, the method further comprising:

calculating a bias field for the writing surface of the display device, the calculating comprising;

for a given location proximate to an expected location on the writing surface, calculating a weighted sum of bias vectors; and

dividing the weighted sum by a normalizing coefficient being the sum of all the weights to obtain a weighted average vector.

7. The method of claim 6, wherein the weighted sum of the bias vector is weighted by 1/R², where R is the distance from the given location on the writing surface to a starting position of a particular vector.

8. The computer-implemented method of claim 1, wherein proximity to a user-selectable element of a graphical user interface is determined by calculating whether a corresponding operational user input is within a cut-off distance value where the cut-off distance value depends upon an acceptable type of input associated with the corresponding user-selectable element.

9. The computer-implemented method of claim 8, wherein the cut-off distance value varies between an x-axis and a y-axis.

10. The computer-implemented method of claim 1, wherein determining a particular expected location corresponding to a particular operational user input includes determining a type of user-selectable element based on the type of input received, and wherein the type of user-selectable element influences a corresponding expected location.

11. The computer-implemented method of claim 1, wherein determining a type of input for each operational user input includes determining a number of operational user inputs received within a predetermined time.

12. The computer-implemented method of claim 11, wherein determining the type of input includes, for a plurality of received user inputs, determining whether each subsequent user input is within a level of precision distance from a previous user input.

13. A computer device comprising a processor, a display device having a writing surface thereon, and a computer-readable storage medium, wherein the computer-readable storage medium has computer-executable instructions for performing acts comprising:

displaying an output on the display device, wherein the output comprises a graphical representation of at least one aspect of a non-calibration application;

detecting an operational user input on the writing surface of the display device, the input attempting to select at least one graphical representation of the at least one non-calibration application displayed on the display device;

determining a type of input from among recognized user input types including a single tap motion, a double tap motion, and a dragging motion for the operational user input;

determining an expected location on the writing surface for the operational user input;

determining a bias vector between the location on the writing surface of the user input and the expected location on the writing surface of the user input;

recalibrating the writing surface with respect to at least one axis;

detecting a modification in a configuration parameter of the computing device, wherein the configuration parameter is related to a configuration of hardware components of the computing device relative to one another and the modification comprising changing the computing device from a direct current (DC) power to alternating current (AC) power, changing a location of a battery or power source, or changing a use of a hard-disk drive; and

executing a scheme to automatically adjust the calibration of the writing surface, wherein the adjustment is determined by the plurality of operational user inputs previously received prior to the modification.

14. The computer-implemented method of claim 13, wherein the at least one expected location on the writing surface is a user-selectable element of a graphical user interface selected from the group consisting of a button, hyperlink, task bar, edges of a boundary, and combinations thereof.

15. The computer-implemented method of claim 13, wherein the expected location of the at least one operational user input is determined by the criteria comprising the proximity of the actual location of the at least one operational user input relative to a user-selectable element, the type of actual non-calibration user input received upon the writing surface.

16. The computer-implemented method of claim 13, the method further comprising:

calculating a bias field for the writing surface of the display device comprising;

(1) for a given location on the writing surface, calculating a weighted sum of bias vectors; and

(2) dividing the weighted sum by a normalizing coefficient being the sum of all the weights to obtain a weighted average vector.

17. The computer-implemented method of claim 16, wherein the weighted sum of the bias vector is weighted by 1/R², where R is the distance from the given location on the writing surface to a starting position of a particular vector.

18. The computer device of claim 13, wherein determining the bias vector between the location on the writing surface of the user input and the expected location on the writing surface of the user input commences after a predetermined delay or after a specific event related to a change in the hardware components of the computer device or the computer device changing its location in a network.