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:
Oct. 11, 2016
Filed:
Jul. 30, 2013
Canon Kabushiki Kaisha, Tokyo, JP;
Shigeru Sugiyama, Yokohama, JP;
Masato Tanaka, Tokyo, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
Provided is an immersion diffraction element that prevents decrease of diffraction efficiency thereof so as to satisfy optical performance. A reflection type diffraction element is made of a material transmitting a light, beam having a predetermined wavelength. An echelle diffraction grating covered with a reflecting film that prevents transmission of the light beam is formed on one surface of the material. A diffraction grating is formed off in a repeated manner, a blazed surface facing incident light and a non-blazed surface connecting the blazed surface to a neighboring blazed surface. An angle formed between the blazed surface and the non-blazed surface is an acute angle. A defect generated at a grating vertex of the blazed surface fails in a shadow of the neighboring blazed surface so as to prevent the incident light from becoming scattered light due to the defect portion.