Taiyo Yuden Co., Ltd.

Akira Negishi

Ryuichi Sunagawa

Atsuo Shimizu

An optical information recording method and a device which can record information with a laser light irradiating direction kept constant even if an information recording surface of an optical information recording medium is inclined and, a recording medium having a program therefor recorded thereon are provided. When performing OPC, a relational expression between a recording power and asymmetry (a standard expression), a relational expression between a differential light intensity value and a recording power (a first detection expression), a relational expression between a recording power and a difference between a differential light intensity value and a reflected light amount ratio (a second detection expression), a relational expression between a reflected light amount ratio and a recording power (a third detection expression), a differential light intensity value with which optimum asymmetry can be obtained, a recording power, a reflected light amount ratio and the like are determined and stored. When information is actually recorded, the above expressions are used to correct the recording power so as to obtain optimum asymmetry at all times, whereby a decreased portion of the irradiated light amount per unit area caused with the inclination of the information recording surface can be corrected without correcting the irradiating direction of the laser light.

Optical information recording method and apparatus, and recorded medium where optical information recording control program is recorded

An inclination, at a pit forming position, of the information recording surface of an optical disc with respect to a plane that is perpendicular to laser light emitted from an optical pickup is detected by a tilt sensor. Pits are formed while the laser light intensity is increased as the detected inclination increases. The illumination light quantity per unit area decreases as the inclination of the information recording surface increases. Setting the laser light intensity at a larger value as the inclination of the information recording surface increases makes it possible to compensate for reduction of the illumination light quantity per unit area that occurs in association with inclination of the information recording surface without the need for correcting the laser light emitting direction. Therefore, even if the information recording surface of an optical information recording medium is inclined, information recording can be performed with a constant laser light emitting direction.

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Seta-gun, Japan

Akira Negishi