Taiyo Yuden Co., Ltd.

Akimasa Miyata

Takeshi Otsu

Motomitsu Hagiwara

Isao Matsuda

Fumi Hara

Shingo Kato

Yuji Tomizawa

Takuo Kodaira

An optical information recording medium is provided having a superior jitter property even when an organic substance is used for a recording layer. The optical information recording medium has a substrate having a penetrating hole in a central portion thereof and a spiral pre-groove provided in one surface of the substrate, a reflection layer provided on the surface of the substrate in which the pre-groove is provided, a recording layer which is provided on the reflection layer and which is composed of an organic substance including a dye, and a light transmissive cover layer provided on the recording layer. In the optical information recording medium, the cover layer has an elastic modulus of 40 MPa or less at 25&#xb0; C. in an interface region facing the recording layer.

Optical information recording medium

An optical information recording medium includes a disk-like substrate having a hole in a central portion thereof, and a light-reflective layer, a dye recording layer containing an organic dye, an intermediate layer composed of an inorganic substance, and a light-transmissive layer composed of a resin disposed in that order on one principal surface of the substrate, in which information is recorded/reproduced by irradiation of laser light from the light-transmissive layer side. In the optical information recording medium, the light-transmissive layer covers a surface of the intermediate layer from an inner peripheral edge of the intermediate layer to an outer peripheral edge of the intermediate layer, and a vicinity of an outer peripheral edge of the light-transmissive layer is in contact with the substrate in an annular region extending around an outer peripheral side of the substrate.

An optical information recording medium having a disk-shaped substrate formed with spiral grooves on one main surface, and having an optical reflection layer formed with grooves at the surface corresponding to the grooves of the substrate for reflecting a laser beam, an optical recording layer, a protective layer, and an optical transparency layer in this order on the main surface thereof. The optical information recording medium has a main information area and a sub-information area to the inner circumferential side thereof, in which the track pitch TrB of the grooves in the sub-information area is about 0.32 &#x3bc;m or less, and the depth D of the grooves and the half-band width W of the grooves satisfy a relation represented by: W&#x2267;2D+70, whereby the difference between the reflectivity at the land surface and the reflectivity at the groove surface in the sub-information area can be restricted to less than 30%, thereby preventing occurrence of mis-decipherment for BCA marks.

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Gunma, Japan

Akimasa Miyata