Sparse modulation codes for holographic data storage
US6549664B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 1999 |
| Grant date | Apr 15, 2003 |
| Priority date | — |
| Expiry date | Jun 30, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0065
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method for storing data in a holographic storage medium comprises the steps of dividing a bit stream of binary data into data groups, encoding the data groups as binary patterns, and storing the binary patterns holographically as data pages. Each binary pattern comprises channel bits, wherein the number of “off” channel bits is greater than the number of “on” channel bits. To retrieve information from the storage medium, the medium is illuminated and resultant light signals are gathered. The light signals are converted to the binary patterns, and the binary patterns are converted to the data groups. Binary patterns stored in the storage medium only slightly perturb subsequent reading and writing of data, since the patterns have fewer “on” channel bits than “off” channel bits.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.