Patent US4377805A successfully refreshed from Google Patents.
US4377805A
Expired / Lapsed
US
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Magnetic recording
Assignee: QED Intellectual Property Ltd
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Filing: 1981-04-20
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Granted: 1983-03-22
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Expires: 2001-04-20
Abstract
Abstract A method and apparatus for encoding or decoding data in accordance with a coding format, referred to herein as Yφ and which is based on the 3PM coding format. Data encoded in accordance with the Yφ format is generated by initially encoding, at a prearranged clocking frequency, binary data in accordance with 3PM format, applying such encoded data to one input terminal of an exclusive OR gate and applying clocking pulses, at the prearranged frequency to the other input terminal. Decoding is similarly achieved by passing the encoded data through an exclusive OR gate. Data encoded according to the Yφ format is particularly advantageous on account of the relatively high density of flux transitions which it generates, which may be desirable in certain circumstances particularly if both high and low rate data is to be encoded on the same magnetic tape.
Inventors
- 👤 Paul Youhill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 07:17
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; G11B20/14; G11B20/1403; G11B20/1423; G11B20/1426
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
72 words
An apparatus for encoding binary data signals comprising means for encoding said data signals, at a prearranged clocking frequency, according to the 3PM format, and an exclusive OR gate for receiving said encoded signals at one input terminal, and for receiving clocking pulses, at said prearranged frequency, at the other input terminal, and means for receiving at an output location encoded data signals generated at the output terminal of said OR gate.
Claim 2
Independent Claim
72 words
An apparatus for encoding binary data signals comprising means for encoding said data signals, at a prearranged clocking frequency, according to the 3PM format, and an exclusive OR gate for receiving said encoded signals at one input terminal, and for receiving clocking pulses, at said prearranged frequency, at the other input terminal, and means for receiving at an output location encoded data signals generated at the output terminal of said OR gate.
Claim 3
Dependent Claim
73 words
An apparatus for decoding data signals generated by an apparatus according to claim 1, comprising, an exclusive OR gate for receiving the signals to be decoded at one input terminal and for receiving clocking pulses at said prearranged frequency at the other input terminal, so as to generate at the output terminal thereof data signals encoded in accordance with the 3PM format, and means for decoding the signals generated at the output terminal.
Claim 4
Dependent Claim
111 words
A magnetic recording apparatus including an apparatus for encoding binary data signals comprising means for encoding said data signals at a prearranged clocking frequency, according to the 3PM format and an exclusive OR gate for receiving said encoded signals at one input terminal and for receiving clocking pulses, at said prearranged frequency, at the other input terminal and means for receiving, at an output location, encoded data signals generated at the output terminal of said OR gate, the recording apparatus further including means for selectively recording the data generated at the output terminal of said OR gate or encoded according to the 3PM format at respective relatively high or low rates.
Claim 5
Dependent Claim
111 words
A magnetic recording apparatus including an apparatus for encoding binary data signals comprising means for encoding said data signals at a prearranged clocking frequency, according to the 3PM format and an exclusive OR gate for receiving said encoded signals at one input terminal and for receiving clocking pulses, at said prearranged frequency, at the other input terminal and means for receiving, at an output location, encoded data signals generated at the output terminal of said OR gate, the recording apparatus further including means for selectively recording the data generated at the output terminal of said OR gate or encoded according to the 3PM format at respective relatively high or low rates.
Claim 6
Dependent Claim
76 words
A magnetic recording apparatus according to claim 3 including a further exclusive OR gate for receiving at one input terminal signals recorded at said relatively high rate and for receiving clocking pulses at said prearranged frequency at the other input terminal so as to generate at the output terminal thereof data signals encoded in accordance with the 3PM format, and means for decoding the signals generated at said output terminal of the further exclusive OR gate.
References Cited (Backward Citations)
US3685033A
Cited
US3988729A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-03-21 | 1986-09-20 | 1987-03-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-03-21 | 1990-09-20 | 1991-03-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-03-21 | 1994-09-20 | 1995-03-22 | $7700.00 | Window Closed / Lapsed |