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:
Sep. 12, 2006
Filed:
Dec. 03, 2002
Hitoshi Ohmori, Wako, JP;
Yoshihiro Uehara, Wako, JP;
Yoshiyuki Ueno, Wako, JP;
Yutaka Yamagata, Wako, JP;
Shinya Morita, Wako, JP;
Hitoshi Ohmori, Wako, JP;
Yoshihiro Uehara, Wako, JP;
Yoshiyuki Ueno, Wako, JP;
Yutaka Yamagata, Wako, JP;
Shinya Morita, Wako, JP;
Riken, Saitama, JP;
Abstract
A method of manufacturing a large double-sided curved Fresnel lens. The method includes a machining step (A) of performing ultra-precise three-dimensional machining on an upper mold and a lower mold to each have an upper transfer surface and a lower transfer surface engaging an upper surface and a lower surface of a thermoplastic resin plate, respectively. Further, the method includes a hot press molding step (B) of pressing the thermoplastic resin plate between the upper and lower molds by a predetermined pressure with the resin plate being held at a temperature higher than a softening temperature thereof and lower than a melting temperature thereof so that the thermoplastic resin plate is curved, and both lens surfaces for the double-sided Fresnel lens are respectively transferred to an upper surface and a lower surface of the thermoplastic resin plate.