Patent EP0098688A1 successfully refreshed from Google Patents.
US4586173A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical disk
Assignee: Toshiba Corp
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Filing: 1983-07-08
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Granted: 1986-04-29
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Expires: 2003-07-08
Abstract
Abstract In an optical disk, a light reflective layer is formed on a transparent substrate, and a groove serving as a tracking guide is formed on the surface of said light reflective layer, continuously extending along the circumference of the optical disk. Pits are formed in a light reflective layer on the bottom surface of the tracking guide. The depth and width of said groove are ##EQU1## and w0/2, respectively, and those of said pits are ##EQU2## and w0/3, respectively, where λ is the wavelength of a laser beam, w0 is the diameter of a laser beam spot on the optical disk, and n is an integer.
Inventors
- 👤 Hideo Ando
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:18
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/2407; G11B7/24085
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
171 words
A laser beam readable optical disk comprising: a disk-shaped plate having a first light reflective surface; a tracking guide defined by a groove which is so formed on said first light reflective surface of the plate as to continuously extend along the circumference of the plate, said groove having a flat light reflective bottom surface and a depth of substantially ##EQU5## where λ is the wavelength of a laser beam converged on the optical disk, and n is an integer and a width of substantially w0/2, where w0 is the diameter of a laser beam spot formed on the optical disk; first pits formed on said bottom surface of the groove, to reflect light, having a width narrower than that of the tracking guide said first pits having a depth of ##EQU6## where λ is the wavelength of said laser beam converged on the optical disk, and n is an integer the width being substantially w0/3, where w0 is the diameter of a laser beam spot formed on the optical disk.
Claim 2
Dependent Claim
171 words
A laser beam readable optical disk comprising: a disk-shaped plate having a first light reflective surface; a tracking guide defined by a groove which is so formed on said first light reflective surface of the plate as to continuously extend along the circumference of the plate, said groove having a flat light reflective bottom surface and a depth of substantially ##EQU5## where λ is the wavelength of a laser beam converged on the optical disk, and n is an integer and a width of substantially w0/2, where w0 is the diameter of a laser beam spot formed on the optical disk; first pits formed on said bottom surface of the groove, to reflect light, having a width narrower than that of the tracking guide said first pits having a depth of ##EQU6## where λ is the wavelength of said laser beam converged on the optical disk, and n is an integer the width being substantially w0/3, where w0 is the diameter of a laser beam spot formed on the optical disk.
Claim 3
Dependent Claim
39 words
The optical disk according to claim 1, wherein said disk-shaped plate is composed of a transparent substrate with a light reflective layer formed thereon, and said tracking guide and said first pits are composed of said light reflective layer.
Claim 4
Dependent Claim
27 words
The optical disk according to claim 2, further comprising second pits which are formed by removing a light reflective layer from the bottom surface of the groove.
Claim 5
Dependent Claim
16 words
The optical disk according to claim 1, wherein said tracking guide is of a spiral configuration.
Claim 6
Dependent Claim
13 words
The optical disk according to claim 1, wherein said tracking guide is concentric.
Claim 7
Dependent Claim
176 words
An optical disk comprising: a disk-shaped plate having a first light reflective surface; a tracking guide defined by a ridge which is so formed on said first light reflective surface of the plate as to continuously extend along the circumference of the plate, said ridge having a flat light reflective top surface said tracking guide having a height of substantially ##EQU7## where λ is the wavelength of a laser beam converged on the optical disk, and n is an integer said tracking guide having a width of substantially w0/2, where w0 is the diameter of a laser beam spot formed on the optical disk; and projections formed on the top surface of the ridge, to reflect light, having a width narrower than that of the tracking guide said projections having a height of ##EQU8## where λ is the wavelength of a laser beam converged on the optical disk, and n is an integer said projections having a width of substantially w0/3, where w0 is the diameter of a laser beam spot formed on the optical disk.
Claim 8
Dependent Claim
176 words
An optical disk comprising: a disk-shaped plate having a first light reflective surface; a tracking guide defined by a ridge which is so formed on said first light reflective surface of the plate as to continuously extend along the circumference of the plate, said ridge having a flat light reflective top surface said tracking guide having a height of substantially ##EQU7## where λ is the wavelength of a laser beam converged on the optical disk, and n is an integer said tracking guide having a width of substantially w0/2, where w0 is the diameter of a laser beam spot formed on the optical disk; and projections formed on the top surface of the ridge, to reflect light, having a width narrower than that of the tracking guide said projections having a height of ##EQU8## where λ is the wavelength of a laser beam converged on the optical disk, and n is an integer said projections having a width of substantially w0/3, where w0 is the diameter of a laser beam spot formed on the optical disk.
Claim 9
Dependent Claim
38 words
The optical disk according to claim 6, wherein said disk-shaped plate is composed of a transparent substrate with a light reflective layer formed thereon, and said tracking guide and said projections are composed of said light reflective layer.
Claim 10
Dependent Claim
27 words
The optical disk according to claim 7, further comprising second pits which are formed by removing a light reflective layer from the top surface of the ridge.
Claim 11
Dependent Claim
16 words
The optical disk according to claim 6, wherein said tracking guide is of a spiral configuration.
Claim 12
Dependent Claim
13 words
The optical disk according to claim 6, wherein said tracking guide is concentric.
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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) | 1989-04-28 | 1989-10-28 | 1990-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-28 | 1993-10-28 | 1994-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-28 | 1997-10-28 | 1998-04-29 | $7700.00 | Window Closed / Lapsed |