US5023408A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic blackboard and accessories such as writing tools
Assignee: Wacom Co Ltd
•
Filing: 1989-06-13
•
Granted: 1991-06-11
•
Expires: 2009-06-13
Abstract
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.
Inventors
- 👤 Azuma Murakami
- 👤 Kazuo Aoki
- 👤 Tsuguya Yamanami
- 👤 Yoshiaki Tomofuji
- 👤 Takeshi Tanaka
- 👤 Satoshi Inashima
- 👤 Takahiko Funahashi
- 👤 Toshihide Chikami
- 👤 Toshiaki Senda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:03
CPC Classifications
G; G06; G06F; G06F3/00; G06F3/01; G06F3/03; G06F3/041; G06F3/046; B; B43; B43L; B43L1/00; G06F3/033; G06F3/0354; G06F3/03545
Claims Analysis
Total Claims: 102
Claim 1
Independent Claim
137 words
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.
Claim 2
Dependent Claim
137 words
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.
Claim 3
Dependent Claim
26 words
An electronic blackboard apparatus according to claim 1, wherein said electric wave generating means and said electric wave detection means are arranged to be alternately operated.
Claim 4
Dependent Claim
29 words
An electronic blackboard apparatus according to claim 1 or 2, wherein said electric wave generating means and said electric wave detection means include x and y-direction loop coil groups.
Claim 5
Dependent Claim
123 words
An electronic blackboard apparatus according to claim 1 or 2 further wherein a plurality of said tools are provided, each of said tools having a tuned circuit with a different resonant frequency, equal to frequencies of the plural frequencies of the generated electric waves; the coordinate detection means detecting the different resonant frequencies; writing tool identification means for generating identification information expressing, on the basis of the detected frequency a characteristic of said tool which is being used on said sensing portion; and image information processing means for processing image information which corresponds to the image on said writing surface on the basis of the detected coordinates of said tool and identification information expressing the characteristic of said tool which is being used.
Claim 6
Dependent Claim
75 words
An electronic blackboard apparatus according to claim 1 or 2 wherein: a pair of said writing surfaces are disposed on opposite sides of said means for sensing, said writing surfaces being capable of being used repeatedly; means for detecting the surface which is being used for detecting the writing surface which is being used; and coordinate conversion means for deriving indications in two coordinate directions of said tool as derived from said coordinate detection means.
Claim 7
Dependent Claim
17 words
The apparatus of claim 5 wherein the two coordinate directions are in the x and y directions.
Claim 8
Dependent Claim
14 words
The apparatus of claim 5 wherein the coordinate conversion means derives the indications intact.
Claim 9
Dependent Claim
31 words
The apparatus of claim 5 wherein the coordinate conversion means derives the indications intact after the coordinates have been converted on the basis of the writing surface which is being used.
Claim 10
Dependent Claim
145 words
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.
Claim 11
Dependent Claim
145 words
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.
Claim 12
Dependent Claim
22 words
The combination of claim 9 wherein the energy at the different frequencies is sequentially supplied to different coils of the coil arrangement.
Claim 13
Dependent Claim
72 words
The combination of claim 10 wherein the change is detected by supplying each of the coils during a first interval with the AC energy at one of the predetermined frequencies, the means for sensing being activated to be responsive to energy coupled back to each of the coils from the tuned circuit during a second interval while the particular coil is not supplied with the AC energy at the one predetermined frequency.
Claim 14
Dependent Claim
23 words
The combination of claim 9 wherein said tool means is cordless and no electric power supply is connected to the tuned circuits thereof.
Claim 15
Dependent Claim
28 words
The combination of claim 9 wherein the signal is further indicative of first and second characteristics of the tool means respectively associated with the first and second frequencies.
Claim 16
Dependent Claim
164 words
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.
Claim 17
Dependent Claim
164 words
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.
Claim 18
Dependent Claim
22 words
The combination of claim 14 wherein the energy at the different frequencies is sequentially supplied to different coils of the coils arrangement.
Claim 19
Dependent Claim
72 words
The combination of claim 15 wherein the change is detected by supplying each of the coils during a first interval with the AC energy at one of the predetermined frequencies, the means for sensing being activated to be responsive to energy coupled back to each of the coils from the tuned circuit during a second interval while the particular coil is not supplied with the AC energy at the one predetermined frequency.
Claim 20
Dependent Claim
28 words
The combination of claim 16 further including another two coordinate display responsive to the signal indicative of the position of the modified markings for displaying the modified markings.
