Method for producing holographic recording medium

Abstract

A holographic recording medium, with a first substrate shaped in a disk and having a hole at a central portion thereof; and a second substrate shaped in a disk, having a hole at a central portion thereof and arranged to face the first substrate. The recording medium includes a space retaining member for retaining a predetermined distance between the first and second substrates; and a holographic recording layer provided in the space between the first and second substrates.

1 . A holographic recording medium, comprising: 
 a first substrate shaped in a disk and having a hole at a central portion thereof;    a second substrate shaped in a disk, having a hole at a central portion thereof and arranged to face the first substrate;    a space retaining member for retaining a predetermined distance between the first and second substrates; and    a holographic recording layer provided in the space between the first and second substrates.    
   
   
       2 . The holographic recording medium described in  claim 1 , wherein the space retaining member includes an inner side space retaining member provided in the vicinity of the hole of each of the first and second substrates.  
   
   
       3 . The holographic recording medium described in  claim 2 , wherein the inner side space retaining member includes a cylinder inserted in the hole and a flange mounted on an outer surface of the cylinder and arranged between the first and second substrates so as to retain the predetermined distance between the first and second substrates.  
   
   
       4 . The holographic recording medium described in  claim 2 , wherein the inner side space retaining member having an opening section through which a holographic recording material is charged into or discharged from the space between the first and second substrates.  
   
   
       5 . The holographic recording medium described in  claim 1 , wherein the space retaining member includes an outer side space retaining member provided around the periphery of each of the first and second substrates.  
   
   
       6 . The holographic recording medium described in  claim 5 , wherein the outer side space retaining member includes a ring coming in contact with the periphery of each of the first and second substrates and a flange mounted on an inner surface of the ring and arranged between the first and second substrates so as to retain the predetermined distance between the first and second substrates.  
   
   
       7 . The holographic recording medium described in  claim 5 , wherein the outer side space retaining member having an opening section through which a holographic recording material is charged into or discharged from the space between the first and second substrates.  
   
   
       8 . The holographic recording medium described in  claim 5 , wherein the outer side space retaining member includes a second claw to contact an outer surface of the second substrate.  
   
   
       9 . The holographic recording medium described in  claim 5 , wherein the outer side space retaining member includes a first claw to contact an outer surface of the first substrate.  
   
   
       10 . The holographic recording medium described in  claim 1 , wherein the holographic recording medium satisfies the relation of 0.15≦Dh/(D 1 +D 2 )≦2.0, where D 1  is the thickness of the first substrate, D 2  is the thickness of the second substrate and Dh is the thickness of the holographic recording layer.  
   
   
       11 . The holographic recording medium described in  claim 10 , wherein the thickness of the holographic recording layer Dh is from 200 μm to 2.0 mm.  
   
   
       12 . The holographic recording medium described in  claim 10 , wherein the relation of the thickness of the first substrate D 1  and the thickness of the second substrate D 2  is D 1 ≦D 2 .  
   
   
       13 . The holographic recording medium described in  claim 1 , wherein the space retaining member is made in one body with one of the first and second substrates.