Patent ID: 8223326
Filing Date: 2012-07-17
Classification: G01N,G02F

Abstract:
1. A dark-field inspection apparatus comprising: an illuminating unit which emits light toward a region where a subject on a base is positioned; a reflecting unit which returns incident light reflected from the subject or incident light passed through the base toward the subject, wherein the reflecting unit comprises a first reflecting mirror to reflect the incident light reflected from the subject or the base, and a second reflecting mirror to reflect the incident light reflected from the first reflecting mirror again toward the subject, and wherein an optical path exists between the subject and the first reflecting mirror without coinciding with an optical path between the second reflecting mirror and the subject; and an image sensing unit which receives light scattered by the subject and senses an image of the subject, wherein the subject is laid on one surface of the base, and the illuminating unit and the reflecting unit are arranged at a distance from the one surface of the base, and the light incident on the reflecting unit comprises light reflected from the subject or light reflected from the base, and wherein the illuminating unit, the reflecting unit and the image sensing unit are arranged so that some of the light emitted from the illuminating unit is scattered by the subject and enters the image sensing unit, and some of the light emitted from the illuminating unit is returned toward the subject by the reflecting unit, is scattered by the subject and then enters the image sensing unit to improve efficiency of using light.