Wireless display systems and stylii

• US 20040169644A1
• Filed: 03/05/2004
• Published: 09/02/2004
• Est. Priority Date: 12/29/2000
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Xu, Jianping, Hunt, Stephen H.
• Granted Patent: US 7,248,251 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/0433 in which the acoustic waves are either generated by a movable member and propagated within a surface layer or propagated within a surface layer and captured by a movable member

Abstract

A wireless coordinate input system for a display system includes a stylus that transmits ultrasonic energy to a plurality of ultrasonic receiving stations in a projection plane. In an embodiment, the stylus may include one ultrasonic transmitter used for determination of three-dimensional coordinates of the stylus relative to the projection plane. The stylus may also include a second ultrasonic transmitter controlled by a pressure-activated switch. When the stylus is pressed against the projection plane, the second transmitter turns on and is used for determination of two-dimensional coordinates of the stylus in the projection plane. The stylus may also include a higher frequency burst transmitter used to generate a time reference. One or more of the ultrasonic receiving stations may also include an ultrasonic transmitter for calibration.

Claims

1. A stylus comprising:

a stylus tip;

a first ultrasonic transmitter controllable by application of pressure to the stylus tip;

a second ultrasonic transmitter; and

a first switch to control the second ultrasonic transmitter.

2. The stylus of claim 1 wherein the first and second ultrasonic transmitters are to emit ultrasonic energy at different frequencies.

3. The stylus of claim 2 wherein the first and second ultrasonic transmitters are to emit ultrasonic energy between substantially forty kilohertz and eighty kilohertz.

4. The stylus of claim 1 wherein the first and second ultrasonic transmitters are to emit ultrasonic energy at the same frequency.

5. The stylus of claim 1 further comprising a pressure-activated switch coupled to the stylus tip, wherein the pressure-activated switch is operable to turn on the first ultrasonic transmitter when pressure is applied to the stylus tip.

6. The stylus of claim 5 further comprising a higher frequency transmitter to provide a time reference for the first and second ultrasonic transmitters, wherein the higher frequency transmitter is controllable by one of the first switch and the pressure-activated switch.

7. The stylus of claim 1 wherein the first ultrasonic transmitter is located at the stylus tip, and wherein the first ultrasonic transmitter comprises a polymer.

8. The stylus of claim 1 wherein the first ultrasonic transmitter is located at the stylus tip, wherein the first ultrasonic transmitter is cylindrical and formed of a polymer material, and wherein the first ultrasonic transmitter is to transmit omni-directional ultrasonic energy.

9. The stylus of claim 1 wherein the second ultrasonic transmitter is located at an end of the stylus opposite the tip, and wherein the second ultrasonic transmitter comprises a piezoelectric material.

10. The stylus of claim 1 wherein the second ultrasonic transmitter is located at an end of the stylus opposite the tip, and wherein the second ultrasonic transmitter comprises a plurality of semi-hemispherical discs of piezoelectric material.

11. The stylus of claim 1 further comprising a higher frequency transmitter to provide a time reference for the first and second ultrasonic transmitters.

12. The stylus of claim 11 wherein the higher frequency transmitter comprises one of a radio frequency transmitter and an infrared transmitter.

13. The stylus of claim 11 wherein the first and second ultrasonic transmitters and the higher frequency transmitter are burst transmitters.

14. The stylus of claim 13 wherein the first and second ultrasonic transmitters are to transmit bursts between 50 and 100 pulses/second.

15. The stylus of claim 11, wherein the stylus is to use with a wireless display system having a projection plane and at least three ultrasonic receivers, wherein the first ultrasonic transmitter is to transmit ultrasonic energy to at least two of the ultrasonic receivers in determining a position of the stylus relative to the projection plane in two dimensions, wherein the second ultrasonic transmitter is to transmit ultrasonic energy to at least three ultrasonic receivers in determining a position of the stylus relative to the projection plane in three dimensions, wherein at least one of the ultrasonic receivers includes a higher frequency receiver, and wherein the higher frequency transmitter is to transmit one of radio frequency energy and infrared energy to the higher frequency receiver.

