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:
Aug. 25, 2009
Filed:
Jun. 16, 2005
Mitsuru Kitamura, Tokyo, JP;
Akiko Tanaka, Tokyo, JP;
Mitsuru Kitamura, Tokyo, JP;
Akiko Tanaka, Tokyo, JP;
Dai Nippon Printing Co., Ltd., Tokyo, JP;
Abstract
The invention provides a diffractive optical element that can be used as a light beam splitter device, an optical low-pass filter or the like having a two-dimensionally multi-valued fine periodic structure. The surface of a transparent substrate for the diffractive optical element is divided into fine rectangular areas of identical shape which line up in two orthogonal directions while a plurality of rows line up with ends in alignment in any one of the directions. With respect to standard wavelength light incident vertically on the surface of the transparent substrate, an l-th, and a (l+1)-th rectangular area in an l-th row, where l is an odd number, gives a phase 2pπ, and a phase {(4q+1)π/2+δπ/2}, respectively, and an l-th, and a (l+1)-th rectangular area in a (l+1)-th row gives a phase {(4r+3)π/2+3δπ/2}, and a phase {(4s+2)π/2+δπ}, respectively. However, −0.25≦δ≦0.25, and p, q, r, and s is an integer.