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US3670184A
Expired / Lapsed
US
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Light sensitive amplifier circuit having improved feedback arrangement
Assignee: Fujinon Corp
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Filing: 1971-02-09
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Granted: 1972-06-13
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Expires: 1991-02-09
Abstract
Abstract A light sensitive amplifier circuit arrangement for detecting light comprising a source follower field effect transistor having at least one resistor connected to its gate as well as between its source and ground; a second transistor whose base is connected to the field effect transistor, and whose collector is connected to a power source through a resistor; a constant voltage supply element connected between emitter of the second transistor and ground; a photocell connected in a negative feedback loop disposed between the gate of the field effect transistor and the output side of the second transistor; and a load connected to the output side of the second transistor and which driven in response to the variation of the resistance of the photocell due to the intensity of incident light. Further included is a negative feedback transmitting element from the output side of the second transistor to the grounded point of the resistor included in the source circuit of said field effect transistor. The resistor placed between the source of said field effect transistor and the grounded point may be a variable or semifixed type, there may be connected in parallel with the variable resistor a circuit including a first resistor, a heat sensitive resistor element and a second resistor all connected in series, the junction of the first resistor and the heat sensitive resistor element or second resistor is connected to the base of the second transistor. Still further, an additional resistor may be connected between the power source and either or both of the gate of said field effect transistor and the base of the second transistor.
Inventors
- 👤 Gijun Idei
- 👤 Saburo Numata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:24
CPC Classifications
G; G06; G06G; G06G7/00; G06G7/12; G06G7/20; G03; G03B; G03B7/00; G03B7/08; G03B7/081; G03B7/085; H; H03; H03F; H03F1/00; H03F1/30; H03F1/306; H03F3/00; H03F3/04; H03F3/08; H03F3/082
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
163 words
A light sensitive amplifier circuit arrangement for detecting light comprising: a source follower field effect transistor having at least a gate resistor coupled between its gate and ground, and a source resistor coupled between its source and ground; a second transistor whose base is connected to the source of said field effect transistor, and whose collector is connected to a power source through a resistor; a constant voltage supply element connected between the emitter of said second transistor and ground; a photoconductive element connected in a negative feedback loop disposed between the gate of said field effect transistor and the output side of said second transistor; a load coupled to the output side of said second transistor and which is driven in response to the variation of the resistance of the photoconductive element due to the intensity of incident light; and a feedback transmitting element coupled in a negative feedback loop disposed between the output side and the base of said second transistor.
Claim 2
Dependent Claim
163 words
A light sensitive amplifier circuit arrangement for detecting light comprising: a source follower field effect transistor having at least a gate resistor coupled between its gate and ground, and a source resistor coupled between its source and ground; a second transistor whose base is connected to the source of said field effect transistor, and whose collector is connected to a power source through a resistor; a constant voltage supply element connected between the emitter of said second transistor and ground; a photoconductive element connected in a negative feedback loop disposed between the gate of said field effect transistor and the output side of said second transistor; a load coupled to the output side of said second transistor and which is driven in response to the variation of the resistance of the photoconductive element due to the intensity of incident light; and a feedback transmitting element coupled in a negative feedback loop disposed between the output side and the base of said second transistor.
Claim 3
Dependent Claim
87 words
A light sensitive amplifier circuit arrangement according to claim 1 wherein said source resistor coupled between the source of said field effect transistor and ground comprises a variable resistance, and including a circuit coupled in parallel with said source resistor, said circuit including a first resistor, a heat sensitive resistance element and a second resistor all connected in series, the junction of said first resistor and at least one of said heat sensitive resistance element and second resistor being connected to the base of said second transistor.
Claim 4
Dependent Claim
24 words
A light sensitive amplifier circuit arrangement according to claim 1 including a further amplifier stage coupled to the output terminal of said second transistor.
