Automatic control device for electronic flash
Abstract
Abstract A DEVICE FOR AUTOMATIC CONTROL OF THE QUANTITY OF LIGHT FROM AN ELECTRONIC FLASH, BY COMPARING THE BRIGHTNESS OF A PHOTOGRAPHIC OBJECT WITH THE QUANTITY OF LIGHT REQUIRED FOR PARTICULAR PHOTGRAPHING CONDITINS INCLUDING THE DEGREE OF LENS APERTURE SELECTED AND THE SENSITIVITY OF THE FILM USED. THE BRIGHTNESS OF THE PHOTOGRAPHIC OBJECT IS MEASURED AS THE SUM OF THE NETURAL LIGHT BRIGHTNESS AND THE BRIGHTNESS DUE TO ELECTRONIC FLASH, AND AS SOON AS THE SUM BRIGHTNESS THUS MEASURED REACHES THE REQUIRED QUANTITY OF LIGHT, A STOP SIGNAL IS GIVEN. THEREBY, THE ELECTRONIC FLASH IS CONTROLLED, AND AT THE SAME TIME SIGNAL IS GIVEN FOR THE SUFFICIENT BRIGHTNESS OF THE PHOTOGRAPHIC OBJECT.
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Bibliographic Details
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-05-27 | 1977-11-26 | 1978-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-27 | 1981-11-26 | 1982-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-27 | 1985-11-26 | 1986-05-28 | $7700.00 | Window Closed / Lapsed |