Dual-layer DVD+R discs arrive
p2pnet.net News:- The first dual-layer DVD+R disc able to record four hours of DVD-quality video or 16 hours of VHS-quality video will go on sale in the US in June and in Japan this month.
Developed by Philips in cooperation with Mitsubishi Kagaku Media, the technology boosts current capacity from 4.7 to 8.5 gigs and was introduced at the CEATEC Japan 2003 exhibition last October.
The dual-layer DVD+R system uses two thin embedded organic dye films for data storage separated by a spacer layer.
Heating with a focused laser beam irreversibly modifies the physical and chemical structure of each layer such that the modified areas have different optical properties to those of their unmodified surroundings. This causes a variation in reflectivity as the disc rotates to provide a read-out signal as with commercially pressed read-only discs.
“Initial investigations were started by Philips Research around 2 years ago at a time when there was general scepticism throughout the optical storage industry that compatible dual-layer DVD recordable would ever be possible,” says Philips. “Developments since then, initially by Philips and later in cooperation with media manufacturer MKM, have dispelled this scepticism and the new dual-layer DVD+R technology is now fully endorsed by the DVD+RW Alliance.”
Recorders for both the PC and consumer electronics markets are expected to become available during the course of 2004.
