Using edges and corners for character input

• US 20040196256A1
• Filed: 03/29/2004
• Published: 10/07/2004
• Est. Priority Date: 04/04/2003
• Status: Active Grant

• Current Assignee: Carnegie Mellon University
• Original Assignee: Carnegie Mellon University
• Inventors: Myers, Brad A., Wobbrock, Jacob O.
• Granted Patent: US 7,729,542 B2
• Time in Patent Office: Days
• US Class Current: 345/156
• CPC Class Codes: G04G 21/08 Touch switches specially adapted for time-pieces
• CPC Class Codes: G06F 1/1626 with a single-body enclosure integrating a flat display, e.g. Personal Digital Assistants [PDAs]
• CPC Class Codes: G06F 1/163 Wearable computers, e.g. on a belt
• CPC Class Codes: G06F 1/169 the I/O peripheral being an integrated pointing device, e.g. trackball in the palm rest area, mini-joystick integrated between keyboard keys, touch pads or touch stripes G06F1/1643 takes precedence; constructional details of pointing devices G06F3/033
• CPC Class Codes: G06F 3/0233 Character input methods
• CPC Class Codes: G06F 3/04883 for inputting data by handwriting, e.g. gesture or text
• CPC Class Codes: G06F 3/04886 by partitioning the display area of the touch-screen or the surface of the digitising tablet into independently controllable areas, e.g. virtual keyboards or menus

Abstract

A new unistroke text entry method for handheld or wearable devices is designed to provide high accuracy and stability of motion. The user makes characters by traversing the edges and diagonals of a geometric pattern, e.g. a square, imposed over the usual text input area. Gesture recognition is accomplished not through pattern recognition but through the sequence of corners that are hit. This means that the full stroke path is unimportant and the recognition is highly deterministic, enabling better accuracy than other gestural alphabets. This input technique works well using a template with a square hole placed over a touch-sensitive surface, such as on a Personal Digital Assistant (PDA), and with a square boundary surrounding a joystick, which might be used on a cell-phone or game controller. Another feature of the input technique is that capital letters are made by ending the stroke in a particular corner, rather than through a mode change as in other gestural input techniques. Because of the rules governing abstracts, this abstract should not be used to construe the claims.

Claims

1. A character recognition method, comprising:

determining a sequence of corner hits within a guide; and

identifying a character based on said sequence of corner hits.

2. The method of claim 1 wherein each of said sequences of corner hits defines a single stroke, and wherein each single stroke is representative of one of a letter, number, punctuation or mode.

3. The method of claim 2 additionally comprising identifying a character as being upper case when said stroke representative of said character ends in a predetermined corner.

4. The method of claim 2 additionally comprising detecting loss of contact with a touch sensitive surface, said loss of contact indicating the end of a stroke.

5. The method of claim 2 additionally comprising detecting the actuation of a switch, said actuation indicating the end of a stroke.

6. The method of claim 2 additionally comprising detecting lack of movement of a joystick for a predetermined period of time, said lack of movement indicating the end of a stroke.

7. The method of claim 6 wherein said detecting lack of movement includes detecting the joystick at two identical positions within said predetermined period of time.

8. The method of claim 7 wherein said points correspond to center points.

9. The method of claim 1 wherein said identifying a character is comprised of comparing the determined sequence of corner hits to data representative of a plurality of stored sequences of corner hits, selecting one of the stored sequences of corner hits based on said comparing, and outputting a character linked to said selected one of said stored sequences of corner hits.

10. The method of claim 9 wherein said comparing includes comparing the determined sequence of corner hits to a library of stored sequences of corner hits which is representational of a printed alphabet.

11. The method of claim 9 additionally comprising changing the stored sequences of corner hits that are linked to each character.

12. The method of claim 11 wherein said changing includes providing one example of a sequence of corner hits and the character to which that sequence is to be linked.

13. The method of claim 1 additionally comprising varying the size of the corners.

14. The method of claim 13 wherein said varying the size includes decreasing the size of only certain corners.

15. The method of claim 13 wherein said varying the size includes decreasing the size of certain corners more than the size of other corners.

16. The method of claim 1 additionally comprising varying the shape of the corners.

17. A character recognition method, comprising:

determining a sequence of corner hits within a unistroke;

identifying a character based on said sequence of corner hits.

