Method and system for producing multiple images in a single image plane using diffraction

Abstract

Methods create images viewable under different selected angles on optical storage devices and other photosensitive surfaces and optical storage devices with super-imposed images. Generally, a photosensitive surface is exposed with multiple diffraction patterns creating super-imposed images. These diffraction patterns create super-imposed images on the photosensitive surfaces, which can be read by either a human or a computer.

What is claimed is: 
     
         1 . An apparatus with multiple diffraction images, the apparatus comprising:
 a substrate; and   a plurality of diffractive elements coupled to the substrate,   wherein a first portion of the plurality of diffractive elements is reconstructable to form a first image viewable at a first angle,   wherein a second portion of the plurality of diffractive elements is reconstructable to form a second image viewable at a second angle different from the first angle,   wherein the plurality of diffractive elements are formed by pressing the substrate with a stamper,   wherein the stamper is formed by replicating an exposed photosensitive substrate,   wherein the exposed photosensitive substrate is formed by exposing the photosensitive substrate, during rotation of the photosensitive substrate, to a single laser beam wavefront,   wherein the exposing is accomplished without a reference beam impacting the photosensitive substrate, and   wherein the exposing is accomplished with one laser beam impact point.   
     
     
         2 . The apparatus of  claim 1 , wherein the first portion and the second portion have at least one diffractive element in common. 
     
     
         3 . The apparatus of  claim 1 , wherein the first portion and the second portion have diffractive elements which vary in depth. 
     
     
         4 . The apparatus of  claim 1 , wherein the first portion and the second portion have diffractive elements which vary in width. 
     
     
         5 . The apparatus of  claim 1 , wherein the first portion and the second portion have diffractive elements which vary in spatial spacing. 
     
     
         6 . The apparatus of  claim 1 , wherein the first portion and the second portion have diffractive elements which vary in angular orientation. 
     
     
         7 . The apparatus of  claim 1 , wherein the plurality of first diffractive elements make up a holographic optical element. 
     
     
         8 . The apparatus of  claim 1 , wherein the plurality of first diffractive elements make up a computer generated diffractive optical element. 
     
     
         9 . The apparatus of  claim 1 , wherein the plurality of diffractive elements make up a hologram. 
     
     
         10 . The apparatus of  claim 1 , wherein the plurality of diffractive elements make tip a 3D image. 
     
     
         11 . The apparatus of  claim 1 , further comprising a plurality of data elements coupled to the substrate. 
     
     
         12 . The apparatus of  claim 1 , wherein the apparatus is a disc. 
     
     
         13 . The apparatus of  claim 12 , wherein the disc comprises a polycarbonate material. 
     
     
         14 . The apparatus of  claim 12 , wherein the disc further comprises:
 a reflective metallization layer; and   a protective layer.   
     
     
         15 . The apparatus of  claim 14 , wherein the disc further comprises a printed layer. 
     
     
         16 . A method for pressing a disc, comprising:
 providing a disc configured to be pressed by a stamper; and   pressing the disc with the stamper to form a plurality of diffractive elements on the disc,   wherein the stamper is formed by:
 exposing, solely by a single spherical wavefront, a rotating photosensitive substrate a first time to form a plurality of first diffractive elements, wherein the plurality of first diffractive elements are reconstructable to form a first image viewable at a first angle; 
   exposing, solely by the single spherical wavefront, the rotating photosensitive substrate a second time to form a plurality of second diffractive elements, wherein the plurality of second diffractive elements are reconstructable to form a second image viewable at a second angle different from the first angle; and   replicating the photosensitive substrate.   
     
     
         17 . A method for pressing a disc, comprising:
 providing a disc configured to be pressed by a stamper; and   pressing the disc with the stamper to form a plurality of diffractive elements on the disc,   wherein the stamper is formed by replicating a master,   wherein the master is formed by exposing a rotating photosensitive substrate to a single laser beam wavefront, wherein the exposing is accomplished without a reference beam impacting the rotating photosensitive substrate, and wherein the exposing is accomplished with one laser beam impact point.   
     
     
         18 . The method of  claim 17 , wherein a first portion of the plurality of diffractive elements is reconstructable to form a first image viewable at a first angle, and
 wherein a second portion of the plurality of diffractive elements is reconstructable to form a second image viewable at a second angle different from the first angle.   
     
     
         19 . The method of  claim 17 , wherein the exposing is accomplished without the use of a beamsplitter. 
     
     
         20 . The method of  claim 17 , wherein the single laser beam wavefront does not contain interference information intended for recordation in the photosensitive substrate. 
     
     
         21 . The method of  claim 17 , wherein the single laser beam wavefront does not contain interference information associated with the first image. 
     
     
         22 . The method of  claim 17 , wherein the disc comprises a polycarbonate material. 
     
     
         23 . The method of  claim 17 , further comprising overcoating the disc with:
 a reflective metallization layer, and   a protective layer.   
     
     
         24 . The method of  claim 23 , further comprising overcoating the disc with a recording layer containing a dye.