US4024534A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Keyboard encoding with repeat key pause
Assignee: Xerox Corp
•
Filing: 1975-11-24
•
Granted: 1977-05-17
•
Expires: 1995-11-24
Abstract
Abstract A keyboard encoding system having a pause built into the repeat key function. A multi-stage counter has a first of its stages coupled to a first bistable switching device and another, higher order stage coupled to a second bistable switching device. When a repeat key is closed, the counter is incremented past the first stage to the higher order stage which renders the second bistable switching device conductive and, due to the interconnection between the switching devices, primes the first bistable switching device. When the counter again increments to the first stage, the first bistable switching device conducts to produce, after the pause provided by the system, a repeat key encoding signal.
Inventors
- 👤 Wilbur E. DuVall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:35
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/94; H03K17/965; H03K17/975; H03K17/98; H03M; H03M11/00; H03M11/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
338 words
A system for encoding an array of switching devices, each of which has a low impedance in a closed state and a high impedance in an open state, at least one of said keys being a repeat key, comprising: a voltage source, signal amplitude sensing means, first means coupled to said array, to said voltage source, and to said signal amplitude sensing means for continuously cyclically sensing in a predetermined sequence the state of each of said switching devices of said array such that each of said switching devices of said array is coupled to said voltage source and said signal amplitude sensing means, whereby a signal of one amplitude is supplied to said signal amplitude sensing means when a closed switching device is coupled to said voltage source and said signal amplitude sensing means and a signal of a different amplitude is supplied to said signal amplitude sensing means when an open switching device is coupled to said voltage source and said signal amplitude sensing means, said signal amplitude sensing means providing an output signal of a high value when the input signal supplied thereto is above a certain amplitude, said output signal providing a first encoding signal, storage means coupled to said signal amplitude sensing means for storing the state of each of said switching devices during the previous scanned sequence, a multi-stage counter coupled to the outputs of said signal amplitude sensing means and said storage means, said counter incrementing when the output of said signal amplitude sensing means is high, the inverted output of said storage means is high, and the key being sensed is a repeat key, and first and second switching devices, said first switching device being coupled to a first stage of said counter, said second switching device being coupled to a second, higher order stage of said counter and to said first switching device, said first switching device being rendered conductive only after said second switching device is rendered conductive to provide a pause in the repeat key function encoding.
Claim 2
Independent Claim
338 words
A system for encoding an array of switching devices, each of which has a low impedance in a closed state and a high impedance in an open state, at least one of said keys being a repeat key, comprising: a voltage source, signal amplitude sensing means, first means coupled to said array, to said voltage source, and to said signal amplitude sensing means for continuously cyclically sensing in a predetermined sequence the state of each of said switching devices of said array such that each of said switching devices of said array is coupled to said voltage source and said signal amplitude sensing means, whereby a signal of one amplitude is supplied to said signal amplitude sensing means when a closed switching device is coupled to said voltage source and said signal amplitude sensing means and a signal of a different amplitude is supplied to said signal amplitude sensing means when an open switching device is coupled to said voltage source and said signal amplitude sensing means, said signal amplitude sensing means providing an output signal of a high value when the input signal supplied thereto is above a certain amplitude, said output signal providing a first encoding signal, storage means coupled to said signal amplitude sensing means for storing the state of each of said switching devices during the previous scanned sequence, a multi-stage counter coupled to the outputs of said signal amplitude sensing means and said storage means, said counter incrementing when the output of said signal amplitude sensing means is high, the inverted output of said storage means is high, and the key being sensed is a repeat key, and first and second switching devices, said first switching device being coupled to a first stage of said counter, said second switching device being coupled to a second, higher order stage of said counter and to said first switching device, said first switching device being rendered conductive only after said second switching device is rendered conductive to provide a pause in the repeat key function encoding.
References Cited (Backward Citations)
US3675239A
Cited
US3932838A
Cited
US3918051A
Cited
US3792466A
Cited
US3886543A
Cited
US3892915A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-05-16 | 1980-11-15 | 1981-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-16 | 1984-11-15 | 1985-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-16 | 1988-11-15 | 1989-05-17 | $7700.00 | Window Closed / Lapsed |