Ricoh Company, Ltd.

Kazunori Ito

Nobuaki Onagi

Hajime Yuzurihara

Makoto Harigaya

Eiko Hibino

Hiroko Ohkura

Hiroshi Deguchi

Hiroshi Miura

Masaru Shinkai

Masaki Kato

Katsuyuki Yamada

Hiroyoshi Sekiguchi

Michiharu Abe

Takashi Shibaguchi

Hiroko Tashiro

Yoshiyuki Kageyama

Mikiko Abe

Shinya Narumi

Eiko Suzuki

Noriyuki Iwata

Katsuhiko Tani

Michiaki Shinotsuka

Mikiko Takada

Katsunari Hanaoka

Yasutomo Aman

Hiroyuki Iwasa

Wataru Ohtani

Miku Mizutani

Kiyoto Shibata

Yuki Nakamura

Akihiko Shimizu

Ikue Kawashima

Takahiko Kuroda

Akira Shimofuku

Mitsugu Irinoda

Kaichi Ueno

Mamoru Ishida

Shigeru Kinpara

Hiroko Okura

Mikiko Kawasakidaishi Park Familia 403 Abe

An optical recording medium contains a recording layer being composed of a phase-change recording material where at least four elements, Ga, Sb, Sn and Ge are contained and the transfer linear velocity is 20 m/s to 30 m/s, and when the wavelength of a recording/reproducing light is within the range of 650 nm to 665 nm and the recording linear velocity is 20 m/s to 28 m/s, the refractive index Nc and the extinction coefficient Kc in a crystalline state and the refractive index Na and the extinction coefficient Ka in an amorphous state in the recording layer respectively satisfy the following numerical expressions: 2.0&#x2266;Nc&#x2266;3.0, 4.0&#x2266;Kc&#x2266;5.0, 4.0&#x2266;Na&#x2266;5.0, and 2.5&#x2266;Ka&#x2266;3.1, and information is recordable at the range of 20 m/s to 28 m/s of recording linear velocity.

Optical recording medium

An optical recording medium having first protective layer, recording layer, second protective layer, and reflective layer, wherein the recording layer contains a phase-change material represented by Formula (1&#x2033;1), Formula (1-2), or Formula (1-3); the second protective layer contains one selected from zinc oxides, indium oxides, tin oxides, mixtures thereof, and materials Formula (2), and materials Formula (3). Formula (1&#x2033;1): InSbX1(X1: Ge, Te, Zn, Mn, or mixture thereof, 0.10&#x2266;&#x3b1;1&#x2266;0.25, 0.65&#x2266;&#x3b2;1&#x2266;0.80, and 0.04&#x2266;&#x3b3;1&#x2266;0.15) Formula (1-2): GaSbSnGeX2(X2: Te, Zn, Mn, In, or mixture thereof, 0.04&#x2266;&#x3b1;2&#x2266;0.09, 0.56&#x2266;62&#x2266;0.79, 0.05&#x2266;&#x3b3;2&#x3c;0.30, 0.03&#x2266;&#x3b4;2&#x2266;0.19, and 0&#x2266;&#x2208;2&#x2266;0.09) Formula (1-3): MnSbSnGeX3(X3: Te, In, Zn, Bi, or mixture thereof, 0.04&#x2266;&#x3b1;3&#x2266;0.09, 0.56&#x2266;63&#x2266;0.79, 0.05&#x2266;&#x3b3;3&#x2266;0.29, 0.03&#x2266;&#x3b4;3&#x2266;0.23, and 0&#x2266;&#x2208;3&#x2266;0.09) Formula (2): ZnO&#x2014;Al&#x2014;Y [(100&#x2212;&#x3b1;4&#x2212;64):&#x3b1;4:&#x3b2;4] (Y: Mn, Ge, Ti, or mixture thereof, 0.5&#x2266;&#x3b1;4&#x2266;10.0, and 0&#x2266;B4&#x2266;25.0) Formula (3): ZnO&#x2014;AlO&#x2014;Z [(100&#x2212;&#x3b1;5&#x2212;65):&#x3b1;5:&#x3b2;5] (Z: Mn oxide, Ge oxide, Ti oxide, or mixture thereof, 0.5&#x2266;&#x3b1;5&#x2266;10.0, and 0&#x2266;65&#x2266;30.0).

To provide an optical recording medium in which error-causing short marks are produced in numbers small enough excellent high-recording characteristics and in which amorphous marks are uniform in shape. The optical recording medium includes: a first protective layer; a recording layer containing Sb as a main ingredient; a second protective layer; and a reflective layer, the first protective layer, the recording layer, the second protective layer and the reflective layer being provided in the order in which light passes through the medium for recording and reproduction of information, wherein the first protective layer and/or the second protective layer, both of which are in contact with the recording layer, are/is formed of a crystalline oxide.

