Copy protection apparatus and method
US6310956A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 16, 1999 |
| Grant date | Oct 30, 2001 |
| Priority date | — |
| Expiry date | Mar 16, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2005/91328
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An apparatus and method of copy protection for use in digital data recorders such as DVD-RAM recorders, which includes embedding transmission time information into a digital data stream by digital watermarking and comparing the transmission time with the current time at the data recorder (30, 50). If the time difference is less than a threshold value it is presumed that the recording is for time-shifting purposes, namely recording a programme to watch later, which is generally allowed by copyright laws. If the time difference is greater than a threshold value it is presumed that the recording is an attempted unauthorised recording such as from a pre-recorded copy, and further recording is prevented.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.