US5315573A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Non-linear optical saturable absorber layer in an optical disk to discriminate wavelength above or below a threshold level of intensity
Assignee: Hitachi Ltd
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Filing: 1992-07-31
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Granted: 1994-05-24
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Expires: 2012-07-31
Abstract
Abstract An information recording medium for suppressing the interferences of bits before and after reproduction and improving the optical resolution with saturable absorber 102 disposed adjacent or in an information recording medium layer 103. The recorded information is detected only from a region having a predetermined optical intensity or more of the focused spot so that minute information bits smaller than the optical resolution can be reproduced to improve the recording density of an optical disk drive drastically.
Inventors
- 👤 Takeshi Nakao
- 👤 Akira Arimoto
- 👤 Kensuke Ogawa
- 👤 Hirofumi Sukeda
- 👤 Hisataka Sugiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 15:12
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/004; G11B7/005; G11B7/12; Y; Y10; Y10S; Y10S430/00; Y10S430/146
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
182 words
An optical information device, comprising: an information recording layer having a stored information correlated pattern for one of transmitting or reflecting an incident beam of light in a corresponding information related beam of light; a non-linear optical saturable absorber that is effectively transparent to light of a first wavelength, that is effectively transparent to light of a second wavelength above a threshold level of intensity, and that is opaque to light of the second wavelength below the threshold level of intensity; recording laser means for producing a first beam of recording light at the first wavelength; optical means for shaping the first beam of light and directing it along a path intersecting the saturable absorber and the information recording layer; separate laser means for producing a second beam of reproducing light of the second wavelength; second optical means for shaping the second beam of light and directing it along a path intersecting the saturable absorber and the information recording layer; and optical means for receiving light reflected by or transmitted through the information recording layer from the second beam for reading information.
Claim 2
Dependent Claim
182 words
An optical information device, comprising: an information recording layer having a stored information correlated pattern for one of transmitting or reflecting an incident beam of light in a corresponding information related beam of light; a non-linear optical saturable absorber that is effectively transparent to light of a first wavelength, that is effectively transparent to light of a second wavelength above a threshold level of intensity, and that is opaque to light of the second wavelength below the threshold level of intensity; recording laser means for producing a first beam of recording light at the first wavelength; optical means for shaping the first beam of light and directing it along a path intersecting the saturable absorber and the information recording layer; separate laser means for producing a second beam of reproducing light of the second wavelength; second optical means for shaping the second beam of light and directing it along a path intersecting the saturable absorber and the information recording layer; and optical means for receiving light reflected by or transmitted through the information recording layer from the second beam for reading information.
Claim 3
Dependent Claim
12 words
The device of claim 1, wherein said saturable absorber is nickel phtalocyanine.
Claim 4
Dependent Claim
29 words
The device of claim 1, wherein said saturable absorber has an absorptivity of about 1.00 at the second wavelength and an absorptivity of about 0 at the first wavelength.
Claim 5
Dependent Claim
20 words
The device of claim 1, wherein said second wavelength for reproducing is substantially shorter than said first wavelength for recording.
Claim 6
Dependent Claim
60 words
The device of claim 1, further including means for mounting the saturable absorber and information recording layer on an optical disk for rotation about an axis; an optical recording head and an optical reproducing head mounted for radial movement adjacent to said disk with respect to said axis, and said heads respectively carrying said recording laser and said reproducing laser.
Claim 7
Dependent Claim
22 words
The device of claim 1, wherein said first wavelength is about 800 nm and wherein said second wavelength is about 650 nm.
Claim 8
Dependent Claim
12 words
The device of claim 1, wherein said saturable absorber is copper naphtalocyanine.
Claim 9
Dependent Claim
15 words
The device of claim 1, wherein said saturable absorber is a metal complex of naphtalocyanine.
Claim 10
Dependent Claim
19 words
The device of claim 1, wherein said saturable absorber has an absorbing wavelength of 600 mm to 800 mm.
Claim 11
Dependent Claim
123 words
An optical information device, comprising: an information recording layer having a stored information correlated pattern for one of transmitting or reflecting an incident beam of light in a corresponding information related beam of light; a non-linear optical saturable absorber that is effectively transparent to light of a wavelength above a threshold level of intensity, and that is opaque to light of the wavelength below the threshold level of intensity; laser means for producing a first beam of light at the wavelength; optical means for shaping the first beam of light and directing it along a path intersecting the saturable absorber and the information recording layer; and optical means for receiving light reflected by or transmitted through the information recording layer for reading information.
Claim 12
Dependent Claim
123 words
An optical information device, comprising: an information recording layer having a stored information correlated pattern for one of transmitting or reflecting an incident beam of light in a corresponding information related beam of light; a non-linear optical saturable absorber that is effectively transparent to light of a wavelength above a threshold level of intensity, and that is opaque to light of the wavelength below the threshold level of intensity; laser means for producing a first beam of light at the wavelength; optical means for shaping the first beam of light and directing it along a path intersecting the saturable absorber and the information recording layer; and optical means for receiving light reflected by or transmitted through the information recording layer for reading information.
Claim 13
Dependent Claim
50 words
The device of claim 10, further including means for mounting the saturable absorber and information recording layer on an optical disk for rotation about an axis; an optical reproducing head mounted for radial movement adjacent to said disk with respect to said axis, and said heads carrying said reproducing laser.
Claim 14
Dependent Claim
21 words
The device of claim 11, wherein said non-linear optical saturable absorber has an absorbing wavelength of 600 nm to 800 nm.
Claim 15
Dependent Claim
13 words
The device of claim 11, wherein said non-linear optical material is copper naphtalocyanine.
Claim 16
Dependent Claim
21 words
The device of claim 13, wherein said non-linear optical saturable absorber has an absorbing wavelength of 600 mm to 800 mm.
Claim 17
Dependent Claim
16 words
The device of claim 11, wherein said non-linear optical material is a metal complex of naphtalocyanine.
Claim 18
Dependent Claim
21 words
The device of claim 15, wherein said non-linear optical saturable absorber has an absorbing wavelength of 600 nm to 800 nm.
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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) | 1997-05-23 | 1997-11-22 | 1998-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-05-23 | 2001-11-22 | 2002-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-05-23 | 2005-11-22 | 2006-05-24 | $7700.00 | Window Closed / Lapsed |