Computer input system and method of using same

• US 5,515,079 A
• Filed: 11/29/1993
• Issued: 05/07/1996
• Est. Priority Date: 11/07/1989
• Status: Expired due to Term

• Current Assignee: Straight Signals LLC (Intellectual Ventures LLC)
• Original Assignee: Proxima Corporation (Ask ASA)
• Inventors: Hauck, Lane
• Primary Examiner(s): Hjerpe, Richard
• Assistant Examiner(s): WU, XIAO MIN
• Application Number:
  US08/158,659
• Time in Patent Office: 890 Days
• Field of Search: 345/157, 345/156, 345/158, 345/162, 345/169, 345/180, 345/181, 345/182, 345/183, 348/734, 348/744, 356/375, 353/122, 353/28, 353/42-43, 434/323, 434/324, 434/337
• US Class Current: 345/157
• CPC Class Codes: G06F 3/0386 for light pen
• 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
• CPC Class Codes: H04N 9/3185 Geometric adjustment, e.g. keystone or convergence optical or mechanical adjustment of convergence H04N9/317; using scanning means H04N3/22; optical or mechanical adjustments of projectors not peculiar to the presence of an electronic spatial light modulator G03B21/14

Abstract

A computer input system for a computer generating images appearing on a screen. For the purpose of modifying the images appearing on the screen, a light generating device causes an auxiliary light image to appear on the screen. An image sensor responds to the auxiliary image, and a circuit responds to the sensor for causing auxiliary image information to be stored concerning the auxiliary light image. Another circuit responds to the stored auxiliary image information to supply the auxiliary light image information to the computer for utilization therein.

Claims

1. An interactive optical input system for position control of equipment produced images, said equipment produced images including information images, comprising:

visualization projection means for causing an equipment produced image to be projected onto a remote viewing surface;

means for generating a position control image upon said surface;

light sensing means for scanning the equipment produced image and the position control image on the remote viewing surface, said light sensing means including means for determining light sensing coordinate values for said position control image;

means for storing predetermined reference coordinate values;

signal processing means responsive to the predetermined reference coordinate values and to the determined light sensing coordinate values for the position control image for converting the light sensing coordinate values for said position control image to equipment coordinate values;

means responsive to said equipment coordinate values of the position control image for generating a signal indicative of a positioning control command when said position control image is sequenced on and off; and

whereby the command and the location of the position control image relative to said information image causes the equipment produced images to be modified.

2. An interactive optical input system according to claim 1, wherein the information images include menu images,

wherein said signal is further indicative of a positioning point command when said position control image is sequenced on and off, and

whereby the command and the location of the position control image relative to said menu images causes the equipment produced images to be modified.

3. An interactive optical input system according to claim 1, wherein the information images include button images,

wherein said signal is further indicative of a positioning click command when said position control image is sequenced on and off, and

whereby the command and the location of the position control image relative to said button images causes the equipment produced images to be modified.

4. An interactive optical input system according to claim 1 wherein said signal is further indicative of a positioning drag command when said position control image is sequenced on and off and

whereby the command and the location of the position control image relative to the equipment produced image causes the information image to be displayed at the location of the position control image.

5. An interactive optical input system according to claim 1, further including:

means for determining the corners of the equipment produced image; and

means responsive to said corner determining means for modifying the equipment produced image.

6. An input system according to claim 5 wherein the visualization projection means includes a computer means for generating the equipment produced image and wherein the modifying means includes another computer means for facilitating the modification of the equipment produced image.

7. An input system according to claim 5 wherein the visualization projection means further includes a liquid crystal display means for generating the equipment generated image to be projected.

8. An input system according to claim 5 wherein said position control image generating means includes

a wand means for generating a beam of light to produce the position control image on said surface.

9. An input system according to claim 5 wherein the light sensing means is a charge coupled device.

10. An input system according to claim 5 wherein the modifying means modifies the equipment produced image to provide selective ones of POINT, CLICK and DRAG subroutines.

11. An input system according to claim 1, further including:

means for determining if the position control image has been detected within a particular time, and

means responsive to said determining means for calibrating the operation of the light sensing means in sensing the position control image if the position control image has not been detected within the particular time.

