US4306142A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical modulation device
Assignee: Mitsubishi Electric Corp
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Filing: 1979-11-20
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Granted: 1981-12-15
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Expires: 1999-11-20
Abstract
Abstract The disclosed device comprises two duty ratio detectors for detecting respective duty ratios of an input modulation signal modulating an incoming light beam and a modulated intensity-of-light signal proportional to an intensity of an outgoing light beam, a differential amplifier for producing a difference between both duty ratios, and a bias control for supplying this difference to an optical modulator through a bias amplifier.
Inventors
- 👤 Isao Watanabe
- 👤 Satoshi Komurasaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:34
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/12; G11B7/125; G11B7/128; G02; G02F; G02F1/00; G02F1/01; G02F1/0121; G02F1/0123
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
108 words
An optical modulation device comprising an optical modulator for modulating an incoming light beam in accordance with an input modulation signal, an optical detector for producing from a modulated optical output from said optical modulator an intensity-of-light signal proportional to an intensity of said modulated optical output, a first and a second duty ratio detector for detecting duty ratios of said input modulation signal and said intensity-of-light signal from said optical detector respectively, a differential amplifier for producing a difference signal between outputs from said first and second duty ratio detectors, and a bias amplifier for applying said difference signal from said differential amplifier to said optical modulator.
Claim 2
Dependent Claim
108 words
An optical modulation device comprising an optical modulator for modulating an incoming light beam in accordance with an input modulation signal, an optical detector for producing from a modulated optical output from said optical modulator an intensity-of-light signal proportional to an intensity of said modulated optical output, a first and a second duty ratio detector for detecting duty ratios of said input modulation signal and said intensity-of-light signal from said optical detector respectively, a differential amplifier for producing a difference signal between outputs from said first and second duty ratio detectors, and a bias amplifier for applying said difference signal from said differential amplifier to said optical modulator.
Claim 3
Dependent Claim
47 words
An optical modulation device as claimed in claim 1 wherein each of said first and second duty ratio detectors includes a voltage comparator for comparing an input signal with a reference signal to produce a binary voltage signal, and a low-pass filter connected to said voltage comparator.
Claim 4
Dependent Claim
71 words
An optical modulation device as claimed in claim 1 wherein each of said first and second duty ratio detectors includes a positive inversion circuit for delivering an input signal as intact and a signal inverted therefrom, a pair of low-pass filters having said input signal and said inverted signal applied thereto from said positive inversion circuit respectively, and a differential amplifier having applied thereto outputs from said pairs of low-pass filters.
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) | 1984-12-14 | 1985-06-15 | 1985-12-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-12-14 | 1989-06-15 | 1989-12-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-12-14 | 1993-06-15 | 1993-12-15 | $7700.00 | Window Closed / Lapsed |