Patent EP0026320A1 successfully refreshed from Google Patents.
EP0026320A1
Expired / Lapsed
EP
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Data recorder/reader and method of operating same
Assignee: International Business Machines Corp
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Filing: 1980-08-21
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Granted: —
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Expires: 2000-08-21
Abstract
Abstract A data recorder/reader provides forward/backward compatibility with record members of similar physical characteristics, but differing data record track densities. In a rotating head, helical tape recorder/reader, a single head 16 has a wide write gap 17 followed by a pair of aligned half width read gaps 18 and 19. During recording at high track density, the tape is stepped between recordings by drive 27 under the control of half step circuit 29 for a distance equal to half the width W2 of the write gap and to the width W1 of each read gap. During recording at low track density, the tape is stepped between recordings by drive 27 under the control of whole step circuit 28 for a distance equal to the width W2 of the write gap. Switching between circuits 28 and 29 is effected by pole 54 of switch S1. During read back at high density, two adjacent tracks are sensed simultaneously by read gaps 18 and 19 . Signals are fed back to individual read back circuits 31 and 37, those from the first read gap 18 being passed through switch 43 to data circuit 33 for immediate processing. Signals from the second read gap 19 are passed to a buffer 39 and buffered until a dead time occurs when no data is being sensed. The switch 43 is then operated to direct the buffered signals to data circuit 33 for processing. Between read backs, the tape is stepped by drive 27 under the control of whole step circuit 28 for a distance equal to the width W2 of the write gap. Circuit 28 is selected through pole 54 of switch S1 and pole 49 of switch S2. During read back at low track density, a single wide track is sensed simultaneously by read gaps 18 and 19. Signals from the first read gap 18 are processed immediately. Signals from the second read gap 19 may be inhibited or buffered for later processing in data circuit 33 in the event of error correction being required. Between read backs, the tape is stepped for a distance equal to the width W2 of the write gap.
Inventors
- 👤 Nelson Kay Arter
- 👤 Ernest William Devore
- 👤 Arthur Barton Wills
- 👤 Leslie Ray Zelenka
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 13:12
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/265; G11B15/00; G11B15/02; G11B15/12; G11B15/60; G11B15/602; G11B23/00; G11B23/0007; G11B27/00; G11B27/10; G11B27/19; G11B27/28; G11B27/30; G11B27/3027; G11B27/32; G11B27/322; G11B27/327; G11B27/328; G11B5/008; G11B5/00804; G11B5/00808; G11B5/00813; G11B5/00878; G11B5/012; G11B5/48; G11B5/52; G11B5/53; G11B15/05; G11B15/087
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
218 words
1 A data recorder/reader adapted to exchange data with a record member, including a transducer (16) adapted to scan tracks on the record member and having a write gap (17) with a first track width (W2) and a plurality N of read gaps (18,19) aligned with each other parallel to the write gap and aligned with the write gap in the direction of scan, each of the read gaps having a width (W1) corresponding to a second track width, being substantially a fraction 1/N of the first track width, whereby to scan simultaneously a plurality N of second width tracks, or a single first width track, track switching means operative during recording to cause relative movement of the transducer and record member for switching between juxtaposed second width tracks for high track density recording or between juxtaposed first width tracks for low track density recording, and operative during reproducing to cause relative movement of the transducer and record member for switching between juxtaposed groups of a plurality N of second width tracks for high track density reading or between juxtaposed first width tracks for low track density reading, means for simultaneously receiving signals from the read gaps which simultaneously scan a plurality N of second width tracks, and means for serializing all signals produced from the simultaneous scanning.
Claim 2
Dependent Claim
218 words
1 A data recorder/reader adapted to exchange data with a record member, including a transducer (16) adapted to scan tracks on the record member and having a write gap (17) with a first track width (W2) and a plurality N of read gaps (18,19) aligned with each other parallel to the write gap and aligned with the write gap in the direction of scan, each of the read gaps having a width (W1) corresponding to a second track width, being substantially a fraction 1/N of the first track width, whereby to scan simultaneously a plurality N of second width tracks, or a single first width track, track switching means operative during recording to cause relative movement of the transducer and record member for switching between juxtaposed second width tracks for high track density recording or between juxtaposed first width tracks for low track density recording, and operative during reproducing to cause relative movement of the transducer and record member for switching between juxtaposed groups of a plurality N of second width tracks for high track density reading or between juxtaposed first width tracks for low track density reading, means for simultaneously receiving signals from the read gaps which simultaneously scan a plurality N of second width tracks, and means for serializing all signals produced from the simultaneous scanning.