12. An input system according to claim 11, further including:

means for providing a reference level for distinguishing the position control image from the equipment produced image,

the reference level means being responsive to the determinations from the calibrating means for adjusting the reference level if the position control image has not been detected within the particular time.

13. An input system according to claim 12 wherein

the position control image determining means provides a raster scan in a plurality of successive horizontal lines and wherein

the reference level means includes a means for initially providing a maximum level, then for providing a first particular level indicating the detection of light by the light sensing means, then for providing a second particular level indicating the detection of light in each of the successive horizontal lines and then for providing the reference level at a particular value between the first and second particular levels.

14. An input system according to claim 11, further including

means for determining the extremities of the equipment produced image to facilitate the conversion of the light sensing coordinate values to equipment coordinate values.

15. An interactive optical input system according to claim 1, further including:

means operatively coupled to the light sensing means for distinguishing the position control image from the equipment produced image

means for determining the coordinates of the boundaries of the equipment produced image sensed by the light sensing means and

means for converting the coordinates of the position control image in accordance with the coordinates of the boundaries of the equipment produced image.

16. An input system according to claim 15, further including

means responsive to the coordinates from the boundary determining means and the position control image converting means for modifying the equipment produced image.

17. An input system according to claim 16, wherein

the equipment produced image modifying means is operative to modify the equipment produced image to provide selective ones of POINT, CLICK and DRAG subroutines.

18. An input system according to claim 15, wherein the

equipment produced image modifying means is operatively coupled to the distinguishing means for preventing other data from being converted by said position control image converting means when the light sensing coordinate values determining means determines the coordinates of the position control image distinguished by the distinguishing means.

19. An interactive optical input system according to claim 1, further including:

means for distinguishing the position control image from the equipment produced image

means for determining the coordinates of the extremities of the equipment produced image; and

means responsive to the coordinates of the extremities for modifying the equipment produced image.

20. An input system according to claim 19, wherein

the modifying means is operative to modify the equipment produced image in accordance with selective ones of POINT, CLICK and DRAG subroutines.

21. An input system according to claim 19, further including

means for calibrating the operation of the distinguishing means when the distinguishing means does not distinguish the position control image from the equipment produced image within a particular period of time.

22. An input system according to claim 19, further including

means for preventing the extremity determining means from determining the coordinates of the extremities again, and for preventing the modifying means from modifying the equipment produced image in response to the position control image.

23. An input system according to claim 19, further including

means for verifying the coordinates of the extremities in accordance with the provision of the position control image at the extremities of the equipment produced image.

24. An input system according to claim 5, wherein said

position control image generating means includes means for providing the position control image on the surface.

25. An input system according to claim 11, wherein said

position control image generating means includes means for providing the position control image on the surface.

26. An input system according to claim 15, wherein said

position control image generating means includes means for providing the position control image on the surface.

27. An input system according to claim 19, wherein said

position control image generating means includes means for providing the position control image on the surface.

28. A method for controlling equipment produced images, said equipment produced images including information images, comprising:

projecting an equipment produced image onto a remote viewing surface for displaying the image thereon;

generating a position control image on said surface;

scanning the equipment produced image and the position control image on the remote viewing surface;

determining light sensing coordinate values for said position control image;

storing predetermined reference coordinate values;

responding to the predetermined reference coordinate values and to the determined light sensing coordinate values for the position control image by converting the light sensing coordinate values for said position control image to equipment coordinate values;

responding to said equipment coordinate values of the position control image for generating a signal indicative of a positioning control command when said position control image is sequenced on and off; and

whereby the command and the location of the position control image relative to said information image causes the equipment produced images to be modified.

29. A method according to claim 28, wherein the information images include menu images and said signal is further indicative of a positioning point command when said position control image is sequenced on and off, the method further including

causing the equipment produced images to be modified in response to the positioning point command and the location of the position control image relative to said menu images.

30. A method according to claim 28, wherein the information images include button images and said signal is further indicative of a positioning click command when said position control image is sequenced on and off, the method further including

causing the equipment produced images to be modified in response to the positioning click command and the location of the position control image relative to said button images.

31. A method according to claim 28, wherein said signal is further indicative of a positioning drag command when said position control image is sequenced on and off, the method further including

causing an information image to be displayed at the location of the control image in response to the positioning drag command and the location of the position control image.

