Production of pressed lens

Abstract

PURPOSE: To enable the production of pressed lens even in normal atmosphere preventing the fusion of the lens to a mold and the reduction of even a PbO- containing raw material, by coating the surface of a glass material having low transition temperature with an SiO 2 film, placing the glass in a mold and hot-pressing the glass. CONSTITUTION: The surface of a glass having a transition temperature lower than that of SiO 2 and preformed to a form capable of giving the form of finished lens by hot-pressing is coated with an SiO 2 layer having a thickness of 50W2,000Å e.g. by vacuum evaporation. The glass material is placed in a mold and hot-pressed by heating the material and the mold at a temperature above the softening point of the glass and ≤900°C. The SiO 2 coating layer on the glass surface prevents the fusion of the glass to the mold during compression molding and prevents the reduction of the glass even is the glass contains PbO. The molding can be carried out in normal atmosphere as well as in a neutral gas or reducing gas. It is not necessary to use a mold made of an expensive material. COPYRIGHT: (C)1987,JPO&Japio

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    CN-102862347-AJanuary 09, 2013Hoya株式会社Glass material for press molding, method for manufacturing optical glass element employing same, and optical glass element
    CN-102862347-BMarch 25, 2015Hoya株式会社压制成型用玻璃材料、以及使用该玻璃材料的玻璃光学元件的制造方法、以及玻璃光学元件
    JP-2007269544-AOctober 18, 2007Hoya Corp, Hoya株式会社Glass material for mold-press forming, manufacturing method of glass material, and manufacturing method of glass optical element
    JP-H03242332-AOctober 29, 1991Canon IncProduction of optical element
    JP-H0477319-AMarch 11, 1992Canon IncDevice for producing optical element
    US-5192352-AMarch 09, 1993Canon Kabushiki KaishaMolding method using glass blank
    US-5720791-AFebruary 24, 1998Minolta Co., Ltd.Method of producing an optical lens element
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