Patent US4744074A successfully refreshed from Google Patents.
US4744074A
Expired / Lapsed
US
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Disk-type recording medium
Assignee: Panasonic Holdings Corp
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Filing: 1985-09-02
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Granted: 1988-05-10
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Expires: 2005-09-02
Abstract
Abstract A disk-type recording medium having circular or spiral tracks storing information. The tracks are radially and regularly spaced from one another. Each track has pregrooves (2), ridges, or protrusions, and discrete depressions (7,9), ridges, or protrusions. The depressions (7,9) are so disposed that the depressions of neighboring tracks do not neighbor one another. In playback, the depressions (7,9) of neighboring tracks do not cause crosstalk. Thus, the disk permits the identifying signals to be stably and correctly reproduced.
Inventors
- 👤 Ryoichi Imanaka
- 👤 Masatsugu Tanji
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 21:07
CPC Classifications
G; G11; G11B; G11B27/00; G11B27/10; G11B27/19; G11B27/28; G11B27/30; G11B23/00; G11B23/0014; G11B23/0021; G11B7/00; G11B7/007; G11B7/00745; G11B7/24; G11B7/2407; G11B7/24085; G11B7/24073; G11B7/24076
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
106 words
A disk-type recording medium, comprising a disk having curved tracks thereon around the center thereof which are radially regularly spaced from one another for storing information thereon, each track having elongated information storage pregrooves, ridges or protrusions therealong and having identifying signal depressions, ridges or protrusions therealong, the information storage pregrooves, ridges or protrusions having changed condition portions corresponding to information signals, and the discrete identifying signal depressions, ridges or protrusions being disposed along the tracks at positions other than positions neighboring the identifying signal depressions, ridges or protrusions on adjacent tracks, and which positions further neighbor information storage pregrooves, ridges or protrusions on adjacent tracks.
Claim 2
Dependent Claim
106 words
A disk-type recording medium, comprising a disk having curved tracks thereon around the center thereof which are radially regularly spaced from one another for storing information thereon, each track having elongated information storage pregrooves, ridges or protrusions therealong and having identifying signal depressions, ridges or protrusions therealong, the information storage pregrooves, ridges or protrusions having changed condition portions corresponding to information signals, and the discrete identifying signal depressions, ridges or protrusions being disposed along the tracks at positions other than positions neighboring the identifying signal depressions, ridges or protrusions on adjacent tracks, and which positions further neighbor information storage pregrooves, ridges or protrusions on adjacent tracks.
Claim 3
Dependent Claim
34 words
A disk-type recording medium as claimed in claim 1 in which the discrete identifying signal depressions, ridges or protrusions are wider than the changed condition portions in said information storage pregrooves, ridges or protrusions.
Claim 4
Dependent Claim
31 words
A disk-type recording medium as claimed in claim 1 in which said tracks further have mark signal geometrical variations therealong at positions preceding the discrete identifying signal depressions, ridges or protrusions.
Claim 5
Dependent Claim
16 words
A disk-type recording medium as claimed in claim 1 in which said pregrooves are V-shaped grooves.
References Cited (Backward Citations)
DE2066017B1
Cited
GB2018489A
Cited
JPS57103136A
Cited
JPS5812149A
Cited
JPS5832239A
Cited
JPS58102347A
Cited
JPS58128043A
Cited
JPS5930252A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-05-10 | 1991-11-09 | 1992-05-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-10 | 1995-11-09 | 1996-05-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-10 | 1999-11-09 | 2000-05-10 | $7700.00 | Window Closed / Lapsed |