Transmitter pen location system

• US 6,414,673 B1
• Filed: 11/10/1998
• Issued: 07/02/2002
• Est. Priority Date: 11/10/1998
• Status: Expired due to Term

• Current Assignee: Luidia Incorporated (Luidia Global Co., Ltd.)
• Original Assignee: Tildenet, Inc.
• Inventors: Plotkin, Serge, Wood, Robert P., Harel, Jacob, Hou, Alfred Samson
• Primary Examiner(s): Liang, Regina
• Application Number:
  US09/189,299
• Time in Patent Office: 1,330 Days
• Field of Search: 178/19.01, 178/19.02, 178/18-1-, 178/18.09, 178/19.07, 345/157, 345/158, 345/173-175, 345/177-179, 345/183
• US Class Current: 345/173
• CPC Class Codes: G01S 5/20 Position of source determined by a plurality of spaced direction-finders
• CPC Class Codes: G01S 5/30 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: G06F 3/043 using propagating acoustic waves

Abstract

A transmitter pen location system is provided, in which a pen is adapted to send a repeated output signal to external receivers at two or more receiver locations, wherein the location of the pointing tip of the pen is determined in relation to the writing surface of a whiteboard. In one embodiment an output element, preferably an ultrasonic transducer, transmits a time dependent output signal from a single signal transmitter pen to two or more external receivers at two or more receiver locations. The direction of arrival of the output signal to each of the receiver locations is determined, and the pointing tip of the single transmitter pen is then determined, as the intersection of direction vectors from the pen to the external receivers. In another embodiment, the transducer transmits a time dependent output signal from the transmitter pen to three or more external receivers, wherein the received signal is processed to determine the time of arrival to each of the receivers, and the location of the pointing tip of the pen is determined as the calculated distance between the receivers. In another alternate embodiment having a dual signal transmitter pen, a third receiver located at a receiver location is used to determine the time of arrival of a secondary output signal, to determine the distance between the dual signal transmitter pen and the receiver location, while two or more receivers at the receiver location are used to determine the direction of arrival of the primary time dependent output signal. Alternative embodiments allow the transmission of supplementary information from the transmitter pen to the receivers, using waveshaping of the output signal.

Claims

1. A transmitter location system, comprising:

a plurality of receiver locations each having a plurality of external receivers;

a time dependent output signal comprising a shaped pulse waveform having consistently identifiable features being transmitted repeatedly from a movable transmitter to each of the plurality of external receivers;

means for determining a relative time of arrival for the time dependent output signal to reach each of the plurality of external receivers at each of the receiver locations, the determination comprising a comparison of the consistently identifiable features of the time dependent output signal at each of the external receivers at each of the plurality of receiver locations;

means for defining a direction between the movable transmitter and each of the plurality of receiver locations, the defined direction based upon the determined relative time of arrival for the time dependent signal to reach each of the plurality of external receivers at each of the receiver locations; and

means for determining location of the movable transmitter, based upon the direction from the movable transmitter to each of the plurality of receivers.

2. The transmitter location system of claim 1, wherein the output signal is an ultrasound signal.

3. The transmitter location system of claim 1, wherein the output signal contains encoded information regarding the movable transmitter.

4. The transmitter location system of claim 3, wherein the encoded information includes a determined color of the movable transmitter.

5. The transmitter location system of claim 3, wherein the encoded information includes a determined line width of the movable transmitter.

6. The transmitter location system of claim 3, wherein the encoded information includes a determined line style of the movable transmitter.

7. The transmitter location system of claim 3, wherein the encoded information includes a user identification of the movable transmitter.

8. A location system, comprising:

a surface having a writing area, a plurality of receiver locations each having a plurality of external receivers, and a signal processor;

a movable device adapted to be located within the writing area of the surface, the movable device adapted to send an output signal comprising a shaped pulse waveform having consistently identifiable features repeatedly from the movable device to each of the plurality of receiver locations; and

a signal processor connected to each of the plurality of external receivers, which processes the output signal to determine a phase difference of the output signal between each of the plurality of external receivers at each of the plurality of receiver locations, the determination comprising a comparison of the consistently identifiable features of the output signal at each of the external receivers at each of the plurality of receiver locations, to calculate direction of the movable device to each of the receiver locations based upon the determined phase difference at each of the plurality of receiver locations, and to determine the location of the movable device, based upon the calculated direction from the portable transmitter to each of the plurality of receiver locations.

