Ricoh Company, Ltd.

Katsuyuki Yamada

Yuki Nakamura

Hiroko Iwasaki

Makoto Harigaya

Yukio Ide

Shinya Narumi

Hiroshi Deguchi

Masaki Kato

Yujiro Kaneko

Eiji Noda

Yoshiyuki Kageyama

Hajime Yuzurihara

Kenichi Aihara

Fumiya Ohmi

Kyohji Hattori

Michiaki Shinotsuka

Kazunori Ito

Eiko Hibino

Masaetsu Takahashi

Masaki Katoh

Nobuaki Onagi

Yoshitaka Hayashi

Hiroshi Miura

Hiroyoshi Sekiguchi

Masaru Shinkai

Mikiko Abe

Satoshi Taniguchi

Kenji Kameyama

Eiichi Ohta

Yuji Kimura

Hitoshi Kondo

Ippei Ogawa

Michihisa Takahashi

Takeshi Kibe

Masahiko Nakayama

Tatsuo Mikami

Narihito Kojima

Noboru Sasa

Hiroko Ohkura

Akira Shimofuku

Toshishige Fujii

Takashi Shibaguchi

Noriyuki Iwata

Masataka Mohri

Toshihide Sasaki

Masayuki Fujiwara

Katsuhiko Tani

Osamu Nonoyama

Kayo Katoh

Makoto Tanabe

An optical recording medium containing a substrate and a recording layer over the substrate, wherein the recording layer primarily contains Bi and O, and further contains B and at least one element X selected from Ge, Li, Sn, Cu, Fe, Pd, Zn, Mg, Nd, Mn and Ni, and a sputtering target containing Bi, B and at least one element X selected from Ge, Li, Sn, Cu, Fe, Pd, Zn, Mg, Nd, Mn and Ni.

Optical recording medium, and sputtering target and method for producing the same

A dual-layer structure phase-change type optical recording medium includes a substrate (), a reflective layer (), a first protective layer (), a first recording layer (), a second protective layer (), a resin intermediate layer (), a third protective layer (), a heat release layer () made of Cu or a Cu alloy, a fourth protective layer (), a second recording layer (), a fifth protective layer () and a cover substrate (). A product of a reflectance of a high-reflection part and a modulation after recording is a value equal to or higher than a lower limit value for reproduction.

Phase-change type optical recording medium and reproduction method and apparatus for such a recording medium

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 power determining method is disclosed for determining the light emitting power of a light source upon recording information on an optical disk having plural rewritable recording layers, the method involving obtaining an optimum erasing power with respect to an optimum recording power by recording test data on the optical disk.

Power determining method, single-sided multilayer optical disk, recording method, computer program product, computer-readable medium, and optical disk apparatus

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

An optical disc having a transition linear velocity of 8-11 m/s when irradiating continuous light with 11&#xb1;1 mW and a wavelength of 660&#xb1;10 nm using a pickup head with a numerical aperture (NA) of 0.65, and satisfying the following condition:&#x394;|&#x2266;3%where Rb is a reflectance of an unrecorded area, and Ra is a reflectance of the top of an eye pattern after ten cycles of recording. In one recording mode therefor, the disc is rotated at a constant angular velocity so as to have a linear velocity of 3-4 m/s on an innermost track and a linear velocity of 8-9 m/s on an outermost track. In another mode, the disc is rotated at a constant angular velocity so as to have a linear velocity of 5-6 m/s on an innermost track and a linear velocity of 13-14 m/s on an outermost track.

Optical recording medium

The object is to provide an optical recording method improving the recording characteristics and uniformity in a CAV recording on a phase-change optical recording medium, particularly a high-speed rewritable DVD medium, and a phase-change optical recording medium and an optical recording apparatus used by the method. Regarding a recording method for recording on the phase-change optical recording medium where a recording light comprises a pulse string of heating and cooling pulses, and a light for erasing, an irradiation power is controlled by peak power (Pp), bottom power (Pb) and erase power (Pe), at least any one of Pe/Pp, Pp, Pb and Pe is variable from the minimum to maximum recording linear velocities allowed for the medium, and further the irradiation time of each pulse is varied proportionally with clock T corresponding to a recording linear velocity, the present invention provides an optical recording method which performs a recording by varying at least Pe/Pp from a specific recording linear velocity lower than a peculiar recording linear velocity at which the recording linear velocity degrades abruptly showing a local maximum value, and an optical recording medium and an optical recording apparatus used by the method.

