Pioneer Electronic Corporation

Pioneer Corporation

Satoshi Jinno

Takahiro Kobayashi

Seiro Fujii

Yasuo Hosoda

Ayumi Mitsumori

Takanobu Higuchi

Masataka Yamaguchi

Hideo Kudo

Takamasa Yoshikawa

Nobuyasu Negishi

Kiyohide Ogasawara

Tetsuya Iida

Nobuaki Onagi

Yoichi Okumura

Megumi Sato

Shinichiro Suzuki

Masayasu Yamaguchi, Deceased

Tomoaki Izumi

An information recording medium has an excellent jitter characteristic with a considerable difference in reflectance between prior to and subsequent to recording. The information recording medium includes a recording layer which contains a material having a reflectance which varies by irradiation of a light beam, on which information is recorded as reflectance variations, and a substrate for supporting the recording layer, the recording layer including a metal nitride as a major component. In a method of manufacturing the information recording medium having a recording layer which includes a material having a reflectance which varies by irradiation of a light beam, on which information is recorded as reflectance variations, and the substrate for supporting the recording layer, the recording layer including a metal nitride as a major component, the method includes a recording layer forming step for forming the recording layer by a reactive sputtering method which uses a target comprised of a metal constituting a metal nitride, wherein a flow ratio Ar:Nin an atmosphere including Ar and Nin the recording layer forming step is set within the range of 80:10 to 10:80.

Information recording medium and process for producing the same

An object of the present invention is to provide a phase-change optical recording medium of an amorphous recording mark type. The optical recording medium is a write once type medium capable of decreasing the degradation of an information signal which has been already recorded. The recording layer of the optical recording medium according to the present invention includes a first recording layer and a second recording layer. The first recording layer comprises a first composition which can be changed into another composition more stable in an amorphous state by combining with a component included in the second recording layer.

Write once optical recording medium

A film constitution in an optical recording medium including a light incident side substrate and a light reflecting side substrate cooperatively acting as a base of the medium, and includes, between these substrates, those layers formed by sputtering so as to constitute a laminated structure, which layers include: a phase-change recording layer to be phase-changed between an amorphous phase and a crystal phase by laser light irradiation; a first dielectric layer and a second dielectric layer, each having a protective function and an optical adjusting function for the phase-change recording layer; a reflecting film layer for reflecting the laser light transmitted through the phase-change recording layer; a hardness enhancing layer for enhancing the mechanical strength of the medium; and a protecting layer having a function for reducing thermal damages to the light incident side substrate and an optical adjusting function.

Optical recording medium

A double-layer optical disk having characteristics that are less wavelength dependent, allows the use of a pickup comprising a light beam of a different wavelength to read each layer accurately and stably. In the double layer optical disk which comprises, a first reflection layer carrying first information, a spacer layer, and a second reflection layer carrying second information, each laminated on a transparent substrate having a specific refractive index thereby allowing a pickup to read said first and second information, the first reflection layer is formed by laminating a metal layer made of a metal thin film and a dielectric layer made of a dielectric having a refractive index higher than the refractive index of the transparent substrate.

Multi-layer optical disk having a reflection layer comprising thin metal

An optical recording medium of a multi-layer type comprises; a single or plural spacer layers each carrying pits and/or grooves; a single or plural reflective layers layered on the spacer layers; and a silane coupling treatment layer formed between the reflective layer and the spacer layer adjacent to each other.

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.

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Yamanashi-ken, Japan

Satoshi Jinno