Abstract:
A method and apparatus for permanently rendering data recorded on an optical disc unreadable, comprising a slotted alignment plate and a scarifying component. A disc rests against the plate so that the slot traverses the disc. The scarifying component slides through the slot and contacts the disc surface, thus creating an optically disruptive groove across a surface layer of the optical disc. This disruptive groove can pass through the index and data region and prevents access to previous data and information stored on the disc.

Description:
BACKGROUND 
     1. Field of the Invention 
     The present invention is related to a method and apparatus for permanently erasing data stored on an optical disc, such as a CD or a DVD. 
     2. Description of the Related Art 
     Optical discs include discs such as the CD (Compact Disc) and the DVD (Digital Versatile Disc). These exist in commercial, R (Recordable), and RW (Rewritable)-types. In general, data is stored on an optically reflective foil layer, which is physically supported by a rigid transparent layer, through which a laser beam reads and writes data. The market for CD and DVD recorders and drives has exploded with the growing demand to store digital pictures, video, music, and other data. Optical storage, in turn, creates the need for the capability to erase and/or destroy unwanted or confidential information. 
     For RW-type discs, erasure may be accomplished by using a recorder or computer drive to re-write over the old information, as disclosed in U.S. Pat. No. 4,816,385 entitled “METHOD OF OPTICALLY RECORDING AND ERASING INFORMATION” to Gravesteijn issued on Mar. 28, 1989; U.S. Pat. No. 6,469,963 entitled “OPTICAL RECORDING MEDIUM AND METHOD OF INFORMATION RECORDING/READING AN OPTICAL RECORDING MEDIUM” to Sawada issued on Oct. 22, 2002; and U.S. Pat. No. 6,709,802 entitled “METHODS AND APPARATUS FOR RENDERING AN OPTICALLY ENCODED MEDIUM UNREADABLE” to Lawandy issued on Mar. 23, 2004. These methods and apparatus involve changing the optical properties of the reflective layer of an RW-type disc, which occurs during a play or record process. Therefore, these methods and apparatus require a computer drive or other recording device in order to erase the contents of the disc. 
     Furthermore, it may be possible, with the use of sophisticated data recovery and reconstruction methods, to recover data that has been erased on RW-type discs. 
     For commercial as well as R-type discs, once data is recorded or burned onto the disc, it cannot be erased during a read or write process because of the optically unchangeable foil layer. Sensitive and confidential information, once recorded onto these discs, cannot be simply deleted. 
     As a result, a need exists for a method and/or apparatus to securely erase commercial, R-type, and RW-type discs that require special handling because they were used to record highly sensitive information. 
     Once an optical disc becomes useless, the user may break the disc to dispose of it, but the resulting sharp fragments of the broken disc may harm the hands. A compact disc shredder may be used, as described in U.S. Pat. No. 6,676,050 entitled “PAPER SHREDDER HAVING THE FUNCTION OF BREAKING A COMPACT DISC” to Chang issued on Jan. 13, 2004. Such machines, however, are costly and require electric power to operate. Furthermore, their operation generates a great amount of noise in destroying the CDs, and creates waste materials that may require additional disposal measures. 
     Other existing machines and apparatus demonstrate further shortcomings. The Bosser CD Destroyer (Patent Pending) is a motor-driven machine that dents both surfaces of the optical disc to prevent data retrieval. A dented disc, however, may damage the player if there is an attempt to play the dented disc. In addition, the dents may be smoothed out with commercially available polishing devices and polishes, which can render the disc readable again. Furthermore, this apparatus may not be able to dent through discs with labels applied to them. 
     Another existing device is the manually operated Disc Peeler™, by Disc Dealer™ (San Diego, Calif.), which features sharp teeth that grind off the reflective foil layer from the compact disc. However, discs that have applied labels would make operation of this device more difficult. Furthermore, this device can generate a great deal of metallic dust, which can be difficult to clean and may be harmful to the user. Obviously, inserting such a frayed disc with metal dust into a playing device could result in damage to the playing device. 
     Therefore, it is desired to provide a method and device for erasing an optical disc that is inexpensive and simple to operate. It is desirable to have a small, portable device that accomplishes this in a relatively effortless manner without the need for electrical power, and without creating excessive waste material. Finally, the resulting disc should neither pose any harm to the user, nor damage a playing device if there is an attempt to play it. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the plate of the apparatus;  FIG. 1   a  is a cross-sectional view of the plate, taken generally along line  1   a — 1   a  of  FIG. 1 ; 
         FIG. 2  is a top plan view of the plate with an optical compact disc placed underneath; 
         FIG. 3  shows an optical disc with optically disruptive grooves cut from its surface; 
         FIG. 4  is a perspective view showing an embodiment of the apparatus; 
         FIG. 4   a  is a cross-sectional view taken generally along line  4   a — 4   a  of  FIG. 4 ; 
         FIG. 5  is a perspective view of another embodiment of the present invention, featuring a hinged base plate. 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1 and 1   a  show one embodiment of the apparatus. Plate  102  is shown with a slot  104  within that extends parallel to the length of plate  102  and is of length slightly less than that of plate  102 . Slot  104  is located substantially centrally with respect to the major and minor axes of plate  102  and extends through the thickness of plate  102 . Raised surfaces  106 ,  108 , and  110 , either singly or in any combination, properly align the optical disc in relation to slot  104 . In particular, raised surface  110  can be circular and fit into the central spindle hole of optical discs. However, in alternate embodiments the raised surface  110  can have any convenient shape. Additionally, in alternate embodiments, the raised surface  110  can be configured to removeably fasten a disc to the plate  102 . An optical disc placed into the plate is able to rotate on an axis centered on raised surface  110 . Plate  102  guides a scarifying component  112  through slot  104  such that it contacts the surface of an optical disc that is placed against disc resting surface  114  on the bottom side of plate  102 . The scarifying component  112  can be attached to a hand-held holder  116  in any known or convenient way. 
