Patent ID: 6317261
Filing Date: 2001-11-13
Classification: G02B

Abstract:
A phase contrast observation device for observing an object, comprising along an optical axis:a light source capable of providing light;an illumination optical system condensing the light from said light source and illuminating the object;an aperture stop having an aperture therein, arranged in said illumination optical system;an objective lens for converging light from the illuminated object and forming an image of the object; anda phase-modulation member arranged at a position inside said objective lens at a position conjugate to said aperture stop, said member having a first transmittance-modulation portion formed at a portion corresponding to said aperture of said aperture stop, and a second transmittance-modulation portion formed surrounding an inside and outside of the first transmittance-modulation portion,wherein said first and second transmittance-modulation portions have first and second transmittances TA and respectively, satisfying the following condition: TA<