Matsushita Electric Industrial Co., Ltd.

Sumita Optical Glass, Inc.

Tadao Shioyama

Masaaki Sunohara

Shoji Nakamura

Noriyuki Kawata

Tadayoshi Yonemoto

Takafumi Asada

Makoto Umetani

Kiyoshi Kuribayashi

Hideto Monji

Cyuryo Yoshida

Takasi Inoue

Yoshiyuki Shimizu

Yukio Nishikawa

Yuji Uesugi

Minoru Koda

Katsuhiro Kuriyama

Yoshiteru Hosokawa

Kazuyoshi Kurose

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

A machine is provided for molding an optical element by using a molding block having upper and lower molding dies, a sleeve die and a glass blank combined integrally with each other. The machine includes a chamber which accommodates a heating zone having a plurality of sections for heating the molding block from above and below, a deformation zone for pressing the molding dies and a cooling zone having a plurality of sections for cooling the molding block. The chamber is formed with an inlet and an outlet for the molding block. The sections of the heating zone, the deformation zone and the sections of the cooling zone are provided independently of one another. A transport member is provided for sequentially transporting the molding block through the heating zone, the deformation zone and the cooling zone, and first and second shutters are provided for opening gas supply member is provided for introducing nonoxidizing gas into the chamber.

Method of producing the optical element

Machine for molding optical element

A laser cutting method for a glass material, includes steps of forming a continuous scribing line at least on one side face of the glass material, and projecting a laser beam onto the scribing line. A laser cutting apparatus for effecting the laser cutting method, includes a laser oscillating source for emitting the laser beam, a light condensing device for condensing the laser beam onto a surface of the glass material, a scribing device for forming the scribing line on the surface of the glass material, and a displacing device for displacing the laser beam on the scribing line following movement of the scribing point.

Laser cutting method and apparatus for effecting said method

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

Rotary head cylinder device with fluid bearing

Rotary head device with fluid bearing

A guide drum apparatus includes: a stator plate having armature windings fixedly mounted on a surface thereof perpendicular to the axis of a center shaft. Rotary magnets are fixedly supported by the center shaft on a plane perpendicular to the axis of the center shaft and face the armature windings so that the magnetic fluxes from the armature windings cause the rotary magnets to rotate according to the operational principle of a brushless d.c. motor. A stationary hollow cylindrical drum coaxially and rotatably mounts the center shaft. A rotary hollow cylindrical drum coaxially and fixedly mounted on the center shaft and has a rotary head fixedly mounted at an outer peripheral surface thereof. The outer surfaces of the stationary and the rotary drums are arranged on the same cylindrical surface to form a magnetic tape guiding surface, and the hollows of the stationary and the rotary drums form a contiguous bore containing all of the rotary magnets, the armature windings and a rotary transformer therein. This guide drum apparatus can be made compact in size and yet can smoothly rotate the rotary head without disturbing the signals on the magnetic tape.

Guide drum apparatus in a magnetic recording and/or reproducing apparatus

Growing community of inventors

Sakurai, Japan

Tadao Shioyama