16. The stylus of claim 1, wherein the stylus is to use with a wireless display system having a projection plane and at least three ultrasonic receivers, wherein the first ultrasonic transmitter is to transmit ultrasonic energy to at least two of the ultrasonic receivers in determining a position of the stylus relative to the projection plane in two dimensions, and wherein the second ultrasonic transmitter is to transmit ultrasonic energy to at least three ultrasonic receivers in determining a position of the stylus relative to the projection plane in three dimensions.

17. A wireless display system comprising:

a first ultrasonic receiver mountable on a projection surface;

a second ultrasonic receiver mountable on the projection surface a distance from the first ultrasonic receiver; and

an ultrasonic transmitter mountable on the projection surface to transmit ultrasonic energy to at least one of the first ultrasonic receiver and the second ultrasonic receiver.

18. The wireless display system of claim 17, wherein the projection surface is one of a wall and a screen.

19. The wireless display system of claim 17 wherein the ultrasonic transmitter is co-located with the first ultrasonic receiver.

20. The wireless display system of claim 17 wherein at least one of the first and second ultrasonic receivers is to calculate time of arrival information.

21. The wireless display system of claim 17 further comprising a computer coupled to the first and second ultrasonic receivers.

22. The wireless display system of claim 21 wherein the computer is coupled to the first and second ultrasonic receivers via a wireless interface.

23. The wireless display system of claim 22 wherein the wireless interface comprises a processor to calculate time of arrival difference information.

24. The wireless display system of claim 21 wherein the computer is to calculate the distance between the first and second ultrasonic receivers.

25. The wireless display system of claim 21 further comprising a projection system responsive to the computer to project an image on the projection surface.

26. The wireless display system of claim 17 further comprising a stylus to transmit ultrasonic energy to the first and second ultrasonic receivers.

27. The wireless display system of claim 17 wherein the first ultrasonic receiver includes circuitry to receive energy at more than one ultrasonic frequency.

28. The wireless display system of claim 17 further comprising a radio frequency transmitter, wherein the radio frequency transmitter is co-located with the ultrasonic transmitter.

29. The wireless display system of claim 28 further comprising a radio frequency receiver, wherein the radio frequency receiver is co-located with the first or second ultrasonic receiver.

30. The wireless display system of claim 17 further comprising a third ultrasonic receiver mountable on the projection surface, and wherein the ultrasonic transmitter is to transmit ultrasonic energy to at least one of the first ultrasonic receiver, the second ultrasonic receiver, and the third ultrasonic receiver.

31. The wireless display system of claim 30 further comprising a computer coupled to the first, second, and third ultrasonic receivers.

32. The wireless display system of claim 31 further comprising a projection system responsive to the computer to project an image on the projection surface.

33. The wireless display system of claim 30 further comprising a stylus to transmit ultrasonic energy to the first, second, and third ultrasonic receivers.

34. The wireless display system of claim 30 wherein the first ultrasonic receiver includes circuitry to receive energy at more than one ultrasonic frequency.

35. The wireless display system of claim 30 further comprising a radio frequency transmitter, wherein the radio frequency transmitter is co-located with the ultrasonic transmitter.

36. The wireless display system of claim 35 further comprising a radio frequency receiver, wherein the radio frequency receiver is co-located with the first or second ultrasonic receiver.

37. A wireless display system comprising:

a rear-projection screen comprising a viewable surface to display information for viewing;

a first ultrasonic receiver mountable on the viewable surface;

a second ultrasonic receiver mountable on the viewable surface a distance from the first ultrasonic receiver; and

a stylus with at least one ultrasonic transmitter to transmit ultrasonic energy to the first and second ultrasonic receivers.

38. The wireless display system of claim 37 wherein the at least one ultrasonic transmitter is controllable by application of pressure to a tip of the stylus upon the viewable surface.

39. The wireless display system of claim 37 wherein at least one of the first and second ultrasonic receivers is to calculate time of arrival information.

40. The wireless display system of claim 37 further comprising a computer coupled to the first and second ultrasonic receivers.

41. The wireless display system of claim 40 wherein the computer is coupled to the first and second ultrasonic receivers via a wireless interface.

