AUTOMATIC DIMMING DEVICE OF LIGHTING FOR MICROSCOPE

摘要

PURPOSE:To perform automatic dimming operation so that a video signal level is invariably constant even when the reflection factor and transmissivity of a subject vary or even when an objective lens is moved by comparing the microscope video signal level of a cable TV(CCTV) camera with a reference value and controlling a lighting lamp circuit. CONSTITUTION:A rectifying circuit 6 is supplied with the video signal of the magnified image of a microscope from the CCTV camera 4 and outputs a DC voltage corresponding to the level of the video signal. Its voltage is compared with the reference voltage by a differential amplifier circuit 7 to control a light lamp 3 for the microscope automatically according to the difference to perform the automatic dimming of the lighting lamp of the microscope so that the level of the video signal is invariably constant even when the reflection factor and transmissivity of the subject vary or even when the objective lens is shifted.