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:
Mar. 31, 2015
Filed:
Aug. 12, 2011
Yuka Okada, Hyogo, JP;
Takamasa Ando, Osaka, JP;
Tsuguhiro Korenaga, Osaka, JP;
Abstract
A diffraction grating lens according to the present invention is a diffraction grating lensincluding: a lens body; and a plurality of diffraction steps relative to a base shape and a plurality of diffraction gratingsinterposed between the diffraction steps, provided on a surface of the lens body. The lens bodyis made of a first material having a refractive index n(λ) at a used wavelength λ; the diffraction gratingis in contact with air; and the relationship of an inequality below is satisfied, where d is a design step length of the diffraction steps, and m is an order of diffraction. Each of the plurality of annular zones includes an intermediate portion and a pair of end portions sandwiching the intermediate portion along a radial direction, and in at least one of the plurality of annular zones, either one of a recessand a protrusionis provided in at least a portion of one of the pair of end portions, and the other one of the recessand the protrusionis provided in at least a portion of the other of the pair of end portions. Between two kinds of diffraction stepsA andB of the diffraction grating, one is provided at a position where the phase difference from the base shape given the design wavelength λis not 2 nmπ.