Wireless input device, for use with a computer, employing a movable light-emitting element and a stationary light-receiving element

• US 5,945,981 A
• Filed: 07/29/1997
• Issued: 08/31/1999
• Est. Priority Date: 11/17/1993
• Status: Expired due to Term

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Aoyagi, Tetsuji, Paull, Mike M., Sanchez, Russell I., Svancarek, Mark K.
• Primary Examiner(s): NGUYEN, CHANH DUY
• Application Number:
  US08/901,878
• Time in Patent Office: 763 Days
• Field of Search: 345/156, 345/157, 345/158, 345/175, 345/176, 345/179, 345/180, 345/182, 345/166, 250/221, 178/18.01, 178/18.03, 178/18.1, 178/18.09, 178/19.01, 341/20, 341/21
• US Class Current: 345/180
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/0425 using a single imaging device like a video camera for tracking the absolute position of a single or a plurality of objects with respect to an imaged reference surface, e.g. video camera imaging a display or a projection screen, a table or a wall surface, on which a computer generated image is displayed or projected tracking a projected light spot to determine a position on a display surface G06F3/0386

Abstract

The wireless computer input system uses a pen-type input device and a receiver. The pen-type input device includes an LED, at least one switch, a rechargeable battery, and a control circuit. The control circuit provides signals to the LED upon activation of the switch, and provides for power management functions allowing the pen to conserve power during idle periods. The receiver includes one or more light-detecting elements connected to position computation circuitry. The light-detecting element or elements are either a two-dimensional PSD, two one-dimensional PSDs or a four division photodiode. Optional lenses, optical filters, and apertured plates are positioned before the light-detecting element(s), improving the signal-to-noise ratio of the system. The computation circuitry receives the signals from the light-detecting element(s), digitizes them, and computes the coordinates of the pen which are output to a host computer. A recharging circuit, connected to the computation circuit, allows the pen to be recharged within the receiver or connected by a cord when the battery lacks sufficient power.

Claims

1. A wireless computer input system for a computer comprising:

a hand-held pen having a single light-emitting element capable of emitting light;

an optical receiver having a single light-detecting element, the receiver forming and detecting the light emitted by the single light-emitting element as a single incident light spot and producing simultaneously a plurality of output signals, wherein the plurality of output signals have a proportional relationship corresponding to the x-axis and y-axis positions of the single light-emitting element of the hand-held pen on a work surface; and

a processing circuit coupled to the single light-detecting element and adapted to receive the plurality of output signals from the receiver and calculate x-axis and y-axis position coordinates corresponding to the two-dimensional position of the single light-emitting element on the work surface based on the position of the single light spot on the single light-detecting element.

2. The wireless computer input system according to claim 1 wherein the single light-detecting element is a position sensing device and wherein the output signals includes x and y position signals.

3. The wireless computer input system according to claim 2 wherein the optical receiver further includes an optical filter and an apertured plate positioned between the pen and the single light-detecting element.

4. The wireless computer input system according to claim 3 wherein the optical receiver includes a frame for fixedly holding the single light-detecting element and the apertured plate, the frame composed of a material capable of eliminating noise.

5. The wireless computer input system according to claim 2, further comprising a housing for supporting and selectively positioning the optical receiver in a first position wherein the optical receiver is positioned at a selected height from a surface and at a first selected angle toward the surface, and wherein the processing circuit is adapted to calculate coordinates on the basis of the selected height and the first selected angle with respect to the surface when the optical receiver is in the first position.

6. The wireless computer input system according to claim 5 wherein the first selected angle is approximately 45°

.

7. The wireless computer input system according to claim 5 wherein the optical receiver can be selectively positioned in a second position wherein the optical receiver is positioned at a second selected angle from the surface.

8. The wireless computer input system according to claim 7 wherein the second selected angle is approximately 90°

.

9. The wireless computer input system according to claim 1, further comprising a portable work surface adapted to selectably receive the optical receiver.

10. The wireless computer input system according to claim 9 wherein the portable work surface includes a flat panel display.

11. The wireless computer input system according to claim 1 wherein the pen includes a first switch adapted to cause the light-emitting element to emit the light, and the light-emitting element is adapted to emit the light in a fan-like dispersion.

12. The wireless computer input system according to claim 11 wherein the first switch is a motion-detecting switch and wherein the pen includes a second switch positioned at a tip of the pen.

13. The wireless computer input system according to claim 11 wherein the pen includes a housing, the first switch positioned within a recessed region on the housing, the recessed region adapted to receive the tip of a user'"'"'s finger.

14. The wireless computer input system according to claim 1 wherein the pen includes a motion-detecting switch, a control circuit coupled to the motion-detecting switch and to the light-emitting element, and a power supply coupled to the control circuit, wherein the control circuit is adapted to produce data pulses, the data pulses modulated with the emitted light.

