Abstract:
Briefly, in accordance with one embodiment of the present principles, a Blu-ray disc is described. The Blu-ray disc has a structure including a substrate having one of either a Compact Dics data layer and a DVD data layer along with a Blu-ray data layer. The Blu-ray discs of the present invention advantageously use Compact Discs (or DVDs) that are due to be scrapped or recycled as donor substrates for new Blu-ray discs, thereby saving polycarbonate material and eliminating the need to purchase injection molding equipment to manufacture Blu-ray discs.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to and all benefits accruing from a provisional application filed in the United States Patent and Trademark Office on Sep. 21, 2007, and there assigned Ser. No. 60/994,882. 
     
    
     TECHNICAL FIELD 
       [0002]    This relates to a method for recycling Compact Discs (CDs) or Digital Video Discs (DVDs) that are due to be scrapped. 
       BACKGROUND ART 
       [0003]    Compact Discs often referred to as CDs, have proliferated greatly since their introduction in the 1970s. Indeed, the CD has become the medium of choice for hard copy delivery of music and software. Similarly, Digital Vide Discs (DVDs) have also proliferated and now serve as the medium of choice for hard copy distribution of audio visual programs, such as movies and television shows. Indeed disc replicators make millions of CDs and DVDs annually. 
         [0004]    As with the manufacture of any product, the manufacture of CDs and DVDs results in some scrap. Heretofore, recycling of scrap CDs and DVDs has proven difficult because of the metallized layers within such discs. As a result, scrap discs are currently shredded, and remnants serve as filler for roads and highways. While some have experimented with using scrap paper for making new discs, none have attempted to recycle old discs to make new ones. 
       BRIEF SUMMARY OF THE INVENTION 
       [0005]    Briefly, in accordance with one embodiment of the present principles, a Blu-ray disc is described. The Blu-ray disc has a structure including a substrate having one of either a Compact Dics data layer and a DVD data layer along with a Blu-ray data layer. The Blu-ray discs of the present invention advantageously use Compact Discs (or DVDs) that are due to be scrapped or recycled as donor substrates for new Blu-ray discs, thereby saving polycarbonate material and eliminating the need to purchase injection molding equipment to manufacture Blu-ray discs. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is a cross-sectional view of one embodiment of the Blu-ray disc of the present invention formed using a Compact Disc substrate; 
           [0007]      FIG. 2  is a cross-sectional view of another embodiment of the Blu-ray disc of the present invention formed using a DVD substrate; and 
           [0008]      FIG. 3  is a flow diagram depicting a method for forming the Blu-ray disc of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0009]    The present invention makes use of the fact that Blu-ray discs have the same dimensions and form factor as CDs and DVDs with the important feature on Blu-ray discs being that the data surface is on the bottom surface of the disc as opposed to CD which has the data surface on the top directly under the printed label, and DVDs where the data layers are in the center of the two bonded half-discs. The clear, flat bottom surface of CDs and DVDs lend themselves to the addition of a newly embossed Blu-ray data layer that supersedes the previous CD (DVD) data and effectively turns the CD (DVD) into a Blu-ray disc. 
         [0010]    A CD disc structure is typically comprised of a CD (Compact Disc) data layer  103  formed on a plastic substrate  105  as shown in  FIG. 1 . The disc  100  of the present principles includes a Blu-ray data layer  104  formed on a surface of the plastic substrate  105  opposite the CD data layer  103 . Such a structure provides a Blu-ray disc structure in which the CD data layer  103  may be ignored. Blu-ray data layer  104  may be formed of one or more layers of resin material (not shown). For example, a first resin layer may comprise a spacer layer formed directly on the CD substrate  105 . A second resin layer may be formed on the first resin layer. The second resin layer typically contains the Blu-ray data surface. 
         [0011]    Referring to  FIG. 3  the method of manufacture for the Blu-ray disc  100  of the present principles is described. A discarded and/or unused CD substrate  105  having a CD data layer  103  formed thereon is cleaned as indicated in step  301 . 
         [0012]    Thereafter, referring to step  302 , the cleaned CD substrate  105  may be coated on a surface opposite the CD layer  103  (read-through surface for laser) with a resin layer  104  as is used to make conventional Blu-ray disc via, for example, a wet-embossing process. 