32. A computer input system, comprising:

visual image projection means for causing a displayed calibration image to be projected onto a remote viewing surface, said calibration image including at least one high intensity reference area;

light sensing means for scanning the calibration image on the remote viewing surface and for determining light sensing coordinate values for said high intensity reference area;

means for converting the light sensing coordinate values for said high intensity reference area to equipment coordinate values for said high intensity reference area;

means for calculating scaling factors based on the light sensing coordinate values of the high intensity reference area with prestored reference coordinate values for said high intensity reference area;

means for storing said scaling factors; and

means responsive to the stored scaling factors for converting subsequently determined light sensing coordinate values to equipment coordinate values for said high intensity reference area during normal operation of the system.

33. A computer input system according to claim 32, wherein said visual image projection means includes display means.

34. A computer input system according to claim 33, wherein said visual image projection means further includes projection means for projecting the calibration image onto said remote viewing surface.

35. A computer input system according to claim 32, wherein said light sensing means is charge couple means.

36. An input system according to claim 32, wherein said light sensing means is charge couple means for generating a video signal indicative of the presence of said calibration image;

said charge couple means including signal level means for controlling generating a detection signal in response to said calibration image only; and

timing means for generating synchronizing signals to synchronize the detection signal with a series of recurring video signals for helping to calibrate the system.

37. A computer input system according to claim 35, wherein said charge couple means is a charge couple device.

38. A computer input system according to claim 32, further including:

image projecting equipment;

wherein said calibration image is defined by a plurality of X, Y equipment coordinate values;

said light sensing means including scanning means for generating a video signal including a horizontal scan line signal and a vertical scan line signal for helping to define a detected image defined by a plurality of x, y light sensing coordinate values;

said X, Y equipment coordinate values and said x, y light sensing coordinate values having substantially different values from one another;

signal processing means responsive to said video signal for generating data signals to be supplied to the equipment;

calibrating means for determining whether said signal processing means has been calibrated to generate as part of said data signals an equipment coordinate signal indicative of the X, Y equipment coordinate values of at least a portion of the calibration image generated by the equipment;

said calibrating means generating a calibration signal when it determines that said signal processing means has not been calibrated;

visual image corner intensification means for causing the luminance level to be intensified at each corner coordinate of the calibration image to a sufficient luminance level relative to the remaining portion of the calibration image so that only the luminance level of each respective corner of the calibration image is sufficient for causing said signal processing means to store x, y light sensing coordinate values for each one of the detected corner coordinates of the calibrated image;

wherein said means for calculating scaling factors is responsive to said stored x, y light sensing coordinate values and to said calibration signal for generating said scaling factors to convert x, y light sensing coordinate values to X, Y equipment coordinate values;

means for setting a calibration flag indicative that said scaling factors have been determined;

communication means responsive to said calibration flag for enabling said signal processing means to communicate to the computer that the calibration process is completed;

whereby the video signals received by said signal processing means, during each time frame interval after calibration process is completed, are scaled to X, Y equipment coordinate values and communicated to the equipment for visual image changing purposes.

39. A computer input system according to claim 38, further comprising:

signal conversion means responsive to said video signal for generating a reference signal, said signal conversion means being coupled to an adjustable reference voltage for causing said reference signal to be adjustable between a maximum value and a minimum value for calibrating purposes;

initialization means responsive to the equipment for generating a vertical retrace synchronizing flag signal for enabling said signal processing means to synchronize its operation during the occurrence of each vertical blanking interval associated with the calibration image;

comparator means responsive to said video signal and said reference signal for supplying an electrical signal to said signal processing means to facilitate the discrimination of said calibration image from background light;

position detector means responsive to said calibration signal and to said vertical retrace synchronizing flag signal for determining whether or not said electrical signal has been received by said signal processing means during any frame period between vertical blanking intervals, said electrical signal being indicative of the detection of light by said light sensing means;

detection adjustment means for generating an adjustment signal when it determines that said signal processing means has not received said electrical signal;

reference voltage adjustment means responsive to said adjustment signal to cause the adjustable reference voltage to be decreased a sufficient amount to enable said signal processing means to just detect light reflecting from said remote viewing surface;

said reference voltage adjustment means further including determination means for generating a saturation signal when a determination is made that said electrical signal is received by said signal processing means on every horizontal scan line of said light sensing means;

