Patent ID: 7035200

Claim:
A method for fabricating an optical medium readable by an optical reader, said method comprising the steps of: molding a substrate so as to have a first major surface with information pits and information lands thereon and a second major surface that is relatively planar, said information lands on said first major surface being in either a first plane or a second plane, said first plane being further from the bottom of said pits than said second plane by a factor of about 2; applying a reflective material over the first major surface so as to cover said information pits and information lands; removing the reflective material over said information lands in said first plane; applying a layer over said first major surface comprising an optically changeable security material; wherein the locations of the first and second planes are pre-selected taking into account said optical reader and said optically changeable security material, wherein said information lands in said fabricated optical medium may be read by a signal directed by said optical reader through said second major surface so as to ascertain whether the optically changeable security material is in a first optical state or a second optical state, and wherein the read by said optical reader is true to the physical structure of said information pits and said information lands when the optically changeable security material is in at least one of said optical states.