Toshiba Machine Co., Ltd.

Toshiba Kikai Kabushiki Kaisha

Toshihisa Kamano

Isao Matsuzuki

Yoshizo Komiyama

Tetsuya Tanioka

Hirotaka Masaki

Kazunori Urushibata

Toshiyuki Takagi

Hiroshi Murakoshi

Satoshi Fukuyama

Ryuji Tanaka

In the initial stage of die-opening operation when an upper coremoves upward together with an upper die plate, an upper cavity dieis biased downwardly by an elastic memberso as to press the lower surface of the upper cavity dieagainst the upper surface of a lower cavity dieand keep their contact, thereby forcing a molded glass elementto remain on a lower coreby utilizing the difference in outside diameter between the lower coreand the upper core. This makes it possible to securely release the molded glass elementfrom the upper coreand leave the molded product on the lower coreupon die opening, enabling smooth removal and automated transportation of the molded product.

Die assembly for molding of glass element

A metallic material is placed between an upper die and a lower die Inert gas is fed into the processing chamber defined by a transparent quartz tube The dies and are heated together with the metallic material by infrared lamps The dies and are closed to form the material

Method and apparatus for forming metallic materials

A press forming machine for optical devices which manufactures, an optical device from silica glass with a high glass transition point. A transparent quartz tube surrounds an upper die unit, lower die unit, fixed shaft, and moving shaft to form an airtight chamber inside it. Infrared lamps are arranged along the outer surface of the transparent quartz tube, and a reflecting mirror is arranged behind the infrared lamps. A cooling gas jacket is formed to cover the rear surface of the reflecting mirror. The inner-diameter side wall surface of the jacket and the reflecting mirror have many through holes. A cooling gas is sprayed from the interior of the jacket toward the transparent quartz tube through the through holes, thereby cooling the reflecting mirror, quartz bulbs constituting the outer surfaces of the infrared lamps, and the transparent quartz tube.

Press forming machine for optical devices

In press molding, a shaft (metal mold 13) is moved by positional or torque control to cause upper and lower molds to reach a set position slightly before a position where the upper and lower molds are set in a final mold closed state. As soon as the upper and lower molds reaches the set position, the control is switched to torque control using a small force which does not deform a glass material to perform feedback control. For this reason, when the cooling process is started, the mobile shaft is moved by the same amount as a contraction amount of the shaft, the actual position of the shaft is moved. However, a tight contact state between the molds and the glass material is kept without changing the thickness of the glass material, and positional control and torque control can be apparently performed at once. Thereafter, when temperature reaches an almost glass transition point, final pressing is performed. A position where the material is press-molded is exactly controlled by correcting an origin position of lower mold by closing the molds before press-molding. According to this method, a highly accurate optical element having thickness reproducibility can be obtained.

Method for manufacturing press-molded glass object and apparatus therefor

A method of manufacturing an optical waveguide comprises a first step of laminating, on one major surface of a first glass material, a second glass material to a desired thickness, the second glass material having optical characteristics different from those of the first glass material, a second step of forming the second glass material to have a desired circuit pattern, and a third step of laminating a third glass material having optical characteristics similar to those of the first glass material on an entire surface of the first glass material on which the circuit pattern is formed by the second glass material. In at least one of the first and third steps, the glass material to be laminated is laminated by coupling.

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Numazu, Japan

Toshihisa Kamano