The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 17, 1996
Filed:
Jun. 09, 1994
Seiya Miura, Utsunomiya, JP;
Michio Kohno, Utsunomiya, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A surface inspection device and method wherein an illumination system is arranged so that light from a laser diode is transformed into parallel light which is then directed through a half waveplate to a surface of a reticle to be inspected. A detecting system is arranged so that scattered light from a particle on the surface, for example, is collected by a lens array onto a sensor array. The direction of polarization of the parallel light defined by the half waveplate is made substantially parallel to a plane containing optical axes of the illumination system and the detecting system. Thus, even if an error occurs in the angle of incidence of the parallel light upon the reticle, a change in scattered light intensity due to interference between scattered light is kept small to assure accurate discrimination of the particle.