Sony Corporation

Toshihiro Akimori

Michihiko Iida

Nobutake Kagami

Manabu Sato

Somei Endo

Sohmei Endoh

Toru Yano

Koichi Shigeno

Masatsugu Suwabe

Keiji Oya

Junko Shimada

Manabu Satoh

In a recording material, physical characteristic information of the recording medium, and more specifically, material information representing the material of the disc, is recorded. Accordingly, a recording apparatus and a reading apparatus easily and accurately determine the physical characteristics of the disc, thereby making it possible to provide suitable setting for performing an operation.

Recording medium, recording apparatus, and reading apparatus

An optical recording medium comprises a transmission substrate and a recording layer formed on the transmission substrate, the recording layer containing at least a dye material expressed by a general formula shown at the following chemical formula (in the chemical formula 1, R1 represents alkyl group having carbon numbers 1 to 4, R2, R3 represent alkyl group having carbon numbers 1 to 4, benzyl group or groups combined to form 3 to 6 rings, Y1 and Y2 independently represent organic groups and X represent ClO, BF, PF, SbF) and a dye material expressed by a general formula represented by the following chemical formula 2(in the chemical formula 2, R1 and R2 represent alkyl groups having carbon numbers 1 to 4, benzyl groups or groups combined to form 3 to 6 rings, Y1, Y2 independently represent organic groups and X represent ClO, BF, PF, SbF):  In a write once type optical recording medium such as DVD&#x2212;R and DVD+R, satisfactory recording characteristics can be obtained from low-speed recording to high-speed recording.

Optical recording medium

This invention provides a method for producing a CD-R optical recording medium. A first stack at a first stage is created by forming on a substrate a recording layer containing an organic dyestuff and a metal layer. At least after a formation of the metal layer; the first stack is transported from the first stage along a transport path towards a second stage through an atmosphere having a relative humidity. The relative humidity is maintained at 40% or less. To control the relative humidity, a shielding plate may be provided around the transport path. An air conditioner may locally control the relative humidity of an area encircled by this shielding plate.

Method for producing optical recording medium

Optical recording medium and master disc for preparation thereof

An optical recording medium which can provide a wobbling signal at a sufficiently high level even if the track pitch is reduced to enhance the recording density. The recording medium can attain a practically adequate recording-reproducing characteristic such as jitter characteristic. The medium has a wobbling groove that has a depth falling within the range of &lgr;/2.90 n to &lgr;/2.15 n. Here, &lgr; is the wavelength of a light beam applied to record and reproduce signals and n is the refractive index of the substrate of the optical recording medium. The ratio of the width Wg of the wobbling groove to the track pitch Tp (Wg/Tp) falls within the range of 25.0% to 45.5%.

Optical recording medium having wobbling groove extending along the tracks

The present invention enables to realize a high recording density while suppressing the wobble signal jitter component to a sufficiently low value for practical use, thereby enabling to perform information recording/reproducing in a stable manner. The recording track has a track pitch set to 1.3 micrometers or below and the recording layer is formed by a recording material containing a dye having a characteristic appropriate to suppress the wobble signal jitter component to a low value.

Growing community of inventors

Miyagi, Japan

Toshihiro Akimori