US4868807A
Expired / Lapsed
US
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Wavelength selective optical data storage system
Assignee: Mitsubishi Electric Corp
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Filing: 1988-04-15
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Granted: 1989-09-19
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Expires: 2008-04-15
Abstract
Abstract A recording medium for wavelength selective optical data storage has at least one memory element on which information is recorded by creating recording holes on the absorption spectrum thereof. The spectrum has at least one prerecorded hole for identifying the wavelength positions of the recording holes.
Inventors
- 👤 Kazuo Okada
- 👤 Michihiro Tadokoro
- 👤 Hitoshi Imai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:35
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/007; G11B7/00745; G11B27/00; G11B27/36; G11B7/004; G11B7/0045; G11B7/00453
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
151 words
A wavelength selective optical data storage system comprising: a light source emitting a light beam with a variable wavelength, a storage medium having at least one memory element with a characteristic of wavelength selective optical data storage, on which information is recorded by creating recording holes by a narrow band light beam at selected wavelength positions on an absorption spectrum of said memory element of said medium; an optical means for guiding and focusing the beam emitted from the source onto the recording medium, and a photodetector for detecting the beam emitted from said source after it is transmitted through or reflected by the recording medium, and wherein the absorption spectrum of every memory element has at least one prerecorded hole at a predetermined wavelength position for acting as a reference for identifying wavelength positions of the recording holes to be recorded on or read from each of said memory elements.
Claim 2
Dependent Claim
151 words
A wavelength selective optical data storage system comprising: a light source emitting a light beam with a variable wavelength, a storage medium having at least one memory element with a characteristic of wavelength selective optical data storage, on which information is recorded by creating recording holes by a narrow band light beam at selected wavelength positions on an absorption spectrum of said memory element of said medium; an optical means for guiding and focusing the beam emitted from the source onto the recording medium, and a photodetector for detecting the beam emitted from said source after it is transmitted through or reflected by the recording medium, and wherein the absorption spectrum of every memory element has at least one prerecorded hole at a predetermined wavelength position for acting as a reference for identifying wavelength positions of the recording holes to be recorded on or read from each of said memory elements.
Claim 3
Dependent Claim
70 words
A wavelength selective optical data storage system according to claim 1, and further comprising a synchronous signal generator for generating a synchronous signal; and wherein said photodetector generates a pulse output signal corresponding to the presence of said prerecorded hole so that the wavelength positions are identified in accordance with said synchronous signal which is generated at a constant period in synchronism with said pulse output signal from the photodetector.
Claim 4
Dependent Claim
41 words
A wavelength selective optical data storage system according to claim 1, wherein the prerecorded hole has an absorption level in said recording medium different from that of the recording hole to allow discrimination between said prerecorded hole and said recording hole.
Claim 5
Dependent Claim
36 words
A wavelength selective optical data storage system according to claim 1, wherein the prerecorded hole is created at the beginning of a wavelength range of the absorption spectrum of said memory element occupied by recording holes.
Claim 6
Dependent Claim
36 words
A wavelength selective optical data storage system according to claim 1, wherein an address code of the memory element is recorded at a wavelength position preceding or following the predetermined wavelength position of the prereorded hole.
Claim 7
Dependent Claim
22 words
A wavelength selective optical data storage system according to claim 1, wherein the prerecorded hole represents an address code of the element.
Claim 8
Dependent Claim
52 words
A wavelength selective optical data storage system according to claim 2, wherein the absorption spectrum of said memory element has at least one additional prerecorded hole in the middle of a wavelength range of the absorption spectrum occupied by said recording holes for enabling adjustment of the period of the synchronous signal.
Claim 9
Dependent Claim
23 words
A wavelength selective optical data storage system according to claim 1, wherein the recording medium has a reflective film for reflecting the beam.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-09-18 | 1993-03-20 | 1993-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-18 | 1997-03-20 | 1997-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-18 | 2001-03-20 | 2001-09-19 | $7700.00 | Window Closed / Lapsed |