US3688307A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ring core keyboard entry device
Assignee: Data Electronics Corp
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Filing: 1970-09-28
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Granted: 1972-08-29
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Expires: 1990-09-28
Abstract
Abstract A keyboard entry device which employs a plurality of ring cores which are selectively threaded in a different combination by leads from a plurality of keys in a keyboard. Depending upon the particular keys depressed, a different combination of cores will be energized.
Inventors
- 👤 Stanley K Chao
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:38
CPC Classifications
H; H03; H03M; H03M11/00; H03M11/22
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
120 words
A keyboard entry device comprising: a source of current varying substantially sinusoidally in time, a plurality of ring cores; a plurality of electrically conductive lines, being threaded through a unique combination of one or more of said cores a plurality of switching means each for connecting said source to a corresponding one of said conductive lines so as to pass said current through the latter and thereby induce a varying magnetic field in each of said cores through which said one line is threaded; and a plurality of secondary windings, each coupled to one of said cores so that upon actuation of any one of said switching means, a sinusoidally varying output signal is generated in the corresponding secondary winding.
Claim 2
Dependent Claim
120 words
A keyboard entry device comprising: a source of current varying substantially sinusoidally in time, a plurality of ring cores; a plurality of electrically conductive lines, being threaded through a unique combination of one or more of said cores a plurality of switching means each for connecting said source to a corresponding one of said conductive lines so as to pass said current through the latter and thereby induce a varying magnetic field in each of said cores through which said one line is threaded; and a plurality of secondary windings, each coupled to one of said cores so that upon actuation of any one of said switching means, a sinusoidally varying output signal is generated in the corresponding secondary winding.
Claim 3
Dependent Claim
43 words
A device as set forth in claim 1 Including means for generating a strobe output signal after a predetermined delay following actuation of any of said switching means, said means for generating comprising one of said cores threaded by all of said lines.
Claim 4
Dependent Claim
28 words
A device as set forth in claim 2 further including means for disabling any output signal upon substantially simultaneous actuation of two or more of said switching means.
Claim 5
Dependent Claim
55 words
A device as set forth in claim 3 wherein said means for disabling includes a separate ring core threaded by all of said electrically conductive lines and having a secondary winding wound therearound whereby simultaneous closure of two or more of said switching means disables any output signal from any of the other ring cores.
Claim 6
Dependent Claim
22 words
A device as set forth in claim 1 wherein said ring cores are made of material having a substantially linear hysteresis characteristic.
Claim 7
Dependent Claim
24 words
A device as set forth in claim 1 wherein said output signal generated in each of said secondary windings is detected by rectifying means.
Claim 8
Dependent Claim
15 words
A device as set forth in claim 1 wherein said switching means are capacitive switches.
Claim 9
Dependent Claim
22 words
A device as set forth in claim 1 wherein each of said plurality of electrically conductive lines is a single electrical lead.
Claim 10
Dependent Claim
52 words
A device as set forth in claim 1 including means for inverting the output from each of said individual conductive lines, and means for combining selected inverted and noninverted outputs from each of said individual conductive lines so as to form a plurality of different signal combinations from said plurality of cores.
Claim 11
Dependent Claim
52 words
A device as set forth in claim 1 wherein each of said plurality of electrically conductive lines is a corresponding plurality of trunk lines, each of said trunk lines of a corresponding one of said first plurality being threaded through a different combination of cores than the other lines of that trunk.
Claim 12
Dependent Claim
41 words
A device as set forth in claim 10 including means for coupling one trunk line from each of said plurality to a corresponding common terminal, and means for selectively switching any one of said terminals to be energized from said source.
References Cited (Backward Citations)
US3319234A
Cited
US3396373A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-29 | 1976-02-28 | 1976-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-29 | 1980-02-28 | 1980-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-29 | 1984-02-28 | 1984-08-29 | $7700.00 | Window Closed / Lapsed |