| 摘要 |
PROBLEM TO BE SOLVED: To optimize the detectability condition of fluxes contributing to the imaging out of the reflected lights from the surface of an object in an image measuring optical system even when an illumination light is emitted on an inclined object by using only a single illumination system by an adequate arrangement structure. SOLUTION: A half mirror 10 that divides a rear side focus of an objective lens 11 into an illumination optical path and an imaging optical path is provided and a face of an object is irradiated with a Koehler illumination by a differ 9 provided to the rear side focus FB' on the illumination optical path. An image of the diffuser 9, i.e., the size of an illumination pupil is adjusted by means of a diaphragm 13 provided at the rear side focus FB on the imaging optical path. As a result, it is possible to readily optimize detectability condition of fluxes served as imaging in reflection lights reflected by the object even when the illumination light is incident on the inclined object by using a single illumination system. |