15. The wireless computer input system according to claim 14, further comprising a charging circuit coupled to the processing circuit and recharging contacts electrically coupled to the charging circuit, and a housing for receiving the optical receiver, the processing circuit and the charging circuit, the housing having a bore adapted to receive the pen and the recharging contacts located within the bore, wherein the power supply is a rechargeable power supply, and wherein the pen includes electrical contacts, the electrical contacts capable of electrically coupling with the recharging contacts when the pen is inserted in the bore for permitting the charging circuit to recharge the power supply.

16. The wireless computer input system according to claim 15, further comprising a cord electrically coupled to the charging circuit, the cord adapted to electrically couple with the electrical contacts so as to supply power to the pen when the power supply lacks sufficient power.

17. The wireless computer input system according to claim 1 wherein the processing circuit includes at least one analog to digital converter adapted to receive the output signal and produce a digital output signal, and a central processing unit adapted to receive the digital output signal and calculate position coordinates.

18. The wireless computer input system according to claim 17 wherein the processing circuit includes a filter circuit coupled to the single light-detecting element and a multiplexer circuit coupled in series between the filter circuit and the analog to digital converter.

19. The wireless computer input system according to claim 1 wherein the processing circuit includes at least one analog to digital converter adapted to receive the output signal and produce a digital signal, and a digital signal processing circuit adapted to receive the digital signal and calculate position coordinates.

20. The wireless computer input system according to claim 1 wherein the optical receiver is positioned within and extends without a housing of a visual display device.

21. The wireless computer input system according to claim 1, further comprising a housing for supporting and selectively positioning the optical receiver in a plurality of heights from a supporting surface upon which the housing rests, and wherein the processing circuit is adapted to coordinate on the basis of the selected plurality of heights.

22. The wireless computer input system according to claim 1 wherein the light-detecting element is a four division photodiode.

23. The wireless computer input system according to claim 1 wherein the processing circuit simultaneously processes the plurality of output signals from the receiver to calculate x-axis and y-axis position coordinates.

24. The wireless computer input system according to claim 1 wherein the processing circuit serially processes the plurality of output signals from the receiver to calculate x-axis and y-axis position coordinates.

25. A receiver for use in a wireless computer input system, wherein the computer input system provides signals to a computer having a display screen, and wherein the wireless computer input system includes an input device for producing light, and usable on a work surface, the receiver comprising:

an optical receiver having at least one light detecting element, the optical receiver receiving the produced light as at least one spot of light and generating signals in response to a position of the spot of light produced on the light-detecting element;

a frame positionable on the work surface and having a base portion and a portion extending vertically from the base portion, the vertically extending portion receiving the optical receiver, the frame supporting the light detecting element in position over the work surface and at an angle down toward the worksurface wherein the angle is neither 0°

nor 90°

with respect to the worksurface, wherein the vertically extending portion extends a distance, above the work surface, that is greater than a height of the optical receiver, and wherein the work surface differs from the display screen;

a filter circuit coupled to the optical receiver to filter the generated signals and produce a filtered signal;

an analog to digital converter coupled to the filter circuit to convert the filtered signal to a digital signal; and

a processor circuit coupled to the analog to digital converter to convert the digital signal to a coordinate signal representing a two-dimensional position of the input device based on the position of the spot of light produced on the light-detecting element.

26. The receiver according to claim 25, further comprising a plurality of analog to digital converters coupled in parallel between the filter circuit and the processor circuit, and wherein the filter circuit includes a programmable gain amplifier.

27. The receiver according to claim 25 further comprising an amplifier coupled between the at least one light-detecting element and the filter circuit, and wherein the at least one light-detecting element is a position sensing device.

28. The receiver according to claim 25 wherein the optical receiver includes a plurality of light-detecting elements and a plurality of optical elements positioned between the light-detecting elements and the input device, the optical elements adapted to receive the light and produce spots of light on the plurality of light-detecting elements, the plurality of light-detecting elements capable of generating the signals in response to the received spots of light, and wherein the plurality of light-detecting elements are position-sensing devices.

29. The receiver according to claim 25 wherein the plurality of light-detecting elements are three position sensing devices, and the coordinate signal represents the three-dimensional position of the input device.

30. The receiver according to claim 28 wherein the frame is positionable at an edge of the work surface and supports and selectively positions the optical receiver in a first position wherein the optical receiver is positioned at a selected height over the work surface and at a first selected angle toward the work surface.

31. The receiver according to claim 30 wherein the optical receiver is selectively positionable in a second position at a second selected angle away from the work surface.

