US4567446A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light-receiving device for optical data transfer system
Assignee: Toshiba Corp
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Filing: 1983-09-26
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Granted: 1986-01-28
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Expires: 2003-09-26
Abstract
Abstract A light-receiving device including a photo-detector, for issuing a current signal corresponding to a received light signal, preamplifier, variable attenuating circuit and main amplifier. The preamplifier acts as a current amplifier for amplifying an output current signal from the photo-detector. The variable attenuating circuit acts as a current attenuating circuit for attenuating an output current signal from the preamplifier. The main amplifier amplifies an output current from the variable attenuating circuit and issues an amplified voltage.
Inventors
- 👤 Kuniyoshi Konishi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:15
CPC Classifications
H; H03; H03H; H03H7/00; H03H7/24; H03H7/25; H03H7/253; H03H7/255; H04; H04B; H04B10/00; H04B10/60; H04B10/66; H04B10/69; H04B10/697; H04B10/6973
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
94 words
A light-receiving device which comprises: photo-detecting means which converts a received light signal to a current signal; a preamplifier for amplifying a current signal produced from said photo-detecting means; varible attenuating means, which includes a variable resistance means, for attenuating a current signal produced from said preamplifier in accordance with the resistance of said variable resistance means and for sending forth a current signal thus attenuated; and a main amplifier for amplifying said current signal produced from said variable attenuating means and issuing a signal thus amplified in the form of a voltage signal.
Claim 2
Dependent Claim
94 words
A light-receiving device which comprises: photo-detecting means which converts a received light signal to a current signal; a preamplifier for amplifying a current signal produced from said photo-detecting means; varible attenuating means, which includes a variable resistance means, for attenuating a current signal produced from said preamplifier in accordance with the resistance of said variable resistance means and for sending forth a current signal thus attenuated; and a main amplifier for amplifying said current signal produced from said variable attenuating means and issuing a signal thus amplified in the form of a voltage signal.
Claim 3
Dependent Claim
25 words
A light-receiving device according to claim 1, wherein said photo-detecting means includes a photo-detector and resistor connected in series between first and second power sources.
Claim 4
Dependent Claim
23 words
A light-receiving device according to claim 1, wherein said variable resistance means in said variable attenuating means comprises at least one PIN diode.
Claim 5
Dependent Claim
70 words
A light-receiving device according to claim 1, wherein said variable attenuating means comprises first and second PIN diodes connected in series, a third PIN diode connected to the node of said first and second PIN diodes through a capacitor, a first constant current source connected to said first PIN diode, a second constant current source connected to said third PIN diode, and a resistor connected to said second PIN diode.
References Cited (Backward Citations)
US4019160A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-01-27 | 1989-07-29 | 1990-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-01-27 | 1993-07-29 | 1994-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-01-27 | 1997-07-29 | 1998-01-28 | $7700.00 | Window Closed / Lapsed |