Hitachi, Ltd.

Other

Hitachi Maxell, Limited

Hitachi Maxwell, Ltd.

Keikichi Andoo

Motoyasu Terao

Makoto Miyamoto

Tetsuya Nishida

Akemi Hirotsune

Junko Ushiyama

Yumiko Anzai

Hideki Saga

Tsuyoshi Toda

Masatoshi Ohtake

Harukazu Miyamoto

Masahiro Ojima

Hiroshi Yasuoka

Yasushi Miyauchi

Atsushi Saito

Norio Ohta

Toshimichi Shintani

Hiroyuki Awano

Toshio Niihara

Takeshi Maeda

Takeshi Shimano

Hisataka Sugiyama

Takahiro Kurokawa

Nobuhiro Tokushuku

Yukio Fukui

Kouichirou Wakabayashi

Osamu Komoda

Reiji Tamura

Koichi Moritani

Hiroyuki Minemura

Hitoshi Watanabe

Yoshio Suzuki

Masaaki Futamoto

Yutaka Sugita

Yuzuru Hosoe

Masahiko Takahashi

Shigenori Okamine

Yoshihiro Ikari

Norio Murase

Tamotsu Fuchioka

Hisae Wakabayashi

Recording information is disclosed in which an information recording medium is irradiated with a recording energy beam that is power-modulated into at least a record power level and a record-ready power level lower than the record power level. The information is recorded on the recording medium in the form of length and interval of a mark portion. When forming a mark portion of a predetermined length, the radiation energy of the energy beam is increased as compared with when forming a mark portion of a different length before or after the first pulse of an energy beam pulse train including at least a pulse for forming the mark portion.

Information recording method and apparatus with suppressed mark edge jitters

Problem to be solved is that when an information recording medium is repeatedly subjected to recording of information several hundreds times, the atoms in a protective layer are diffused and dissolved into a recording layer to lower a reflectivity greatly and make the medium unendurable to many times of overwriting. This problem can be solved by a medium constituted of interference layer, interface layer, phase-change type recording layer, protective layerhaving a tin content of from 23.3 atomic % to 32.3 atomic %, and a heat sink layersuccessively formed on substrate, as seen from a light-incidence side. By use of this medium, the dissolution of atoms can be prevented, and overwriting for many times can be achieved.

Information recording media, manufacturing technique and information recording method

A method for recording information is disclosed in which an information recording medium is irradiated with a recording energy beam power-modulated into at least a record power level and a record-ready power level lower than the record power level. When forming a mark portion of a predetermined length, the radiation energy of the energy beam is increased as compared with when forming a mark portion of a different length before or after the first pulse of an energy beam pulse train including at least a pulse for forming the mark portion. Also, only in the case where the energy beam is modulated by the power lower in power level than the record-ready power level after the last pulse of the energy beam pulse train including at least one pulse for forming a mark portion and the mark portion is followed by a space portion of a predetermined length, the particular radiation energy of low power level is reduced as compared with when the mark portion is followed by a space potion of a different length. The radiation energy is increased and/or decreased.

Information recording medium

An information recording medium, which comprises three thin films of different compositions, comprising first and second interference layers and a first interface layer, stacked in this order from the laser beam incident side of a recording layer, the refractive index of the second interference layer being lower than that of any one of the first interference layer and the recording layer, the first interface layer being provided in contact with the recording layer and between the second interference layer and the recording layer, the second interference layer containing oxygen, and an oxygen barrier layer having a smaller oxygen content than that of the second interference layer being provided in contact with the second interference layer and between the second and first interface layers, can control diffusion of oxygen from the second interference layer into the recording layer and prevents deterioration of overwriting at the time of many runs of overwriting and lowering of storage life.

Optical recording medium having a plurality of interference layers of different refractive index

An information recording medium having a substrate, a recording layer on which information is recorded in accordance with a change of atomic arrangement caused by irradiation of light, a first reflective layer, and a second reflective layer. The second reflective layer is formed on the first reflective layer. The first reflective layer includes an Al alloy as a main component and the second reflective layer includes an Ag alloy as a main component.

To provide an information recording medium which permits high density recording/reproduction, which has good thermal stability, and which, due to the use of an interface layer with a high sputter rate, has good recording/reproduction characteristics and is excellent for mass production. An information recording medium wherein the thickness of an interface layer is 0.25 or more but 0.67 or less of the total thickness of a first protective layer and the interface layer , and the interface layer contains at least tantalum (Ta) and oxygen (O). The medium is excellent for mass production and has good recording/reproduction characteristics for high density recording/reproduction.

Information recording medium and method for manufacturing an information recording medium

A high-density information recording medium free from lowering the reflectance by over-write of a large number of times and exfoliation defect in a structure for suppressing cross-erase. This medium includes, over a substrate having a groove shape, a recording layer, and three-layered thin films of a first interference layer, a second interference layer and an interface layer having mutually different compositions and disposed on a laser beam incidence side of the recording layer in order named from the laser beam incidence side. The first interference layer has a smaller refractive index and a larger thermal conductivity than the second interference layer, the interface layer is interposed between the second interference layer and the recording layer, and a distance between the first interference layer and the recording layer is greater than at least a groove depth.

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Musashino, Japan

Keikichi Andoo