said saturation signal being indicative that the reference level voltage established by said reference voltage adjustment means is so low that all ambient light and all image light from the displayed visual image generated by the computer is detected for processing by said signal processing means;

said reference voltage adjustment means includes means for storing an initial reference voltage level signal indicative of that reference voltage level which is sufficient to enable said signal processing means to just process light reflecting from said remote viewing surface;

said reference voltage adjustment means further including means for storing a saturation reference voltage level signal indicative of that reference voltage level which is sufficient to enable said signal processing means to process light on every generated horizontal scan line of said light sensing means;

said reference voltage adjustment means further responsive to said saturation signal to cause the adjustable reference voltage to be decreased a sufficient amount to enable said signal processing means to process said electrical signal on every horizontal scan line of said light sensing means;

reference means responsive to said means for storing an initial reference voltage signal and to said means for storing a saturation voltage level signal for generating a detection signal indicative of a reference voltage level midway between said initial reference voltage signal and said saturation voltage level signal;

said detection signal having a value dependent upon ambient lighting conditions, projector lamp voltage, and light dispersion due to the distance between said light sensing means and the remote viewing surface;

said visual image projection means including auxiliary light generating means for causing said high intensity reference area to be superimposed on the calibration image generated by the equipment;

threshold means for causing said reference voltage adjustment means to generate a threshold voltage level signal indicative of a reference voltage value for enabling the signal processing unit to detect only light generated by said auxiliary light generating means; and

wherein said auxiliary light generating means is incandescent light generating means or infrared light generating means.

40. An input system according to claim 38, wherein said calibrating means comprises:

position detection means for establishing a horizontal position signal indicative of the width of the detected calibration image;

microprocessor means for establishing a vertical position signal indicative of the height of the detected calibration image and for scaling said horizontal position signal and said vertical position signal into a surface coordinate signal; and

said microprocessor means being electrically coupled to the equipment for permitting said microprocessor means to transfer said surface coordinate signal to the equipment.

41. An input system according to claim 40, wherein said position detecting means comprises:

horizontal counter means coupled to said timing generator for developing a horizontal coordinate reference data signal indicative of a pixel location of the detected calibration image; and

latching means for storing the horizontal position of the beginning of the detected calibration image in a given scan line and the horizontal position of the end of the detected calibration image in the same scan line.

42. An input system according to claim 39, wherein said auxiliary light generating means is a light emitting diode.

43. An input system according to claim 39, wherein said auxiliary light generating means is a laser pointer.

44. A input system according to claim 35, wherein said light sensing means is television camera means.

45. An optical input system according to claim 32, wherein said visual image projection means includes information projection means for projecting visual images onto the remote viewing surface, said visual images indicative of equipment information;

wherein said light sensing means generates an electrical signal indicative of equipment information;

signal conversion means responsive to said electrical signal for generating an information signal, said signal conversion means being coupled to a reference voltage for signal control purposes;

signal processing means coupled to said information signal for generating data control signals to be supplied to equipment to change the equipment information;

calibration means for determining whether said signal conversion means has been calibrated for system lighting conditions, said system lighting conditions including variable ambient lighting conditions, distance variables between said information projection means and the remote viewing surface, and variable background lighting conditions for the information projection means;

said calibration means generating a calibration signal when it determines that said signal conversion means has not been calibrated;

reference voltage adjustment means responsive to said calibration signal for automatically adjusting the potential level of said reference voltage for system lighting conditions so that information signals generated by said signal conversion means corresponds substantially to the equipment information supplied by the equipment;

means responsive to said reference voltage adjustment means for setting a calibration flag indicative that said signal conversion means has been calibrated; and

communication means responsive to said calibration flag for enabling said signal processing means to communicate said data control signals to said computer.

46. A computer input system according to claim 32, further including:

means for determining the coordinates of the extremities of the calibration image; and

means for verifying the coordinates of the extremities in accordance with the provision of the high intensity reference area at the extremities.

47. An input system according to claim 46, wherein the

calculating means is responsive to the coordinates of the extremities determined by the determining means for converting the light sensing coordinate values to equipment coordinate values.

