Pioneer Electronic Corporation

Yasushi Araki

Fumio Matsui

Takashi Chuman

Shuichi Yanagisawa

Tatsuro Sakai

Satoru Tanaka

Atsushi Yoshizawa

Taishi Tsuji

Shingo Iwasaki

Makoto Okano

Takako Miyake

An optical recording medium is provided with: a first substrate of optically transparent type; a first recording layer formed on one surface of the first substrate, which includes phthalocyanine dye; a second substrate of optically transparent type; a second recording layer formed on one surface of the second substrate which includes phthalocyanine dye; a first elastic body layer formed on a surface of the first recording layer at a side opposite to the first substrate; a second elastic body layer formed on a surface of the second recording layer at a side opposite to the second substrate; and a bonding layer formed between the first elastic body layer and the second elastic body layer.

Optical recording medium

Disclosed is an information recording medium having a recording layer which contains a phenol type compound. This information recording medium therefore exhibits very excellent effects in light resistance and is safe to use.

Information recording medium

A recordable optical recording medium having sufficiently high reflectance and modulation factor to insure consistent reproduction on CD players. The optical recording medium of the present invention has a light-transparent substrate having pregrooves formed in the face of one surface, a light-absorbing layer formed on the pregrooves, a light-reflecting layer formed on said light-absorbing layer, wherein the pregrooves have a depth of .lambda./6.5 n-.lambda./2.5 n (where .lambda. is the wavelength of recording or reproducing light in nanometers, and n is the refractive index of the substrate) and a width of 0.35-0.47 .mu.m.

A WORM optical disk that not only has a sufficiently improved reflectance to permit the setting of higher RF signal levels but that also permits the setting of higher levels for the tracking error signals to insure consistent performance in operation. This WORM optical disk of the present invention comprises a substrate 1 that has grooves 2 formed in its surface and that is coated with a dye film 3 which, in turn, is coated with a reflecting film 4, wherein the part of the dye film 3 which is formed on the lands 5 of the substrate 1 and a portion of that part of the dye film 3 which is formed in the grooves 2 are subjected to irradiation to effect color fading in the irradiated dye regions.

Write-once-read-many optical disk

An optical recording medium comprises a light transmissive substrate, a light absorption layer provided on the light transmissive substrate and a light reflecting layer provided on the light absorption layer. The light absorption layer contains a cyanine type dye represented by a following structural formula: ##STR1## and a quencher represented by a following general formula: ##STR2## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 denote hydrogen or substituent group, respectively. A protective layer may be further provided on the light reflecting layer for protecting the same.

Disclosed is an information recording medium having a recording layer which contains a benzotriazole type compound. This information recording medium therefore exhibits very excellent effects in light resistance and is safe to use.

A recordable optical recording medium having a sufficiently high reflectance and modulation factor to comply with the CD specifications. The light-absorbing layer in the optical recording medium has a first cyanine dye having a light absorption band in the wavelength region of recording or reproducing light, and a second cyanine dye having a light absorption band in the wavelength range shorter than the first cyanine dye and having a smaller light absorption in the wavelength region of recording or reproducing light. The second cyanine dye is contained in the light-absorbing layer in an amount larger than the first cyanine dye.

A writable recording medium having reduced jitter, improved performance on repeated reproduction, improved light resistance, and sensitivity controllability is disclosed, in which a light-absorbing layer thereof contains (D-1) a cyanine dye having an absorption band in the wavelength region of light for recording or reproduction, (D-2) a cyanine dye having an absorption band in a shorter wavelength region than that of cyanine dye (D-1) and having a smaller absorption than that of cyanine dye (D-1) in the wavelength region of light for recording or reproduction, (Q-1) a quencher for preventing photo-deterioration of cyanine dyes, and (Q-2) a quencher selected from an azo compound and a diphenylamine compound, the weight ratio of cyanine dye (D-2) to cyanine dye (D-1), taken as .alpha., being from 1 to 3, the weight ratio of quencher (Q-1) to quencher (Q-2), taken as .beta., being from 0.5 to 1, the ratio of the total weight of quenchers (Q-1) and (Q-2) to the total weight of cyanine dyes (D-1) and (D-2), taken as .gamma., being from 0.25 to 0.5, and the product of .alpha. by .gamma. (.alpha..cndot..gamma.) being less than 1.1.

Recording medium

An optical recording medium, comprising: a light transparent substrate, a light absorbing layer disposed on the light transparent substrate, a light reflection layer disposed on the light absorbing layer, and a protection layer disposed on the light reflection layer, wherein the protection layer has been formed by curing a photo-setting resin which is capable of providing a glass transition point of not lower than 110.degree. C., a shrinkage factor of not larger than 8%, and a water vapor permeability of not higher than 110 g/m.sup.2 .multidot.24 H after being cured. The optical recording medium having the above structure is capable of showing stable performances, even in an environment of high humidity.

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Saitama, Japan

Yasushi Araki