Abstract: A method and apparatus for initializing a recording film by heating it over its crystallizing temperature with heat that is generated based on the current flowing on the recording film or induced thereon, the current being generated from applying electric energy to the recording film of a phase transformation typed optical disk. The electric energy is provided through conductive wires being directly in contact with the recording film, or through an induction heating technique in which electric energy is provided via induction.

Abstract: Method and apparatus are disclosed for initializing a recording film by heating it over its crystallizing temperature with Joule heat which is obtained by the current flowing on the recording film or induced thereon, the current being generated from applying electric energy to the recording film of a phase transformation typed optical disk. According to a feature of the present invention, the electric energy is provided through conductive wires being directly in contact with the recording film. According to another feature of the present invention, the recording film is heated by the induction heating technique.

Abstract: A cartridge for reducing air resistance therein which is induced by the rotation of a disc-shaped storage medium housed in the cartridge. Air resistance is reduced by forming holes and/or grooves on a housing case through which air flows in and out spontaneously.