9. The transmitter location system of claim 8, wherein the output signal is an ultrasonic output signal.

10. The location system of claim 8, wherein the output signal has a first signal state and a second signal state.

11. The location system of claim 10, wherein the movable device is located in a transmitter pen, wherein the first signal state corresponds to a pen up position of the transmitter pen, and wherein the second signal state corresponds to a pen down position of the transmitter pen.

12. The location system of claim 8, wherein the output signal contains encoded information regarding the movable device.

13. The location system of claim 12, wherein the encoded information includes a determined color of the movable device.

14. The location system of claim 12, wherein the encoded information includes a determined line width of the movable device.

15. The location system of claim 12, wherein the encoded information includes a determined line style of the movable device.

16. The location system of claim 12, wherein the encoded information includes a user identification of the movable device.

17. A process for calculating a location of a transmitter pen relative to a writing area of a surface, the process comprising:

sending an output signal comprising a shaped pulse waveform having consistently identifiable features from the transmitter pen to a plurality of receiver locations, each of the receiver locations having a plurality of external receivers;

determining a phase difference of the output signal between each of the plurality of external receivers at each of the plurality of receiver locations, the determination comprising a comparison of the consistently identifiable features of the output signal at each of the external receivers at each of the plurality of receiver locations;

determining a direction from the transmitter pen to each of the plurality of receiver locations based on the determined phase difference of the output signal at each of the receiver locations; and

determining the location of the transmitter pen based upon the determined direction from the transmitter pen to each of the plurality of receiver locations.

18. The process of claim 17, wherein the output signal is an ultrasonic output signal.

19. The process of claim 17, wherein the output signal has a first signal state and a second signal state.

20. The process of claim 19, wherein the first signal state corresponds to a pen up position of the transmitter pen, and wherein the second signal state corresponds to a pen down position of the transmitter pen.

21. The process of claim 17, wherein the output signal contains encoded information regarding the transmitter pen.

22. The process of claim 21, wherein the encoded information includes a determined color of the transmitter pen.

23. The process of claim 21, wherein the encoded information includes a determined line width of the transmitter pen.

24. The process of claim 21, wherein the encoded information includes a determined line style of the transmitter pen.

25. The process of claim 21, wherein the encoded information includes a user identification of the transmitter pen.

26. A transmitter location system, comprising:

at least three external receivers;

a time dependent output signal comprising a shaped pulse waveform having consistently identifiable features being transmitted repeatedly from a movable transmitter to each of the external receivers, wherein time to reach each of the external receivers defines a distance between the movable transmitter and each of the external receivers; and

means for determining location of the movable transmitter, based upon the distance between the movable transmitter and each of the external receivers, and a comparison of the consistently identifiable features between the output signal and a stored prior time dependent output signal.

27. The transmitter location system of claim 26, wherein the time dependent output signal is an ultrasound signal.

28. The transmitter location system of claim 26, wherein the time dependent output signal contains encoded information regarding the movable transmitter.

29. The transmitter location system of claim 28, wherein the encoded information includes a determined color of the movable transmitter.

30. The transmitter location system of claim 28, wherein the encoded information includes a determined line width of the movable transmitter.

31. The transmitter location system of claim 28, wherein the encoded information includes a determined line style of the movable transmitter.

32. The transmitter location system of claim 28, wherein the encoded information includes a user identification of the movable transmitter.

33. A location system, comprising:

a surface having a writing area, at least three external receivers, and a signal processor;

a movable device adapted to be located within the writing area of the surface, the movable device adapted to send a time dependent output signal comprising a shaped pulse waveform having consistently identifiable features repeatedly from the movable device to each of the external receivers; and

a signal processor connected to each of the external receivers, the signal processor determining distance between the movable device and the external receivers based on time of arrival of the output signal to the external receivers and a comparison of the consistently identifiable features between the output signal and a prior time dependent output signal, and determining the location of the movable device, based upon the calculated distance between the movable device and each of the external receivers.

