Holographic Recording Medium

Abstract

In a hologram recording medium, a bleaching beam irradiated to fix recorded information is prevented from spreading and advancing into an unrecorded area. The hologram recording medium is provided with a hologram material layer for recording information to be recorded by irradiating a same area with an information beam which corresponds to the information to be recorded and a reference beam for reading out the recorded information. The hologram material layer is divided into a plurality of recording zones by a plurality of light blocking walls, and the light blocking walls are formed in the recording zone to which recording process has been performed, by using a material not passing through the bleaching beam irradiated for fixing the recorded information.

1 - 11 . (canceled) 
   
   
       12 . A holographic recording medium comprising:
 a holographic material layer in which information is to be recorded by irradiating the same region with information light corresponding to the information to be recorded and reference light to read the recorded information,   wherein the holographic material layer is divided into a plurality of recording zones by a plurality of light shielding walls,   the light shielding walls are formed of a material which does not transmit bleaching light irradiated for being fixed the recorded information to the recording zone in which a recording process has been performed, and   each of the recording zones, divided by the light shielding walls, has the same area.   
   
   
       13 . The holographic recording medium according to  claim 12 , wherein
 the light shielding walls reflect or absorb the bleaching light so that the bleaching light proceeds only to a recording zone in which the recorded information is to be fixed, and   the bleaching light does not proceed to a recording zone adjacent to the recording zone in which the recorded information is to be fixed.   
   
   
       14 . The holographic recording medium according to  claim 12 , wherein the light shielding walls include either acrylic or polycarbonate material. 
   
   
       15 . The holographic recording medium according to  claim 12 , wherein
 the holographic material layer is formed on a disk-shaped or polygonal substrate,   the light shielding walls are formed on the substrate and in the holographic material layer in a latticed pattern, and   the recording zones are regions surrounded by the lattice-shaped light shielding walls.   
   
   
       16 . The holographic recording medium according to  claim 12 , wherein the shape of the light shielding walls are any of a linear shape, a wobble shape having changed linearly corresponding to recording spots of the bleaching light, and a wobble shape having changed in a curve corresponding to recording spots of the bleaching light. 
   
   
       17 . A holographic recording medium comprising:
 a holographic material layer in which information is to be recorded by irradiating the same region with information light corresponding to the information to be recorded and reference light to read the recorded information,   wherein the holographic material layer is divided into a plurality of recording zones by a plurality of light shielding walls,   the light shielding walls are formed of a material which does not transmit bleaching light irradiated for being fixed the recorded information to the recording zones in which a recording process has been performed, and   each of the recording zones, divided by the light shielding walls, has a different area.   
   
   
       18 . The holographic recording medium according to  claim 17 , wherein
 the light shielding walls reflect or absorb the bleaching light so that the bleaching light proceeds only to a recording zone in which the recorded information is to be fixed, and   the bleaching light does not proceed to a recording zone adjacent to the recording zone in which the recorded information is to be fixed.   
   
   
       19 . The holographic recording medium according to  claim 17 , wherein the light shielding walls include either acrylic or polycarbonate material. 
   
   
       20 . The holographic recording medium according to  claim 17 , wherein
 the holographic material layer is formed on a disk-shaped or polygonal substrate,   the light shielding walls are formed on the substrate and in the holographic material layer in a latticed pattern, and   the recording zones are regions surrounded by the lattice-shaped light shielding walls.   
   
   
       21 . The holographic recording medium according to  claim 17 , wherein
 the shape of the light shielding walls are any of a linear shape, a wobble shape having changed linearly corresponding to recording spots of the bleaching light, and a wobble shape having changed in a curve corresponding to recording spots of the bleaching light.   
   
   
       22 . A holographic recording medium comprising:
 a holographic material layer in which information is to be recorded by irradiating the same region with information light corresponding to the information to be recorded and reference light to read the recorded information,   wherein the holographic material layer is divided into a plurality of recording zones by a plurality of light shielding walls,   the light shielding walls are formed of a material which does not transmit bleaching light irradiated for being fixed the recorded information to the recording zone in which a recording process has been performed, and   the shape of the light shielding walls are any of a linear shape, a wobble shape having changed linearly corresponding to recording spots of the bleaching light, and a wobble shape having changed in a curve corresponding to recording spots of the bleaching light.   
   
   
       23 . The holographic recording medium according to  claim 22 , wherein
 the light shielding walls reflect or absorb the bleaching light so that the bleaching light proceeds only to a recording zone in which the recorded information is to be fixed, and   the bleaching light does not proceed to a recording zone adjacent to the recording zone in which the recorded information is to be fixed.   
   
   
       24 . The holographic recording medium according to  claim 22 , wherein the light shielding walls include either acrylic or polycarbonate material. 
   
   
       25 . The holographic recording medium according to  claim 22 , wherein
 the holographic material layer is formed on a disk-shaped or polygonal substrate,   the light shielding walls are formed on the substrate and in the holographic material layer in a latticed pattern, and   the recording zones are regions surrounded by the lattice-shaped light shielding walls.