Ricoh Company, Ltd.

Michiharu Abe

Masaakira Umehara

Hideaki Oba

Makoto Harigaya

Kazunori Ito

Yoshiyuki Kageyama

Tsutomu Sato

Yutaka Ueda

Takashi Shibaguchi

Nobuaki Onagi

Hiroko Tashiro

Eiko Suzuki

Hiroshi Deguchi

Hajime Yuzurihara

Hiroshi Miura

Michiaki Shinotsuka

Hiroko Iwasaki

Eiko Hibino

Mikiko Abe

Makoto Kunikane

Akiyoshi Oride

Yukio Ide

Tetsu Yamamuro

Masahiko Nakayama

Hiroyoshi Funato

Kiyoshi Tanikawa

Kenya Yokoi

Mikio Kinoshita

Fusakichi Okouchi

Seiko Kobayashi

Yukio Yamada

Hitoshi Funakoshi

Masahiko c/o Ricoh Company Ltd Nakayama

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

An optical recording medium has a phase-change recording layer containing Sb and Te as essential elements therefor, to which is added at least one element selected from the group consisting of Ag, Au, Cu, Zn, B, Al, Ga, In, Si, Ge, Sn, Pb, N, P, Bi, La, Ce, Gd, and Tb, the recording layer being capable of assuming an amorphous phase changed from a crystalline phase by the application of a laser beam thereto, thereby optically recording information. Recording marks are formed in the recording medium by converting a light emission wave of laser beam into a recording pulse train comprising a plurality of on-pulses and off-pulses, with a recording frequency being continuously changed corresponding to the location of each of the recording marks in the radial direction of said recording medium. A recording apparatus has laser beam driving circuit means, signal generation means, and signal transmission means for achieving the above recording method.

Phase-change optical recording medium and recording method and apparatus for the same

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.

The present invention provides a recording method for a phase-change optical recording medium. The recording method of the present invention contains the step of irradiating an electromagnetic wave having a multipulse pattern so as to perform recording on a phase-change optical recording medium containing a phase-change recording layer. This method is characterised in that a starting time of a front pulse of the multipulse pattern delays 0.5T to 1.25T from a starting point of the first reference clock relative to the recording mark, where T is a reference clock of the multipulse pattern.

Recording method for a phase-change optical recording medium

An input bit sequence with predetermined bit periods T is converted into a corresponding light-emission waveform; and a beam with the thus-obtained light-emission waveform is applied onto a phase-change optical disk so as to record the input bit sequence thereon. The light-emission waveform comprises a heating pulse for heating the recording medium occurring for an interval tw and a cooling pulse for cooling the recording medium occurring for an interval tc, and the intervals tw and tc on the heating/cooling pulses satisfy the following requirement in case the heating/cooling pulses occur alternately with repetition: 1.5T&lE;tw&plus;tc&lE;3T.

Information recording with effective pulse control scheme

An optical recording medium has a phase-change recording layer containing Sb and Te as essential elements therefor, to which is added at least one element selected from the group consisting of Ag, Au, Cu, Zn, B, Al, Ga, In, Si, Ge, Sn, Pb, N, P, Bi, La, Ce, Cd, and Tb, the recording layer being capable of assuming an amorphous phase changed from a crystalline phase by the application of a laser beam thereto, thereby optically recording information. Recording marks are formed in the recording medium by converting a light emission wave of laser beam into a recording pulse train comprising a plurality of on-pulses and off-pulses, with a recording frequency being continuously changed corresponding to the location of each of the recording marks in the radial direction of said recording medium. A recording apparatus has laser beam driving circuit means, signal generation means, and signal transmission means for achieving the above recording method.

A phase-change optical recording medium has a substrate, and a lower heat-resistant protective layer, a recording layer capable of recording and erasing information by utilizing changes in the phase of a phase-change recording material in the recording layer, an upper heat-resistant protective layer and a light reflecting and heat dissipating layer, which are successively overlaid on the substrate in this order, the recording material including Ag, In, Sb and Te as the main elements, at least one additional element selected from the group (1) consisting of B, C, N, Al, Si and P, and at least one additional element selected from the group (2) consisting of halogen atoms and alkali metal elements.

Phase-change optical recording medium

An erasable phase change recording medium includes a transparent substrate, a recording layer of a phase change material provided on the substrate, and a protection layer provided to protect the recording layer on the substrate. Tracks are formed with alternate grooves and lands on the substrate of the recording medium and data is recorded to at least one of the grooves and the lands. The recording medium is configured to have a track pitch between 0.6 .mu.m and 0.8 .mu.m and a groove depth between 0.11.L and 0.18.L where L is a wavelength of a laser beam.

Phase change recording medium for allowing a tracking servo control

An irradiation method of applying a light spot or a light pattern to an object with high resolution is performed by disposing, in close vicinity to the object, a light-absorbing contrast-increasing layer whose transmittance or reflectivity with respect to an incident light thereto increases as the intensity of the incident light or the exposure thereof to the incident light increases; and applying light to the object through the light-absorbing contrast-increasing layer. This method is applied to an optical information recording and reproducing method using an optical information recording medium including an optical information recording layer and an auxiliary layer whose transmittance or reflectance increases in a real time manner correspondingly to the energy of an incident light thereto.

Light irradiation method and optical information recording method

An optical data recording/reproducing method in which data is recorded for testing in a pattern including a not-recorded section and a recorded section as changing a recording power P onto an optical data recording medium from time to time, An amplitude m of the recorded data corresponding to the recording power P is monitored by reproducing the data recorded for testing. A standardized gradient g(P) is calculated from the following expression:

Optical data recording/reproducing method and apparatus for determing an

A method of recording a bit stream on a Phase Change media by illuminating a laser beam on the Phase Change media includes assigning a predetermined number of channel bits to each bit of the bit stream, and assigning one of a highest power level, an intermediate power level, and a lowest power level of the laser beam to each of the channel bits so as to modulate the laser beam, wherein an arrangement of the highest power level, the intermediate power level, and the lowest power level for one bit of the bit stream depends on values of the one bit and an immediately preceding bit.

Information recording method and device

When recording data according to the PWM recording system by modulating signals, pulse modulation for pulse modulation for recording for recording a 0 signal or the like having a signal width of nT (T: Clock time) after modulation is a continuous electro-magnetic wave at a power level e, a record signal pulse array for recording a 1 signal or the like having a signal width of nT after modulation comprises a pulse section fp having a time width x and a power level a, a multi-pulse section mp in which a low level pulse at a power level b and a high power pulse at a power level c having a time width T in total alternately appear (n-n') times in all with a duty ratio y, and a pulse section op having a time width z and a power level d, and x, y, z are integers satisfying the conditions of 0.5 T.ltoreq.x.ltoreq.2 T, 0.4.ltoreq.y.ltoreq.0.6 and 0.5 T.ltoreq.z.ltoreq.1 T, and n' is a positive integer which is equal to or smaller than n, and controls are provided so that the condition of (a and c)&gt;e &gt;(b and d) is satisfied.

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Yokohama, Japan

Michiharu Abe