CORRECTION OF ALIGNMENT AND LINEARITY ERRORS IN A STYLUS INPUT SYSTEM

• US 20060279556A1
• Filed: 08/21/2006
• Published: 12/14/2006
• Est. Priority Date: 08/01/2001
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Tsang, Michael H.
• Granted Patent: US 7,646,380 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/04186 Touch location disambiguation
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact
• CPC Class Codes: G06F 3/046 by electromagnetic means

Abstract

A method and system for correcting alignment and linearity errors in devices using a finger or stylus input device with a display device interactively coupled to a digitizer is disclosed. Touching intersections in a calibration grid on the display device may be performed to create a linearity map. Subsequently, detected stylus input is mapped to a sector in the linearity map, and resultant screen coordinates are calculated using ratios within a reference rectangle corresponding to the detected stylus input and the mapped sector.

Claims

1. One or more computer readable media storing computer executable instructions for performing a method of creating a linearity map, said method comprising the steps of:

(i) touching a display device at a plurality of predetermined locations defined by a calibration grid corresponding to the display device, wherein the calibration grid is non-uniform, and the calibration grid comprises a first area of a first calibration density and a second area of a second calibration density different from said first calibration density;

(ii) detecting in a digitizer coupled to the display device, coordinates for each touched predetermined location; and

(iii) recording each predetermined location'"'"'s screen coordinates and corresponding detected digitizer coordinates.

2. The computer readable media of claim 1, wherein the calibration grid is displayed on the display device.

3. The computer readable media of claim 1, wherein the information recorded in step (iii) is recorded in an array.

4. The computer readable media of claim 3, wherein the array is two-dimensional, and each array element corresponds to an intersection of the calibration grid.

5. The computer readable media of claim 1, wherein the calibration grid is non-uniform along both its X-axis and Y-axis.

6. One or more computer readable media storing computer executable instructions for performing a method for creating a linearity map, said method comprising the steps of:

(i) detecting touch input on a display device at a plurality of predetermined locations;

(ii) detecting on a digitizer, coordinates for each touched predetermined location; and

(iii) recording each predetermined location'"'"'s screen coordinates and corresponding detected digitizer coordinates,

wherein a calibration grid displayed on the display device coupled to the digitizer defines the predetermined locations, and

wherein the calibration grid is non-uniform, and comprises a first area of a first density and a second area of a second density.

7. The computer readable media of claim 6, wherein the first area corresponds to an area of higher distortion within a data processing device, and the second area corresponds to an area of lower distortion within the data processing device.

8. The computer readable media of claim 6, wherein the information recorded in step (iii) is recorded in a non-linear array.

9. The computer readable media of claim 6, wherein the calibration grid is non-uniform along both its X-axis and Y-axis.

10. One or more computer readable media storing computer executable instructions for performing a method of creating a linearity map, said method comprising the steps of:

(i) detecting touch input corresponding to a plurality of predetermined locations on a display device, said locations defined by a calibration grid corresponding to the display device, wherein the calibration grid is non-uniform, and the calibration grid comprises a first area of a first calibration density and a second area of a second calibration density different from said first calibration density;

(ii) detecting in a digitizer coupled to the display device, coordinates for each touched predetermined location; and

(iii) recording each predetermined location'"'"'s screen coordinates and corresponding detected digitizer coordinates,

wherein the first area corresponds to an area of higher distortion within a data processing device, and the second area corresponds to an area of lower distortion within the data processing device.

11. The computer readable media of claim 10, wherein the calibration grid is displayed on the display device.

12. The computer readable media of claim 10, wherein the information recorded in step (iii) is recorded in an array.

13. The computer readable media of claim 12, wherein the array is two-dimensional, and each array element corresponds to an intersection of the calibration grid.

14. The computer readable media of claim 10, wherein the information recorded in step (iii) is recorded in a non-linear array.

15. The computer readable media of claim 10, wherein the calibration grid is non-uniform along both its X-axis and Y-axis.