Claim 21
Dependent Claim
83 words
The combination of claim 17 further including a plurality of said markers, each of said markers being for a different color and including a tuned circuit with a different resonant frequency, the means for supplying feeding AC energy at each of the resonant frequencies to the coil, the means for sensing responding to change sin the current flowing in said coil at each of the resonant frequencies, said another display displaying the position and colors of markings made by each of said markers.
Claim 22
Dependent Claim
72 words
The combination of claim 16 wherein the means for supplying supplies different frequencies in sequence to the coil arrangement such that in response to the marker having the first resonant frequency being proximate to and not being proximate the tablet the means for supplying respectively derives said first resonant frequency for first and second durations prior to deriving a second frequency, said first duration being considerably in excess of said second duration.
Claim 23
Dependent Claim
22 words
The combination of claim 19 wherein each of the first durations is divided into a plurality of said first and second intervals.
Claim 24
Dependent Claim
28 words
The combination of claim 14 further including another two coordinate display responsive to the signal indicative of the position of the modified markings for displaying the modified markings.
Claim 25
Dependent Claim
83 words
The combination of claim 21 further including a plurality of said markers, each of said markers being for a different color and including a tuned circuit with a different resonant frequency, the means for supplying feeding AC energy at each of the resonant frequencies to the coil, the means for sensing responding to changes in the current flowing in said coil at each of the resonant frequencies, said another display displaying the position and colors of markings made by each of said markers.
Claim 26
Dependent Claim
24 words
The combination of claim 14, wherein said marker and eraser are cordless and no electric power supply is connected to the tuned circuits thereof.
Claim 27
Dependent Claim
133 words
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.
Claim 28
Dependent Claim
133 words
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.
Claim 29
Dependent Claim
21 words
The combination of claim 24 wherein the energy at the different frequencies is sequentially supplied to coils of the coil arrangement.
Claim 30
Dependent Claim
71 words
The combination of claim 25 wherein the change is detected by supplying each of the coils during a first interval with the AC energy at one of the different frequencies, the means for sensing being activated to be responsive to energy coupled back to each of the coils from the tuned circuit during a second interval while the particular coil is not supplied with the AC energy at the one frequency.
Claim 31
Dependent Claim
73 words
The combination of claim 26 wherein the means for supplying supplies different frequencies in sequence to the coil arrangement such that in response to an implement having a first resonant frequency being proximate to and not being proximate to the tablet the means for supplying respectively derives said first resonant frequency for first and second durations prior to deriving a second frequency, said first duration being considerably in excess of said second duration.
Claim 32
Dependent Claim
22 words
The combination of claim 27 wherein each of the first durations is divided into a plurality of said first and second intervals.
Claim 33
Dependent Claim
128 words
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.
Claim 34
Dependent Claim
128 words
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.
Claim 35
Dependent Claim
21 words
The combination of claim 29 wherein the energy at the different frequencies is sequentially supplied to coils of the coil arrangement.
Claim 36
Dependent Claim
72 words
The combination of claim 30 wherein the change is detected by supplying each of the coils during a first interval with the AC energy at one of the predetermined frequencies, the means for sensing being activated to be responsive to energy coupled back to each of the coils from the tuned circuit during a second interval while the particular coil is not supplied with the AC energy at the one predetermined frequency.
Claim 37
Dependent Claim
72 words
The combination of claim 31 wherein the means for supplying supplies different frequencies in sequence to the coil arrangement such that in response to an implement having a first resonant frequency being proximate to and not being proximate the tablet the means for supplying respectively derives said first resonant frequency for first and second durations prior to deriving a second frequency, said first duration being considerably in excess of said second duration.
Claim 38
Dependent Claim
22 words
The combination of claim 32 wherein each of the first durations is divided into a plurality of said first and second intervals.
Claim 39
Dependent Claim
22 words
The apparatus of claim 29 further including a two-coordinate direction display superposed with the tablet adapted to be marked by the implement.
Claim 40
Dependent Claim
27 words
The apparatus of claim 34 further including another two-coordinate direction display responsive to the signal for displaying the position and characteristics of the implement on the tablet.
Claim 41
Dependent Claim
27 words
The apparatus of claim 29 further including a two-coordinate direction display responsive to the signal for displaying the position and characteristics of the implement on the tablet.
Claim 42
Independent Claim
125 words
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.
Claim 43
Independent Claim
125 words
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.
Claim 44
Dependent Claim
21 words
The method of claim 37 wherein the energy at the different frequencies is sequentially supplied to coils of the coil arrangement.
