US3573466A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light detector discriminator
Assignee: ROCHESTER DATRONICS Inc
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Filing: 1968-07-22
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Granted: 1971-04-06
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Expires: 1988-07-22
Abstract
Abstract Two matched semiconductor junctions at least one of which is included in a transistor, connected in circuit with a pair of resistors and a capacitor so that each of the junctions receives a portion of an input current supplied by a light sensitive device, the portion received being dependent upon the ratio of the resistances, said capacitor acting to cause the transistor to switch from a normally saturated condition to a nonconducting condition when the current supplied by the light sensitive means drops below a predetermined level.
Inventors
- 👤 John L Von Feldt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:14
CPC Classifications
G; G01; G01J; G01J1/00; G01J1/42; G01J1/44; G01N; G01N21/00; G01N21/84; G01N21/88
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
159 words
Light detector discriminator means comprising: a. light sensitive means connected to a suitable source of electrical energy for supplying current at a normal level when a reference level of light is impinged thereon and for supplying a lower level of current when a lesser level of light is impinged thereon; b. two matched semiconductor junctions at least one of which is included in semiconductor switching means; and c. capacitive and resistive components connected in circuit with said semiconductor junctions and said light sensitive means for causing said semiconductor switching means to switch when current at a level at least a predetermined amount less than the normal current level is supplied by said light sensitive means, the resistive components including two resistors one each connected in series with one of the two matched semiconductor junctions to form two parallel current paths, the predetermined current level less than the normal current level being determined by the resistance ratio of said resistors.
Claim 2
Dependent Claim
159 words
Light detector discriminator means comprising: a. light sensitive means connected to a suitable source of electrical energy for supplying current at a normal level when a reference level of light is impinged thereon and for supplying a lower level of current when a lesser level of light is impinged thereon; b. two matched semiconductor junctions at least one of which is included in semiconductor switching means; and c. capacitive and resistive components connected in circuit with said semiconductor junctions and said light sensitive means for causing said semiconductor switching means to switch when current at a level at least a predetermined amount less than the normal current level is supplied by said light sensitive means, the resistive components including two resistors one each connected in series with one of the two matched semiconductor junctions to form two parallel current paths, the predetermined current level less than the normal current level being determined by the resistance ratio of said resistors.
Claim 3
Dependent Claim
138 words
Light detector means as set forth in claim 1 wherein the capacitive and resistive components include first and second resistors and a capacitor connected so that one side of one semiconductor junction is connected to receive a portion of the current supplied by the light sensitive means and the other side is connected through said first resistors to a common point, the other semiconductor junction is connected at one side to normally receive the remainder of the current through said Second resistor and the other side of the other semiconductor junction is connected to the common point, and one side of the capacitor is connected to a point between the first resistor and the one semiconductor junction and the other side of the capacitor is connected to a point between the second resistor and the other semiconductor junction.
Claim 4
Dependent Claim
63 words
A plurality of light detector discriminator means as set forth in claim 1 having in addition a blanking circuit connected to receive a relatively small portion of the current supplied by each of the light sensitive means and provide a blanking pulse when each of the light sensitive means is producing a current less than the normal current at least the predetermined amount.
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) | 1974-04-05 | 1974-10-05 | 1975-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-05 | 1978-10-05 | 1979-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-05 | 1982-10-05 | 1983-04-06 | $7700.00 | Window Closed / Lapsed |