Electronic flash apparatus
US4486086A · kind A · utility
7Cited by
4References
4Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Nov 23, 1983 |
| Grant date | Dec 4, 1984 |
| Priority date | — |
| Expiry date | Nov 23, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B2215/05
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Electronic flash apparatus produces a variable amount of flash illumination corresponding to pre-flash photographic conditions, i.e. subject distance, film speed, ambient light intensity, etc. Circuitry, which has a threshold adjustable in response to a pre-flash signal relating to the flash illumination required for the photographic conditions, monitors energy as it is delivered to a flash tube to produce flash illumination, for activating quenching circuitry to limit the discharging of a flash capacitor to an amount of energy corresponding to the pre-flash signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.