US4646103A
Expired / Lapsed
US
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Optical recording method
Assignee: Hitachi Ltd
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Filing: 1986-02-26
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Granted: 1987-02-24
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Expires: 2006-02-26
Abstract
Abstract In an optical recording system wherein the intensity of a laser beam is modulated with an input modulation signal so as to record information on a recording medium, the intensity modulation of the laser beam is performed after the pulse waveform of the input modulation signal is converted into two pulses which express the front edge and rear edge of the pulse waveform respectively.
Inventors
- 👤 Hisataka Sugiyama
- 👤 Kazuo Shigematsu
- 👤 Takeshi Maeda
- 👤 Atsushi Saitoh
- 👤 Wasao Takasugi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:36
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/12; G11B7/125; G11B7/126; G11B11/00; G11B11/10; G11B11/105; G11B11/10502; G11B11/10504; G11B11/10506; G11B11/10515; G11B11/1053; G11B20/00; G11B20/10; G11B20/10009; G11B20/14; G11B20/1403; G11B7/004; G11B7/0045; G11B7/24; G11B7/2407; G11B7/24085
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
77 words
An optical recording method which includes modulating an intensity of a laser beam with an input modulation signal, and recording a signal on a recording medium by means of the modulated laser beam; comprising: the step of forming two pulses respectively corresponding to a front edge part and a rear edge part of a pulse waveform of the input modulation signal; and the step of modulating the intensity of the laser beam with the two pulse waveforms.
Claim 2
Dependent Claim
77 words
An optical recording method which includes modulating an intensity of a laser beam with an input modulation signal, and recording a signal on a recording medium by means of the modulated laser beam; comprising: the step of forming two pulses respectively corresponding to a front edge part and a rear edge part of a pulse waveform of the input modulation signal; and the step of modulating the intensity of the laser beam with the two pulse waveforms.
Claim 3
Dependent Claim
41 words
An optical recording method according to claim 1, wherein said two pulses corresponding to said front edge and rear edge parts are caused to continue by a pulse whose pulse height is smaller than a pulse height of said two pulses.
Claim 4
Dependent Claim
29 words
An optical recording method according to claim 1, wherein at least one pulse is further existent between said two pulses corresponding to said front edge and rear edge parts.
Claim 5
Dependent Claim
80 words
A reproducing method for optical recording in which information is reproduced from a reproduced signal expressive of edges of the information recorded on a recording medium; comprising: the step of detecting signals respectively corresponding to the front edge and rear edge of the information recorded on the recording medium; the step of regenerating timing signals respectively from said signals corresponding to said front edge and rear edge; and the step of reproducing data by the use of said timing signals.
Claim 6
Dependent Claim
80 words
A reproducing method for optical recording in which information is reproduced from a reproduced signal expressive of edges of the information recorded on a recording medium; comprising: the step of detecting signals respectively corresponding to the front edge and rear edge of the information recorded on the recording medium; the step of regenerating timing signals respectively from said signals corresponding to said front edge and rear edge; and the step of reproducing data by the use of said timing signals.
References Cited (Backward Citations)
US4583210A
Cited
US4416002A
Cited
US4397010A
Cited
US4419750A
Cited
US4545044A
Cited
US4483262A
Cited
US4488277A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-02-23 | 1990-08-25 | 1991-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-23 | 1994-08-25 | 1995-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-23 | 1998-08-25 | 1999-02-24 | $7700.00 | Window Closed / Lapsed |