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:
Sep. 04, 2007
Filed:
Jun. 20, 2005
Toshihiko Tsuji, Tochigi-ken, JP;
Toshihiko Tsuji, Tochigi-ken, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An illumination optical system for illuminating a target surface using light from a light source includes a modified illumination generator for generating a modified illumination with a predetermined polarization state for the target surface, wherein the modified illumination generator includes a λ/4 phase plate unit that includes a λ/4 phase plate for converting a circularly polarized light into a linearly polarized light in a predetermined direction, and a diffractive optical element unit that is arranged in a substantially conjugate relationship with the target surface, and includes a diffractive optical element used for the λ/4 phase plate to generate a predetermined illumination intensity distribution when the diffractive optical element unit receives the linearly polarized light.