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:
Feb. 01, 2011
Filed:
Jun. 24, 2008
Ryota Kadowaki, Utsunomiya, JP;
Yu Yamauchi, Utsunomiya, JP;
Ryota Kadowaki, Utsunomiya, JP;
Yu Yamauchi, Utsunomiya, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An illumination optical system configured to guide a light flux from a light source unit onto an illuminated surface includes a compression system configured to compress the light flux at a different compression ratio in a first cross section and a second cross section which are orthogonal to each other, and a polarized light splitting unit including a polarization split surface. The second cross section includes a line normal to the polarization split surface. Where a compression ratio for compressing a light flux in the first cross section is α, a compression ratio in the second cross section is β, and an F number smaller of F numbers calculated according to a maximum angle of a light flux incident on an illuminated surface in the first and the second cross sections is Fno, the following conditions are satisfied:−0.18*()+1.245*()−1.260<α/β<1 1.4≦≦3.6.