A method of recording information using a laser on a multilayer optical disk having a plurality of recording layers is provided. The plurality of recording layers include a first recording layer and a second recording layer adjacent the first recording layer. The first recording layer is provided with a first test writing area to be used for calibration of write power, and the second recording layer is provided with a second test writing area to be used for calibration of write power. The disk is arranged so that a first region of the first test writing area is superposed with a second region of the second test writing area when considered in the direction in which the laser is arranged to irradiate. The method comprises, if the second region of the second test writing area is unrecorded, recording data in the second region of the second test writing area, thereby converting the second region of the second test writing area into a recorded state; and once the second region of the second test writing area has been converted into a recorded state, performing test writing in the first region of the first test writing area.

Optical disk, recording method, recording medium, and optical disk unit, for recording information on multilayer optical disk

A recording method of an optical recording medium comprises irradiating the medium with a laser having m pulse sets each comprising a heating pulse and a cooling pulse, in which m is a natural number; and scanning the medium with the laser at a scanning speed v to record marks each of a length nT, in which n is a natural number of 3 or more and T is a clock cycle, wherein a length Tof a final cooling pulse is determined in accordance with the scanning speed v using the following functions, in v&#x3c;v, T/T=f(v) in v v, T/T=f(v), where the f(v) and f(v) each represents a continuous function of the scanning speed v and satisfies the condition where an existence ratio of abnormal marks is 1.0&#xd7;10or less, and vis a selectable scanning speed.

Optical recording medium, recording method thereof and evaluation method of optical recording medium

The present invention relates to an recording method for a multi-layered optical recording medium including M phase change recording layers, with M&#x2267;2. The method comprises recording a mark in a Kth one of said recording layers by using a laser to irradiate the Kth recording layer using a recording pulse train including a plurality of laser beam pulses. The recording pulse train for the Kth recording layer has a cycle of t[T], the 1st recording layer is the recording layer closest the laser beam, and the Mth recording layer is the recording layer furthest from the laser beam, T is a clock cycle. The following relationship is satisfied: t&#x3c;t, and the cycle of recording pulse train does not decrease from one recording layer to the next recording layer in the direction in which the laser beam irradiates.

Optical recording medium, multi-layered optical recording medium, and optical recording method and recording apparatus using the same

To provide a method of recording information to an optical recording medium comprising recording a mark of time length nT (n: natural number of 3 or more, T: clock cycle) in an optical recording medium capable of supporting different recording speeds and having constant information line density, and irradiating the optical recording medium, the optical recording medium irradiated with light of alternating mheating pulses of power Pw and mcooling pulses of power Pc (where mis a natural number smaller than n) provided v&#x3c;v(where v is a scanning speed and vis a scanning speed unique to each optical recording medium), the optical recording medium irradiated with light of alternating mheating pulses of power Pw and mcooling pulses of power Pc (where mis a natural number smaller than n) provided v&#x2267;v, wherein the condition n/m&#x2267;n/mis satisfied.

Optical recording medium and method of recording to the same

The phase-change optical recording medium having a substrate, and at least a first protective layer, a recording layer composed of a phase-change material, a second protective layer and a reflective layer disposed on the substrate in this sequence has a maximum recording linear velocity Vof 20 m/s to 60 m/s, a range of linear velocity recordable even when the recording linear velocity is continuously changed of 0.3Vto 1.0V, and no occurrence of crystals causing a reproduction error in recorded marks.

Phase-change optical recording medium and recording and reproducing method thereof

An optical information recording medium is provided. This medium at least stores information that indicates a maximum recording linear velocity Vh. The medium comprises a substrate having a concentric circular guide groove. This guide grove has land portions and groves portions. At least a phase change type recording layer is formed on the substrate. The recording layer has such a composition and thickness that a dislocation linear velocity V satisfies the relation V&#x2267;Vh&#xd7;0.85.

Optical information recording medium, method of manufacturing the optical information recording medium, and method of and apparatus for recording/reproducing optical information

An optical recording medium including: a substrate having translucency; a first protective layer thereon; a recording layer composed of a phase-change material; a second protective layer; and a reflective layer, wherein laser beam irradiation causes phase-change of the recording layer between a crystalline phase and an amorphous phase thereby at least one of to rewrite and to record information, wherein the phase-change material comprises Ga, Sb and Sn, Ga content, Sb content, and Sn content satisfy the following formula, and the total content of Ga, Sb and Sn is at least 80 atomic % of the entire phase-change material:GaSbSn(where, &#x3b1;+&#x3b2;+&#x3b3;=100 atomic %),where 20&#x2266;&#x2212;2.75&#x3b1;+0.708&#x3b2;+1.18&#x3b3;&#x2212;7.56&#x2266;43,and &#x3b1;/(&#x3b1;+&#x3b2;)&#x2266;0.12.

