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:
Dec. 16, 1986
Filed:
Jul. 09, 1985
Shinichiro Hirota, Tokyo, JP;
Tetsuro Izumitani, Tokyo, JP;
Hoya Corporation, Tokyo, JP;
Abstract
A method of manufacturing a pressed lens based upon the discovery that a high quality lens may be molded despite the fact that the lens is cooled without pressure being applied to the mold. A lens preform is inserted into the pressing mold and pressure is applied to the mold while the preform and mold are at a temperature corresponding to a viscosity of the preform of 10.sup.8.5 -10.sup.10.5 poise. The pressure is then removed while the resulting molding remains in contact with the mold and the preform and mold are then cooled. When the temperature of the preform has fallen to a value corresponding to a viscosity of the molding of not smaller than 10.sup.11.5, the molding may be removed from the pressing mold. The preform may be inserted into the mold and then the preform and the mold may be heated prior to pressing, or alternately, the preform and the mold may be heated separately and the preform may be transferred into the mold for pressing. In the latter case, the preform is held by a holder which remains in the mold during pressing. To increase the lens production rate, the lens and the mold may be cooled at a location different from the location at which pressing occurred.