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:
Apr. 20, 2004
Filed:
Jan. 30, 2001
Masahiro Oono, Saitama-ken, JP;
PENTAX Corporation, Tokyo, JP;
Abstract
An optical low-pass filter used in association with an imaging element which has a plurality of pixels arranged in vertical and horizontal direction with regularity, is provided with first through third birefringent plates arranged in the order from a light incident side. The low-pass filter separates an incident ray into four rays, a separation width of the rays in the vertical direction being &dgr;v, and a separation width of the rays in the horizontal direction being &dgr;h. A separation angles of the first through third birefringent plates are &thgr;, (&thgr;−90°) and 0°, respectively, and separation widths of the first through third birefringent plates are (&dgr;v×sin &thgr;), (&dgr;v×cos &thgr;) and &dgr;h, respectively.