Taiyo Yuden Co., Ltd.

Taiyo Yudenco., Ltd.

Yoshikazu Takagishi

Isao Matsuda

Emiko Hamada

Mitsuo Sekiguchi

Ryuichi Sunagawa

Atsuo Shimizu

Keiichi Ida

Toru Fujii

Takanori Yoshizawa

Kazuyuki Shibuya

Yuaki Shin

Fumi Hara

Takanobu Matsumoto

Kunihiro Otaguro

Satoshi Nagaya

Mitsue Sakaino

An optical information recording medium comprises at least a substrate on which a groove is formed in a recording area, a recording layer comprising an organic dye, and a reflective layer. The recording area has a preformat area and a data area, and the groove in the preformat area is narrower or shallower than that in the data area.

Optical information recording medium and mold apparatus for manufacturing the same

An optical information recording medium, recording and reproducing method and device for same, and an optical pickup, which enables high-density recording and high-speed recording. Recording or reproduction is performed to or from the optical information recording medium having a track pitch Tp of 1.0 &#x3bc;m&#x2266;Tp&#x2266;1.2 &#x3bc;m, using laser light having a wavelength &#x3bb; of 770 nm&#x2266;&#x3bb;&#x2266;830 nm, and a spot diameter Sd of 1.1 &#x3bc;m&#x2266;Sd&#x2266;1.3 &#x3bc;m.

Optical information recording medium, method for recording/reproducing the same, and optical pickup

An optical information recording medium recordable at a high density two times or more higher than that of currently-used CD-Rs by optimally determining the thicknesses of a recording layer and a reflecting layer. The optical information recording medium comprises the recording layer formed on a transparent substrate having a spiral pregroove formed thereon, wherein a track pitch Tp of the pregroove is 1.0 &#x3bc;m&#x2266;Tp&#x2266;1.2 &#x3bc;m and a thickness Dg of the recording layer on the pregroove is 80 nm&#x2266;Dg&#x2266;120 nm.

Optical information recording medium

An optical information recording medium recordable at a high density two times or more higher than that of currently-used CD-Rs by devising the shape of a pregroove is provided. It is provided with a recording layer formed on a transparent substrate having a spiral pregroove formed thereon, wherein a track pitch Tp of the pregroove is 1.0 &mgr;m&lE;Tp&lE;1.2 &mgr;m and an inclination angle Ga of sidewalls of the pregroove is 30&deg;&lE;Ga&lE;70&deg;.

Provided is a medium for recording optical information and a method for recording optical information that allow recording sensitivity to be increased, and particularly a prescribed recording sensitivity to be maintained together with reflectivity and other playback characteristics during high-speed recording, by employing the temperature dependence of recording sensitivity of the light-absorbing layer instead of the light attenuation coefficient of the light-absorbing layer, and selecting a material which is prone to increased absorption of a laser beam at high temperatures during recording. A distinctive feature is that the absorbance or recording sensitivity of the dye material film used in the medium for recording optical information that has a writable structure is dependent on temperature. Specifically, it was found that the absorption spectrum of the dye material varies at high temperatures, and a relation A /A &gE;1.30 was established. In this relation, A (Abs) is an absorbance of the light-absorbing layer at a wavelength of recording light under room-temperature conditions, T (&deg;C.) is a pyrolysis temperature of the light-absorbing layer, and A (Abs) is an absorbance at a wavelength of recording light under T&minus;50 (&deg;C.) conditions.

Medium and method for recording optical information

An optical data recording medium in which the shape of the dye spectrum of a dye film having a thin film thickness per unit absorbance is controlled so as to enable improvements in the recording speed during high speed recording, jitter, and modulation, wherein the optical data recording medium is characterized in that 0<D/C&lE;100, and 80&lE;D/B, where D (nm) is the mean film thickness of the light-absorbing layer, C (Abs) is the maximum absorbance (based on molecular absorption) of the light-absorbing substance, B (Abs) is the maximum absorbance (based on association absorption) of the light-absorbing substance, D/C is the unit absorbance thickness based on the molecular absorption, and D/B is the unit absorbance thickness based on the association absorption.

Optical data recording medium

An optical information recording medium provided on a substrate thereof with a recording layer comprising a dye-containing layer, wherein the recording layer further comprises an organometallic dye compound containing a metal or a metallic ion, which is characterized in that an absorption spectrum curve of the recording organic dye is intersected with an absorption spectrum curve of the organometallic dye compound, and that the organometallic dye compound exhibits a maximum absorption wavelength on a longer wavelength side in relative to a maximum absorption wavelength of the recording organic dye.

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Fujioka, Japan

Yoshikazu Takagishi