US4942486A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Recording disk having read-only recording area and writable recording area and a driving apparatus therefor
Assignee: Sony Corp
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Filing: 1988-06-30
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Granted: 1990-07-17
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Expires: 2008-06-30
Abstract
Abstract A record disk has a read-only track area and a writable track area in which a guard band of a sufficient width is formed between such two areas for prevention of erroneous writing into the read-only track area during data writing into the writable track area. Apparatus using such disk employs a pair of heads with opposite azimuth angles and erasing of a track is first checked to prevent a read-only track from being erased. During such track erasing, a track recorded by a head with one azimuth is erased by a head with the other azimuth.
Inventors
- 👤 Ken Kutaragi
- 👤 Shoji Tanaka
- 👤 Yasushi Fujinami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:03
CPC Classifications
G; G11; G11B; G11B27/00; G11B27/10; G11B27/19; G11B27/28; G11B27/30; G11B27/3027; G11B20/00; G11B20/10; G11B20/12; G11B11/00; G11B11/10; G11B11/105; G11B11/10595; G11B11/10597; G11B19/00; G11B19/02; G11B19/04; G11B20/1217; G11B20/1252; G11B20/18; G11B20/1833; G11B27/11; G11B27/13; G11B5/00; G11B5/012; G11B5/48; G11B5/488; G11B5/4886; G11B2020/1259; G11B2220/00; G11B2220/20; G11B2220/25; G11B2220/2508; G11B2220/2512
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
105 words
A recording disk comprising: a magnetic recording medium forming the recording disk; a read-only track area including a plurality of read-only tracks each separated by read-only guard band; a writable track area including a plurality of writable tracks, each separated by a write guard band; and an additional write guard band between a last read-only track in said read-only track area and an adjacent writable track in said writable track area, all of said write guard bands having a selected width wider than said read-only guard bands for preventing erroneous writing into said read-only track area during writing of data into said writable track area.
Claim 2
Dependent Claim
105 words
A recording disk comprising: a magnetic recording medium forming the recording disk; a read-only track area including a plurality of read-only tracks each separated by read-only guard band; a writable track area including a plurality of writable tracks, each separated by a write guard band; and an additional write guard band between a last read-only track in said read-only track area and an adjacent writable track in said writable track area, all of said write guard bands having a selected width wider than said read-only guard bands for preventing erroneous writing into said read-only track area during writing of data into said writable track area.
Claim 3
Dependent Claim
35 words
A recording disk according to claim 1, wherein said read-only track area contains data recorded therein and wherein said data includes a read-only code for preventing said read-only track area from being written and erased.
Claim 4
Dependent Claim
32 words
A recording disk according to claim 1, wherein a recording azimuth of the read-only tracks and a writable track adjacent to each other are selected to be equal and in opposite directions.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-07-16 | 1994-01-15 | 1994-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-16 | 1998-01-15 | 1998-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-16 | 2002-01-15 | 2002-07-17 | $7700.00 | Window Closed / Lapsed |