Forum sets course for blue-laser DVD standard

TOKYO ? The DVD Forum will use the 0.6-mm bonded disk proposed by NEC Corp. and Toshiba Corp. as the basis of its next-generation DVD standard utilizing a blue laser. The Forum will not consider the rival blue-laser technology backed by the Blu-ray Consortium, which was not formally submitted to the DVD Forum for consideration.

The standards-setting body had formed two groups earlier this year to study the two optical disk systems. The approach advocated by NEC and Toshiba uses the same 0.6-mm disk substrate employed in current DVDs, while the Blu-ray approach uses a disk with a 0.1-mm cover layer.

NEC and Toshiba jointly proposed the Advanced Optical Disk System to the DVD Forum in August, but the Blu-Ray Disk proponents have not taken a similar step. "As there is no practical proposal of 0.1-mm cover layer disk systems, the working group is virtually dormant," a DVD Forum spokesman said.

The Forum's steering committee decided at a meeting in Paris on Oct. 29 to set specifications for blue-laser DVD systems using 0.6-mm disks.

Aside from the blue laser, the disk system proposed by NEC and Toshiba maintains features of current DVD disk systems. The numerical aperture of the system's lens is 0.65 and the disk consists of two 0.6-mm platters bonded back-to-back. Storage capacity is 20 Gbytes per side for a single-layer recordable disk and 15 Gbytes per side for a read-only disk. That's less than the Blu-Ray disk system, which can story 27 Gbytes per side of a single-layer disk. The Blu-Ray system uses a lens with a numerical aperture of 0.85.

NEC and Toshiba say their specifications are friendly to the current DVD infrastructure and are thus more beneficial to both manufacturers and users than the Blu-ray system.