Claim 45
Dependent Claim
63 words
The method of claim 38 wherein the change is detected by supplying each of the coils during a first interval with the AC energy at one of the predetermined frequencies, sensing energy coupled back to one of the coils from the tuned circuit during a second interval while the particular coil is not supplied with the AC energy at the one predetermined frequency.
Claim 46
Dependent Claim
65 words
The method of claim 39 wherein the different frequencies are supplied in sequence to the coil arrangement such that in response to an implement having a first resonant frequency being on and not being on the tablet the first frequency is respectively derived for first and second durations prior to deriving a second frequency, said first duration being considerably in excess of said second duration.
Claim 47
Dependent Claim
22 words
The method of claim 40 wherein each of the first durations is divided into a plurality of said first and second intervals.
Claim 48
Dependent Claim
131 words
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.
Claim 49
Dependent Claim
131 words
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.
Claim 50
Dependent Claim
21 words
The eraser of claim 42 wherein the eraser is cordless and not electric power supply is connected to the tuned circuits.
Claim 51
Dependent Claim
146 words
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.
Claim 52
Dependent Claim
146 words
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.
Claim 53
Dependent Claim
22 words
The combination of claim 44 wherein the energy at the different frequencies is sequentially supplied to different coils of the coil arrangement.
Claim 54
Dependent Claim
72 words
The combination of claim 45 wherein the changes are detected by supplying each of the coils during a first interval with the AC energy at one of the predetermined frequencies, the means for sensing being activated to be responsive to energy coupled back to one of the coils from the tuned circuit during a second interval while the particular coil is not supplied with the AC energy at the one predetermined frequency.
Claim 55
Dependent Claim
28 words
The combination of claim 46 further including another two coordinate display responsive to the signal indicative of the position of the markings and the identification of the implements.
Claim 56
Dependent Claim
44 words
The combination of claim 47 wherein the implements include a plurality of markers, each of said markers being for a different color, said another display displaying the position and colors of the markings made by each of the markers on the first named display.
Claim 57
Dependent Claim
28 words
The combination of claim 44 further including another two coordinate display responsive to the signal indicative of the position of the marking and the characteristics of the implements.
Claim 58
Dependent Claim
44 words
The combination of claim 49 wherein the implements include a plurality of markers, each of said markers being for a different color, said another display displaying the position and colors of the markings made by each of the markers on the first named display.
Claim 59
Dependent Claim
24 words
The combination of claim 44 wherein each of said implements is cordless and no electric power supply is connected to the tuned circuits thereof.
Claim 60
Dependent Claim
57 words
The combination of claim 50 wherein one of the implements is a marker and another of the implements is an eraser for markings of the marker, said signal being indicative of markings by the marker as modified by the eraser, the another display being responsive to the signal to indicate the markings as modified by the eraser.
Claim 61
Dependent Claim
44 words
The combination of claim 52 wherein the implements include a plurality of markers, each of said markers being for a different color, said another display displaying the position and colors of the markings made by each of the markers on the first named display.
Claim 62
Dependent Claim
149 words
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.
Claim 63
Dependent Claim
149 words
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.
Claim 64
Dependent Claim
22 words
The combination of claim 54 wherein the energy at the different frequencies is sequentially supplied to different coils of the coil arrangement.
Claim 65
Dependent Claim
72 words
The combination of claim 55 wherein the change is detected by supplying each of the coils during a first interval with the AC energy at one of the predetermined frequencies, the means for sensing being activated to be responsive to energy coupled back to one of the coils from the tuned circuit during a second interval while the particular coil is not supplied with the AC energy at the one predetermined frequency.
Claim 66
Dependent Claim
30 words
The combination of claim 56 further including another two coordinate color-display responsive to the signal indicative of the position of markings for displaying the position and color of the markings.
Claim 67
Dependent Claim
30 words
The combination of claim 54 further including another two coordinate color-display responsive to the signal indicative of the position of markings for displaying the position and color of the markings.
Claim 68
Dependent Claim
22 words
The combination of claim 54 wherein said markers are cordless and no electric power supply is connected to the tuned circuits thereof.
Claim 69
Independent Claim
129 words
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.
Claim 70
Independent Claim
129 words
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.
Claim 71
Dependent Claim
19 words
The method of claim 60 wherein each of the frequencies is sequentially applied to the markers on the display.
Claim 72
Dependent Claim
32 words
The method of claim 61 wherein the frequencies are applied during a first interval and the response to the interaction is derived during a second interval while the frequencies are not applied.
