Glass lens blank for polishing, manufacturing method therefore, and optical lens manufacturing method
AssigneeHoya Corporation
InventorsMikio Ikenishi, Akihiro Shoji, Yoshitake Tanno, Isao Tanaka
Life of this patent
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Abstract
A glass lens blank for polishing in which a thickness of a defect-containing layer is suppressed to a minimum and thus it is possible to shorten the processing time required for grinding and polishing the glass lens blank for polishing after press-molding, a method of manufacturing the same, and a method of manufacturing an optical lens. A glass lens blank for polishing of which at least a main surface is a press-molding surface, wherein a defect-containing layer formed on the main surface has a thickness of 50 μm or less.
Claims17
A glass lens blank for polishing, comprising at least a main surface that is a press-molded surface,
- wherein a defect-containing layer formed on the main surface has a thickness of 50 μm or less, and
- the main surface has a surface roughness Rz of 12 μm or more.
A method of manufacturing a glass blank for polishing, comprising the steps of:
- receiving a molten glass from a nozzle comprising a mold;
- molding the molten glass with the mold to obtain a glass gob;
- reheating the glass gob to a viscosity from 104 to 106 dPa·s under an air atmosphere while maintaining a surface state thereof;
- and
- press-molding the reheated glass gob with a mold for press-molding under an air atmosphere, thereby obtaining a glass-molded article having a press-molded surface in at least a main surface thereof,
- wherein a defect-containing layer formed on the main surface of the glass-molded article obtained by the press-molding step has a thickness of 50 μm or less, and the main surface has a surface roughness Rz of 12 μm or more.
Dependencies are inferred from the claim text.