Electronic blackboard and accessories such as writing tools
First Claim
1. An electronic blackboard apparatus comprising:
- a writing surface,a tool for modifying an image on the surface including a tuned circuit having a predetermined resonant frequency;
means for sensing the presence of the tool relative to said surface, said means including electric wave generating means for generating an electric wave with plural frequencies, one of which is resonant to said frequency, and an electric wave detection means for detecting an electric wave reflected by said tuned circuit;
said sensing means including coordinate detection means responsive to the electric wave reflected from said tool and generated by said generating means for detecting a coordinate corresponding to the position of said tool; and
image information processing means for processing, on the basis of the thus-detected coordinate, image information corresponding to an image formed by the tool on the surface.
1 Assignment
0 Petitions
Accused Products
Abstract
A characteristic and the position of an implement with a tuned circuit having one of plural resonant frequencies are determined. AC energy at the plural different resonant frequencies is supplied to a two-coordinate direction coil arrangement of a position sensing tablet. The tuned circuit changes the current flowing in the coil arrangement at the implement resonant frequency. The current change is used to signal the implement position and characteristic. The implement may be an eraser for supplying a signal to an electronic display and for removing a mark from a surface of a visual display overlaying the tablet of the eraser. A housing includes a surface for erasing the marking and two tuned circuits each having a reactance positioned close to opposite edges of the erasing surface. Two switches, when activated, cause the tuned circuits to have different resonant frequencies. The switches are respectively activated when opposite eraser edges are being pushed against the display surface. The implement may also be one of a plurality of markers, each for a different color. Another display responds to the signals to display the position and colors of the markings and selectively remove markings from areas corresponding to the eraser position.
176 Citations
85 Claims
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1. An electronic blackboard apparatus comprising:
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a writing surface, a tool for modifying an image on the surface including a tuned circuit having a predetermined resonant frequency; means for sensing the presence of the tool relative to said surface, said means including electric wave generating means for generating an electric wave with plural frequencies, one of which is resonant to said frequency, and an electric wave detection means for detecting an electric wave reflected by said tuned circuit; said sensing means including coordinate detection means responsive to the electric wave reflected from said tool and generated by said generating means for detecting a coordinate corresponding to the position of said tool; and image information processing means for processing, on the basis of the thus-detected coordinate, image information corresponding to an image formed by the tool on the surface. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 85)
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9. In combination, a position sensing tablet;
- a two coordinate, direction coil arrangement associated with the tablet;
a tool means adapted to be moved relative to the tablet and coil arrangement, the tool means including tuned circuits having first and second resonant frequencies;
means for supplying AC energy at the first and second resonant frequencies to the coil arrangement;
the tuned circuits on the tool means when the tool means is placed in proximity to the tablet and coil arrangement respectively causing changes in currents flowing in the coil arrangement of said first and second frequencies; and
means for sensing the changes in the current flowing in the coil arrangement at said first and second frequencies and responding to the current changes at said first and second frequencies for deriving a signal indicative of coordinates of the tool means relative to the tablet and coil means. - View Dependent Claims (10, 11, 12, 13)
- a two coordinate, direction coil arrangement associated with the tablet;
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14. In combination, a position sensing tablet;
- a two coordinate, direction coil arrangement associated with the tablet;
a two coordinate direction display superposed with the tablet;
a marker for the display;
an eraser for the display;
the marker including a tuned circuit having a first resonant frequency;
the eraser including a tuned circuit having a second resonant frequency;
means for supplying AC energy at the first and second resonant frequencies to the coil arrangement;
the tuned circuits on the marker and the eraser when the marker is placed in proximity to the tablet and coil arrangement respectively causing changes in currents flowing in the coil arrangement of said first and second frequencies; and
means for sensing the changes in the current flowing in the coil arrangement at said first and second frequencies and responding to the current changes at said first and second frequencies for deriving a signal indicative of the position of marking by the marker on the display as modified by the eraser. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23)
- a two coordinate, direction coil arrangement associated with the tablet;
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24. In combination, a position sensing tablet;
- a two coordinate direction coil arrangement associated with the tablet;
multiple implements for movement relative to the tablet, each of said implements having a different characteristic associated therewith and including a tuned circuit having a different resonant frequency;
means for supplying AC energy at the different resonant frequencies to the coil arrangement;
the tuned circuits on the implements when the implements are placed in proximity to the tablet and coil arrangement causing changes in the currents flowing in the coil arrangement at said different frequencies; and
