| 摘要 |
PURPOSE:To enable to record information and optically read the recorded information, by applying thermal energy to a recording material to generate a thermal hysteresis. CONSTITUTION:Thermal energy is applied to an amorphous substance having a change of specific heat at a glass transition temperature [DELTACp (J.K<-1>.g<-1>)] satisfying the relationship of DELTACp>=0.86exp(-Tg/394.3) and a change of specific heat per one mole of an average molecular weight of molecular component units constituting the substance at the glass transition temperature [M'.DELTACp (J.K<-1>. mol<-1>)] satisfying the relationship of M'.DELTACp>=10.9 to generate a thermal hysteresis. The recording material is once heated to a temperature not lower than the glass transition temperature, followed by slowly or rapidly cooling to obtain a uniform state. After this pretreatment, the positions for recording in the material are irradiated with IR rays, laser light or the like to partially heating the material to a temperature not lower then the glass transition point, followed by rapidly or slowly cooling to impart a thermal hysteresis, whereby parts differing from other parts in density or refractive index are provided, resulting in performing recording. |