         [0013]    Resin layer  104  is then cured, as indicated in step  303  of  FIG. 3 . The resin layer  104  may be cured using for example, ultra-violet radiation. The cured resin  104  is then coated with a 1-10 micron thick layer of “pit resin” as used in conventional Blu-ray wet-embossing process. The “pit resin” is used to form the Blu-ray data surface of the Blu-ray disc  100 , as indicated in step  304  of  FIG. 3 . 
         [0014]    Referring to step  305  of  FIG. 3 , the pit-resin is embossed using a Blu-ray stamper and cured to form Blu-ray disc data surface. The embossing step replicates the Blu-ray data in the disc data surface. Thereafter, the curing step hardens the resin to prevent alteration of the replicated data. 
         [0015]    After the Blu-ray data surface is formed in resin layer  104 , this surface is metallized to form a reflective surface thereover as indicated in step  306  of  FIG. 3 . For a Blu-ray dual layer disc (not shown) steps  302 - 306 . 
         [0016]    Referring to step  307  of  FIG. 3 , a cover-layer and hardcoat are next applied to the Blu-ray disc structure as with conventional BD manufacturing process. Finally, the original CD (DVD) printed label  101  is coated with ink and overprint with a desired printed label for Blu-ray disc using conventional disc printing techniques. 
         [0017]    A DVD disc structure is typically comprised of a DVD data layer  203  formed between two plastic substrates  202  as shown in  FIG. 2 . The disc  200  of the present principles includes a Blu-ray data layer  204  formed on a surface of the plastic substrate  202  opposite the DVD data layer  203 . Such a structure provides a Blu-ray disc structure in which the DVD data layer  203  may be ignored. 
         [0018]    Blu-ray data layer  204  may again be formed of one or more layers of resin material (not shown). For example, a first resin layer may comprise a spacer layer formed directly on the CD substrate  105 . A second resin layer may be formed on the first resin layer. The second resin layer typically contains the Blu-ray data surface. 
         [0019]    Referring to  FIG. 3  the method of manufacture for the Blu-ray disc  200  of the present principles is described. A discarded and/or unused CD substrate  202  having a DVD data layer  203  formed thereon is cleaned as indicated in step  301 . 
         [0020]    Thereafter, referring to step  302 , the cleaned DVD substrate  202  may be coated on a surface opposite the DVD layer  203  (read-through surface for laser) with a resin layer  204  as is used to make conventional Blu-ray disc via, for example, a wet-embossing process. 
         [0021]    Resin layer  204  is then cured, as indicated in step  303  of  FIG. 3 . The resin layer  104  may be cured using for example, ultra-violet radiation. The cured resin  204  is then coated with a 1-10 micron thick layer of “pit resin” as used in conventional Blu-ray wet-embossing process. The “pit resin” is used to form the Blu-ray data surface of the Blu-ray disc  200 , as indicated in step  304  of  FIG. 3 . 
         [0022]    Referring to step  305  of  FIG. 3 , the pit-resin is embossed using a Blu-ray stamper and cured to form Blu-ray disc data surface. The embossing step replicates the Blu-ray data in the disc data surface. Thereafter, the curing step hardens the resin to prevent alteration of the replicated data. 
         [0023]    After the Blu-ray data surface is formed in resin layer  204 , this surface is metallized to form a reflective surface thereover as indicated in step  306  of  FIG. 3 . For a Blu-ray dual layer disc (not shown) steps  302 - 306 . 
         [0024]    Referring to step  307  of  FIG. 3 , a cover-layer and hardcoat are next applied to the Blu-ray disc structure as with conventional BD manufacturing process. Finally, the original DVD printed label  201  is coated with ink and overprint with a desired printed label for Blu-ray disc using conventional disc printing techniques. 
         [0025]    The present invention makes use of the fact that Blu-ray discs have the same dimensions and form factor as CDs and DVDs with the important feature on Blu-ray discs being that the data surface is on the bottom surface of the disc as opposed to CD which has the data surface on the top directly under the printed label, and DVDs where the data layers are in the center of the two bonded half-discs. The clear, flat bottom surface of CDs and DVDs lend themselves to the addition of a newly embossed Blu-ray data layer that supersedes the previous CD (DVD) data and effectively turns the CD (DVD) into a Blu-ray disc. The manufacturing of such a disc would require no material changes limited to the glass master or disc recording stage. 
         [0026]    The foregoing illustrates some of the possibilities for practicing the invention. Many other embodiments are possible within the scope and spirit of the invention. Therefore, it is intended that the foregoing description be regarded as illustrative rather than limiting, and that the scope of the invention is given by the appended claims together with their full range of equivalents.