32. In a wireless computer input system having a pen capable of emitting light, and a receiver adapted to receive the light and produce an output signal for a computer having a display screen, a method of computing the coordinates of the pen comprising:

emitting light by the pen from a single light-emitting element;

positioning a light-detecting element at a selected height above a work surface and at an angle down toward the worksurface, wherein the angle is neither 0°

nor 90°

with respect to the worksurface, wherein the selected height is greater than a height of the single light detecting element, and wherein the work surface differs from the display screen;

producing a light spot from the single light-emitting element whose point of incidence on the light detecting element corresponds to a two-dimensional position of the pen;

generating a digital signal corresponding to the two-dimensional position of the light spot on the light detecting element;

computing a coordinate signal corresponding to the digital signal; and

outputting the coordinate signal to a computer.

33. The method according to claim 32 wherein the receiver is adapted to receive a data signal selectively produced by the pen, the method further comprising the steps of determining if the data signal is produced by the pen, and outputting the data signal to the computer.

34. The method according to claim 32 wherein the receiver is capable of being oriented in first and second positions, the method further comprising the step of determining whether the receiver is in the second position.

35. The method of claim 32, further comprising:

receiving, at the light-detecting element, the light spot from the single light-emitting element of the pen at an angle of incidence directed upwardly from the work surface.

36. The method of claim 32, further comprising:

receiving, at the light-detecting element, the light spot from the single light-emitting element of the pen as a non-horizontal ray of light, wherein the non-horizontal ray of light is non-horizontal with respect to the work surface.

37. A wireless computer input system for a computer comprising:

a hand-held pen having a single light-emitting element capable of emitting light;

an optical receiver having a light-detecting element, the receiver forming and detecting the light emitted by the light-emitting element as a single incident light spot and producing at a single sampling interval a plurality of output signals corresponding to a two-dimensional position of the single light spot on the light-detecting element; and

a processing circuit coupled to the light-detecting element and adapted to receive the output signals from the receiver and calculate two-dimensional position coordinates corresponding to the two-dimensional position of the single light-emitting element on the work surface based on the two-dimensional position of the single light spot on the light-detecting element.

38. The wireless computer input system according to claim 37 wherein the light-detecting element is a single position sensing device and wherein the output signals includes x and y position signals.

39. The wireless computer input system according to claim 37 wherein the light-detecting element is a four-position photodiode.

40. The wireless computer input system according to claim 37 wherein the optical receiver further includes an optical filter and an apertured plate positioned between the pen and the light-detecting element.

41. The wireless computer input system according to claim 37, further comprising a housing for supporting and selectively positioning the optical receiver in a first position wherein the optical receiver is positioned at a selected height from a surface and at a first selected angle toward the surface, and wherein the processing circuit is adapted to calculate coordinates on the basis of the selected height and the first selected angle with respect to the surface when the optical receiver is in the first position.

42. The wireless computer input system according to claim 37, further comprising a portable work surface adapted to selectably receive the optical receiver.

43. The wireless computer input system according to claim 37 wherein the pen includes a first switch adapted to cause the light-emitting element to emit the light, and the light-emitting element is adapted to emit the light in a fan-like dispersion.

44. The wireless computer input system according to claim 37 wherein the first switch is a motion-detecting switch and wherein the pen includes a second switch positioned at a tip of the pen.

45. The wireless computer input system according to claim 37 wherein the pen includes a motion-detecting switch, a control circuit coupled to the motion-detecting switch and to the light-emitting element, and a power supply coupled to the control circuit, wherein the control circuit is adapted to produce data pulses, the data pulses modulated with the emitted light.

46. The wireless computer input system according to claim 37, further comprising a charging circuit coupled to the processing circuit and recharging contacts electrically coupled to the charging circuit, and a housing for receiving the optical receiver, the processing circuit and the charging circuit, the housing having a bore adapted to receive the pen and the recharging contacts located within the bore, wherein the power supply is a rechargeable power supply, and wherein the pen includes electrical contacts, the electrical contacts capable of electrically coupling with the recharging contacts when the pen is inserted in the bore for permitting the charging circuit to recharge the power supply.

47. The wireless computer input system according to claim 37 wherein the optical receiver is positioned within and extends without a housing of a visual display device.

48. The wireless computer input system according to claim 37, further comprising a housing for supporting and selectively positioning the optical receiver in a plurality of heights from a supporting surface upon which the housing rests, and wherein the processing circuit is adapted to coordinate on the basis of the selected plurality of heights.

49. The wireless computer input system according to claim 37 wherein the processing circuit simultaneously processes the output signals from the receiver to calculate two-dimensional position coordinates.

50. The wireless computer input system according to claim 37 wherein the processing circuit serially processes the output signals from the receiver to calculate two-dimensional position coordinates.