US3821765A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photographic arrangement with viewfinder indication of flash readiness
Assignee: Agfa Gevaert AG
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Filing: 1973-02-16
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Granted: 1974-06-28
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Expires: 1993-02-16
Abstract
Abstract A LIQUID CRYSTAL ELEMENT IS CONNECTED IN PARALLEL WITH THE RELEASE CONTACTS OF THE CAMERA WHICH IN TURN ARE CONNECTED TO THE IGNITION CIRCUIT OF THE FLASH UNIT. THE LIQUID CRYSTAL ELEME NT IS ARRANGED IN THE CAMERA HOUSING AND AN IMAGE OF IT IS REFLECTED INTO THE VIEWFINDER. THE LIQUID CRYSTAL CHANGES FROM A LIGHT TRANSMISSIVE TO AN OPAQUE STATE WHEN THE VOLTAGE ACROSS THE IGNITION CAPACITOR REACHES THE VOLTAGE REQUIRED FOR FLASH INITIATION.
Inventors
- 👤 K Wagner
- 👤 E Wagensonner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:55
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/30; H05B41/32
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-27 | 1977-12-27 | 1978-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-27 | 1981-12-27 | 1982-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-27 | 1985-12-27 | 1986-06-28 | $7700.00 | Window Closed / Lapsed |