Copyright information embedding apparatus
US5960398A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 28, 1997 |
| Grant date | Sep 28, 1999 |
| Priority date | — |
| Expiry date | Jul 28, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B20/10527
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A copyright information embedding system is provided which is designed to embed information for copyright protection into digital audio signals without deterioration of analog audio signals reproduced. The copyright information embedding system includes an A/D converter, a modulator, a level detector, and a copyright data embedding circuit. The A/D converter converts an analog audio signal into a digital signal. The modulator modulates a copyright data signal for the digital signal using spectrum spread. The level detector detects a variation in level of the digital signal. The copyright data embedding circuit divides the copyright data signal into several codes and embeds them into the digital signal each time the variation in level of the digital signal shows a preselected variation such as a rapid rise or drop.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.