Touch restriction region for touch-sensitive display

1. A touch-sensitive display device, comprising:

a touch-sensitive display including a plurality of display electrodes configured to detect proximity of input objects to the touch-sensitive display; and

a touch controller configured to:

determine a two-dimensional position of a stylus touch input based on information from the plurality of display electrodes;

define a touch restriction region of the touch-sensitive display based at least on the two-dimensional position of the stylus touch input, the touch restriction region including a first region boundary extending away from the two-dimensional position of the stylus touch input at a first boundary angle, and a second region boundary extending away from the two-dimensional position of the stylus touch input at a second boundary angle, such that the stylus projects onto the touch restriction region between the first and second region boundaries, where the first boundary angle and the second boundary angle are set based at least in part on a stylus identifier associated with a known identity of a user; and

process touch inputs within the touch restriction region differently than touch inputs outside the touch restriction region.

2. The touch-sensitive display device of claim 1 , where the touch controller is further configured to receive one or both of an indication of a tilt angle of the stylus and an indication of an azimuthal angle of the stylus.

3. The touch-sensitive display device of claim 2 , where the touch restriction region is defined at least in part based on one or both of the tilt angle and the azimuthal angle of the stylus.

4. The touch-sensitive display device of claim 1 , where a first angular difference between the first boundary angle and an azimuthal angle of the stylus is equal to a second angular difference between the second boundary angle and the azimuthal angle of the stylus.

5. The touch-sensitive display device of claim 1 , where processing the touch inputs within the touch restriction region differently than the touch inputs outside the touch restriction region includes only reporting the touch inputs outside the touch restriction region.

6. The touch-sensitive display device of claim 1 , where processing the touch inputs within the touch restriction region differently than the touch inputs outside the touch restriction region includes reporting the touch inputs within the touch restriction region with a flag indicating potentially invalid touch inputs.

7. The touch-sensitive display device of claim 6 , where the flag is useable as a biasing factor for biasing toward classifying the touch inputs within the touch restriction region as invalid inputs.

8. The touch-sensitive display device of claim 1 , where the first region boundary and second region boundary each extend to an edge of the touch-sensitive display.

9. The touch-sensitive display device of claim 1 , where the first region boundary has a first length, the second region boundary has a second length, and either or both of the first and second lengths are proportional to a tilt angle of the stylus.

10. The touch-sensitive display device of claim 1 , where the touch controller is further configured to, after detecting a touch input that meets one or more touch restriction criteria and has a two-dimensional position outside of the touch restriction region, change either or both of the first and second boundary angles such that the two-dimensional position of the touch input is within the touch restriction region.

11. The touch-sensitive display device of claim 1 , where either or both of the first and second boundary angles are set based on a known handedness of the user.

12. A method for touch restriction, comprising:

determining a two-dimensional position of a stylus touch input on a touch-sensitive display based on information received from a plurality of display electrodes of the touch-sensitive display, the plurality of display electrodes configured to detect proximity of input objects to the touch-sensitive display;

defining a touch restriction region of the touch-sensitive display based at least in part on the two-dimensional position of the stylus touch input, the touch restriction region including a first region boundary extending away from the two-dimensional position of the stylus touch input at a first boundary angle, and a second region boundary extending away from the two-dimensional position of the stylus touch input at a second boundary angle, such that the stylus projects onto the touch restriction region between the first and second region boundaries; and

processing touch inputs within the touch restriction region differently than touch inputs outside the touch restriction region, such that touch inputs within the touch restriction region are reported with a flag indicating potentially invalid touch inputs.

13. The method of claim 12 , further comprising receiving one or both of an indication of a tilt angle of the stylus and an indication of an azimuthal angle of the stylus.

14. The method of claim 13 , where the touch restriction region is defined at least in part based on one or both of the tilt angle and the azimuthal angle of the stylus.

15. The method of claim 12 , where a first angular difference between the first boundary angle and an azimuthal angle of the stylus is equal to a second angular difference between the second boundary angle and the azimuthal angle of the stylus.

16. The method of claim 12 , where a first angular difference between the first boundary angle and an azimuthal angle of the stylus, and a second angular difference between the second boundary angle and the azimuthal angle of the stylus, are set based on a known identity of a user of the stylus.

17. A touch-sensitive display device, comprising:

a touch-sensitive display including a plurality of display electrodes configured to detect proximity of input objects to the touch-sensitive display; and

a touch controller configured to:

determine a two-dimensional position of an active stylus touch input based on information from the plurality of display electrodes;

define a touch restriction region of the touch-sensitive display based at least on the two-dimensional position of the active stylus touch input, the touch restriction region including a first region boundary extending away from the two-dimensional position of the active stylus touch input at a first boundary angle, and a second region boundary extending away from the two-dimensional position of the active stylus touch input at a second boundary angle, such that the active stylus projects onto the touch restriction region between the first and second region boundaries;

process touch inputs within the touch restriction region differently than touch inputs outside the touch restriction region; and

after detecting a touch input that meets one or more touch restriction criteria and has a two-dimensional position outside of the touch restriction region, change either or both of the first and second boundary angles such that the two-dimensional position of the active stylus touch input is within the touch restriction region.