AUTOMATIC FOCUSING AND ILLUMINATING DEVICE

摘要

PURPOSE:To allow the exact illumination of a surface to be detected by constituting the device in such a manner that the 1st driving means focuses a coupling optical system in accordance with the detection signal of a position detecting means, a moving quantity detecting means detects the moving quantity of the 1st driving means to measure the thickness of the object to be detected and the 2nd driving means focuses a transmission of the moving quantity detecting means. CONSTITUTION:This device consists of the imagery optical system 1 having the position detecting means for detecting the position of the object 200 to be detected and the transmission illuminating optical system 2 for illuminating this object 200. The imagery optical system 1 is provided with the 1st driving means 15 for focusing the coupling optical system 1 in accordance with the detection signal of the position detecting means 14 and the moving quantity detecting means 16 for detecting the thickness of the object 200 by detecting the moving quantity by the 1st driving means 15. The transmission illuminating optical system 2 is provided with the 2nd driving means 23 for focusing the transmission illuminating optical system 2 in accordance with the detection signal of the moving quantity detecting means 16. The inspection of a semiconductor mask 200 is exactly and efficiently executed in this way under the optimum conditions without deviating the illuminating position.