Blue Laser Leapfrog

Despite the ongoing rumors of back-room talks aimed at averting a format war over the next generation of blue-laser optical discs, each camp is continuing to develop its own standard. In our last report on this game, Toshiba had announced a 3-layer HD DVD with 45GB of storage capacity. Now, TDK has upped the ante again by announcing that they've developed a 4-layer Blu-ray Disc (BD) prototype with a total capacity of 100GB; each layer holds 25GB, just as in single- and dual-layer BDs.

Not only that, the new disc is capable of recording data at twice the rate originally specified for BD (72 megabits per second compared with 36Mbps). According to Nobuyuki Koike, a spokesman for TDK, the faster write speed is achieved by using a more powerful laser as well as making some changes in the recording-layer material. The Blu-ray Disc Association (BDA) has already standardized a 2X version of BD-R (write-once) and BD-RE (rewritable) discs.

Sony spokesman Taro Takamine says that the current road map calls for 4-layer BDs to enter the market in 2007. Of course, this road map could change at any time in response to new technological advances or compromises that might or might not be reached with the HD DVD camp. And as far as I can tell at this point, no one is waving a white flag.