Method for encoding and decoding digital data in holographic storage media
US5450218A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 4, 1994 |
| Grant date | Sep 12, 1995 |
| Priority date | — |
| Expiry date | Aug 4, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B13/045
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method for encoding and decoding digital data for storage in a holographic medium (12). Digital data, consisting of binary data (B.sub.i) or grey scale data (A.sub.i), is encoded in bit groups or digit groups (B.sub.k, A.sub.k) containing at least k=1 bits or digits, respectively, by assigning to each bit group (B.sub.k) one reference bit (B.sub.r) and to each digit group (A.sub.k) two reference digits (A.sub.r1, A.sub.r2), assigning the bits of group (B.sub.k) to information bits (B.sub.j), assigning the digits of group (A.sub.k) to information digits (A.sub.j), assigning the reference bit (B.sub.r) and information digits (B.sub.j) to a reference pixel (P.sub.r) and information pixels (P.sub.j) chosen from pixels (24) of a holographic signal modulator (18), and assigning the reference digits (A.sub.r1, A.sub.r2) and information digits (A.sub.j) to reference pixels (P.sub.r1, P.sub.r2) and information pixels (P.sub.j) chosen from pixels (24) of the holographic signal modulator (18). Storing all pixels (24) by illuminating the holographic signal modulator (18) with a signal beam (22) which impresses upon the signal beam (29) pixels (24), guiding the signal beam (22) to the hologra…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.