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:
Jan. 23, 2007
Filed:
Oct. 27, 2004
Hideki Obara, Machida, JP;
Kazumasa Endo, Kawasaki, JP;
Hideki Obara, Machida, JP;
Kazumasa Endo, Kawasaki, JP;
Nikon Corporation, Tokyo, JP;
Abstract
A method of manufacturing an optical member includes a crystal growing step and a carving step. The crystal growing step includes melting a mixture of fluoride powder and a scavenger at a melting temperature of a melting point for the fluoride and above, and then crystallizing the melted fluid and further cooling down an obtained fluoride crystal in a temperature range from 1000° C. to 900° C. by a temperature decreasing rate in a range from 0.1 to 5° C./hr. The carving step includes carving an optical member out of the fluoride crystal obtained in the crystal growing step such that the optical member is made of a fluoride crystal in which a maximum diameter dof scattering bodies existing internally and a quantity nof the scattering bodies per 1 cmsatisfy a condition represented by the following formula (1):0(cm).   (1)