48. An input system according to claim 46, further including:

means for providing a reference to help distinguish the high intensity reference area from the calibration image,

means for distinguishing the high intensity reference area from the calibration image in accordance with such reference, and

means for adjusting the reference when the distinguishing means fails to distinguish the high intensity reference area from the calibration image within a particular period of time.

49. An input system according to claim 48, wherein said visual image projection means further includes means for displaying an equipment produced image on said surface, the system further including

means for modifying the equipment produced image in accordance with the scaling factors.

50. A computer input system according to claim 32, further including:

means for providing a reference for distinguishing the high intensity reference area from the calibration image;

means for distinguishing the high intensity reference area from the calibration image; and

means for recalibrating the reference if the high intensity reference area is not distinguished from the calibration image within a particular time period.

51. An input system according to claim 49, wherein

the reference constitutes a first particular reference and wherein the determining means provides a scan in a plurality of horizontal lines progressively displaced in a vertical direction and wherein

the reference providing means includes means for determining a second particular level at which the light sensing means just senses light from the high intensity reference area and the calibration image, the determining means includes means for determining a third particular level at which the light sensing means senses light in every horizontal line in the scan, and wherein the reference providing means includes means for providing the first particular reference at a particular value between the second and third particular levels.

52. An input system according to claim 50, further including

means for determining the coordinates of the boundaries of the calibration image, and

means for converting the high intensity reference area coordinates in accordance with the calibration boundary coordinates.

53. An input system according to claim 51, further including

means for determining the coordinates of the boundaries of the calibration image,

means for converting the high intensity reference area coordinates in accordance with the calibration image coordinates, and

means for modifying the equipment produced image in accordance with the converted coordinates provided by the converting means.

54. A computer input system according to claim 32, further including:

means for distinguishing the high intensity reference area from the calibration image,

means for determining the coordinates of the extremities of the calibration image,

said light sensing coordinate converting means including means for converting the high intensity reference area coordinates in accordance with the coordinates of the calibration image extremities; and

means for inhibiting the converting of the high intensity reference area coordinates.

55. An input system according to claim 54, wherein said visual image projection means includes means for displaying an equipment produced image on said surface, the system further including

means for receiving the converted coordinates of the high intensity reference area and for modifying the equipment produced image in accordance with such converted coordinates.

56. An input system according to claim 54, further including

means for storing the determinations by the light sensing means of the coordinates of the high intensity reference area, and

means for clearing the determination storing means of any storage of coordinates upon the reception by the receiving means of the converted coordinates of the high intensity reference area.

57. An input system according to claim 54, further including

means for providing a reference level for distinguishing the high intensity reference area from the calibration image,

the light sensing means being operative to distinguish the high intensity reference area from the calibration image in accordance with the reference level, and

means for recalibrating the reference level when the distinguishing means fails to distinguish the high intensity reference area from the calibration image within a particular time interval.

58. An input system according to claim 56, further including

means for providing a first reference level above which light reflected from the surface is not sensed by the light sensing means and at which light is initially sensed by the light sensing means,

the light sensing means being operative to sense the calibration image and the high intensity reference area on consecutive lines,

means for scanning in the successive horizontal lines the calibration image and the high intensity reference area,

means for providing a second reference level at which light is detected in every horizontal line by the light sensing means,

means for providing a third reference level at a particular value between the first and second reference levels,

the distinguishing means being operative to distinguish the high intensity reference area from the calibration image in accordance with the third reference level.

59. An input system according to claim 58, further including

means for obtaining an operation of the first reference level means in providing the first reference level, the said reference level means in providing the second reference level and the third reference level means in providing the third reference level when the distinguishing means fails to distinguish the high intensity reference area from the calibration image within a particular time.

60. An input system according to claim 46, wherein said

visual image projection means includes means for providing the high intensity reference area on the surface.

61. An input system according to claim 50, wherein said

visual image projection means includes means for providing the high intensity reference area on the surface.

62. An input system according to claim 54, wherein said

visual image projection means includes means for providing the high intensity reference area on the surface.

63. An input system according to claim 32, further comprising:

light generating means for generating said high intensity reference area to illuminate a portion of said calibration image.

64. An input system according to claim 63, wherein said light sensing means is charge couple means for generating a video signal indicative of the presence of said high intensity reference area on the calibration image;

said charge couple means including signal level means for controlling generating a detection signal in response to said high intensity reference area only; and

timing means for generating synchronizing signals to synchronize the detection signal with a series of recurring video signals for helping to produce the calibration image.

