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:
Nov. 13, 2012
Filed:
Feb. 05, 2007
Takashi Sudo, Utsunomiya, JP;
Hiroyuki Kodama, Utsunomiya, JP;
Makoto Takahashi, Utsunomiya, JP;
Canon Kabushiki Kaisha, , JP;
Abstract
A color separation optical system is disclosed which is effective in improving black color and black unevenness. Linearly polarized light impinging on a dichroic surface at an incident angle smaller than 45 degrees and then impinging on a polarization beam splitting surface at an incident angle larger than 45 degrees is referred to as first incident-angle light. A wavelength which is longer than a wavelength at the maximum transmittance of the dichroic surface for the first incident-angle light and at which the transmittance of the dichroic surface for the first incident-angle light is 10% is referred to as Wa, and a wavelength range shorter than Wa is referred to as W. The polarization beam splitting surface has a characteristic in which its transmittance for the first incident-angle light in the wavelength range W is 5% or lower.