Self-adjusting digital filter for smoothing computer mouse movement

• US 5,661,502 A
• Filed: 02/16/1996
• Issued: 08/26/1997
• Est. Priority Date: 02/16/1996
• Status: Expired due to Term

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: AST Research, Inc. (Samsung Electronics Co. Ltd.)
• Inventors: Cheng, Xuejiang
• Primary Examiner(s): Chow, Dennis-Doon
• Application Number:
  US08/602,967
• Time in Patent Office: 557 Days
• Field of Search: 345/145, 345/146, 345/157, 345/158, 345/167, 345/163, 345/164, 345/165, 345/166, 395/118, 341/22
• US Class Current: 345/159
• CPC Class Codes: G06F 3/038 Control and interface arrangements therefor, e.g. drivers or device-embedded control circuitry

Abstract

A self-adjusting digital filter for smoothing computer mouse movement is disclosed. In one embodiment, a user-selectable inertial constant is applied to all types of mouse movements regardless of whether the movement is fast or slow and corrected mouse position data, or coordinates, are computed using the current actual mouse coordinates and the previous corrected mouse coordinates as adjusted by the inertial constant. In an alternative embodiment, a speed sensitive inertial constant, the value of which is dependent upon the values of a user-selectable speed sensitivity constant, the inertial constant, and the speed of the mouse movement, is substituted for the inertial constant such that the amount of filtering that occurs is at least partially dependent on the speed of mouse movement.

Claims

1. In a computer comprising an input device for manipulating presentation of a pointer on a display, a computer program stored on a computer-readable medium for smoothing the movement of the pointer as presented on the display, the computer program comprising:

instructions for determining current device coordinates identifying a location on said display as indicated by a position of said input device;

instructions for determining previous device coordinates identifying a previous location of said pointer on said display;

instructions for determining a value of an inertial constant;

instructions for calculating corrected device coordinates using said current device coordinates, said previous device coordinates and said inertial constant; and

instructions for displaying said pointer on said display at a location identified by said corrected device coordinates;

wherein said value of said inertial constant is dependent upon a value of a constant indicative of a desired amount of speed sensitivity, the speed of movement of said input device, and a value of a constant indicative of a desired amount of filtering.

2. The computer program of claim 1 further comprising instructions for saving said corrected device coordinates as said previous device coordinates.

3. The computer program of claim 1 wherein said value of said constant indicative of a desired amount of speed sensitivity and said value of said constant indicative of a desired amount of filtering are user-selectable.

4. The computer program of claim 1 wherein said inertial constant is a speed sensitive inertial constant β

calculated using the following equation;

space="preserve" listing-type="equation">β

=α

(1-e.sup.-cs)

wherein c represents said constant indicative of a desired amount of speed sensitivity, s represents the speed of movement of said input device, and α

represents said constant indicative of a desired amount of filtering.

5. The computer program of claim 4 wherein said corrected device coordinates are calculated using the following equation:

space="preserve" listing-type="equation">(x,y).sub.corrected =(1-β

)(x,y).sub.current +β

(x,y).sub.previous

where (x,y)_corrected represents said corrected device coordinates, (x,y)_current represents said current device coordinates, and (x,y)_previous represents said previous corrected device coordinates.

6. The computer program of claim 1 wherein said computer program is incorporated into a device driver of said computer.

7. The computer program of claim 1 wherein said computer program is incorporated into an application program of said computer.

8. The computer program of claim 1 wherein said input device is one of a mouse, joystick, trackball or stylus.

9. In a computer comprising an input device for manipulating presentation of a pointer on a display, an apparatus for implementing a self-adjusting digital filter for smoothing the movement of the pointer as presented on the display, the apparatus comprising:

means for determining current device coordinates identifying a location on said display as indicated by a position of said input device;

means for determining previous device coordinates identifying a previous location of said pointer on said display;

means for determining a value of an inertial constant;

means for calculating corrected device coordinates using said current device coordinates, said previous device coordinates and said inertial constant; and

means for displaying said pointer on said display at a location identified by said corrected device coordinates;

wherein said value of said inertial constant is dependent upon a value of a constant indicative of a desired amount of speed sensitivity, the speed of movement of said input device, and a value of a constant indicative of a desired amount of filtering.

10. The apparatus of claim 9 further comprising means for saving said corrected device coordinates as said previous device coordinates.

11. The apparatus of claim 9 wherein said value of said constant indicative of a desired amount of speed sensitivity and said value of said constant indicative of a desired amount of filtering are user-selectable.

12. The apparatus of claim 9 wherein said inertial constant is a speed sensitive inertial constant β

calculated using the following equation;

space="preserve" listing-type="equation">β

=α

(1-e.sup.-cs)

wherein c represents said constant indicative of a desired amount of speed sensitivity, s represents the speed of movement of said input device, and α

represents said constant indicative of a desired amount of filtering.

13. The apparatus of claim 12 wherein said corrected device coordinates are calculated using the following equation:

space="preserve" listing-type="equation">(x,y).sub.corrected =(1-β

)(x,y).sub.current +β

(x,y).sub.previous

where (x,y)_corrected represents said corrected device coordinates, (x,y)_current represents said current device coordinates, and (x,y)_previous represents said previous corrected device coordinates.

14. The apparatus of claim 9 wherein said apparatus is incorporated into a device driver of said computer.

15. The apparatus of claim 9 wherein said apparatus is incorporated into an application program of said computer.

16. The apparatus in claim 9 wherein said input device is one of a mouse, joystick, trackball stylus.

17. In a computer comprising an input device for manipulating presentation of a pointer on a display, a method of smoothing the movement of the pointer as presented on the display, the method comprising:

determining current device coordinates identifying a location on said display as indicated by a position of said input device;

determining previous device coordinates identifying a previous location of said pointer on said display;

determining a value of an inertial constant;

calculating corrected device coordinates using said current device coordinates, said previous device coordinates and said inertial constant; and

displaying said pointer on said display at a location identified by said corrected device coordinates;

wherein said value of said inertial constant is dependent upon a value of a constant indicative of a desired amount of speed sensitivity, the speed of movement of said input device, and a value of a constant indicative of a desired amount of filtering.

18. The method of claim 17 further comprising saving said corrected device coordinates as said previous coordinates.

19. The method of claim 17 wherein said value of said constant indicative of a desired amount of speed sensitivity and said value of said constant indicative of a desired amount of filtering are user-selectable.

20. The method of claim 17 wherein said inertial constant is a speed sensitive inertial constant β

calculated using the following equation;

space="preserve" listing-type="equation">β

=α

(1-e.sup.-cs)

wherein c represents said constant indicative of a desired amount of speed sensitivity, s represents the speed of movement of said input device, and α

represents said constant indicative of a desired amount of filtering.

21. The method of claim 20 wherein said corrected device coordinates are calculated using the following equation:

space="preserve" listing-type="equation">(x,y).sub.corrected =(1-β

)(x,y).sub.current +β

(x,y).sub.previous

where (x,y)_corrected represents said corrected device coordinates, (x,y)_current represents said current device coordinates, and (x,y)_previous represents said previous corrected device coordinates.

22. The method of claim 17 wherein said input device is one of a mouse, joystick, trackball or stylus.