Importance

Loading Importance Indicators...

Abstract

A recording medium for optical high-density data storage and retrievel, comprising a flat transparent plastic substrate characterized by the following relationship between the refractive index (n.sub.z) in the direction perpendicular to the flat surfaces of the transparent substrate, and the refractive indexes (n.sub.x) and (n.sub.y) in the direction parallel to the flat surfaces of the transparent substrate: .vertline.n.sub.z -n.sub.x .vertline. smaller than 4.times.10.sup.-4 ; and .vertline.n.sub.z -n.sub.y .vertline. smaller than 4.times.10.sup.-4. The recording medium is produced by an injection molding process wherein the pressure on the molten resin filled into the molding cavity of a mold is decreased or increased, as appropritate, in order to maintain the desired differences between the refractive index n.sub.z in the direction perpendicular to the flat surfaces of the transparent substrate, and the refractives indexes (n.sub.x) and (n.sub.y) in the direction parallel to the flat surfaces of the transparent substrate.

Loading the Abstract Image...

First Claim