Abstract: A disk cartridge in which a disk is loaded is formed with composite synthetic resin including at least two types of thermoplastic resin, an anti-static polymer, and an inorganic filler, heat-deforming temperatures of at least two types of the thermoplastic resin mutually differing. The disk cartridge is provided by a method comprising the steps of mixing at least two types of thermoplastic resin to provide a mixture, heat-deforming temperatures of at least two types of the thermoplastic resin mutually differing, mixing an inorganic filler with a mixture of at least two types of the thermoplastic resin, mixing an anti-static polymer with the mixture of at least two types of the thermoplastic resin including the inorganic filler to provide a composite synthetic resin, injection molding the composite synthetic resin to provide component parts of the disk cartridge, and assembling the component parts to form the disk cartridge with the disk loaded therein.

Abstract: A multi-layer optical storage medium includes a transparent substrate, a partially reflective layer, a transparent spacer, and a highly reflective layer. One pattern of data pits is provided on the substrate, adjacent the partially reflective layer, and another pattern of pits is provided on the spacer layer, adjacent the highly reflective layer. The partially reflective layer may be made of amorphous selenium (a-Se) and preferably has an index of refraction having a real component, n, greater than 2.8 and an imaginary component, K, less than 0.01. The invention also includes the optical data storage systems compatible with such media.