AUTOFOCUSING DEVICE FOR ENDOSCOPE

摘要

PROBLEM TO BE SOLVED: To obtain an autofocusing device for an endoscope formed in such a manner that the device can be easily built into a macro-endoscope apparatus. SOLUTION: This autofocusing device has an imaging optical system which houses a movable focusing element and is disposed at the distal end of an internal insertion portion 1a; a contrast detector 15 which detects the contrast of the observation object image photographed by the imaging optical system; a focusing drive system 16 which drives the focusing element of the imaging optical system in accordance with the contrast value detected by the contrast detection 15; operating direction detecting means 14 which detects whether the distal end of the internal insertion portion 1a approaches the observation object or not; and initial operating direction determining means (13) for first determining the operating direction of the focusing element by the focusing drive system 16 without considering the contrasts value by the contrast detector 15.