Victor Company of Japan, Limited

Jvc Kenwood Corporation

Kazuo Yonehara

Hiroshi Tabata

Ikuo Matsumoto

Kenichi Shimomai

Kenji Tokui

Yasuhiro Ueki

A mark having a length nT (n being an integer equal to or greater than 3 and T being a clock period) is formed by modulating irradiation laser power with three values of recording power Pw, erase power Pe, and bias power Pb (Pw&#x3e;Pe&#x3e;Pb). Constant strength periods (A) of the recording power Pw are set as AT, AT, . . . , and AT and constant strength periods (B) of the bias power Pb are set as BT, BT, . . . , BT, and CT (C=&#x2212;1 to 3). The application of laser is divided into pulses in order of AT, BT, AT, BT, . . . , AT, BT, and CT (m=(n&#x2212;k)/2, k=3 (if n is an odd number), or k=4 (if n is an even number)). (Here, the constant strength period of the recording power Pw for n=3, n=4, n&#x2267;5 (odd number), and n&#x2267;6 (even number) is set as A, A, A, and A, the constant strength period of the bias power Pb for n=3, n=4, n&#x2267;5 (odd number), and n&#x2267;6 (even number) is set as B, B, B, and B, and then, A+B=A+B=A+B=2T and A+B=A+B=3T).

Optical recording method, optical recording medium, optical recording medium recording apparatus, optical recording apparatus, optical disk, and optical disk recording/reproducing apparatus

A phase-change optical storage medium has a substrate and a recording layer having a plurality of tracks for storing information. A material of which the recording layer is made has been initialized in a crystalline state in which an amplitude of a tracking-detection signal is smaller than a saturation value of the amplitude, the tracking-detection signal being obtained by receiving a reflected beam from the recording layer when the recording layer is irradiated with a laser beam in an off-track state while the optical storage medium is being rotated.

Phase-change optical recording medium having tracking signal smaller than saturation value

A phase-change optical storage medium has a substrate, and a recording layer, to be recorded on which is at least one recorded mark representing information to be recorded by irradiating a recording light beam onto the recording layer in accordance with a recording pulse pattern of recording pulses rising from an erasing power and formed between a recording power larger than the erasing power and a bottom power smaller than the erasing power and of erasing pulses rising from the bottom power to the erasing power. The expressions (1) and (2): 1.00&#x3c;(R/R)&#x3c;1.15 . . . (1), 1.05&#x3c;(R/R)&#x3c;1.20 . . . (2) are satisfied for the recording layer, in which Ris a reflectivity exhibited by an un-recorded section of the recording layer, on which no data has ever been recorded, when irradiated with a reproducing light beam, Ris a reflectivity exhibited by the un-recorded section when irradiated with the reproducing light beam, after irradiated once with the recording light beam in accordance with the recording pulse pattern, and Ris a reflectivity exhibited by the un-recorded section when irradiated with the reproducing light beam, after irradiated nine times with the recording light beam in accordance with the recording pulse pattern.

Phase-change recording medium having the relation between pulse patterns and reflectivity of un-recorded section

Information to be recorded is recorded in a recording layer of a phase-change optical storage medium. The information to be recorded is modulated to generate modulated data. Desired mark-length data is generated based on the modulated data. Generated further based on the mark-length data is a recording pulse pattern of recording pulses rising from an erasing power and formed between a recording power larger than the erasing power and a bottom power smaller than the erasing power and of erasing pulses rising from the bottom power to the erasing power. A recording light beam is then irradiated onto the recording layer in accordance with the recording pulse pattern to record at least one recorded mark representing the information to be recorded. Used in recording is an optimum erasing power, as the erasing power, the optimum erasing power satisfying an expression (1): 1.000&#x3c;(R/R)&#x3c;1.030 . . . (1) in which Ris a reflectivity exhibited by an un-recorded section of the recording layer, on which no data has ever been recorded, when irradiated with a reproducing light beam, and Ris a reflectivity exhibited by the un-recorded section when irradiated with the reproducing light beam after irradiated once with a beam having the erasing power.

Optical recording method, optical recording apparatus and optical storage medium

An optical disk consists of a first laminated layer structure and a second laminated layer structure. The first structure has a first transparent substrate having a first surface and a second surface on both sides thereof, provided on the first surface being a light-incident plane via which a light beam is to be incident in recording or reproduction, formed alternately on the second surface being a plurality of first lands and first grooves, and a first organic-dye recording layer formed on the second surface to cover the first lands and grooves. The second structure has a second substrate, alternately formed on which are a plurality of second lands and second grooves, a reflective film formed on the second transparent substrate to cover the second lands and grooves, and a second organic-dye recording layer formed on the reflective film to face the second transparent substrate. The first and the second structures are bonded to each other via a bonding layer so that the first and second recording layers are provided between the first and second substrates. A formula &#x3b1;&#x2267;cos(20/Tb) is satisfied in which Tb is a thickness of the reflective film formed on a bottom of each second groove and &#x3b1;is an angle between a plane passing through an upper surface of each second land and a side wall of each second groove.

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Hitachinaka, Japan

Kazuo Yonehara