Claim 3
Dependent Claim
100 words
2 A recorder/reader according to claim 1, in which the recorder/reader has a cyclic period of operation during a predetermined portion of which the transducer scans a data record area on the record member, means for serially transferring signals from one of the read gaps while the head is scanning the record area, means for momentarily storing signals read from the other read gap or gaps during the predetermined portion of the cyclic period, and means for serially transferring the stored signals from the other read gap or gaps during a portion of the cyclic period outside the predetermined portion.
Claim 4
Dependent Claim
74 words
3 A recorder/reader according to claim 2, in which the transducer alternately scans data and non-data areas, the means for serializing signals includes means for immediately processing signals from the one read gap, the means for momentarily storing signals includes a buffer for each read gap other than the one read gap, and the means for serially transferring the stored signals includes means for selectively transferring buffer signals through the immediate signal processing means.
Claim 5
Dependent Claim
86 words
4 A recorder/reader according to any preceding claim, including density indication means for indicating a high track density or a low track density recording to be read, the means for serializing signals being responsive to a low track density indication for supplying signals from the one read gap to the exclusion of signals read from any read gap other than the one read gap and means responsive to a low track density indication to inhibit the track switching means from switching between juxtaposed second width tracks.
Claim 6
Dependent Claim
52 words
5 A recorder/reader according to claim 4, in which the record member includes a recorded indication of recording track density, and the transducer is operative to sense the recording track density indication and to initiate control of the signal serializing means and track switching means in accordance with the indication so sensed.
Claim 7
Dependent Claim
25 words
6 A recorder/reader according to claim 5, including means to force a low track density indication whenever the recorded density indication is to be sensed.
Claim 8
Dependent Claim
49 words
7 A recorder/reader according to any preceding claim, including density indication means for indicating a high track density or a low track density recording to be recorded, and means responsive to a high track density indication to enable the track switching means to switch between juxtaposed second width tracks.
Claim 9
Dependent Claim
72 words
8 A record/reader according to claim 3 or any claim appendant to claim 3, in which the signal receiving means includes a readback circuit for each of the read gaps, each of the readback circuits, except the first readback circuit, being connected to supply output signals to a buffer, and electronic switch means connecting the immediate signal processing means to receive signals selectively from the first readback circuit or from the buffers.
Claim 10
Dependent Claim
60 words
9 A recorder/reader according to any preceding claim, in which a rotor supports the transducer for rotation along a scan path and the record member is an elongated flexible tape scanned obliquely by the transducer as it rotates, and the track switching means includes tape transport means for selectively moving the record member a half step or a whole step.
Claim 11
Dependent Claim
73 words
10 A recorder/reader according to claim 9, in which the transducer is arranged to transduce data on the record medium during substantially one half revolution of the head, the signal receiving means includes a buffer for signals received from each of the read gaps, except a first read gap, and the signal serializing means includes means to transfer signals from the buffer or buffers during the non-data transducing portion of the head rotation.
Claim 12
Dependent Claim
24 words
11 A recorder/reader according to claim 10 including means inhibiting transfer of signals from the buffer or buffers during low track density record reading.
Claim 13
Dependent Claim
39 words
12 A recorder/reader according to any of claims 1 to 8, in which the record member is a circular disk and the transducer scans radially displaced tracks on the disk, the tracks having interleaved track position and data areas.
Claim 14
Dependent Claim
90 words
13 A method of operating a data recorder/reader according to claim 1, to record signals with high track density, including the steps of recording signals on the record medium using the write gap of the transducer to record signals in a track having the first track width, causing relative movement between the record medium and the transducer by a predetermined transverse distance equal to the second track width, and repeating the recording and relative movement causing steps a plurality of times to record signals in a plurality of parallel tracks.
Claim 15
Dependent Claim
78 words
14 A method of operating a data recorder/reader according to claim 1, to read signals recorded in parallel data tracks with high track density, including the steps of simultaneously longitudinally scanning a selected plurality N of record tracks using the read gaps of the transducer to produce a plurality N of simultaneous trains of sensed signals, and causing relative movement of the record medium and the transducer by a predetermined transverse distance equal to the first track width.
Claim 16
Dependent Claim
62 words
15 A method according to claim 14, further including the steps of repeating the simultaneous scanning and relative movement causing steps and, for each such repetition, processing one of the trains of sensed signals as such signals are sensed from the record medium, buffering and storing all other trains of sensed signals, and processing the buffered trains before repeating each simultaneous scanning.
References Cited (Backward Citations)
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