Reversible Read-Write-Erase Properties of Styrene Oligomer Optical Recording Media

Abstract

Optical recording media consisting of a thermoplastic oligomer resin blended with a photoabsorbing pigment permit heat-mode pit writing without corona discharge, as well as heat erasure and rewriting. The properties of recording layers consisting of styrene oligomers having number-average molecular weights ( M n ) of 400 or 3000 blended with copper phthalocyanine or anthraquinone pigment, when subjected to recording and playback operations with a helium-neon (He–Ne) laser, are investigated. In addition, full-surface heat erasure, and scanning heat erasure are discussed. Pits with an outside diameter of 2.5 µm were recorded (writing time, 2 µsec) with a 10 mW He–Ne laser light. A readout signal contrast (ratio of reflected light intensity in the absence of pits to that in the presence of pits) of 3 was obtained.