Device for controlling an amount of light of a lighting unit for an endoscope

摘要

A device for controlling an amount of light of a lighting unit for use in an endoscope that is used to view an image of an object. A light shielding system shields light generated by a light source and transmitted to the endoscope and a stepping motor drives the light shielding system for a plurality of predetermined time intervals. A system detects a brightness of the image during each of the plurality of predetermined time intervals and an input system inputs one of a plurality of desired brightnesses of the image. A generating system generates a predetermined number of pulses during each of the plurality of predetermined time intervals, the predetermined number of pulses being transmitted to the stepping motor and a system determines an angular position of the light shielding system. A setting system sets one of a plurality of allowed brightness ranges of the image in response to the determined angular position of the light shielding system and a system determines whether the detected brightness is within the set one of the plurality of allowed brightness ranges.