Claim 5
Dependent Claim
183 words
A light sensitive amplifier circuit arrangement for detecting light comprising: a source follower field effect transistor having at least a gate resistor coupled between its gate and ground, and a source resistor coupled between its source and ground; a second transistor whose base is connected to the source of said field effect transistor, and whose collector is connected to a power source through a resistor; a constant voltage supply element connected between the emitter of said second transistor and ground; a photoconductive element connected in a negative feedback loop disposed between the gate of said field effect transistor and the output side of said second transistor; a load coupled to the output side of said second transistor and which is driven in response to the variation of the resistance of the photoconductive element due to the intensity of incident light; and a feedback transmitting element coupled in a negative feedback loop through a resistor, said feedback transmitting element being coupled between the output side of said second transistor and ground through a resistor included in the source circuit of said field effect transistor.
Claim 6
Dependent Claim
183 words
A light sensitive amplifier circuit arrangement for detecting light comprising: a source follower field effect transistor having at least a gate resistor coupled between its gate and ground, and a source resistor coupled between its source and ground; a second transistor whose base is connected to the source of said field effect transistor, and whose collector is connected to a power source through a resistor; a constant voltage supply element connected between the emitter of said second transistor and ground; a photoconductive element connected in a negative feedback loop disposed between the gate of said field effect transistor and the output side of said second transistor; a load coupled to the output side of said second transistor and which is driven in response to the variation of the resistance of the photoconductive element due to the intensity of incident light; and a feedback transmitting element coupled in a negative feedback loop through a resistor, said feedback transmitting element being coupled between the output side of said second transistor and ground through a resistor included in the source circuit of said field effect transistor.
Claim 7
Dependent Claim
170 words
A light sensitive amplifier circuit arrangement for detecting light comprising: a source follower field effect transistor having at least a gate resistor coupled between its gate and ground, and a source resistor coupled between its source and ground; a second transistor whose base is connected to the source of said field effect transistor, and whose collector is connected to a power source through a resistor; a constant voltage supply element connected between the emitter of said second transistor and ground; a photoconductive element connected in a negative feedback loop disposed between the gate of said field effect transistor and the output side of said second transistor; a load coupled to the output side of said second transistor and which is driven in response to the variation of the resistance of the photoconductive element due to the intensity of incident light; and at least one further resistor coupled between the power source and at least one of tee gate of said field effect transistor and the base of said second transistor.
Claim 8
Dependent Claim
170 words
A light sensitive amplifier circuit arrangement for detecting light comprising: a source follower field effect transistor having at least a gate resistor coupled between its gate and ground, and a source resistor coupled between its source and ground; a second transistor whose base is connected to the source of said field effect transistor, and whose collector is connected to a power source through a resistor; a constant voltage supply element connected between the emitter of said second transistor and ground; a photoconductive element connected in a negative feedback loop disposed between the gate of said field effect transistor and the output side of said second transistor; a load coupled to the output side of said second transistor and which is driven in response to the variation of the resistance of the photoconductive element due to the intensity of incident light; and at least one further resistor coupled between the power source and at least one of tee gate of said field effect transistor and the base of said second transistor.
Claim 9
Dependent Claim
46 words
A light sensitive amplifier circuit arrangement according to claim 5 including a first further resistor is coupled between said power source and said gate of said field effect transistor, and a second further transistor coupled between said power source and said base of said second transistor.
Claim 10
Dependent Claim
219 words
A light sensitive amplifier circuit arrangement for detecting light comprising: a source follower field effect transistor having at least a gate resistor coupled between its gate and ground, and variable source resistor coupled between its source and ground; a second transistor whose base is connected to the source of said field effect transistor, and whose collector is connected to a power source through a resistor; a constant voltage supply element connected between the emitter of said second transistor and ground; a photoconductive element connected in a negative feedback loop disposed between the gate of said field effect transistor and the output side of said second transistor; a load coupled to the output side of said second transistor and which is driven in response to the variation of the resistance of the photoconductive element due to the intensity of incident light; a feedback transmitting element coupled in a negative feedback loop disposed between the output side and the base of said second transistor; and a circuit coupled in parallel with said variable source resistor, said circuit including a first resistor, a heat sensitive element and a second resistor all connected in series, the junction of said first resistor and at least one of said heat sensitive resistance element and second resistor being connected to the base of said second transistor.