means for sensing changes in current flowing in the coil arrangement at said different frequencies and responsive to the current changes at said frequencies for deriving a signal indicative of the position and characteristics of the implements relative to the tablet. - View Dependent Claims (25, 26, 27, 28)
- a two coordinate direction coil arrangement associated with the tablet;
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29. Apparatus for identifying a characteristic and position of an implement having one of plural characteristics, the implement including a tuned circuit having one of plural different resonant frequencies, comprising a position sensing tablet;
- a two coordinate direction coil arrangement associated with the tablet;
means for supplying AC energy at the plural different resonant frequencies to the coil arrangement;
the tuned circuit on the implement when placed in proximity to the tablet and coil arrangement causing changes in current flowing in the coil arrangement at said one frequency;
means for sensing changes in the current flowing in the coil arrangement at said different frequencies and responsive to the current changes at said frequencies for deriving a signal indicative of the position and characteristic of the implement on the tablet. - View Dependent Claims (30, 31, 32, 33, 34, 35, 36)
- a two coordinate direction coil arrangement associated with the tablet;
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37. A method of identifying a characteristic and position of an implement on a position sensing tablet having a two coordinate direction coil arrangement associated therewith, the implement having one of plural characteristics and including a tuned circuit having one of plural different resonant frequencies, comprising supplying AC energy at the plural different resonant frequencies to the coil arrangement;
- the tuned circuit on the implement when placed in proximity to the tablet and coil arrangement causing changes in current flowing in the coil arrangement at said one frequency;
sensing changes in the current flowing in the coil arrangement at said different frequencies and responding to current changes at said frequencies for deriving a signal indicative of the position and characteristic of the implement on the tablet. - View Dependent Claims (38, 39, 40, 41)
- the tuned circuit on the implement when placed in proximity to the tablet and coil arrangement causing changes in current flowing in the coil arrangement at said one frequency;
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42. An eraser for supplying a signal to an electronic display and for removing a marking from a surface of a visual display comprising a housing, the housing including:
- a surface for erasing the marking, first and second tuned circuits each having a reactance positioned in proximity to first and second opposite edges of the erasing surface, first and second switches which when activated respectively cause the first and second tuned circuits to have different first and second resonant frequencies, the first and second switches being positioned and arranged so that the first switch is activated in response to the first edge of the eraser being pushed against the display surface and the second switch is activated in response to the second edge of the eraser being pushed against the display surface.
- View Dependent Claims (43)
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44. In combination, a position sensing tablet;
- a two coordinate direction coil arrangement associated with the tablet;
a two-coordinate direction display superposed with the tablet;
multiple implements for modifying markings on the display, each of said implements having a different characteristic associated therewith and including a tuned circuit having a different resonant frequency for each characteristic;
means for supplying AC energy at the different resonant frequencies to the coil arrangement;
the tuned circuit on the implements when the implements are placed in proximity to the tablet and coil arrangement respectively causing changes in the currents flowing in the coil arrangement at said different frequencies; and
means for sensing changes in the current flowing in the coil arrangement at said different frequencies and responsive to current changes at said frequencies for deriving a signal indicative of the position and characteristics of markings by the implements on the display. - View Dependent Claims (45, 46, 47, 48, 49, 50, 51, 52, 53)
- a two coordinate direction coil arrangement associated with the tablet;
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54. In combination, a position sensing tablet;
- a two coordinate coil arrangement associated with the tablet;
a two coordinate direction display superposed with the tablet;
plural markers for the display, each of the markers being for a different color on the display;
each of the markers including a tuned circuit having a different resonant frequency, means for supplying AC energy at the different resonant frequencies to the coil arrangement, the tuned circuits on the markers when the markers are placed in proximity to the tablet and coil arrangement causing changes in currents flowing in coils of the coil arrangement at said different frequencies; and
means responsive to energy coupled between the tablet and markers for deriving a signal indicative of the position of the colors of markings by the markers on the display, said last named means sensing changes in current flowing in the coil arrangement at said different frequencies. - View Dependent Claims (55, 56, 57, 58, 59)
- a two coordinate coil arrangement associated with the tablet;
- 60. A method of displaying a polychromic image comprising marking a first two coordinate direction display with plural markers each having a different color and a tuned circuit with a different resonant frequency thereon, applying plural frequencies to a two coordinate direction coil arrangement, the coil arrangement coupling the plural frequencies to each marker as it is marking the first display, activating the coil arrangement so it is responsive to an interaction of each applied frequency and each tuned circuit to provide an indication of the color and position of the mark being made by each marker on the first display, and displaying on a second two coordinate direction display the position and color of the mark made by each marker on the first display by responding to the indication.