65. An input system according to claim 63, further including video signal generating equipment to generate the calibration image, wherein said visual image projection means includes display means, said display means being electrically coupled to the video signal generating equipment for displaying the calibration image, said calibration image being produced by the video signal generating equipment.

66. A computer input system according to claim 65, wherein said display means is liquid crystal display means.

67. A computer input system according to claim 66, wherein said liquid crystal display means is a liquid crystal display panel.

68. A computer input system according to claim 65, wherein said display means is a video monitor.

69. An input system according to claim 65, wherein said visual image projection means further includes projection means for projecting the calibration image onto said viewing surface.

70. A computer input system according to claim 69, wherein said projection means is an overhead projector.

71. An input system according to claim 63, wherein said light generating means is infrared light generating means.

72. A computer input system according to claim 65, wherein said charge couple means is a charge couple device.

73. An input system according to claim 65, wherein said timing means includes:

a timing generator for producing said synchronizing signals;

a resonator for producing clock signals having a predetermined time interval; and

a high voltage drive electronic unit coupled to said timing generator for producing high voltage timing signals to drive said charge couple means.

74. An input system according to claim 73, wherein said predetermined time interval can be increased or decreased to increase or decrease the voltage level of said video signal;

and

wherein said charge couple means includes a video amplifier for generating said video signal.

75. An input system according to claim 74, wherein said means for converting includes:

position detecting means for establishing a horizontal position signal indicative of the width of the detected control image;

microprocessor means for establishing a vertical position signal indicative of the height of the detected control image and for scaling said horizontal position signal and said vertical position signal into a surface coordinate signal; and

said microprocessor means being electrically coupled to the video signal generating equipment for permitting said microprocessor means to transfer said surface coordinate signal to said video generating equipment.

76. An input system according to claim 63, wherein said light generating means is a light emitting diode.

77. An input system according to claim 63, wherein said light generating means is a laser pointer.

78. An input system according to claim 75, wherein said position detecting means comprises:

horizontal counter means coupled to said timing generator for developing a horizontal coordinate reference data signal indicative of a pixel location of the detected control image; and

latching means for storing the horizontal position of the beginning of the detected control image in a given scan line and the horizontal position of the end of the detected control image in the same given scan line.

79. A method of supplying input information to video signal producing means, comprising:

causing a displayed calibration image to be projected onto a remote viewing surface, said calibration image including at least one high intensity reference area;

scanning the calibration image on the remote viewing surface and determining light sensing coordinate values for said high intensity reference area;

converting the light sensing coordinate values for said high intensity reference area to equipment coordinate values for said high intensity reference area;

calculating scaling factors based on the light sensing coordinate values of the high intensity reference area with prestored reference coordinate values for said high intensity reference area;

storing said scaling factors; and

responding to the stored scaling factors by converting subsequently determined light sensing coordinate values to equipment coordinate values for said high intensity reference area during normal operation of the system.

80. A method according to claim 79, further including:

using an information projection means to project a visual image onto the remote viewing surface;

generating an electrical signal in response to the projected visual image indicative of equipment information;

using signal conversion means for generating an information signal, said signal conversion means being coupled to a reference voltage for signal control purposes;

generating data control signals to be supplied to equipment to change the equipment information;

determining whether said signal conversion means has been calibrated for system lighting conditions, said system lighting conditions including variable ambient lighting conditions, distance variables between the information projection means and the remote viewing surface, and variable background lighting conditions for the information projection means;

responding to said calibration signal for automatically adjusting the potential level of said reference voltage for system lighting condition so that the information signal generated by said signal conversion means corresponds substantially to the equipment information supplied by the equipment;

setting a calibration flag indicative that said signal conversion means has been calibrated; and

responding to said calibration flag for enabling said signal processing means to communicate said data control signals to said computer.

81. A method according to claim 79, further including:

sensing the calibration image and the high intensity reference area;

determining the coordinates of the boundaries of the calibration image; and

converting the coordinates of the high intensity reference area to the coordinates of the boundaries of the calibration image.

