US3665430A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Digital tape error recognition method utilizing complementary information
Assignee: ERC ELECT RES CORP
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Filing: 1970-02-16
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Granted: 1972-05-23
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Expires: 1990-02-16
Abstract
Abstract A method for recognizing errors appearing during the playback of digital tape recordings by recording the digital information on one track of a tape and complementary information on the other track of the tape, the complementary information being constituted by pulses which occur during every period when no pulse appears on the information track, and combining the signals in the two tracks during playback to form a reference clock pulse train.
Inventors
- 👤 Kurt Hinrichs
- 👤 Gerd Wilken
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 07:18
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; G11B20/18; G11B20/1803; G06; G06F; G06F11/00; G06F11/07; G06F11/14; G11B20/16
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
138 words
A method for detecting errors which occur during the playback of digital magnetic tape recordings due to the appearance of spurious pulses, or due to the disappearance of a pulse, or due to synchronization variations, which tape has one track recorded with the digital information in the form of a series of pulse blocks each containing a predetermined number of bits to be reproduced, comprising the steps of: recording on a second track of the tape a train of pulses complementary to the recorded information; simultaneously recording, at identical points on both tracks, pulses corresponding to the beginning and end of each pulse block; combining both tracks during playback to form a reference clock pulse train and; counting each occurrence of a pulse on either track during each period between the beginning and end of each pulse block.
Claim 2
Independent Claim
138 words
A method for detecting errors which occur during the playback of digital magnetic tape recordings due to the appearance of spurious pulses, or due to the disappearance of a pulse, or due to synchronization variations, which tape has one track recorded with the digital information in the form of a series of pulse blocks each containing a predetermined number of bits to be reproduced, comprising the steps of: recording on a second track of the tape a train of pulses complementary to the recorded information; simultaneously recording, at identical points on both tracks, pulses corresponding to the beginning and end of each pulse block; combining both tracks during playback to form a reference clock pulse train and; counting each occurrence of a pulse on either track during each period between the beginning and end of each pulse block.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-23 | 1975-11-22 | 1976-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-23 | 1979-11-22 | 1980-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-23 | 1983-11-22 | 1984-05-23 | $7700.00 | Window Closed / Lapsed |