42. The wireless display system of claim 41 wherein the wireless interface comprises a processor to calculate time of arrival difference information.

43. The wireless display system of claim 40 wherein the computer is to calculate the distance between the first and second ultrasonic receivers.

44. The wireless display system of claim 40 further comprising a projection system responsive to the computer to project an image onto the rear-projection screen for viewing on the viewable surface.

45. The wireless display system of claim 37 wherein the stylus further comprises a radio frequency transmitter.

46. The wireless display system of claim 45 further comprising a radio frequency receiver, wherein the radio frequency receiver is co-located with the first or second ultrasonic receiver.

47. A wireless display system comprising:

a first ultrasonic receiver mountable on a projection surface of a wall;

a second ultrasonic receiver mountable on the projection surface a distance from the first ultrasonic receiver; and

a stylus with at least one ultrasonic transmitter to transmit ultrasonic energy to the first and second ultrasonic receivers.

48. The wireless display system of claim 47 wherein the at least one ultrasonic transmitter is controllable by application of pressure to a tip of the stylus upon the projection surface.

49. The wireless display system of claim 47 wherein at least one of the first and second ultrasonic receivers is to calculate time of arrival information.

50. The wireless display system of claim 47 further comprising a computer coupled to the first and second ultrasonic receivers.

51. The wireless display system of claim 50 wherein the computer is coupled to the first and second ultrasonic receivers via a wireless interface.

52. The wireless display system of claim 51 wherein the wireless interface comprises a processor to calculate time of arrival difference information.

53. The wireless display system of claim 50 wherein the computer is to calculate the distance between the first and second ultrasonic receivers.

54. The wireless display system of claim 50 further comprising a projection system responsive to the computer to project an image onto the projection surface.

55. The wireless display system of claim 47 wherein the stylus further comprises a radio frequency transmitter.

56. The wireless display system of claim 55 further comprising a radio frequency receiver, wherein the radio frequency receiver is co-located with the first or second ultrasonic receiver.

57. A wireless display system comprising:

at least three ultrasonic receivers mountable at different locations on a projection surface; and

a stylus comprising a first ultrasonic transmitter to transmit ultrasonic energy to the ultrasonic receivers.

58. The wireless display system of claim 57 wherein the first ultrasonic transmitter is controllable by a user-operable switch on the stylus.

59. The wireless display system of claim 57 wherein the first ultrasonic transmitter is located at an end of the stylus opposite a tip of the stylus, and wherein the first ultrasonic transmitter comprises a plurality of semi-hemispherical discs of piezoelectric material.

60. The wireless display system of claim 57 wherein at least one of the ultrasonic receivers is to calculate time of arrival information.

61. The wireless display system of claim 57 further comprising a computer coupled to the ultrasonic receivers.

62. The wireless display system of claim 61 wherein the computer is coupled to the ultrasonic receivers via a wireless interface.

63. The wireless display system of claim 62 wherein the wireless interface comprises a processor to calculate time of arrival difference information.

64. The wireless display system of claim 61 wherein the computer is to determine position coordinates of the stylus relative to the projection surface.

65. The wireless display system of claim 64 further comprising a projection system responsive to the computer to project an image onto the projection surface.

66. The wireless display system of claim 64 wherein the stylus further comprises a second ultrasonic transmitter to transmit ultrasonic energy to the receivers, wherein the first and second ultrasonic transmitters are to transmit ultrasonic energy at different frequencies, wherein two-dimensional position coordinates of the stylus are to be determined when ultrasonic energy is received by the receivers at a first frequency, and wherein three-dimensional position coordinates of the stylus are to be determined when ultrasonic energy is received by the receivers at a second frequency.

67. The wireless display system of claim 57 wherein the stylus further comprises a second ultrasonic transmitter to transmit ultrasonic energy to the ultrasonic receivers, wherein the first and second ultrasonic transmitters are to transmit ultrasonic energy at the same frequency.

68. The wireless display system of claim 57 and further comprising a higher frequency receiver co-located with one of the ultrasonic receivers, and wherein the stylus further comprises a higher frequency transmitter to provide a time reference for the ultrasonic receivers.