Apparatus and method for controlling a screen pointer
View Patent ↗An apparatus for controlling a position of a screen pointer for an electronic device having a display screen includes a touchpad including a touch-sensitive surface on which a pointing object may be placed. The touchpad is configured to generate position signals indicative of positions of the pointing object on the touch-sensitive surface. The apparatus includes a controller for generating a first set of movement data based on the position signals. The first set of movement data is indicative of motion of the pointing object across the touch-sensitive surface. The controller is configured to generate a second set of movement data when the pointing object is removed from the touch-sensitive surface, thereby leaving the touch-sensitive surface free from contact by a pointing object. The second set of movement data is indicative of motion of the pointing object across the touch-sensitive surface prior to removal of the pointing object.
1. An apparatus for controlling a position of a screen pointer for an electronic device having a display screen, the apparatus comprising:
a touchpad including a touch-sensitive surface on which a pointing object may be placed, the touchpad configured to generate position signals indicative of positions of the pointing object on the touch-sensitive surface; and
a controller for generating a first set of movement data based on the position signals, the first set of movement data indicative of motion of the pointing object across the touch-sensitive surface, the controller configured to generate a second set of movement data when the pointing object is removed from the touch-sensitive surface, thereby leaving the touch-sensitive surface free from contact by a pointing object, the second set of movement data indicative of motion of the pointing object across the touch-sensitive surface prior to removal of the pointing object, the second set of movement data generated based on predetermined acceleration and deceleration characteristics.
2. The apparatus of claim 1 , wherein the second set of movement data is based on an exponential decay.
3. The apparatus of claim 2 , wherein characteristics of the exponential decay are user specifiable.
4. The apparatus of claim 2 , wherein characteristics of the exponential decay are based on a user specifiable time constant.
5. The apparatus of claim 1 , wherein characteristics of the second set of movement data are user definable.
6. The apparatus of claim 5 , wherein characteristics of the second set of movement data are defined by a graphical curve provided by a user.
7. The apparatus of claim 5 , wherein characteristics of the second set of movement data are defined by a mathematical function provided by a user.
8. The apparatus of claim 1 , wherein characteristics of the first set and second set of movement data are user definable.
9. The apparatus of claim 1 , wherein the controller is configured to stop generating the second set of movement data when the pointing object is replaced on the touch-sensitive surface.
10. The apparatus of claim 1 , wherein the second set of movement data is based on inertial properties of a mechanical screen-pointing device.
11. A method of controlling a position of a screen pointer for an electronic device having a screen display, the method comprising:
generating position signals indicative of positions of a pointing object placed against a touch-sensitive surface;
generating a first set of motion data based on the position signals, the first set of motion data indicative of motion in orthogonal axes across the touch-sensitive surface by the pointing object;
adjusting the position of the screen pointer in accordance with the first set of motion data;
generating a second set of motion data based on at least a subset of the first set of motion data after the pointing object is removed from the touch-sensitive surface leaving the touch-sensitive surface free from contact by a pointing object, the second set of movement data generated based on predetermined acceleration and deceleration characteristics; and
adjusting the position of the screen pointer in accordance with the second set of motion data after the pointing object is removed from the touch-sensitive surface.
12. The method of claim 11 , wherein the second set of motion data is based on an exponential decay.
13. The method of claim 12 , and further comprising:
receiving motion definition data from a user specifying characteristics of the exponential decay.
14. The method of claim 12 , and further comprising:
receiving time constant data from a user, the time constant data defining characteristics of the exponential decay.
15. The method of claim 11 , and further comprising:
receiving motion definition data from a user specifying characteristics of the second set of motion data.
16. The method of claim 15 , wherein the motion definition data is a graphical representation of desired characteristics of the second set of motion data.
17. The method of claim 15 , wherein the motion definition data is a mathematical function.
18. The method of claim 11 , and further comprising:
receiving motion definition data from a user specifying characteristics of the first set and second set of motion data.
19. The method of claim 11 , and further comprising:
stopping motion of the screen pointer when the pointing object is replaced on the touch-sensitive surface.
20. A computer-readable medium having computer-executable instructions for performing a method of generating movement data for controlling a position of a screen pointer for an electronic device having a display and a touchpad, the touchpad generating position data indicative of positions of a pointing object on a touch-sensitive surface of the touchpad, comprising:
identifying when a loss of contact occurs between the pointing object and the touch-sensitive surface;
receiving a flint set of movement data, the first set of movement data indicative of relative movement between the pointing object and the touch-sensitive surface prior to the loss of contact; and
generating a second set of movement data based on the first set of movement data when a loss of contact occurs between the pointing object and the touch-sensitive surface, the second set of movement data causing an acceleration of the screen pointer followed by a gradual decrease in a velocity of the screen pointer.