Recording medium of deformable air-sandwich structure

摘要

A recording medium having an air-sandwich structure comprising two disc-shaped substrates opposed to each other at a given distance by interposing therebetween a ring-shaped inner spacer and a ring-shaped outer spacer and a recording layer for writing and/or reading information with laser beam which is provided on the inner surface of at least one substrate, characterized in that the distance between said two substrates satisfies the following expression (I): (I) wherein h is the distance in mm between two substrates, E1 and E2 are each a Young's modulus (in kg/mm2) of each substrate, l is the distance (in mm) between the inner spacer and the outer spacer, and t1 and t2 are each the thickness (in mm) of each substrate.