Claim 73
Dependent Claim
66 words
The method of claim 62 wherein the different frequencies are supplied in sequence to the coil arrangement such that in response to an implement having a first resonant frequency being on and not being on the tablet said first resonant frequency is respectively derived for first and second durations prior to deriving a second frequency, said first duration being considerably in excess of said second duration.
Claim 74
Dependent Claim
22 words
The method of claim 63 wherein each of the first durations is divided into a plurality of said first and second intervals.
Claim 75
Independent Claim
120 words
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.
Claim 76
Independent Claim
120 words
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.
Claim 77
Dependent Claim
31 words
The method of claim 65 further comprising displaying the position of the marking on the display as modified by the eraser by applying the indication to another two coordinate direction display.
Claim 78
Dependent Claim
19 words
The method of claim 66 wherein each of the frequencies is sequentially applied to the markers on the display.
Claim 79
Dependent Claim
32 words
The method of claim 67 wherein the frequencies are applied during a first interval and the response to the interaction is derived during a second interval while the frequencies are not applied.
Claim 80
Dependent Claim
66 words
The method of claim 68 wherein the different frequencies are supplied in sequence to the coil arrangement such that in response to an implement having a first resonant frequency being on and not being on the tablet, said first resonant frequency is respectively derived for first and second durations prior to deriving a second frequency, said first duration being considered in excess of said second duration.
Claim 81
Dependent Claim
22 words
The method of claim 69 wherein each of the first durations is divided into a plurality of said first and second intervals.
Claim 82
Dependent Claim
19 words
The method of claim 65 wherein each of the frequencies is sequentially applied to the markers on the display.
Claim 83
Dependent Claim
32 words
The method of claim 71 wherein the frequencies are applied during a first interval and a response to the interaction is derived during a second interval while the frequencies are not applied.
Claim 84
Dependent Claim
65 words
The method of claim 72 wherein the different frequencies are supplied in sequence to the coil arrangement such that in response to an implement having a first resonant frequency being on and not being on the tablet said resonant frequency is respectively derived for first and second durations prior to deriving a second frequency, said first duration being considered in excess of said second duration.
Claim 85
Dependent Claim
90 words
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.
Claim 86
Dependent Claim
90 words
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.
Claim 87
Dependent Claim
64 words
The eraser of claim 74 wherein the switch means includes first and second switches positioned and arranged so that the first switch is activated in response to a first edge of the eraser being pushed against the display surface and the second switch is activated in response to a second edge of the eraser, opposite the first edge, being pushed against the display surface.
Claim 88
Dependent Claim
21 words
The eraser of claim 74 wherein the eraser is cordless and no electric power supply is connected to the tuned circuit.
Claim 89
Dependent Claim
24 words
The eraser of claim 74 wherein the reactance includes a coil having a longitudinal axis at a right angle relative to the erasing surface.
Claim 90
Dependent Claim
167 words
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.
Claim 91
Dependent Claim
167 words
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.
Claim 92
Dependent Claim
26 words
The combination of claim 78 wherein the display is superposed with the tablet, the first implement and second implement being adapted to bear on the display.
Claim 93
Dependent Claim
32 words
The combination of claim 78 wherein the display is remote from the tablet and is responsive to the signal to indicate the position of the markings as modified by the second implement.
Claim 94
Dependent Claim
144 words
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.
Claim 95
Dependent Claim
144 words
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.
Claim 96
Dependent Claim
162 words
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.
Claim 97
Dependent Claim
162 words
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.
Claim 98
Independent Claim
136 words
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.
Claim 99
Independent Claim
136 words
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.
Claim 100
Independent Claim
175 words
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.
Claim 101
Independent Claim
175 words
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.
Claim 102
Dependent Claim
73 words
An electronic blackboard apparatus according to claim 4 wherein: a pair of said writing surfaces are disposed on opposite sides of said means for sensing, said writing surfaces being capable of being used repeatedly; means for detecting the surface which is being used for detecting the writing surface which is being used; and coordinate conversion means for deriving indications in two coordinate directions of said tool as derived from said coordinate detection means.
References Cited (Backward Citations)
US2812427A
Cited
US2899546A
Cited
US2958781A
Cited
US3117277A
Cited
US3373425A
Cited
US4711977A
Cited
US4786765A
Cited
US4902858A
Cited
US4878553A
Cited
US4878553B1
Cited
US4848496A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-06-10 | 1994-12-10 | 1995-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-06-10 | 1998-12-10 | 1999-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-06-10 | 2002-12-10 | 2003-06-11 | $7700.00 | Window Closed / Lapsed |