US3571510A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coordinated data determination system
Assignee: International Business Machines Corp
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Filing: 1968-12-27
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Granted: 1971-03-16
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Expires: 1988-12-27
Abstract
Abstract The use of graphical display devices in conjunction with digital computer and data processing systems is enhanced by a rectangular, or XY, coordinate determinate system providing a completely unobstructed view of the display by means of electromagnetic fields propagated in the plane of the display. A pair of wire radiating elements are arranged parallel to each other at opposite edges of the display for radiating opposing electromagnetic fields therebetween at a frequency of the order of 25 kilohertz (kHz.) for each ordinate direction (X or Y). An electromagnetic field probe tuned to the frequency of the radiation derives analogue voltages proportional to the distances of the probe with respect to the null at the center of the display. The analogue voltages are converted to digital representation by means of analogue-to-digital converters (ADC). The conversion circuitry comprises a ramp voltage generator having a characteristic compensating for the nonlinear characteristic of the electromagnetic fields which controls an X and Y counter advanced by pulses derived from the 25 kHz. oscillator under control of circuitry comprising conventional gating circuits and latches. Cartesian coordinates are derived from the X and Y coordinate data thus far developed by means of a quadrant detector which is switched by the control circuitry in response to energy picked up by the probe in the particular quadrant at which it is positioned for the desired data input.
Inventors
- 👤 Richard Dean Weir
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:20
CPC Classifications
G; G06; G06K; G06K15/00; G06K15/22; H; H03; H03M; H03M1/00; H03M1/12; H03M1/50
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
160 words
A coordinate determination system, comprising: four elongated electromagnetic energy radiating elements arranged along the sides of a rectangle, a generator of alternating current electric energy of given frequency. switching elements for coupling said generator alternately to pairs of said radiating elements on opposite sides of said rectangle for radiating electromagnetic energy therebetween, a probe tuned to said given frequency for detecting the difference in magnitude of the electromagnetic energy radiated from said radiating elements at any point within said rectangle, a ramp voltage generating circuit, having an output terminal, a voltage comparator having one input coupled to said probe, another input coupled to said ramp generating circuit and an output terminal, and a ramp voltage generating control gating circuit coupled between the output terminal of said comparator and said ramp voltage generating circuit for providing an indication that the ramp voltage is proportional to said difference in electromagnetic energy relating to the locus of a selected point within said rectangle.
Claim 2
Dependent Claim
160 words
A coordinate determination system, comprising: four elongated electromagnetic energy radiating elements arranged along the sides of a rectangle, a generator of alternating current electric energy of given frequency. switching elements for coupling said generator alternately to pairs of said radiating elements on opposite sides of said rectangle for radiating electromagnetic energy therebetween, a probe tuned to said given frequency for detecting the difference in magnitude of the electromagnetic energy radiated from said radiating elements at any point within said rectangle, a ramp voltage generating circuit, having an output terminal, a voltage comparator having one input coupled to said probe, another input coupled to said ramp generating circuit and an output terminal, and a ramp voltage generating control gating circuit coupled between the output terminal of said comparator and said ramp voltage generating circuit for providing an indication that the ramp voltage is proportional to said difference in electromagnetic energy relating to the locus of a selected point within said rectangle.
Claim 3
Dependent Claim
42 words
A coordinate determination system as defined in claim 1 and incorporating control circuitry connected between said comparator and said switching elements for alternating said coupling of said generator to said pairs of radiating elements in accordance with the output of said comparator.
Claim 4
Dependent Claim
38 words
A coordinate determination system as defined in claim 2 and wherein said control circuitry is coupled to said ramp voltage generating gating circuit for resetting said ramp voltage generating circuit in accordance with the output of said comparator.
Claim 5
Dependent Claim
76 words
A coordinate determination system as defined in claim 1 and incorporating: a counting circuit, a gating circuit coupled to said counting circuit for admitting pulses thereto and having one input coupled to said generator for accepting pulses therefrom, a terminal coupled to said comparator and another terminal coupled to said ramp voltage generating circuit for controlling the admission of said pulses whereby the number in said counting circuit is proportional to said difference in electromagnetic energy.
Claim 6
Dependent Claim
76 words
A coordinate determination system as defined in claim 2 and incorporating: electric voltage translating circuit interposed between said probe and said comparator and having an output terminal indicative of the phase difference of said electromagnetic energy as well as the difference in magnitude, and quadrant detecting circuitry coupled to said switching elements and to said output terminal of said electric voltage translating circuit for indicating the quadrant of the point at which said probe is arranged.
Claim 7
Dependent Claim
29 words
A coordinate determination system as defined in claim 5 and wherein: said electric voltage translating circuit is a band-pass amplifier, and Said comparator is a unity gain differential amplifier.
Claim 8
Dependent Claim
84 words
A coordinate determination system as defined in claim 4 and incorporating: two counting circuits, a gating circuit coupled to each of said counting circuits for admitting pulses thereto and having one input coupled to said generator for accepting pulses therefrom, a terminal coupled to said comparator and another terminal couple to said ramp voltage generating circuit for controlling the admission of said pulses, whereby the numbers in said counting circuits are proportional to differences in electromagnetic energy at a given point within said rectangle.
