US4764927A
Expired / Lapsed
US
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Code error correcting method
Assignee: Hitachi Ltd
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Filing: 1986-09-19
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Granted: 1988-08-16
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Expires: 2006-09-19
Abstract
Abstract An error detection and/or correction is achieved in the horizontal direction in a block and then an error state is determined by use of an error correction in the vertical direction; furthermore, the correcting system is changed over according to the result of the determination.
Inventors
- 👤 Morishi Izumita
- 👤 Seiichi Mita
- 👤 Nobukazu Doi
- 👤 Fuyuki Inui
- 👤 Akira Saito
- 👤 Mamoru Kaneko
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:39
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; G11B20/18; H; H03; H03M; H03M13/00; H03M13/29
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
198 words
A code error method for correcting errors in first and second error detection and/or error correction code words, said first error detection and/or error correction code words comprising a plurality of digital symbols in a first arrangement state and first parity symbols thereof and said second error detection and/or error correction code words including a plurality of digital symbols in a second arrangement state including symbols of said first error detection and/or error correction code words and second parity symbols thereof, comprising the steps of: effecting an error detection or an error correction by use of said second parity symbols; and determining thereafter by use of said first parity symbols whether or not errors included in said first error detection and/or correction code words occur successively and changing over, based on the outcome of the determination, to a first one of at least two types of error correcting systems if errors in said first error detection and/or error correction code words were determined to occur successively or to a second of said at least two types of error correcting systems if errors in said first error detecting and/or error correction code words were determined not to occur successively.
Claim 2
Dependent Claim
198 words
A code error method for correcting errors in first and second error detection and/or error correction code words, said first error detection and/or error correction code words comprising a plurality of digital symbols in a first arrangement state and first parity symbols thereof and said second error detection and/or error correction code words including a plurality of digital symbols in a second arrangement state including symbols of said first error detection and/or error correction code words and second parity symbols thereof, comprising the steps of: effecting an error detection or an error correction by use of said second parity symbols; and determining thereafter by use of said first parity symbols whether or not errors included in said first error detection and/or correction code words occur successively and changing over, based on the outcome of the determination, to a first one of at least two types of error correcting systems if errors in said first error detection and/or error correction code words were determined to occur successively or to a second of said at least two types of error correcting systems if errors in said first error detecting and/or error correction code words were determined not to occur successively.
Claim 3
Dependent Claim
34 words
A method according to claim 1, wherein said first of said at least two types of error correcting systems of said first error detecting and/or error correcting code words is an erasure correcting system.
Claim 4
Dependent Claim
25 words
A method according to claim 1 wherein said two types of error correcting systems are a random error correcting system and an erasure correcting system.
Claim 5
Dependent Claim
65 words
A method according to claim 1, wherein said step of changing over further comprises: changing over to an erasure correcting system when it is determined that errors in said first error detection and/or error correction code words occur successively, and changing over to a random error correcting system when it is determined that errors in said first error detection and/or correction code words occur randomly.
Claim 6
Dependent Claim
56 words
A method according to claim 4, wherein said plurality of digital symbols in said first and second arrangements corresponds to vertical columns and horizontal rows of a double-encoding code system, respectively, and wherein said random error correcting system is a vertical random error correction circuit and said erasure correcting system is a vertical erasure correction circuit.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-08-16 | 1992-02-15 | 1992-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-16 | 1996-02-15 | 1996-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-16 | 2000-02-15 | 2000-08-16 | $7700.00 | Window Closed / Lapsed |