In dark field illumination apparatus for epi-illumination system, in order to attain the above and other objects, the present invention provides an annular light beam which is coaxial with the optical axis of the objective lens and is supplied along an optical path formed surrounding the objective lens....http://www.google.fr/patents/US4626079?utm_source=gb-gplus-shareBrevet US4626079 - Dark field illumination apparatus for epi-illumination system
Dark field illumination apparatus for epi-illumination system