     In alternate embodiments, the slot  104  can be geometrically oriented in any convenient way relative to the plate  102  and can have any convenient shape or geometric pattern. 
       FIG. 2  shows the apparatus with an optical disc  200  placed against the resting surface  114 . The raised surfaces  106 ,  108 , and  110  hold the disc in place such that the slot  104  covers an area on the disc surface traversing index track  202  of the optical disc and the data region  204 . As the translatable scarifying component  112  travels along slot  104 , it creates an optically disruptive groove on the surface of the disc through the index track  202  and the data region  204 . Although the slot  104  is depicted as substantially linear, in alternate embodiments the slot  104  can have any convenient geometric shape or curvature. 
       FIG. 3  illustrates how the blade creates an optically disruptive groove  302  on the surface of the disc. A thin strip of material  303  may be excised from the disc during the scarifying process. A plurality of these optically disruptive grooves  302   a ,  302   b  can be created by rotating the optical disc, and then translating the scarifying component  112  within the slot  104 . 
       FIGS. 4 and 4   a  show another embodiment of the apparatus. Referring to  FIG. 4 , scarifying component  112  is attached to a holder  402 , which rectilinearly slides along slot  104 .  FIG. 4   a  shows rails  404  and  406 , protruding from the holder  402  and grooves  408  and  410  to slidably connect the holder to slot  104 . Grooves  408  and  410  are substantially tangentially parallel to the slot  104  and located substantially centrally with respect to the depth of slot  104 . In alternate embodiments, a slidable connection may also be made in any other known or convenient manner. 
     In the embodiment depicted in  FIGS. 4 and 4   a , the scarifying component  112  is a set of double-edged blades  412  which allow cutting during both directions of translation along the slot  104 . Blades  412  can be replaced with any other known or convenient blade designs, abrasive materials or other convenient or known scarifying component. In alternate embodiments, scarifying component  112  can be retractably attached to the holder  402  in any known or convenient manner. 
       FIG. 5  depicts another embodiment of the apparatus in which plate  502  and plate  504  form a hinged apparatus. Plate  504  is shown with a slot  104  that extends parallel to the length of plate  504 . In the embodiment shown if  FIG. 5 , the slot  104  has a length slightly less than that of plate  504 . However in alternate embodiments, the slot  104  can extend to one end of the plate  504 . In the embodiment shown in  FIG. 5 , slot  104  is located substantially centrally with respect to the major and minor axes of plate  504  and extends through the thickness of plate  504 . However in alternate embodiments, the slot  104  can have any convenient shape and/or can be located in any convenient location on the plate  504 . 
     Plate  502  includes raised surfaces  106 ,  108 , and  110 , which, either singly or in any combination, can properly align the optical disc relative to the slot  104 . Plate  504  guides a scarifying component  112  through slot  104  such that it contacts the surface of an optical disc that is placed against disc resting surface  114  of plate  502 . 
     The plates, raised surfaces and scarifying component holder can be comprised of any known or convenient material, including, but is not limited to, plastic, metal, wood, ceramic or any other material known or convenient. 
     The scarifying component  112  can be any component capable of scaring the optical data storage surface of the disc, including, but not limited to, metal, ceramic, plastic, or any other known and convenient material; abrasive material; chemical agent; thermal and/or optical device. 
     OPERATION 
     In the embodiment shown in  FIG. 1 , an optical disc containing data that is to be destroyed is placed with either the foil layer surface (for R-type discs), or the transparent plastic surface (for R-type discs or DVDs) against resting surface  114 . Raised surfaces  106 ,  108 , and  110 , either singly or in any convenient combination, can align the disc with slot  104 . The disc and plate  102  can be placed disc-side down on a table or other surface. The scarifying component  112  can then be translated through slot  104 , creating an optically disruptive groove on the disc surface. In alternate embodiment, one or more of the raised surfaces or alternate engagement mechanisms can engage the disc such that the apparatus may be used without placing it on a table or other surface. 
     Although one optically disruptive groove can render a disc unreadable, the disc can be rotated relate to the slot in the resting area and the scarification process can be repeated to create additional optically disruptive grooves on the disc for added security. 
     During or after the scarifying process, a stripped foil section  303  can detach from the surface of the optical disc. If the adhesion between the foil layer and the disc is slight, strip  303  may be peeled or wiped away by hand and disposed of. If the adhesion is strong, stripped foil section  303  may remain on the disc. Whether the strip  303  is disposed of or remains on the disc, the disc would still be rendered unreadable. 
     Different sizes and shapes of optical discs may also be erased in this manner by using a raised surface to align the disc by its center hole and then translating the scarifying component  112  along slot  104  to create an optically disruptive groove across the disc surface. 
     The resulting optically disruptive groove provides a visual indication that the disc has been rendered unreadable. Further, this can help prevent such a disc from being played in a playing device. 
     Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the invention as described and hereinafter claimed is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.