Sony Corporation

Akio Koshita

Minoru Kikuchi

Takeshi Gouko

Kenji Echizen

Mikio Sato

Jun Nakano

Takeshi Yoshida

An optical recording medium includes a first disk, a second disk, and an adhesive layer for bonding the first disk to the second disk. The first disk and the second disk each include a substrate having a first surface and a second surface and having a gradient on an outer peripheral portion of the second surface, two or more information signal layers disposed on the first surface, an intermediate layer disposed between adjacent information signal layers, and a cover layer covering the two or more information signal layers and the intermediate layer. The second surface of the substrate included in the first disk faces the second surface of the substrate included in the second disk with the adhesive interposed therebetween.

Optical recording medium and method for manufacturing the same

Provided is an optical recording medium including: two discs, each of which includes a substrate and a plurality of recording layers; and an attachment layer which is provided between the two discs and includes ultraviolet curable resin, wherein thickness of each of the substrates in the two discs is equal to or greater than 0.3 mm and equal to or less than 0.545 mm, wherein transmittance of the two discs is equal to or less than 20%, and wherein inversion rates on both surface sides of the attachment layer are equal or substantially equal to each other, and are equal to or greater than 70%.

Optical recording medium and manufacturing method of the same

A boundary lubricant filmis formed on a stampercontact portion of a stationary mirrorand/or a stationary mirrorcontact portion of the stamper. The boundary lubricant filmcontains one of kinds of phosphate esters. A material is injected into a cavity. As a result, a disc substrate for an optical disc is molded.

Lubricant composition and article, disk molding stamper, disk molding apparatus, disk forming method, method of forming lubrication coating

Disk forming method

In an optical disc in which an information signal is recorded/reproduced by irradiating a laser beam to a disc substratein which an information signal portionhas been provided on one principal plane from the side where the information signal portionexists, a clamp reference surfaceis set to the information signal portionside of a replica substrateconstructing the optical disc. The clamp reference surfaceis set to a flat surface and a thickness of the replica substratein a clamping areais set to be larger than that of the convex-shaped replica substratein an information recording area. The replica substratein which a periphery of a center holeis thicker than the information recording areais used.

Growing community of inventors

Miyagi, Japan

Akio Koshita