Claim 9
Dependent Claim
142 words
An ordinate determination system comprising: two elongated radiating elements spaced apart and parallel with respect to one another, a generator of alternating current of given frequency couple to said radiating elements for radiating electromagnetic energy therefrom at least in the area between said radiating elements, said radiating elements being connected in series with the current supplied by said generator effecting opposing electromagnetic fields between said elements whereby a null is present substantially midway between said radiating elements, a probe tuned to said given frequency for detecting the difference in electromagnetic energy radiated from said radiating elements at any point intermediate said radiating elements, and circuitry coupled to said probe for converting said difference in electromagnetic energy detected and the relative location of said null to an indication of the ordinate of the location of said point with respect to said radiating elements.
Claim 10
Dependent Claim
142 words
An ordinate determination system comprising: two elongated radiating elements spaced apart and parallel with respect to one another, a generator of alternating current of given frequency couple to said radiating elements for radiating electromagnetic energy therefrom at least in the area between said radiating elements, said radiating elements being connected in series with the current supplied by said generator effecting opposing electromagnetic fields between said elements whereby a null is present substantially midway between said radiating elements, a probe tuned to said given frequency for detecting the difference in electromagnetic energy radiated from said radiating elements at any point intermediate said radiating elements, and circuitry coupled to said probe for converting said difference in electromagnetic energy detected and the relative location of said null to an indication of the ordinate of the location of said point with respect to said radiating elements.
Claim 11
Dependent Claim
169 words
An ordinate determination system comprising: an elongated electric conductor arranged with two sections parallel to each other defining a plane and extending in directions affording instantaneous opposing electromagnetic radiating fields between said sections upon excitation of said conductor at the terminals thereof, means for applying alternating current electromagnetic energy of given frequency at said terminals of said conductor for radiating electromagnetic energy from said sections at least in said plane, means preventing radiation of such energy from other portions of said conductor from interfering with radiation in said plane and said plane being free of conductive material, a probe electrically isolated from said conductor and electromagnetically tuned to said given frequency for detecting the difference in electromagnetic energy radiated from said two sections of said conductor at any point in said plane defined thereby, and circuitry coupled to said probe for converting said difference in electromagnetic energy detected to an indication of the ordinate of the location of said point with respect to said two sections of said conductor.
Claim 12
Dependent Claim
169 words
An ordinate determination system comprising: an elongated electric conductor arranged with two sections parallel to each other defining a plane and extending in directions affording instantaneous opposing electromagnetic radiating fields between said sections upon excitation of said conductor at the terminals thereof, means for applying alternating current electromagnetic energy of given frequency at said terminals of said conductor for radiating electromagnetic energy from said sections at least in said plane, means preventing radiation of such energy from other portions of said conductor from interfering with radiation in said plane and said plane being free of conductive material, a probe electrically isolated from said conductor and electromagnetically tuned to said given frequency for detecting the difference in electromagnetic energy radiated from said two sections of said conductor at any point in said plane defined thereby, and circuitry coupled to said probe for converting said difference in electromagnetic energy detected to an indication of the ordinate of the location of said point with respect to said two sections of said conductor.
Claim 13
Dependent Claim
216 words
A coordinate determination system comprising: one elongated electric conductor arranged with the radiating sections spaced apart and parallel to each other defining a plane and extending in directions affording instantaneous opposing electromagnetic fields between said sections upon excitation of said conductor at the terminals thereof, another elongated electric conductor with two radiating sections parallel spaced apart and parallel to each other lying substantially in said plane and between the two sections of said one conductor therewith defining a rectangle and extending in directions affording instantaneous opposing electromagnetic fields between the sections upon excitation of said other conductor at the terminals thereof, a generator of alternating current electric energy of given frequency, means coupling said generator alternately to said conductors at said terminal thereof for radiating electromagnetic energy between said radiating sections on opposite sides of said rectangle, means preventing radiation of such energy from portions of said conductors other than said radiating sections from interfering with radiation within said rectangle and saId plane within said rectangle being free of conductive material, a probe tuned to said given frequency for detecting the difference in electromagnetic energy radiated from said radiating sections at point within said rectangle, and circuitry for converting said difference in electromagnetic energy to coordinate indications of the locus of said point within said rectangle.
Claim 14
Dependent Claim
216 words
A coordinate determination system comprising: one elongated electric conductor arranged with the radiating sections spaced apart and parallel to each other defining a plane and extending in directions affording instantaneous opposing electromagnetic fields between said sections upon excitation of said conductor at the terminals thereof, another elongated electric conductor with two radiating sections parallel spaced apart and parallel to each other lying substantially in said plane and between the two sections of said one conductor therewith defining a rectangle and extending in directions affording instantaneous opposing electromagnetic fields between the sections upon excitation of said other conductor at the terminals thereof, a generator of alternating current electric energy of given frequency, means coupling said generator alternately to said conductors at said terminal thereof for radiating electromagnetic energy between said radiating sections on opposite sides of said rectangle, means preventing radiation of such energy from portions of said conductors other than said radiating sections from interfering with radiation within said rectangle and saId plane within said rectangle being free of conductive material, a probe tuned to said given frequency for detecting the difference in electromagnetic energy radiated from said radiating sections at point within said rectangle, and circuitry for converting said difference in electromagnetic energy to coordinate indications of the locus of said point within said rectangle.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-15 | 1974-09-14 | 1975-03-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-15 | 1978-09-14 | 1979-03-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-15 | 1982-09-14 | 1983-03-16 | $7700.00 | Window Closed / Lapsed |