- 65. A method of indicating the position of an image on a two coordinate direction display, comprising marking the display with a marker, erasing from the display at least a portion of marks made by the marker, said marker and eraser respectively having tuned circuits with first and second resonant frequencies, activating a two coordinate direction coil arrangement so it applies said first and second resonant frequencies to the marker and the eraser as they respectively mark and erase the display, and activating the coil arrangement to be responsive to an interaction of the applied first and second frequencies with the tuned circuits to derive an indication of the position of the marking on the display as modified by the eraser.
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74. An eraser for supplying a signal to an electronic display and for removing a marking from a surface of a visual display comprising a housing, the housing including:
- a surface for erasing the marking, a tuned circuit having a reactance positioned immediately behind the eraser surface, and switch means activated in response to the erasing surface being pressed against the display surface for connecting elements of the tuned circuit, including said reactance, together so they have a predetermined resonant frequency while the erasing surface is pressed against the display surface.
- View Dependent Claims (75, 76, 77)
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78. In combination, a position sensing tablet;
- a two coordinate direction coil arrangement associated with the tablet;
a two coordinate direction display;
a first implement for causing marks to appear on the display;
a second implement for causing marks to be erased from the display;
the first implement including a tuned circuit having a first resonant frequency;
the second implement including a tuned circuit having a second resonant frequency;
means for supplying AC energy at the first and second resonant frequencies to the coil arrangement;
the implements are placed in proximity to the tablet and coil arrangement respectively causing changes in currents flowing in the coil arrangement of said first and second frequencies; and
means for sensing the changes in the current flowing in the coil arrangement at said first and second frequencies and responding to the current changes at said first and second frequencies for deriving a signal indicative of the position of markings by the first implement on the display as modified by the second implement. - View Dependent Claims (79, 80)
- a two coordinate direction coil arrangement associated with the tablet;
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81. In combination, a position sensing tablet;
- a two coordinate direction coil arrangement associated with the tablet;
multiple implements adapted to be moved relative to the tablet, each of said implements having a different characteristic associated therewith and including a tuned circuit having a different resonant frequency for each characteristic;
means for supplying AC energy at the different resonant frequencies to the coil arrangement;
the tuned circuits on the implements when the implements are placed in proximity to the tablet and coil arrangement respectively causing changes in the currents flowing in the coil arrangement at said different frequencies; and
means for sensing changes in the current flowing in the coil arrangement at said different frequencies and responsive to current changes at said frequencies for deriving a signal indicative of the position of the implements relative to the tablet and of the characteristics of the implements.
- a two coordinate direction coil arrangement associated with the tablet;
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82. In combination, a position sensing tablet;
- a two coordinate coil arrangement associated with the tablet;
a two coordinate direction display;
implement means for the display, said implement means including plural tuned circuits each having a different resonant frequency, a different resonant frequency being assigned to a different color for the display, means for supplying AC energy at the different resonant frequencies to the coil arrangement, the coil arrangement interacting with the tuned circuits on the implement means when the implement means is placed in proximity to the tablet to cause changes in currents flowing in coils of the coil arrangement at said different frequencies; and
means responsive to energy coupled between the tablet and the tuned circuits for deriving a signal indicative of the position of the colors of marks on the display resulting from the different tuned circuits being positioned relative to the tablet, said last named means sensing changes in current flowing in the coil arrangement at said different frequencies.
- a two coordinate coil arrangement associated with the tablet;
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83. A method of displaying a polychromic image comprising moving implement means having tuned circuit means with resonant frequencies, each associated with a different color, relative to a tablet having a two coordinate direction coil arrangement;
- applying plural frequencies to the two coordinate direction coil arrangement, the coil arrangement coupling the plural frequencies to the implement means as it is moved relative to the tablet;
activating the coil arrangement so it is responsive to an interaction of each applied frequency and each tuned circuit resonant frequency to provide an indication of the position and color assigned to the resonant frequency of the implement means relative to the tablet, and displaying on a two coordinate direction display the position and color associated with the movement of the implement means relative to the tablet by responding to the indication.
- applying plural frequencies to the two coordinate direction coil arrangement, the coil arrangement coupling the plural frequencies to the implement means as it is moved relative to the tablet;
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84. A method of indicating the position of the effective movement of a first implement that causes marks to appear on a two coordinate direction display, the effective movement of the first implement being modified by a second implement that causes the marks to be erased from the display, comprising moving the first and second implements relative to a tablet so that some of the area traversed by the first implement relative to the tablet is subsequently traversed by the second implement, said first and second implements respectively having tuned circuits with first and second resonant frequencies, activating a two coordinate direction coil arrangement of the tablet so it applies said first and second resonant frequencies to the first and second implements as they are respectively traversed relative to the tablet, and activating the coil arrangement to be responsive to an interaction of the applied first and second frequencies with the tuned circuits to derive an indication of the position of the marks on the display as modified by the erasing action of the second implement.
Specification