Ricoh Company, Ltd.

Yamada Chemical Co., Ltd.

Nikon Corporation

Toru Yashiro

Yutaka Ueda

Yasuo Sawada

Eiji Noda

Masatoshi Taniguchi

Toshiro Narizuka

Toshio Konishi

Toshihiko Horibe

Kouji Watanabe

Hiroaki Tomita

Toshiya Shuin

An optical recording medium which includes a PMA area, a TOC area, program area, an area that includes a user area and lead-out area. A portion of the PMA area, which relates to the program area, is in a recorded state and the TOC area is in an unrecorded state. Alternatively, the PMA may be in an unrecorded state. In addition, a password may be recorded in a portion of an information area. A method of erasing the medium and a system for reading and recording information are also provided.

Optical recording medium and method of information recording/reading an optical recording medium

Optical recording medium and method of information recording/reading an

An optical information recording medium includes a substrate, and a light absorption layer formed thereon which includes a phthalocyanine compound (I), a phthalocyanine compound (II) and a phthalocyanine compound (III) as specified in the specification. This optical information recording medium can be produced by providing the light absorption layer, directly or via an intermediate layer, on a substrate with information pits and/or guide grooves being formed on the surface thereof by film formation coating, providing a light reflection layer, directly or via an intermediate layer, on the light absorption layer by vacuum film formation, and then providing a protective layer on the light reflection layer.

Optical information recording medium and method of producing the same

A phthalocyanine compound of formula (I): ##STR1## wherein FIGS. 1 to 16 around the phthalocyanine skeleton indicate the positions of carbon atoms in each benzene ring thereof; an oxygen atom is bonded to the carbon atom with position 1 or 4, to the carbon atom with position 5 or 8, to the carbon atom with position 9 or 12, and to the carbon atom with position 13 or 16; R.sup.1 is a fluorine-atom substituted alkyl group; R.sup.2 is an unsubstituted phenyl group or an alkyl-group-substituted phenyl group; R.sup.3 is an unsubstituted alkyl group, a fluorine-atom substituted alkyl group or a hydrogen atom; and M represents Zn, Cu or Ni.

Phthalocyanine compounds

An optical recording medium has a substrate, and a light absorbing layer serving as a recording layer formed on the substrate. The light absorbing layer contains a metallo-phthalocyanine compound of formula (I): ##STR1## wherein M is Mn, Fe, Co, Zn or Cd; and either A.sup.1 or A.sup.2, either A.sup.3 or A.sup.4, either A.sup.5 or A.sup.6, and either A.sup.7 or A.sup.8 is --OR group or --SR group in which R is an aliphatic, aromatic or alicyclic hydrocarbon group, and the other is hydrogen; and a nitrogen-containing compound selected from the group consisting of an amino compound, an imino compound and an azo compound, each of which may have a substituent or form a ring.

Optical recording medium and method of producing the same

A phthalocyanine compound of formula (1): ##STR1## wherein FIGS. 1 to 16 around the phthalocyanine skeleton indicate the positions of carbon atoms, an oxygen atom is bonded to the carbon atom with position 1 or 4, to the carbon with position 5 or 8, to the carbon atom with position 9 or 12, and to the carbon atom with position 13 or 16, R.sup.1 is a fluorine-atom substituted alkyl group, R.sup.2 is an unsubstituted phenyl group or an alkyl-group-substituted phenyl group, R.sup.3 is an unsubstituted alkyl group, a fluorine-atom substituted alkyl group or a hydrogen atom, and M represents VO or TiO.

An optical information recording medium includes a substrate, and a light absorption layer formed thereon which includes a phthalocyanine compound (I) having a thermal decomposition temperature in a range of 250.degree. C. to 350.degree. C., measured by thermogravimetry with a temperature elevation rate of 10.degree. C. and a phthalocyanine compound (II) having a thermal decomposition temperature in a range of 350.degree. C. to 450.degree. C., measured by thermogravimetry with a temperature elevation rate of 10.degree. C. This optical information recording medium can be produced by providing the light absorption layer, directly or via an intermediate layer, on a substrate with information pits and/or guide grooves being on the surface thereof by film formation coating, providing a light reflection layer, directly or via an intermediate layer, on the light absorption layer by vacuum film formation, and providing a protective layer on the light reflection layer.

An optical recording medium is composed of a substrate and a light absorbing layer serving as recording layer formed on the substrate. The light absorbing layer includes a phthalocyanine compound and a compound having a group which can be coordinated to the phthalocyanine compound.

An optical recording medium has a substrate, and a right absorbing layer serving as a recording layer formed of the substrate. The light absorbing layer contains a metallo-phthalocyanine compound of formula (I): ##STR1## wherein M is Mn, Fe, Co, Zn or Cd; and either A.sup.1 or A.sup.2, either A.sup.3 or A.sup.4, either A.sup.5 or A.sup.6, and either A.sup.7 or A.sup.8 is --OR group or --SR group in which R is a group including --N.dbd. or --N&lt;, and the other is hydrogen.

An optical information recording medium is disclosed which includes a substrate, and an information recording layer provided on the substrate and containing a specific metallophthalocyanine having a substituent which prevents the molecular association of the metallophthalocyanine and which contains at least one of O, S and N atoms.

Optical information recording medium

A plastic lens comprising a plastic lens base material having provided on at least one surface thereof (1) a primer layer comprising a resin containing at least one organosilicon compound represented by the following general formula (I):

Plastic lens

An optical information recording medium including a ROM area and a recordable area is composed of a light-transmitting substrate with prepits and/or guide grooves formed on the surface thereof, a light absorption layer serving as a recording layer which is composed of a dye as the main component overlaid on the light-transmitting substrate, and a light reflection layer which is composed of metallic film overlaid on the light absorption layer. The light absorption layer of this optical information recording medium is formed on the substrate by coating a solution composed of a dye and a solvent of a mixture of a fluoridated alcohol of formula (I) and an alcohol of formula (II):

An optical information recording medium is composed of a substrate and a recording layer which is formed on the substrate and made of a composition comprising at least gold and sulfur, with the gold content being 50 atomic percent or more in the composition.

An optical recording medium is composed of a substrate, and a recording layer formed thereon, which is made of (a) a first recording layer which contains a light-absorbing organic compound and can be deformed upon irradiation of light thereto, and (b) a second recording layer which includes a sulfide containing antimony in an amount of 50 atm % or more, and can be deformed in accordance with the deformation of the first recording layer.

Optical recording medium

An optical recording medium is composed of a substrate, a recording layer containing an inorganic material which includes as the main component a sulfide of at least one element selected from the group consisting of the elements of IIb, IIIb, IVb, Vb, and VIb groups, which is formed on the substrate, with a complex index of refraction of (n-ik), where n.gtoreq.1.8, and k.ltoreq.0.3, and a reflection layer formed on the recording layer. In this invention, an intermediate layer can be interposed either between the substrate and the recording layer, or between the recording layer and the reflection layer.

Growing community of inventors

Yokosuka, Japan

Toru Yashiro