82. A method as set forth in claim 81, further including:

displaying an equipment generated image on the surface; and

modifying the equipment generated image in accordance with the converted coordinates of the high intensity reference area.

83. A method as set forth in claim 82, wherein

the equipment generated image is modified in accordance with POINT, DRAG and CLICK subroutines.

84. A method as set forth in claim 81 wherein

the high intensity reference area is distinguished from the calibration image after the high intensity reference area and the calibration image have been sensed and before the coordinates of the high intensity reference area are determined.

85. A method as set forth in claim 84 wherein

a reference level is provided to distinguish the high intensity reference area from the calibration image within a particular period of time after the calibration image and the high intensity reference area are sensed.

86. A method as set forth in claim 85 wherein

the reference level is recalibrated if the high intensity reference area is not distinguished from the calibration image within the particular period of time after the calibration image and the high intensity reference area are sensed.

87. A method according to claim 79, further including:

sensing the calibration image and the high intensity reference area;

providing a reference level to distinguish the high intensity reference area from the calibration image;

distinguishing the high intensity reference area from the calibration image in accordance with the reference level; and

recalibrating the reference level if the high intensity reference area is not distinguished from the calibration image within a particular time after the calibration image and the high intensity reference area are sensed.

88. A method as set forth in claim 87 wherein

the calibration image is formed in a plurality of lines in an image sensor, and

the reference level is determined by determining a first level at which any light in the image sensor is just able to be sensed and by determining a second level at which light is able to be sensed in each line in the image sensor and by providing the reference level at a particular value between the first and second levels.

89. A method as set forth in claim 88 wherein

the reference level is initially determined before the high intensity reference area is distinguished from the calibration image and wherein

the reference level is recalibrated when the high intensity reference area is not distinguished from the calibration image within a particular time after the initial calibration to determine the reference level.

90. A method as set forth in claim 87 wherein

the coordinates of the high intensity reference area are determined and the coordinates of the extremities of the calibration image are determined and an equipment generated image provided on the surface is modified in accordance with the positioning of the high intensity reference area relative to the extremities of the calibration image.

91. A method as set forth in claim 89 wherein

the coordinates of the high intensity reference area are determined and the coordinates of the boundaries of the calibration image are determined and the coordinates of the high intensity reference area are converted to the coordinates of the boundaries of the calibration image and an equipment generated image is modified in accordance with the converted coordinates of the high intensity reference area.

92. A method according to claim 79, further including:

sensing the calibration image and the high intensity reference area;

determining the coordinates of the boundaries of the calibration image;

providing the high intensity reference area at the corners of the boundaries of the calibration image; and

verifying the coordinates of the boundaries of the calibration image in accordance with the the high intensity reference area at the corners of the boundaries of the calibration image.

93. A method as set forth in claim 92, further including

converting the coordinates of the high intensity reference area in accordance with the determinations of the coordinates of the boundaries of the calibration image.

94. A method as set forth in claim 92, further including

modifying an equipment generated image provided on the surface in accordance with the converted coordinates of the high intensity reference area.

95. A method as set forth in claim 94 wherein

the modification of the equipment generated image provided on the surface include POINT, CLICK and DRAG subroutines.

96. A method as set forth in claim 92, further including:

providing a reference level to distinguish the high intensity reference area from the calibration image, and

calibrating the reference level if the high intensity reference area is not distinguished from the calibration image within a particular time.

97. A method according to claim 79, further including:

sensing the calibration image and the high intensity reference area;

distinguishing the high intensity reference area from the calibration image;

determining the coordinates of the corners of the calibration image;

determining the coordinates of the high intensity reference area; and

using the coordinates determined for the high intensity reference area and the corners of the calibration image to modify an equipment generated image displayed on the surface.

98. A method as set forth in claim 97, further including

disposing the high intensity reference area at the corners of the calibration image and determining the coordinates of the high intensity reference area at such positions to verify the coordinates determined for the corners of the calibration image.

99. A method as set forth in claim 97, further including:

providing a reference level,

using the reference level to distinguish the high intensity reference area from the calibration image, and

adjusting the reference level if the high intensity reference area is not distinguished from the calibration image within a particular time.

100. A method as set forth in claim 97, further including

inhibiting the conversion of any other coordinates after the high intensity reference area is distinguished from the calibration image and until the equipment generated image is modified.