| 摘要 |
PURPOSE:To decrease a tilt angle, to lessen a change at and under a high temp. and high humidity and to enable stable reading by forming a dense and flat org. protective layer on the surface of the optical disk. CONSTITUTION:The org. protective layer is formed on the specular surface side surface and groove surface side surface of a substrate. This org. protective layer is repolymerized from an org. monomer and is formed on the specular surface side surface of the transparent substrate or the surface of the information recording layer, etc., formed on the opposite surface of the substrate under the plasma of an inert gas, such as Ar<+>, Xe<+>, He<+> or Ne<+>, in a vacuum chamber kept under 1X10<-1> to 1X10<-4>Torr. The extremely dense and flat org. protective layer is formed on the surface of the optical disk without applying strains and stresses to the substrate according to such constitution and, therefore, the tilt angle which is the cause for a focus error and tracking error at the time of reading of the optical disk is drastically decreased and the moisture absorption even under the high humidity is decreased. The increase in the tilt angle with lapse of time is thus obviated. |
