Methods for marking digital compact discs as a means to determine its authenticity
US6099930A · kind A · utility
42Cited by
6References
29Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 20, 1998 |
| Grant date | Aug 8, 2000 |
| Priority date | — |
| Expiry date | Jul 20, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/21
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A digital recording medium, such as a compact disc, having a substrate, a reflective layer and a protective layer includes a near infrared fluorophore in one of the layers. The near infrared fluorophore can be incorporated into the CD by coating, admixing, blending or copolymerization and in an amount to impart a detectable fluorescence from the fluorophore when exposed to electromagnetic radiation having a wavelength ranging from about 670 nanometers (nm) to about 1100 nm. A method of marking a CD with an invisible marking and an apparatus for detecting the fluorophore is further provided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.