DVD dual-layer technology arrives
- 24 March, 2004 10:39
The advent of higher capacity DVD media is approaching, following Sony’s decision to commence shipping PC drives based on new DVD dual-layer technology globally in June.
Called DVD-Rec DL (double-layer) or DVD-9, the new dual-layer technology boosts the storage capacity of DVD media from the current 4.7GB limit (on DVD-5 discs) up to 8.5GB per disc. This translates to two hours of double bit-rate hi-definition video, or four hours of video data using standard mode recording.
Dual-layer media consist of two thin films of organic dye separated by a transparent middle layer. The upper layer is semi-transparent, so the laser can be focused through to the lower layer.
Pre-recorded commercial DVD-ROM discs, such as those used to distribute movies, already utilise dual-layer technology. However, up until now, consumers have been unable to purchase recordable discs based on this format.
Dual-layer was agreed upon by the industry as a whole via the DVD Forum, but vendors can choose how they wish to implement the technology individually.
Although Sony plans to produce dual-layer technology for both +R and –R formats, the first range of PC drives and media to support DVD-Rec DL will be +R format only. Dual-layer media will also be write-once.
“+R dual-layer proved easier to produce and that is what we are launching now,” Sony Australia product manager for optical storage Gordon Kerr said.
DL media will retail for around $10 per disc, which is approximately double the current retail price of single-layer discs.
Sony will incorporate the new technology into its broader range of IT and consumer products over the next 12 months.
Kerr said the vendor is also investigating rewritable DVD dual-layer media, although work is still in the analysis stage.
“It will be a while before feasibility is determined.”
He added Sony has no plans to discontinue single-layer media.
“Single-layer discs are cheaper to produce and for some applications (data, music, photo storage, etc.) it will make sense to continue to use them,” he said.
“Even in the video arena it is likely that customers will continue to purchase single-layer media just the way they continue to purchase video tapes in various lengths.”
Competing optical drive vendors are also working on the release of their own products based on the dual-layer technology.
Pioneer spokesperson Michael Broadhurst said he understood Pioneer’s proposal for dual-layer recording had been submitted to the DVD Forum for consideration.
“Right now we are not sure of a release date,” he said. Pioneer will also hand out a technical paper on its dual-layer DVD technology at Cebit this week, he said.
Panasonic’s Chris Lau said the company is also working on a DVD-9 dual-layer product, which will be both –R or +R compatible. Panasonic will release a PC drive, as well as a slim line external USB 2.0 drive based on dual-layer, later this year, he said.
Lau added optical drive vendors were also focusing their attention on the Blu-ray Disc format, and predicted PC and notebook drives based on Blu-ray technology could make their way onto retail shelves in the later half of 2004. Panasonic consumer-oriented Blu-ray decks are already being sold in Japan, Lau said.
Designed for high definition video, Blu-ray technology is based on a blue laser instead of the current red laser used in DVD drives. Blu-ray employs single-layer 12cm discs to store over 23GB of data. The format is supported by over a dozen manufacturers through the Blu-ray disc founders group, including Toshiba, Dell, TDK, Sony, LG, Philips and HP.