Multi-level information recording apparatus, multi-level information recording method, multi-level information recording medium and multi-level information recording-reproducing apparatus
US7126897B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 13, 2003 |
| Grant date | Oct 24, 2006 |
| Priority date | — |
| Expiry date | Aug 17, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/00736
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A multi-level information recording-reproducing apparatus can accurately determine multi-level information even if recording density is increased. A multi-level information recording-reproducing apparatus radiates a laser beam to an information recording medium by switching a radiation energy level of the laser beam in a multi-level fashion and records a recorded mark in the information recording medium. The multi-level information recording-reproducing apparatus reproduces a multi-level data sequence recorded as a test pattern in the information recording medium, sets a reproduction signal level of a recorded mark based on an immediately-before cell located immediately before a cell to be reproduced, and corrects the radiation energy level of the laser beam so that the reproduction signal level can have a separate distribution from a distribution of another reproduction signal level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.