Electronic flash control apparatus
US6272292A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 1999 |
| Grant date | Aug 7, 2001 |
| Priority date | — |
| Expiry date | Dec 22, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B15/05
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An electronic flash unit is caused to perform a pre-flash immediately before a photographing operation, and the quantity of light reflected by the subject during the pre-flash is measured by a flash metering unit. Based upon the output from the flash metering unit, a decision is made as to whether or not another pre-flash is to be implemented. Based upon the results of the decision-making, another pre-flash is performed if necessary. Thus, if the quantity of light measured by the flash metering unit during the pre-flash is too small or too large and a sufficient degree of accuracy is not achieved in the measurement, another pre-flash is performed to assure a high degree of accuracy in metering.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.