Patent ID: 6231504
Filing Date: 2001-05-15
Classification: A61B,G01J,G02B,H04N

Abstract:
A device for controlling an amount of light of a lighting unit for use in an endoscope, said endoscope being used to view an image of an object, said device comprising:a light shielding system that shields light generated by a light source and transmitted to said endoscope;a stepping motor for driving said light shielding system for a plurality of predetermined time intervals;a system that detects a brightness of said image during each of said plurality of predetermined time intervals;a system that generates a predetermined number of pulses during each of said plurality of predetermined time intervals, said predetermined number of pulses being transmitted to said stepping motor during each of said plurality of predetermined time intervals;a system that determines an angular position of said light shielding system; anda system that varies a phase of excitation of said stepping motor in response to said angular position.