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EP0180100A2
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Apparatus and method for recording and recovering a binary symbol sequence using an intermediate step of converting the binary sequence into a ternary sequence
Assignee: International Business Machines Corp
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Filing: 1985-10-17
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Granted: —
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Expires: 2005-10-17
Abstract
Abstract The present invention relates to apparatus for recording representations of a binary symbol sequence which comprises conversion means (1) for converting the binary symbol sequence into a ternary symbol sequence, and recording means (3, 5, 7) for recording representations of the ternary symbol sequence. In accordance with the invention, the recording apparatus is characterised in that the conversion means comprises mapping means for mapping the binary symbol sequence into a direction constrained run length limited ternary symbol sequence, and the recording means comprises means for recording the ternary symbol sequence as selected recording levels with half transitions and full transitions between recording levels in such a way that each half transition is followed by another half transition of the same polarity. The present invention also relates to a method of recording representations of a binary symbol sequence utilising recording apparatus as above. The invention further relates to a combination of recording apparatus as above with means (11 to 16) for recovering the binary symbol sequence from the recorded representations, and to a combination of a method of recording as above with a method of recovering the binary symbol sequence from the recorded representations.
Inventors
- 👤 Glen George Langdon, Jr.
- 👤 Paul Howard Siegel
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 06:23
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; G11B20/14; G11B20/1488; G11B20/1492
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
106 words
Apparatus for recording representations of a binary symbol sequence comprising conversion means (1) for converting said binary symbol sequence into a ternary symbol sequence, and recording means (3, 5, 7) for recording representations of said ternary symbol sequence, characterised in that said conversion means comprises mapping means for mapping said binary symbol sequence into a direction constrained run length limited ternary symbol sequence, and said recording means comprises means for recording said ternary symbol sequence as selected recording levels with half transitions and full transitions between recording levels in such a way that each half transition is followed by another half transition of the same polarity.
Claim 2
Dependent Claim
106 words
Apparatus for recording representations of a binary symbol sequence comprising conversion means (1) for converting said binary symbol sequence into a ternary symbol sequence, and recording means (3, 5, 7) for recording representations of said ternary symbol sequence, characterised in that said conversion means comprises mapping means for mapping said binary symbol sequence into a direction constrained run length limited ternary symbol sequence, and said recording means comprises means for recording said ternary symbol sequence as selected recording levels with half transitions and full transitions between recording levels in such a way that each half transition is followed by another half transition of the same polarity.
Claim 3
Dependent Claim
55 words
Apparatus as claimed in Claim 1 characterised in that said mapping means comprises blocking means for k - bit blocking said binary symbol sequence, and conversion means for converting said blocked binary sequence into a direction constrained run length limited n - bit blocked ternary symbol sequence (where n > k) at a predetermined rate.
Claim 4
Dependent Claim
110 words
Apparatus as claimed in Claim 1 or Claim 2 in combination with apparatus (11 - 16) for recovering said binary symbol sequence from said recorded representations comprising reading means for generating output signals corresponding to said recorded representations and for converting said output signals into said binary symbol sequence, characterised in that said reading means comprises detecting means (11, 12) for detecting each transition in said recording levels, for determining the polarity of each detected transition and for generating corresponding signals, first converting means (15) for converting said signals into a ternary symbol sequence, and second converting means (16) for converting said ternary symbol sequence into said binary symbol sequence.
Claim 5
Dependent Claim
46 words
A combination as claimed in Claim 3 characterised in that said first converting means comprises means for initially assigning a ternary symbol to each detected transition, and means for subsequently modifying said initially assigned ternary symbol in accordance with the polarity of a succeeding detected transition.
Claim 6
Independent Claim
92 words
A method of recording representations of a binary symbol sequence comprising converting said binary symbol sequence into a ternary symbol sequence, and recording representations of said ternary symbol sequence, characterised in that said conversion operation comprises mapping said binary symbol sequence into a direction constrained run length limited ternary symbol sequence, and said recording operation comprises recording said ternary symbol sequence as selected recording levels with half transitions and full transitions between recording levels in such a way that each half transition is followed by another half transition of the same polarity.
Claim 7
Independent Claim
92 words
A method of recording representations of a binary symbol sequence comprising converting said binary symbol sequence into a ternary symbol sequence, and recording representations of said ternary symbol sequence, characterised in that said conversion operation comprises mapping said binary symbol sequence into a direction constrained run length limited ternary symbol sequence, and said recording operation comprises recording said ternary symbol sequence as selected recording levels with half transitions and full transitions between recording levels in such a way that each half transition is followed by another half transition of the same polarity.
Claim 8
Dependent Claim
50 words
A method as claimed in Claim 5 characterised in that said mapping operation comprises k - bit blocking said binary symbol sequence, and converting said blocked binary sequence into a direction constrained run length limited n - bit blocked ternary symbol sequence (where n > k) at a predetermined rate.
Claim 9
Dependent Claim
92 words
A method as claimed in Claim 5 or Claim 6 in combination with a method for recovering said binary symbol sequence from said recorded representations comprising generating output signals corresponding to said recorded representations and converting said output signals into said binary symbol sequence, characterised in that said signal generating operation comprises detecting each transition in said recording levels and detecting the polarity of each detected transition and generating corresponding signals, initially converting said signals into a ternary symbol sequence, and subsequently converting said ternary symbol sequence into said binary symbol sequence.
Claim 10
Dependent Claim
42 words
A combination as claimed in Claim 7 characterised in that said initial converting operation comprises initially assigning a ternary symbol to each detected transition, and subsequently modifying said initially assigned ternary symbol in accordance with the polarity of a succeeding detected transition.
References Cited (Backward Citations)
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