Flash controlling apparatus utilizing characteristics of a logarithmic function

摘要

A flash controlling apparatus is provided including a light receiving unit PS, a current-to-voltage converter IVC, a comparator CR, and a micro-controller MC. The light receiving unit PS generates a current signal corresponding to the flash intensity of a camera. The current-to-voltage converter IVC converts the current signal received from the light receiving unit PS into a voltage signal SPS. The comparator CR compares the voltage signal SPS with a reference voltage VREF to obtain a resultant logic signal SCOM. The micro-controller MC controls the operation of the current-to-voltage converter IVC and controls the operation of a flash device of the camera according to the resultant logic signal SCOM received from the comparator CR. The voltage signal SPS from the current-to-voltage converter IVC has the characteristics of a logarithmic function with respect to time.