Matsushita Electric Industrial Co., Ltd.

Sumita Optical Glass, Inc.

Sumita Optical Glass Co., Ltd.

Tadayoshi Yonemoto

Masaaki Sunohara

Tadao Shioyama

Noriyuki Kawata

Takashi Inoue

Yoshiyuki Shimizu

Makoto Umetani

Shoji Nakamura

Hideto Monji

Kiyoshi Kuribayashi

Kazuaki Takagi

Toshihiko Muroi

A method and an apparatus for producing an optical element capable of performing a molding temperature control required for a plurality of independent molding blocks in a short period of time, and continuously and simultaneously producing a plurality of different optical elements having a high degree of accuracy at a low cost is provided.

Method and apparatus for producing an optical element using a molding

In manufacturing a glass material used for a re-heat press method of manufacturing high-precision optical glass components including a lens, prism or the like, a glass material can be manufactured which has no defect inside of or on the surface of the glass, and without requiring a process of grinding and polishing the glass. The glass material is manufactured by dropping melted glass from the glass outlet of a glass melting furnace to a mold and cooling the dropped glass on the mold. The distance between the mold and the glass outlet is in a range which maintains the temperature of the stretched area of dropping glass--the area where the melted glass dropped on the mold is spontaneously separated by its own weight and surface tension at its softening temperature or above. The temperature of the glass around the stretched area is at least its softening temperature, and the glass around that area is instantaneously incorporated into the glass on the mold after separation. As a result, there is no difference in temperature over the entire glass, and no defect is generated inside and on the surface of the glass.

Method of manufacturing a glass blank used for optical glass elements

A method of producing a glass blank, comprising the steps of: supplying a desired weight of molten glass material to a bearer heated to a temperature of not more than a softening point of the glass material; performing and cancelling, at a temperature of not less than the softening point, pressing of the glass material supplied to the bearer so as to adjust a thickness of the glass material; and cooling the glass material to a temperature of not more than the softening point.

Method of producing glass blank

An apparatus of producing an optical glass element of the present invention comprises the steps of displacing a gob of optical glass on a first heat working jig to a second heat working jig by making the gob of optical glass to adhere to the second heat working jig on the basis of the difference in wettability with high temperature glass between the first heat working jig and the second heat working jig, thermally deforming the gob of optical glass on the second heat working jig to form an optical glass preform, and forming the optical glass preform under heating and pressure by using pressing moulds to form an optical glass element.

Apparatus for producing optical glass element

A method and apparatus are provided for producing an optical glass element, including displacing a gob of optical glass on a first heat working jig to a second heat working jig by making the gob of optical glass adhere to the second heat working jig due to a difference in wettability with high temperature glass between the first heat working jig and the second heat working jig. The gob of optical glass on the second heat working jig is thermally deformed to form an optical glass preform. The optical glass preform is formed under heat and pressure by using pressure molds to form an optical glass element.

Method of producing optical glass element and production apparatus using

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Moriguchi, Japan

Tadayoshi Yonemoto