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. 22, 1992
Filed:
Apr. 29, 1991
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A method of molding an optical element by pressing glass material uses a cavity composed of a pair of mold members and a side mold member. Either or both of the pair of mold members are rendered slidable along the axial direction of the optical element within the side mold member used during the pressurized molding operation, so that the pair of mold members move in close contact with the contracting glass along the axial direction in the side mold member, during the cooling subsequent to the pressurized molding due to adhesion between the contracting glass and either or both of the pair of mold members. The contraction of the glass during the cooling phase is limited by the adhesive force between the glass and the mold members when at least one of the pair of mold members traverses a gap and reaches a limit of travel; thus tension will be created in the glass.