Pioneer Electronic Corporation

Pioneer Video Corporation

Takahiro Kobayashi

Seiro Fujii

Satoshi Jinno

Kenji Suzuki

Takamasa Yoshikawa

Kiyohide Ogasawara

Nobuaki Onagi

Jiro Fujimori

Shinichiro Suzuki

Naoto Kozasa

Nobuyasu Negishi

Masataka Yamaguchi

Masayasu Yamaguchi

Masayasu Yamaguchi, Deceased

An optical element includes a light-transmittable substrate and a light-transmittable dry-light-curing-film layered on the substrate and having an undulant pattern on a surface thereof, characterized by the dry-light-curing-film has a specific range viscosity at room temperature in the unhardened state, a specific range thickness in the unhardened state, the specific range creep and creep recovery characteristics. A method of making an optical element includes steps of: providing a molding die having an undulant pattern on a surface thereof; providing a dry-light-curing-film has a specific range viscosity at room temperature in the unhardened state, a specific range thickness in the unhardened state, the specific range creep and creep recovery characteristics; pressing the film onto the surface of the molding die by a roller under heated and reduced pressure conditions to form undulant pattern on the film; affixing a light-transmittable substrate to the film while pressing the substrate by a roller under an increased pressure condition to form a laminate; irradiating an UV radiation into the film to harden the film; and separating the molding die from the film to form an optical element.

Optical element and a method for forming the same

This optical disk is two-substrates bonding type. In the optical disk, from the first transparent substrate side toward the second substrate side, at least following layers are laminated in that order; (1) the first transparent substrate, (2) the first optical film, (3) the intermediate layer, (4) the second optical film, and (5) the second substrate. The intermediate layer is formed of a dry photohardenable film of light transmissive type, which has a viscosity of 3,500 to 400,000 poises at a room temperature and in a non-hardened condition and has a thickness of 5 to 200 .mu.m in the non-hardened condition. The shapes of pits or grooves and the extent of light transmissive property are set so that both of the first pit-groove surface on the first transparent substrate and the second pit-groove surface on the second substrate can be read by irradiating the optical disk with the beam for reproduction from the first transparent substrate side of the optical disk. According to this optical disk, it is possible to improve the recording or reproducing density, transmission rate, and reproducing time while no reading obstruction is caused.

Two substrates bonding type optical disk and method of producing the same

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.

Growing community of inventors

Saitama, Japan

Takahiro Kobayashi