• PC World
• »Storage
• »Hard Drives

Toshiba has developed a dual-layer rewritable optical disc for use with the blue-laser-based Advanced Optical Disc format that it is developing with NEC.

The disc, which will be introduced at the Optical Storage 2003 conference in Vancouver next week, is the same physical size as a CD or DVD and is capable of storing up to 36GB of data. It is one of two rewritable disc types that make up the initial AOD format proposal, the other being a single-sided disc capable of storing 20GB. The AOD format also includes 15GB and 30GB read-only disc types.

That compares to between 4.7GB and 9.2GB on a DVD disc.

Competition Blues

The AOD format was proposed by Toshiba and NEC to the DVD Forum earlier this year as a next-generation replacement for the existing DVD format. It will compete in the market with Blu-ray, which is also based on blue-laser technology and is being developed by a consortium of nine consumer electronics companies: Sony, Hitachi, LG Electronics, Matsushita Electric Industrial (Panasonic), Philips Electronics NV, Pioneer Electronics, Samsung Electronics, Sharp and Thomson Multimedia SA.

Both AOD and Blu-ray are able to store more data than DVD because of the use of blue lasers. Blue light has a shorter wavelength than the red light used in CD and DVD systems and so the laser beam makes a smaller spot on the disc surface. That means each bit of data takes up less space on the disc and so more data can be stored on a 12 centimeter disc.

Products on the Way?

The Blu-ray format has already been commercialized. Sony put on sale a Blu-ray video recorder in Japan in April to gauge market reaction. The BDZ-S77 carries a premium price tag of $3,820 to match its cutting-edge technology.

AOD is a little further from commercialization.

Format finalization within the DVD Forum is scheduled to be completed later this year and development of the initial version of AOD is expected to be finished sometime in 2004, Junko Furuta, a spokeswoman for Toshiba in Tokyo said. However a commercial launch will also depend on market readiness and so the company has yet decide on when AOD products might go on sale, she said.

Both NEC and Toshiba recently demonstrated AOD drives suitable for use in personal computers at the CeBIT electronics show in Germany. Toshiba was displaying a mock-up while NEC has a functioning drive and was demonstrating high-definition video playback through a computer.