US3740745A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ring core keyboard entry device
Assignee: Eaton Corp
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Filing: 1972-01-14
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Granted: 1973-06-19
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Expires: 1992-01-14
Abstract
Abstract A keyboard entry device has ring transformer cores each core having a different combination of electrically conductive input lines threaded therethrough. Each input line is connected to a switch and a capacitor. Each input line is connected to a switch and a capacitor, the capacitor storing charge from a D. C. supply. When the switch is activated a current pulse is transmitted over the input lines as a result of the capacitor being discharged. An output signal will be provided in the secondary windings of the cores in which the pulse is transmitted through. Registers, utilized for temporarily storing output signals from the secondary windings, as well as a unique N-key rollover feature are provided.
Inventors
- 👤 S Chao
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 08:53
CPC Classifications
H; H03; H03M; H03M11/00; H03M11/22
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
254 words
A keyboard entry device comprising, in combination charge storage means; a substantially constant current course for charging said charge storage means; a plurality of transformer cores; a plurality of electrically conductive lines, each being threaded through a unique combination of one or more of said cores; a plurality of switching means each for connecting said charge storage means to a corresponding one of said conductive lines so as to pass a current pulse between said one line and said charge storage means; a plurality of secondary windings, each disposed about a corresponding one of said cores for providing an output signal; a first register for storing said output signals from said secondary windings; a second register; gating means for selectively coupling said first and second registers; means for detecting the presence of a said output signal at any of said secondary windings; means for providing an enabling signal to said gating means a first predetermined time interval after detection of the presence of any said output signal; means for clearing said first register a second predetermined time interval after said enabling signal is provided; control means for detecting the presence of any said output signal and the resulting enabling signal; means for providing a disabling signal to said means for providing said enabling signal a third predetermined time interval after detection of said output signal by said control means; and, means for clearing said second register after at least a fourth predetermined time interval after detection of the presence of the previous output signal.
Claim 2
Dependent Claim
254 words
A keyboard entry device comprising, in combination charge storage means; a substantially constant current course for charging said charge storage means; a plurality of transformer cores; a plurality of electrically conductive lines, each being threaded through a unique combination of one or more of said cores; a plurality of switching means each for connecting said charge storage means to a corresponding one of said conductive lines so as to pass a current pulse between said one line and said charge storage means; a plurality of secondary windings, each disposed about a corresponding one of said cores for providing an output signal; a first register for storing said output signals from said secondary windings; a second register; gating means for selectively coupling said first and second registers; means for detecting the presence of a said output signal at any of said secondary windings; means for providing an enabling signal to said gating means a first predetermined time interval after detection of the presence of any said output signal; means for clearing said first register a second predetermined time interval after said enabling signal is provided; control means for detecting the presence of any said output signal and the resulting enabling signal; means for providing a disabling signal to said means for providing said enabling signal a third predetermined time interval after detection of said output signal by said control means; and, means for clearing said second register after at least a fourth predetermined time interval after detection of the presence of the previous output signal.
Claim 3
Dependent Claim
30 words
A keyboard entry device as defined in claim 1 wherein said charge storage means comprises a plurality of capacitive means, each associated with a respective one of said conductive means.
Claim 4
Dependent Claim
30 words
A keyboard entry device as defined in claim 2 wherein said current source is connected to said capacitors for charging the latter while the corresponding said switching means are open.
Claim 5
Dependent Claim
31 words
A keyboard entry device as defined in claim 2 wherein each of said capacitive means has associated therewith a comparatively short discharge time constant and a comparatively long charging time constant.
Claim 6
Dependent Claim
31 words
A keyboard entry device as defined in claim 1 wherein said cores are formed of a material in which the magnetic permeability is substantially reduced at frequencies above about 1 MHz.
Claim 7
Dependent Claim
258 words
In a keyboard entry device of the type having means for producing a current, a plurality of encoding elements, a plurality of primary electrically conductive lines each being connected to a unique combination of one or more of said encoding elements, a plurality of switching means each for connecting said means for producing a current to a corresponding one of said primary conductive lines so as to pass a current pulse over said one of said primary lines, a plurality of secondary electrically conductive lines each connected to a corresponding one of said encoding elements for providing an output signal, a first register for storing said output signals from said secondary lines, a second register, gating means for selectively coupling said first and second registers; the improvement comprising; means for detecting the presence of a said output signal at any of said secondary lines; means for providing an enabling signal to said grating means a first predetermined time interval after detection of the presence of any said output signal; means for clearing said first register a second predetermined time interval after said enabling signal is provided; control means for detecting the presence of the any said output signal and the resulting enabling signal; means for providing a disabling signal to said means for providing said enabling signal for a third predetermined time interval after detection of said output signal by said control means; and means for clearing said second register after at least a fourth predetermined time interval after detection of the presence of the previous output signal.
Claim 8
Dependent Claim
258 words
In a keyboard entry device of the type having means for producing a current, a plurality of encoding elements, a plurality of primary electrically conductive lines each being connected to a unique combination of one or more of said encoding elements, a plurality of switching means each for connecting said means for producing a current to a corresponding one of said primary conductive lines so as to pass a current pulse over said one of said primary lines, a plurality of secondary electrically conductive lines each connected to a corresponding one of said encoding elements for providing an output signal, a first register for storing said output signals from said secondary lines, a second register, gating means for selectively coupling said first and second registers; the improvement comprising; means for detecting the presence of a said output signal at any of said secondary lines; means for providing an enabling signal to said grating means a first predetermined time interval after detection of the presence of any said output signal; means for clearing said first register a second predetermined time interval after said enabling signal is provided; control means for detecting the presence of the any said output signal and the resulting enabling signal; means for providing a disabling signal to said means for providing said enabling signal for a third predetermined time interval after detection of said output signal by said control means; and means for clearing said second register after at least a fourth predetermined time interval after detection of the presence of the previous output signal.
References Cited (Backward Citations)
US3500336A
Cited
US3573807A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-06-18 | 1976-12-18 | 1977-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-18 | 1980-12-18 | 1981-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-18 | 1984-12-18 | 1985-06-19 | $7700.00 | Window Closed / Lapsed |