申请人:SONY CORPORATION
公开号:EP1130587A2
公开(公告)日:2001-09-05
A disc-shaped recording medium (40) having transcription characteristics for fine signals simultaneously with resonance characteristics and stiffness which are characteristics contrary to the transcription characteristics. At least a recording layer (42) and a light transmitting layer (41) are sequentially formed on a substrate (44,45) and light (L) is illuminated from a light transmitting layer (41) side to record and/or reproduce information signals. The substrate includes a core layer (45) formed of a resin composition comprised of a mixture of two or more resin sorts. The resin composition has tanδ, as an index indicating the internal loss, equal to not less than 0.015 as a system in its entirety. The resin composition constituting the core layer (45) is a compounded resin of the incompatible system and is of an islands-sea structure.
一种圆盘形记录介质(40),它同时具有精细信号的转录特性以及与转录特性相反的共振特性和硬度。至少一个记录层(42)和一个透光层(41)依次形成于一个基板(44,45)上,光(L)从透光层(41)一侧照射,以记录和/或再现信息信号。基板包括由两种或两种以上树脂混合物组成的树脂组合物形成的芯层(45)。该树脂组合物作为表示内部损耗的指数,其整个系统的 tanδ 值不小于 0.015。构成芯层(45)的树脂组合物是不相容体系的复合树脂,并且是岛海结构。