It is an object of the present invention to provide a phase-change information recording medium, and the like, which is easy to perform initial crystallization, exhibits good recording sensitivity at a linear velocity as high as 10 double speeds or more with as much capacity as DVD-ROM, is capable of overwrite recording and has good storage reliability. For this purpose, the phase-change information recording medium comprises a substrate and at least a first protective layer, a phase-change recording layer, a second protective layer, and a reflective layer disposed on the substrate in one of this sequence and reverse sequence wherein the phase-change recording layer comprises a composition expressed by SnSbGaGeTe&#x2212;X(In this regard, X represents at lease one element selected from Ag, Zn, In and Cu. &#x3b1;, &#x3b2;, &#x3b3;, &#x3b4;, &#x3b5; and &#x3b6; represent composition ratio (atomic percent) of each element and are expressed as 5&#x2266;&#x3b1;&#x2266;25, 40&#x2266;&#x3b2;&#x2266;91, 2&#x2266;&#x3b3;&#x2266;20, 2&#x2266;&#x3b4;&#x2266;20, 0&#x2266;&#x3b5;&#x2266;10, 0&#x2266;&#x3b6;&#x2266;10 and &#x3b1;+&#x3b2;+&#x3b3;+&#x3b4;+&#x3b5;+&#x3b6;=100).

Phase-change information recording medium, manufacturing method for the same, sputtering target, method for using the phase-change information recording medium and optical recording apparatus

An optical recording method of recording information to a phase change optical recording medium with alternate application of peak power and bias power in a pulse manner and with changing a pulse application. interval continuously from an inner part through an outer part of the recording medium with an interval proportional to a window width Tw and a fixed interval, comprising the step of starting a top peak power application interval with a delay from a data input pulse signal starting time for a target mark length nTw, where n denotes an integer in a range between 3 and 14, with changing the delay in proportion to the window width Tw with changing a proportionality factor discretely with respect each linear velocity.

Optical recording method

A phase-change optical information recording medium in which information can be recorded, reproduced and rewritten and which includes a first transparent substrate having a wobbling guide groove which is spirally formed thereon at a pitch; a first dielectric layer located overlying the first transparent substrate and having an optical thickness of from 80 nm to 200 nm; a phase-change recording layer located overlying the first dielectric layer and having an optical thickness of from 20 to 50 nm when the recording layer is in an erased state; a second dielectric layer located overlying the recording layer and having an optical thickness of from 10 nm to 70 nm; a reflection layer located overlying the second dielectric layer; optionally a third dielectric layer located between the second dielectric layer and the reflection layer; and a second transparent substrate located overlying the reflection layer.

Optical information recording medium

To provide an optical recording medium and the like that is adapted to higher density and higher speed recording of 8 times or more than that of DVD (about 28 m/sec or more) and that exhibits superior repeating and reservation properties. An optical recording medium is provided that comprises a substrate, and a recording layer, wherein at least one of recording, reproducing, erasing, and rewriting of information is carried out by means of reversible phase changes at marks on the recording layer, the reversible phase changes at marks are induced between crystalline and amorphous states by laser irradiation, the length of the respective marks is 0.4 &#x3bc;m or less in the traveling direction of the laser irradiation, and the recording layer has a composition expressed by the formula: InSb, wherein &#x3b1; and &#x3b2; are atomic percent of the respective elements; 0.73&#x2266;&#x3b2;/(&#x3b1;+&#x3b2;)&#x2266;0.90, &#x3b1;+&#x3b2;=100, alternatively a composition expressed by the formula: MInSb, wherein M represents an element other than In and Sb or an element combination containing two or more elements other than In and Sb; &#x3b1; and &#x3b2; are atomic percent of the respective elements, &#x3b3; is atomic percent of the element or sum of atomic percent of the respective elements; 0.73&#x2266;&#x3b2;/(&#x3b1;+&#x3b2;)&#x2266;0.90, 0&#x3c;&#x3b3;&#x3c;&#x3b1;, &#x3b1;+&#x3b2;+&#x3b3;=100.

Optical recording medium and process for producing the same, sputtering target, using process of optical recording medium, and optical recording apparatus

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Yokohama, Japan

Kazunori Ito