Claims
- 1. A method of encoding binary data for storage in a holographic storage medium, said method comprising the steps of:a) forming a series of data groups from said binary data; b) converting said data groups into a number of binary patterns, wherein each of said binary patterns comprises channel bits, and wherein a kth of said binary patterns has mk “on” channel bits and nk−mk “off” channel bits, wherein mk<nk/2; and c) storing said binary patterns as a plurality of pages in said holographic storage medium.
- 2. The method of claim 1, wherein a kth of said data groups comprises bk binary bits, and wherein nk-choose-mk≧2bk.
- 3. The method of claim 1, wherein for every value of k between 1 and said number of binary patterns, mk=m.
- 4. The method of claim 3, wherein:a) a sparseness is an average value of nk/m, and b) said sparseness is selected to maximize a storage capacity of said storage medium.
- 5. The method of claim 4 wherein said sparseness is equal to 3.
- 6. The method of claim 1, wherein the step of converting said data groups into said binary patterns comprises the step of using a lookup table.
- 7. The method of claim 1, wherein the step of forming said series of said data groups comprises the step of error correction encoding said binary data.
- 8. The method of claim 1, wherein the step of forming said series of said data groups comprises the step of reordering bytes of said binary data.
- 9. The method of claim 1, further comprising the step of storing reference marks in said storage medium.
- 10. A holographic storage medium comprising:a plurality of regions of perturbations in an index of refraction of said storage medium, wherein said regions correspond to a plurality of pages comprising binary patterns of channel bits, and wherein said binary patterns have fewer “on” channel bits than “off” channel bits; and additional regions of perturbations in said index of refraction, said additional regions corresponding to reference marks.
- 11. The medium of claim 10 wherein each of said binary patterns has m “on” channel bits and n−m “off” channel bits.
- 12. A method of decoding binary data stored as pages in a holographic storage medium, said method comprising the steps of:a) illuminating said storage medium with an address beam; b) detecting a plurality of light signals induced by said address beam; c) using said detected light signals to form a data array; d) identifying a data sector comprising n elements of said data array, wherein n>2; e) identifying the m largest values of said n elements as “on” channel bits, wherein m is a number less than n/2; and identifying the remaining n−m values of said n elements as “off” channel bits, thereby obtaining a binary pattern corresponding to said data sector; and f) converting said binary pattern to a binary number.
- 13. The method of claim 12, further comprising the steps of:a) identifying additional data sectors of said data array, and b) converting said additional data sectors to additional binary patterns, wherein a kth of said additional binary patterns comprises mk “on” channel bits and nk−mk “off” channel bits; wherein an average value of nk/mk optimizes a storage capacity of said storage medium.
- 14. The method of claim 12, wherein said step of converting said binary pattern to a binary number comprises the step of using a lookup table.
- 15. The method of claim 12, further comprising the steps of:a) identifying additional data sectors of said data array; b) converting said additional data sectors into additional binary numbers; c) unshuffling said binary number and said additional binary numbers, to obtain a reordered sequence of binary numbers.
- 16. The method of claim 15, further comprising the step of error correction decoding said reordered sequence of binary numbers.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part application of U.S. patent application Ser. No. 09/224,031 filed Dec. 31, 1998, U.S. Pat. No. 6,064,586, which is hereby incorporated herein by reference.
GOVERNMENT RIGHTS
The present invention was made with government support under contract No. MDA-972-95-3-004, awarded by the ARPA/NSIC HDSS Consortium. The government has certain rights in this invention.
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Continuation in Parts (1)
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Number |
Date |
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Parent |
09/224031 |
Dec 1998 |
US |
Child |
09/343933 |
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US |