Patent US4947384A successfully refreshed from Google Patents.
US4947384A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical disk having narrow and wide guide grooves
Assignee: Pioneer Corp
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Filing: 1988-04-12
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Granted: 1990-08-07
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Expires: 2008-04-12
Abstract
Abstract An optical disk of the type including guide grooves is improved by regulating the width of the grooves, and thus the width of the adjacent land portion, in accordance with the type of information recorded at that part of the land.
Inventors
- 👤 Kenji Suzuki
- 👤 Toshihiko Takishita
- 👤 Satoru Fukuoka
- 👤 Hirokazu Hashikawa
- 👤 Tsuyoshi Hayashi
- 👤 Minemasa Ohta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:37
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/007; G11B7/00745; G11B7/24; G11B7/2407; G11B7/24073; G11B7/24079; G11B7/24076
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
123 words
An optical disk, comprising: guide grooves formed concentrically or spirally on the disk; and land portions each provided between adjacent ones of said guide grooves, said land portions including a signal recording region and a preformat region on which concave/convex pits having address information are formed; wherein said preformat region of said land portions has a substantially uniform width which is broader, in the radial direction of the disk, than that of said signal recording region, and a first portion of said guide grooves adjacent to said preformat region has a substantially uniform width which is narrower, in the radial direction of said guide grooves, than that of a second portion of said guide grooves which is adjacent to said signal recording region.
Claim 2
Dependent Claim
123 words
An optical disk, comprising: guide grooves formed concentrically or spirally on the disk; and land portions each provided between adjacent ones of said guide grooves, said land portions including a signal recording region and a preformat region on which concave/convex pits having address information are formed; wherein said preformat region of said land portions has a substantially uniform width which is broader, in the radial direction of the disk, than that of said signal recording region, and a first portion of said guide grooves adjacent to said preformat region has a substantially uniform width which is narrower, in the radial direction of said guide grooves, than that of a second portion of said guide grooves which is adjacent to said signal recording region.
Claim 3
Dependent Claim
40 words
An optical disk as claimed in claim 1, wherein a first portion of said guide grooves demarcating said preformat portion is narrower in width and shallower in depth than a second portion of said guide grooves demarcating said recording portion.
Claim 4
Dependent Claim
26 words
An optical disk as claimed in claim 2, wherein said guide grooves at said first portion are one of V-shaped and part circular in cross section.
Claim 5
Dependent Claim
33 words
An optical disk as claimed in claim 2, wherein said guide grooves at said second portion are U-shaped in cross section and have bottom surfaces defined by a substrate surface of said disk.
References Cited (Backward Citations)
US4517668A
Cited
US4494226A
Cited
US4587648A
Cited
JPS60236122A
Cited
JPS60247842A
Cited
US4716560A
Cited
US4748609A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-08-06 | 1994-02-05 | 1994-08-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-06 | 1998-02-05 | 1998-08-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-06 | 2002-02-05 | 2002-08-07 | $7700.00 | Window Closed / Lapsed |