Abstract: In order to create a long-lasting memento for a musical performance for example, which also has a practical use, a coin or medal is designed with an embossed soundtrack. Furthermore, a method for embossing this coin or medal is proposed.

Abstract: A recording unit includes a laser diode emitting a recording light for information recording, a strategy signal generating unit generating a strategy signal, a correction signal generating unit generating the correction signal for offsetting a tilt of a waveform level of the recording light, and a driving signal generating unit generating a corrected driving signal for correcting the tilt of the waveform level of the recording light based on the strategy signal and the correction signal.

Abstract: In an optical head for recording on or reproducing from a plurality of kinds of optical information recording media corresponding to a plurality of kinds of different wavelengths, coma aberration is prevented, and low price and high reliability are realized. To that end, in an optical head constituted by laser light sources of three wavelengths and photodetectors corresponding to the laser light sources of the three wavelengths, a two-laser module including laser light sources of two adjacent wavelengths and photodetectors corresponding to the laser light sources, a laser module including a laser light source of the rest one wavelength and a photodetector corresponding to the laser light source, and a dichroic mirror bonded with a rising mirror are combined.

Abstract: A magneto-optical memory medium according to the present invention comprises a reproducing layer, which has in-plane magnetization at room temperature and perpendicular magnetization when heated to above a predetermined temperature by a reproducing light beam; a recording layer, which is magnetostatically coupled to the reproducing layer; and an in-plane magnetized layer, provided adjacent to the recording layer, which has a Curie temperature at the above-mentioned predetermined temperature. In this medium, at temperatures below the predetermined temperature, signals recorded at high density in the recording layer are masked, and the above-mentioned magnetostatic coupling is suppressed, by magnetic masking by the in-plane magnetized layer.