Patent ID: 6144631
Filing Date: 2000-11-07
Classification: G11B

Abstract:
An information recording medium comprising a substrate provided with recessed pits or grooves, and at least a metal layer and a light transmitting layer formed on the substrate in this order, or a metal substrate provided with recessed pits or grooves, and a light transmitting layer formed on the metal substrate, so that a light is applied from the light transmitting layer side to readout information from the pits or grooves, wherein the minimum width W of the pits or grooves and the wavelength .lambda. in air of the readout light satisfy:W/.lambda..ltoreq.0.6and the refractive index n of the light transmitting layer, the thickness Tf of the light transmitting layer and the maximum depth d of the pits or grooves satisfy:n.gtoreq.1.61.2d/n<Tf<.lambda./(2n).