Patent ID: 6726973
Filing Date: 2004-04-27
Classification: G11B,Y10T

Abstract:
An information recording medium comprising:a first substantially transparent plastic disc having a first surface and a second surface opposite to said first surface, said second surface having first information recorded on it by means of local changes in the distance of said second surface from said first surface; a semi-reflective coating on said second surface for reflecting a first portion of light passed through said first disc back through said first disc and for transmitting a second portion of said light through said semi-reflective coating, said semi-reflective coating conforming to said local changes of said second surface so that said first portion of said light is reflected back through said first disc in accordance with the first information recorded by means of said local changes of said second surface; a second plastic disc of approximately the same thickness as said first disc, said second disc having opposite third and fourth surfaces, a first portion of said fourth surface having second information recorded on it by means of local changes in the distance of said first portion of said fourth surface from said third surface and a second portion of said fourth surface having graphical information formed thereon by surface modifications in said fourth surface which tends to scatter light directed to the fourth surface; and a reflective coating on said fourth surface for reflecting said second portion of said light transmitted through said first disc back through said first disc, said reflective coating conforming to said local changes of said first portion of said fourth surface so that said second portion of said light is reflected back through said first disc in accordance with the second information recorded by means of said local changes of said fourth surface, said second disc being stacked on and secured to said first disc so that said fourth surface faces said second surface such that said graphical information formed on said fourth surface is visible through said first disc having said first information and through said semi-reflective coating.