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. 30, 2010
Filed:
Jan. 31, 2005
Yoshiharu Ooi, Koriyama, JP;
Masahiro Murakawa, Yokohama, JP;
Hiromasa Sato, Koriyama, JP;
Masao Miyamura, Koriyama, JP;
Yoshiharu Ooi, Koriyama, JP;
Masahiro Murakawa, Yokohama, JP;
Hiromasa Sato, Koriyama, JP;
Masao Miyamura, Koriyama, JP;
Asahi Glass Company, Limited, Tokyo, JP;
Abstract
A phase correction element comprising a first phase correction layer formed in a region of numerical aperture NA, and a first phase plate; the first phase correction layer comprising a concavo-convex portion having a rotational symmetry with respect to the optical axis of incident light and having a cross-sectional shape of a saw-tooth-form or a saw-tooth-form whose convex portions are each approximated by a step form; the first phase plate generating a birefringent phase difference of about an odd number times of π/2 for linearly polarized light of λ; and the phase correction element that does change a transmitted wavefront of λand changing a transmitted wavefront of the λor transmitted wavefront of both wavelengths of λand λwhen three types of incident light at λ=410 nm, λ=650 nm and λ=780 nm respectively, are incident.