Information recording medium and method for recording information to the same
US5426632A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Aug 11, 1994 |
| Grant date | Jun 20, 1995 |
| Priority date | — |
| Expiry date | Aug 11, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/25718
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical information recording medium recordable of the analogue NTSC color video signal under the conditions of a high S/N ratio and a low jitter, and capable of being played by a commercially available LD player. The medium comprises: a transparent substrate on which pre-grooves are formed with a depth of 1450-2050 angstroms; an optical absorbing layer with an absorbance of 0.7-0.9 made of palladium phthalocyanine dye formed on the substrate, the absorbing layer having pits each having a changed reflectivity being duty-cycle modulated in response to a limited waveform which is formed through the steps of: adding at least one of a second FM carrier and a third pulse carrier to a first FM carrier having a first center frequency and a first frequency band, the second FM carrier having a second center frequency lower than the first center frequency and a second frequency band spaced from the first frequency band, the third pulse carrier having a pulse-repetition frequency lower than the second center frequency and a third frequency band spaced from the second frequency band, to form a frequency-division multiplex signal; and symmetrically clipping the multiplex signal to form the l…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.