AlbertPacino
Explorer
The disc, unveiled at a TDK exhibition in Tokyo, can record data at 72Mbit/s, double the 36Mbit/s rate for current Blu-ray Discs. TDK increased the write speed by using a more powerful laser and making some changes to the material of the disc's recording layer, said Nobuyuki Koike a spokesman for TDK.
The first generation of Blu-ray discs can already record data faster than it is transmitted in high-definition TV broadcasts, so the faster recording speed isn't needed there. But it will be advantageous when content is copied from a hard-disc drive to an optical disc for back-up or archiving, said Koike.
The Blu-ray Disc Association, which is responsible for the disc formats, standardised a 2X version of the read-only BD-R disc and rewritable BD-RE disc in the latter half of 2004, said Taro Takamine, a spokesman for Sony, one of the major backers of the format.
To achieve the higher capacity, TDK added two additional recording layers to the disc to take it up to four layers. Blu-ray Disc stores 25GB on each recording layer and the standard currently includes single layer and dual layer versions.
No standard exists for four-layer discs and Koike said TDK is proposing its prototype to the Blu-ray Disc Association. Sony's Takamine said the current format road map calls for four-layer discs to debut in the market during 2007.
TDK's development comes hot on the heels of an announcement by Toshiba that it has developed a three-layer HD-DVD disc capable of holding up to 45GB of information. HD-DVD is a competing format to Blu-ray Disc and HD-DVD's maximum capacity of 30GB had been viewed unfavorably against Blu-ray Disc's maximum 50GB capacity.
According to the Blu-ray Disc Association, a single-layer 25GB disc can typically hold 135 minutes of high-definition video in MPEG-2 format, with room for a further two hours of standard-definition video.
The recent Toshiba announcement brought the formats much closer together and made capacity less of an issue for the Blu-ray Disc camp to trumpet when promoting their technology. The development of a 100GB disc by TDK will likely open up this avenue for the Blu-ray Disc supporters again.
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