Claim 11
Dependent Claim
219 words
A light sensitive amplifier circuit arrangement for detecting light comprising: a source follower field effect transistor having at least a gate resistor coupled between its gate and ground, and variable source resistor coupled between its source and ground; a second transistor whose base is connected to the source of said field effect transistor, and whose collector is connected to a power source through a resistor; a constant voltage supply element connected between the emitter of said second transistor and ground; a photoconductive element connected in a negative feedback loop disposed between the gate of said field effect transistor and the output side of said second transistor; a load coupled to the output side of said second transistor and which is driven in response to the variation of the resistance of the photoconductive element due to the intensity of incident light; a feedback transmitting element coupled in a negative feedback loop disposed between the output side and the base of said second transistor; and a circuit coupled in parallel with said variable source resistor, said circuit including a first resistor, a heat sensitive element and a second resistor all connected in series, the junction of said first resistor and at least one of said heat sensitive resistance element and second resistor being connected to the base of said second transistor.
Claim 12
Dependent Claim
192 words
A light sensitive amplifier circuit arrangement for detecting light comprising: a source follower field effect transistor having at least a gate resistor coupled between its gate and ground, and a source resistor coupled between its source and ground; a second transistor whose base is connected to the source of said field effect transistor, and whose collector is connected to a power source through a resistor; a constant voltage supply element connected between the emitter of said second transistor and ground; a photoconductive element connected in a negative feedback loop disposed between the gate of said field effect transistor and the output side of said second transistor; a load coupled to the output side of said second transistor and which is driven in response to the variation of the resistance of the photoconductive element due to the intensity of incident light; a feedback transmitting element coupled in a negative feedback loop disposed between the output side and the base of said second transistor; and at least one further resistor coupled between the power source and at least one of the gate of said field effect transistor and the base of said second transistor.
Claim 13
Dependent Claim
192 words
A light sensitive amplifier circuit arrangement for detecting light comprising: a source follower field effect transistor having at least a gate resistor coupled between its gate and ground, and a source resistor coupled between its source and ground; a second transistor whose base is connected to the source of said field effect transistor, and whose collector is connected to a power source through a resistor; a constant voltage supply element connected between the emitter of said second transistor and ground; a photoconductive element connected in a negative feedback loop disposed between the gate of said field effect transistor and the output side of said second transistor; a load coupled to the output side of said second transistor and which is driven in response to the variation of the resistance of the photoconductive element due to the intensity of incident light; a feedback transmitting element coupled in a negative feedback loop disposed between the output side and the base of said second transistor; and at least one further resistor coupled between the power source and at least one of the gate of said field effect transistor and the base of said second transistor.
Claim 14
Dependent Claim
46 words
A light sensitive amplifier circuit arrangement according to claim 8 including a first further resistor is coupled between said power source and said gate of said field effect transistor, and a second further transistor coupled between said power source and said base of said second transistor.
Claim 15
Dependent Claim
228 words
A light sensitive amplifier circuit arrangement for detecting light comprising: a source follower field effect transistor having at least a gate resistor coupled between its gate and ground, and a variable source resistor coupled between its source and ground; a second transistor whose base is conneCted to the source of said field effect transistor, and whose collector is connected to a power source through a resistor; a constant voltage supply element connected between the emitter of said second transistor and ground; a photoconductive element connected in a negative feedback loop disposed between the gate of said field effect transistor and the output side of said second transistor; a load coupled to the output side of said second transistor and which is driven in response to the variation of the resistance of the photoconductive element due to the intensity of incident light; a circuit coupled in parallel with said variable source resistor, said circuit including a first resistor, a heat sensitive resistance element and a second resistor all connected in series, the junction of said first resistor and at least one of said heat sensitive resistance element and second resistor being connected to the base of said second transistor; and at least one further resistor coupled between the power source and at least one of the gate of said field effect transistor and the base of said second transistor.
