Pioneer Electronic Corporation

Seiro Fujii

Takahiro Kobayashi

Satoshi Jinno

Takamasa Yoshikawa

Kiyohide Ogasawara

Nobuaki Onagi

Shinichiro Suzuki

Nobuyasu Negishi

Masataka Yamaguchi

Masayasu Yamaguchi

Masayasu Yamaguchi, Deceased

An apparatus for manufacturing a substrate of an optical recording disk having a transfer layer of uniform thickness. The apparatus forcibly deforms a portion of the substrate ranging from the center portion to an outer circumferential portion so as to provide a substantially conical-convex shape prior to the formation of the transfer layer. The apparatus forms the transfer layer onto a surface side of the conical-convex shape of the substrate.

Apparatus for manufacturing a substrate means for an optical recording

The present invention relates to an optical recording disc comprising two disc bases each having a recording layer formed on one surface side of a substrate bonded to each other by the medium of an adhesive layer with both recording layers facing each other. The adhesive layer, containing an adhesive and a reaction initiator, is hardened through polymerization reaction by the reaction initiator and photopolymerization reaction by ultraviolet-ray irradiation. For this reason, the adhesive layers of both disc bases can be bonded together entirely and uniformly and besides, the adhesive layer can rapidly get hardened, which is advantageous for enhancing productivity of a double-face type optical recording disc.

Optical recording disc

There is provided a substrate for an optical recording disk capable of preventing non-uniformity of thickness of the transfer layer due to a camber of the substrate, and having a transfer layer excellent in uniformity of the thickness thereof. The substrate for the optical recording disk is manufactured in such a manner that a portion ranging from a center portion to an outer circumferencial portion of the substrate is forcively deformed in advance prior to the formation of the transfer layer so as to provide substantially a conical-convex shape, and thereafter, the transfer layer is formed onto a surface side of the conical-convex shape of the substrate.

Manufacturing method of substrate means for optical recording disk and

An optical recording disk in which a transfer layer having grooves made of ultraviolet setting resin is laminated on the surface of a substrate, and in which a recording layer is laminated on the transfer layer, the optical recording disk comprises a peeling protrusion projectingly provided on the inner circumferential side of the transfer layer.

Optical recording disk and manufacturing method thereof

A magneto-optical recording disk comprises a transparent substrate on which a magneto-optical recording layer made of a rare earth-transition metal alloy having an uniaxial magnetic anisotropy is sandwiched by a pair of dielectric layers is characterized that the dielectric layers are deposited in an amorphous state by means of a low pressure sputtering method.

Method of making magneto-optical recording disk

An optical-magnetic recording medium utilizing a recording layer of an amorphous rare-earth-transition metal alloy so as to rely on the Kerr effect. An enhancing layer of ZnS and a fluoride of an alkaline-earth metal (preferably CaF.sub.2) is deposited on a grooved substrate and the recording layer deposited thereover to both enhance the Kerr effect and prevent peeling.

Growing community of inventors

Saitama, Japan

Seiro Fujii