| 摘要 |
PURPOSE:To achieve optimum exposure, which is finely corrected in response to the condition of a field, with simple circuit configuration by providing plural metering means with different areas of a field that these means meter selectively, comparing the metered output with the other converted one and stopping light generation when the relative relation between them is inverted. CONSTITUTION:As at least two metering means, the metering means which is composed of photodetectors 1 and 2 and metering amplifiers 3 and 4, for instance, and which selectively meters the central part, and the average metering means which is composed of the photodetectors 1 and 2 and the metering amplifiers 3 and 4. After a converting circuit 5 converts both of or either of metered outputs, a comparing means 6 compares both converted outputs or the unconverted output with the converted one, and when the relative relation between them is inverted, an emission stop signal is outputted to an emission control circuit 7. As a result, plural reference voltages and comparators necessary for fine control are not needed any more. Under the simple circuit configuration, emission quantity can be controlled by finely correcting it in response to the condition of the field. |