34. The location system of claim 33, wherein the output signal is an ultrasonic output signal.

35. The location system of claim 33, wherein the output signal has a first signal state and a second signal state.

36. The location system of claim 35, wherein the movable device is located in a transmitter pen, wherein the first signal state corresponds to a pen up position of the transmitter pen, and wherein the second signal state corresponds to a pen down position of the transmitter pen.

37. The location system of claim 33, wherein the output signal contains encoded information regarding the movable device.

38. The location system of claim 37, wherein the encoded information includes a determined color of the movable device.

39. The location system of claim 37, wherein the encoded information includes a determined line width of the movable device.

40. The location system of claim 37, wherein the encoded information includes a determined line style of the movable device.

41. The location system of claim 37, wherein the encoded information includes a user identification of the movable device.

42. A process for calculating a location of a transmitter pen relative to a writing area of a surface, the process comprising:

sending a time-dependent output signal comprising a shaped pulse waveform having consistently identifiable features from the transmitter pen to at least three external receivers;

comparing the consistently identifiable features of the output signal received at each of the external receivers to the consistently identifiable features of a stored prior second output signal received at each of the external receivers to determine a time of arrival of the output signal at each of the external receivers;

determining a distance from the transmitter pen to each of the external receivers based on the determined time of arrival of the output signal at each of the external receivers; and

determining the location of the transmitter pen based upon the determined distance from the transmitter pen to each of the external receivers.

43. The process of claim 42, wherein the output signal is an ultrasonic output signal.

44. The process of claim 42, wherein the output signal has a first signal state and a second signal state.

45. The process of claim 44, wherein the first signal state corresponds to a pen up position of the transmitter pen, and wherein the second signal state corresponds to a pen down position of the transmitter pen.

46. The process of claim 42, wherein the output signal contains encoded information regarding the transmitter pen.

47. The process of claim 46, wherein the encoded information includes a determined color of the transmitter pen.

48. The process of claim 46, wherein the encoded information includes a determined line width of the transmitter pen.

49. The process of claim 46, wherein the encoded information includes a determined line style of the transmitter pen.

50. The process of claim 46, wherein the encoded information includes a user identification of the transmitter pen.

51. A location system between a movable device and a receiver location, comprising:

a first output signal having a first speed of propagation, the first output signal being transmitted repeatedly from the movable device to a plurality of first signal receivers at the receiver location, wherein time to reach each of the first signal receivers is dependent on a distance between the movable device and each of the plurality of first signal receivers;

a second output signal having a second speed of propagation different from the first speed of propagation of the first output signal, the second output signal being transmitted repeatedly from the movable device to a second signal receiver at the receiver location; and

means for determining location of the movable device, using the first output signal received at the plurality of first signal receivers to determine a direction of arrival of the first signal to the receiver location, and using the second output signal to calculate distance from the movable device to the receiver location.

52. The location system of claim 51, wherein the received first output signal is compared to a stored prior first output signal.

53. The location system of claim 51, wherein the means for determining location of the movable device uses a stored prior transmitted first output signal to calculate distance from the movable transmitter to each of the plurality of first signal receivers.

54. The location system of claim 51, wherein the means for determining location of the movable device is programmable.

55. The location system of claim 51, wherein the first output signal includes a repeatable feature, and wherein the means for determining location of the movable device compares the repeatable feature of the first output signal and a stored prior transmitted first output signal.

56. The location system of claim 51, wherein the means for determining location of the movable device normalizes the first output signal and a stored prior transmitted first output signal.

57. The location system of claim 51, wherein the second output signal is an electromagnetic output signal.

58. The location system of claim 51, wherein the second output signal is an infrared output signal.

59. The location system of claim 51, wherein the second output signal has a first signal state and a second signal state.

60. The location system of claim 59, wherein the movable device is a transmitter pen, wherein the first signal state corresponds to a pen up position of the transmitter pen, and wherein the second signal state corresponds to a pen down position of the transmitter pen.

