US3218917A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Highly sensitive exposure meter
Assignee: Individual
•
Filing: 1961-10-25
•
Granted: 1965-11-23
•
Expires: 1981-10-25
Abstract
No abstract record available.
Inventors
- 👤 Focrsterling Hans
- 👤 Pfaffenberger Erwin
- 👤 Schoenheinz Richard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 03:29
CPC Classifications
G; G01; G01J; G01J1/00; G01J1/42; G01J1/4209; G01J1/4214; G01J1/44
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
129 words
AN EXPOSURE METER HAVING A PLURALITY OF MEASURING RANGES, COMPRISING A PHOTO-RESISTOR CONNECTED IN A NORMALLY OPEN CIRCUIT WITH A BATTERY AND A CURRENT METER ADAPTED TO PROVIDE AN EXPOSURE READING DEPENDENT ON THE CURRENT FLOW THERETHROUGH, A FIRST PLURALITY OF SERIESCONNETED CALIBRATING RESISTANCE CONNECTING ACROSS SAID METER, THE NUMBER OF RESISTANCE BEING EQUAL TO THE NUMBER OF MEASURING RANGES, EACH OF SAID RESISTANCE INCLUDING A MOVABLE TAP, AND SEPARATE SWITCHES CONNECTED FROM EACH OF SAID MOVABLE TAPS FOR SELECTIVELY CLOSING SAID NORMALLY OPEN CIRCUIT, A SECOND PLURALITY OF VARIABLE RESISTANCES CONNECTED IN SERIES WITH EACH OF SAID SWITCHES WHEREIN SAID SECOND RESISTORS MAY BE VARIED TO ADJUST THE RESPONSE OF THE METER WHEREBY THE MEASURING RANGE OF THE EXPOSURE METER MAY BE SELECTED BY OPERATION OF SAID SWITCHES.
Claim 2
Dependent Claim
129 words
AN EXPOSURE METER HAVING A PLURALITY OF MEASURING RANGES, COMPRISING A PHOTO-RESISTOR CONNECTED IN A NORMALLY OPEN CIRCUIT WITH A BATTERY AND A CURRENT METER ADAPTED TO PROVIDE AN EXPOSURE READING DEPENDENT ON THE CURRENT FLOW THERETHROUGH, A FIRST PLURALITY OF SERIESCONNETED CALIBRATING RESISTANCE CONNECTING ACROSS SAID METER, THE NUMBER OF RESISTANCE BEING EQUAL TO THE NUMBER OF MEASURING RANGES, EACH OF SAID RESISTANCE INCLUDING A MOVABLE TAP, AND SEPARATE SWITCHES CONNECTED FROM EACH OF SAID MOVABLE TAPS FOR SELECTIVELY CLOSING SAID NORMALLY OPEN CIRCUIT, A SECOND PLURALITY OF VARIABLE RESISTANCES CONNECTED IN SERIES WITH EACH OF SAID SWITCHES WHEREIN SAID SECOND RESISTORS MAY BE VARIED TO ADJUST THE RESPONSE OF THE METER WHEREBY THE MEASURING RANGE OF THE EXPOSURE METER MAY BE SELECTED BY OPERATION OF SAID SWITCHES.
References Cited (Backward Citations)
US2111585A
Cited
US2475108A
Cited
US2073790A
Cited
US2143500A
Cited
US2167803A
Cited
US2275344A
Cited
US2389617A
Cited
US2472381A
Cited
FR952002A
Cited
US2766654A
Cited
US2501599A
Cited
US2630735A
Cited
US2891438A
Cited
US2892378A
Cited
US2987957A
Cited
US2820215A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-11-22 | 1969-05-24 | 1969-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-11-22 | 1973-05-24 | 1973-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-11-22 | 1977-05-24 | 1977-11-23 | $7700.00 | Window Closed / Lapsed |