Duplication control system using two differently generated control signals superimposed on the information signal
US6112008A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 12, 1997 |
| Grant date | Aug 29, 2000 |
| Priority date | — |
| Expiry date | Nov 12, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2005/9135
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The invention intends to reliably the control of duplicating information signals. In the duplication control method according to the invention, a main information signal containing a duplication control information transformed into a spread spectrum signal to be superimposed and a duplication control information superimposed by a processing different from the spectrum spreading is transmitted. The duplication control information transformed into a spread spectrum signal is extracted from the main information signal by reverse spectrum spreading, and the duplication control information superimposed by the different processing is extracted from the main information signal. Information closest to duplication prohibition is selected as an output duplication control information out of the plural extracted duplication control information. On the basis of the selected output duplication control information, the main information signal is controlled on duplication.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.