Kokusai Denshin Denwa Kabushiki Kaisha

Jfe Steel Corporation

Fujio Tanaka

Nobutake Imamura

Chuichi Ota

Yasuyuki Nagao

Shigeyuki Akiba

Shinsuke Tanaka

Tatsuo Watanabe

Koji Ono

Soshi Yoshimoto

Hirokazu Sugihara

Yukitoshi Kushiro

Shizuo Suzuki

Tomohiro Hashimukai

Yasuyuki Okamura

A rapid-cooling quenching apparatus in which a high-temperature metal sheet is dipped and cooled in a liquid and a rapid-cooling quenching method for a steel sheet are provided. The rapid-cooling quenching apparatus includes a water tank containing the liquid in which the metal sheet is dipped, a jetting device having a plurality of nozzles through which the liquid is jetted onto front and back surfaces of the metal sheet and at least some of which are placed in the liquid in the water tank, and a pair or a plurality of pairs of restraining rolls which are placed between an entrance-side end of the jetting device and an exit-side end of the jetting device and restrain the metal sheet, in which nozzles nearest to the restraining rolls are inclined toward the restraining rolls from a horizontal plane in the jetting device.

Rapid-cooling quenching apparatus and rapid-cooling quenching method

A television signal recording and reproducing system is disclosed in which the polarity of a television signal is inverted in polarity prior to its recording on an optical recording medium and is again inverted when it is reproduced to avoid any serious degradation of picture quality.

Television signal recording and reproducing system using optical

A magneto-optical recording medium is disclosed in which a magnetic thin film recording layer is formed by a magnetic material having a Curie temperature or magnetic compensation temperature as low as 50.degree. to 250.degree. C. and a coercive force as large as 1 KOe or more and having an easy axis of magnetization perpendicularly to the film surface. A substantially transparent magnetic material film layer of ferrite, garnet or the like is disposed adjacent the recording film layer, large in the Faraday rotation angle and having an easy axis of magnetization perpendicularly to the film surface. A transparent substrate is disposed on the side of incidence of light. The substantially transparent magnetic material layer of the ferrite, garnet or the like may increase the magneto-optical rotation angle in the magnetic thin film recording layer, or may increase the magneto-optical rotation angle by the Faraday effect. The thickness of the substantially transparent magnetic material layer is selected in such a region where the figure of merit .sqroot.R.multidot..theta..sub.k expressed by its reflectivity R and the magneto-optical rotation angle .theta..sub.k is maximum.

Magneto-optical recording medium

A magneto-optical recording medium, in which a transparent synthetic resin substance, a light transparent thin film of a simple substance of metal or a metal compound, a dielectric layer, a recording medium layer formed of an amorphous alloy having an easy axis of magnetization in a direction perpendicular to the layer surface and thick enough to reflect light, and a protective film are provided in this order from the light incidence side. The dielectric layer may be provided with an auxiliary recording medium layer formed of the amorphous alloy having an easy axis of magnetization in the direction perpendicular to the layer surface and thin enough to permit the passage therethrough of light.

A magneto-optical recording medium comprising: a recording layer of a magnetic thin film low in the Curie temperature or magnetic compensation temperature and high in coersive force and having an easy axis of magnetization in a direction perpendicular to the film surface; a reproducing layer disposed adjacent the recording layer and large in the magnetic Kerr rotation angle and having an easy axis of magnetization in a direction perpendicular to the film surface; and a transparent substrate disposed on the side of incidence of light. In accordance with the present invention, a reflecting metal layer is provided for reflecting light having entered from the side of the transparent substrate and passed through the recording layer and the reproducing layer. A dielectric layer may be further disposed at least on one side of the transparent substrate or the reflecting metal layer with respect to the recording layer and the reproducing layer. The order of the recording layer and the reproducing layer may be replaced by each other.

A magneto-optical recording medium having an easy axis of magnetization in a direction perpendicular to the film surface, characterized in that a readout medium layer, a reflection layer and a recording medium layer are sequentially disposed in a direction of the incidence of a reading-out light, thereby to increase a reproduced output.

A semiconductor laser, which comprises a substrate of InP, an active layer, and two clad layers holding therebetween the active layer, and which is constructed so that the refractive index of the active layer may be larger than the refractive indexes of the two clad layers. In one of the two clad layers, the refractive index of a region adjacent to a radiation region in the active layer is larger than the refractive index of a region adjacent to a non-radiation region in the active layer. The refractive index of the other clad layer is equal to the refractive index of that region of said on clad layer adjoining the radiation region or the non-radiation region. The thickness and width of the radiation region of the active layer are selected so that the semiconductor laser may oscillate in the fundamental transverse mode. A buffer layer may be further provided between the active layer and one of the two clad layers.

Growing community of inventors

Tokyo, Japan

Fujio Tanaka