61. The location system of claim 51, wherein the second output signal contains encoded information regarding the movable device.

62. The location system of claim 61, wherein the encoded information includes a determined color of the movable device.

63. The location system of claim 61, wherein the encoded information includes a determined line width of the movable device.

64. The location system of claim 61, wherein the encoded information includes a determined line style of the movable device.

65. The location system of claim 61, wherein the encoded information includes a user identification of the movable device.

66. The location system of claim 51, wherein the first output signal is an ultrasound transmission signal.

67. The location system of claim 51, further comprising:

a wireless connection between the receiver location and the means for determining location of the movable device.

68. The location system of claim 51, further comprising:

a defined functional area, whereby the movable device is selectively activated to send functions to a computer.

69. The location system of claim 51, wherein the first output signal contains encoded information regarding the movable device.

70. The location system of claim 69, wherein the encoded information includes a determined color of the movable device.

71. The location system of claim 69, wherein the encoded information includes a determined line width of the movable device.

72. The location system of claim 69, wherein the encoded information includes a determined line style of the movable device.

73. The location system of claim 69, wherein the encoded information includes a user identification of the movable device.

74. A process for calculating a location a movable device relative to a surface, the process comprising:

repeatedly sending a first output signal having a first speed of propagation from the movable device to at least two first signal receivers at a receiver location;

repeatedly sending a second output signal having a second speed of propagation different from the first speed of propagation of the first output signal from the movable device to a second signal receiver at the receiver location;

determining a distance from the movable device to the receiver location, based on a time of arrival of the second output signal at the second signal receiver, and a time of arrival of the first output signal to at least one of the first signal receivers at the receiver location;

determining a direction of arrival for the first output signal between the movable device and the receiver location, based on the time of arrival of the second output signal at each of the second signal receivers at the receiver location; and

calculating the location of the movable device, based upon the determined distance from the movable device to the receiver location, and upon the determined direction of arrival of the first output signal between the movable device and the receiver location.

75. The process of claim 74, further comprising the step of:

comparing the first output signal to a prior first output signal.

76. The process of claim 75, wherein the step of comparing compares the first output signal received at each of the plurality of first signal receivers to a plurality of stored prior first output signals received at each of the plurality of first signal receivers to calculate distance from the movable device to each of the plurality of first signal receivers.

77. The process of claim 75, wherein the step of comparing the first output signal and the stored prior first output signal is programmable.

78. The process of claim 75, wherein the first output signal and the stored prior said first output signal include a repeatable feature, and wherein the step of comparing compares the repeatable feature of the first output signal and the stored prior first output signal.

79. The process of claim 74, wherein the surface is a white board.

80. The process of claim 74, wherein the second output signal is an electromagnetic output signal.

81. The process of claim 74, wherein the second output signal is an infrared output signal.

82. The process of claim 74, wherein the second output signal has a first signal state and a second signal state.

83. The process of claim 82, wherein the first signal state corresponds to a pen up position of the movable device, and wherein the second signal state corresponds to a pen down position of the movable device.

84. The process of claim 74, wherein the second output signal contains encoded information regarding the movable device.

85. The process of claim 84, wherein the encoded information includes a determined color of the movable device.

86. The process of claim 84, wherein the encoded information includes a determined line width of the movable device.

87. The process of claim 84, wherein the encoded information includes a determined line style of the movable device.

88. The process of claim 84, wherein the encoded information includes a user identification of the movable device.

89. The process of claim 84, wherein the first output signal is an ultrasound transmission signal.

90. The process of claim 74, further comprising the step of:

providing a wireless connection between the receiver location and a signal processor.

91. The process of claim 74, further comprising the step of:

defining a functional area on the surface, whereby the movable device is selectively activated to send information to a computer.

92. The process of claim 74, wherein the first output signal contains encoded information regarding the movable device.

93. The process of claim 92, wherein the encoded information includes a determined color of the movable device.

94. The process of claim 92, wherein the encoded information includes a determined line width of the movable device.

95. The process of claim 92, wherein the encoded information includes a determined line style of the movable device.

96. The process of claim 92, wherein the encoded information includes a user identification of the movable device.