18. The method of claim 17 wherein each unistroke is representative of one of a letter, number, punctuation or mode.

19. The method of claim 18 additionally comprising identifying a character as being upper case when said unistroke representative of said character ends in a predetermined corner.

20. The method of claim 18 additionally comprising detecting loss of contact with a touch sensitive surface, said loss of contact indicating the end of a unistroke.

21. The method of claim 18 additionally comprising detecting the actuation of a switch, said actuation indicating the end of a unistroke.

22. The method of claim 18 additionally comprising detecting lack of movement of a joystick for a predetermined period of time, said lack of movement indicating the end of a stroke.

23. The method of claim 22 wherein said detecting lack of movement includes detecting the joystick at two identical positions within said predetermined period of time.

24. The method of claim 23 wherein said points correspond to center points.

25. The method of claim 17 wherein said identifying a character is comprised of comparing the determined sequence of corner hits to data representative of a plurality of stored sequences of corner hits, selecting one of the stored sequences of corner hits based on said comparing, and outputting a character linked to said selected one of said stored sequences of corner hits.

26. The method of claim 25 wherein said comparing includes comparing the determined sequence of corner hits to a library of stored sequences of corner hits which is representational of a printed alphabet.

27. The method of claim 25 additionally comprising changing the stored sequences of corner hits that are linked to each character.

28. The method of claim 27 wherein said changing includes providing one example of a sequence of corner hits and the character to which that sequence is to be linked.

29. The method of claim 17 additionally comprising varying the size of the corners.

30. The method of claim 29 wherein said varying the size includes decreasing the size of only certain corners.

31. The method of claim 29 wherein said varying the size includes decreasing the size of certain corners more than the size of other corners.

32. The method of claim 17 additionally comprising varying the shape of the corners.

33. A method of generating characters, comprising:

creating a stroke by striking a series of corners irrespective of the path between the corners; and

generating information indicative of the end of each stroke.

34. The method of claim 33 wherein said creating includes moving an object within a guide while the object is in contact with a touch sensitive surface, and wherein said generating includes lifting the object out of contact with the touch sensitive surface.

35. The method of claim 33 wherein said creating includes moving a joystick within a guide and wherein said generating includes activating a switch.

36. The method of claim 33 wherein said creating includes moving a joystick within a guide and wherein said generating includes returning the joystick to a predetermined position for a predetermined period of time.

37. The method of claim 33 wherein said creating a stroke includes creating a stroke from a library of strokes that is representational of a printed alphabet.

38. A memory carrying software which, when executed, performs a method comprising:

determining a sequence of corner hits within a guide; and

identifying a character based on said sequence of corner hits.

39. The memory of claim 38 wherein each of said sequences of corner hits defines a single stroke, and wherein each single stroke is representative of one of a letter, number, punctuation or mode.

40. The memory of claim 39 additionally comprising identifying a character as being upper case when said stroke representative of said character ends in a predetermined corner.

41. The memory of claim 39 additionally comprising detecting loss of contact with a touch sensitive surface, said loss of contact indicating the end of a stroke.

42. The memory of claim 39 additionally comprising detecting the actuation of a switch, said actuation indicating the end of a stroke.

43. The memory of claim 39 additionally comprising detecting lack of movement of a joystick for a predetermined period of time, said lack of movement indicating the end of a stroke.

44. The memory of claim 43 wherein said detecting lack of movement includes detecting the joystick at two identical positions within said predetermined period of time.

45. The memory of claim 44 wherein said points correspond to center points.

46. The memory of claim 38 wherein said identifying a character is comprised of comparing the determined sequence of corner hits to data representative of a plurality of stored sequences of corner hits, selecting one of the stored sequences of corner hits based on said comparing, and outputting a character linked to said selected one of said stored sequences of corner hits.

47. The memory of claim 46 wherein said comparing includes comparing the determined sequence of corner hits to a library of stored sequences of corner hits which is representational of a printed alphabet.

48. The memory of claim 46 additionally comprising changing the stored sequences of corner hits that are linked to each character.

49. The memory of claim 48 wherein said changing includes providing one example of a sequence of corner hits and the character to which that sequence is to be linked.

50. The memory of claim 38 additionally comprising varying the size of the corners.

51. The memory of claim 50 wherein said varying the size includes decreasing the size of only certain corners.

52. The memory of claim 50 wherein said varying the size includes decreasing the size of certain corners more than the size of other corners.

53. The memory of claim 38 additionally comprising varying the shape of the corners.