Claim 16
Dependent Claim
228 words
A light sensitive amplifier circuit arrangement for detecting light comprising: a source follower field effect transistor having at least a gate resistor coupled between its gate and ground, and a variable source resistor coupled between its source and ground; a second transistor whose base is conneCted to the source of said field effect transistor, and whose collector is connected to a power source through a resistor; a constant voltage supply element connected between the emitter of said second transistor and ground; a photoconductive element connected in a negative feedback loop disposed between the gate of said field effect transistor and the output side of said second transistor; a load coupled to the output side of said second transistor and which is driven in response to the variation of the resistance of the photoconductive element due to the intensity of incident light; a circuit coupled in parallel with said variable source resistor, said circuit including a first resistor, a heat sensitive resistance element and a second resistor all connected in series, the junction of said first resistor and at least one of said heat sensitive resistance element and second resistor being connected to the base of said second transistor; and at least one further resistor coupled between the power source and at least one of the gate of said field effect transistor and the base of said second transistor.
Claim 17
Dependent Claim
46 words
A light sensitive amplifier circuit arrangement according to claim 10 including a first further resistor is coupled between said power source and said gate of said field effect transistor, and a second further transistor coupled between said power source and said base of said second transistor.
Claim 18
Dependent Claim
270 words
A light sensitive amplifier circuit arrangement for detecting light comprising: a source follower field effect transistor having at least a gate resistor coupled between its gate and ground, and a variable source resistor coupled between its source and ground; a second transistor whose base is connected to the source of said field effect transistor, and whose collector is connected to a power source through a resistor; a constant voltage supply element connected between the emitter of said second transistor and ground; a photoconductive element connected in a negative feedback loop disposed between the gate of said field effect transistor and the output side of said second transistor; a load coupled to the output side of said second transistor and which is driven in response to tee variation of the resistance of the photoconductive element due to the intensity of incident light; a feedback transmitting element coupled in a negative feedback loop through a resistor, said feedback transmitting element being coupled between the output side of said second transistor and ground through a resistor included in the source circuit of said field effect transistor; a circuit coupled in parallel with said variable source resistor, said circuit including a first resistor, a heat sensitive resistor element and a second resistor all connected in series, the junction of said first resistor and at least one of said heat sensitive resistor element and second resistor being connected to the base of said second transistor; and at least one further resistor coupled between the power source and at least one of the gate of said field effect transistor and the base of said second transistor.
Claim 19
Dependent Claim
270 words
A light sensitive amplifier circuit arrangement for detecting light comprising: a source follower field effect transistor having at least a gate resistor coupled between its gate and ground, and a variable source resistor coupled between its source and ground; a second transistor whose base is connected to the source of said field effect transistor, and whose collector is connected to a power source through a resistor; a constant voltage supply element connected between the emitter of said second transistor and ground; a photoconductive element connected in a negative feedback loop disposed between the gate of said field effect transistor and the output side of said second transistor; a load coupled to the output side of said second transistor and which is driven in response to tee variation of the resistance of the photoconductive element due to the intensity of incident light; a feedback transmitting element coupled in a negative feedback loop through a resistor, said feedback transmitting element being coupled between the output side of said second transistor and ground through a resistor included in the source circuit of said field effect transistor; a circuit coupled in parallel with said variable source resistor, said circuit including a first resistor, a heat sensitive resistor element and a second resistor all connected in series, the junction of said first resistor and at least one of said heat sensitive resistor element and second resistor being connected to the base of said second transistor; and at least one further resistor coupled between the power source and at least one of the gate of said field effect transistor and the base of said second transistor.
Claim 20
Dependent Claim
46 words
A light sensitive amplifier circuit arrangement according to claim 12 including a first further resistor is coupled between said power source and said gate of said field effect transistor, and a second further transistor coupled between said power source and said base of said second transistor.
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) | 1975-06-13 | 1975-12-13 | 1976-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-13 | 1979-12-13 | 1980-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-13 | 1983-12-13 | 1984-06-13 | $7700.00 | Window Closed / Lapsed |