Optical recording method of a phase-change optical recording medium having improved recording characteristics and uniformity and optical recording medium and optical recorder used by the method

A recordable optical information recording medium having an address t for each sector, comprises: an area Astarting from an address tto which access is made only when a recording apparatus performs recording operation; an area Astarting from an address tto which access is made either when the recording apparatus performs the recording operation or when the recording apparatus performs reproducing operation; and an area Astarting from an address tto which access is made either when either the recording apparatus or a reproducing apparatus performs recording or when either the recording apparatus or the reproducing apparatus performs reproducing. The addresses t are set consecutively with respect to a physical arrangement of the sectors in each of the areas Aand A, and the area Ahas at least one inconsecutive part at which the addresses t are not consecutive with respect to the physical arrangement of the sectors.

Optical information recording medium and recording apparatus

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

There is provided a method and a device for recording optical data able to improve recording power setting during recording by means of PWM with a small number of pulses. During the test recording, using a period of a recording channel clock Tw as the minimum unit, marks having different mark lengths of n&#xb7;Tw and n&#xb7;Tw (n&#x3c;n) are recorded with the same number of m (m&#x3c;n) light emitting pulses, while successively changing the maximum power Pw of the recording signals. The recorded marks are reproduced and the mark lengths Tand Tare measured from the reproduced signals. The recording power can be set by evaluating the deviations D=T&#x2212;n&#xb7;Tw and D=T&#x2212;n&#xb7;Tw.

Method and device for recording optical data

A phase change optical recording medium includes at least a supporting substrate and a recording layer essentially consisting of AgInSbTe alloy compositions implementing recording and readout steps utilizing changes in reflectivity. The recording medium is characterized by the relation v&#x2267;0.7 v, where the critical relative velocity of phase change, v, defined by the value of v, at which the differential coefficient, &#x2212;dR/dv, reaches a maximum, when the recording medium moves against an optical unit during the recording steps at a relative velocity, v, ranging from minimum and maximum relative velocities warranted for the recording medium, vand v, respectively. When the reflectivity is measured with varying erase power Pat the linear relative scanning velocity v, the reflectivity of the recording layer as a function of erase power, R(P), preferably has a minimum. The recording layer has an activation energy of deterioration equal to or greater than 1.6 eV, which is obtained by measuring asymmetry, A, and calculating according to the equations, k=dt/dA, and k=k&#xd7;exp(E/kT). The recording medium is also characterized by activation energy of displacement of the boundary, ranging from 1.0 eV to 2.4 eV, which is obtained from the rate of decrease in the area, S, of the amorphous regions as recorded marks with time according to Arrhenius' equation.

Optical information recording medium

A method and apparatus for initializing optical recording media is provided that detects the intensity of a reflective light off of an optical recording media and analyzes the initializing condition based on the detected intensity during an initializing process. The light is radiated on a rotating phase-change optical recording medium. The light may be moved in a radial direction of the optical recording medium. The detected intensity of the reflected light may be used to identify crystallized portions and amorphous portions of the optical media. The initialization process can be adaptively controlled to ensure proper initialization. If desired, re-initialization can be limited to those areas detected to be outside of the predetermined parameters.

Method and apparatus for initializing optical recording media

A phase-change optical recording medium is disclosed including a supporting substrate and the following contiguous layers formed on the supporting substrate in the order recited such as a first dielectric layer, a recording layer, a second dielectric layer, a metal/alloy layer, and an ultraviolet light curing resinous layer. The recording layer is characterized by its uppermost recrystallization linear velocity ranging from about 5.0 m/sec to about 10.0 m/sec, which can be utilized in read/write/erase operations for the recording medium at linear velocities higher than the quad-speed as well.

Phase-change optical recording medium

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.

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Kanagawa, Japan

Katsuyuki Yamada