NEC announced the development of a HD DVD disk system that manages to keep compatible with current DVD disks by using just a single optical head. The HD DVD format has been approved last month, and both NEC and Toshiba are promoters of this new format.
"It should be the first single optical head that mounts a red and a blue laser. We have been giving a big priority to compatibility and are proud to show compatible drives in this early stage," said Hisatsune Watanabe, NEC's associate senior vice president.
The format features the same 0.6 numerical aperture for the object lens and disk structure as the current DVD disk system. The companies stressed the importance of backward compatibility.
Taking advantage of compatibility, NEC said it developed a HD DVD drive that employs a single optical head. The head has a blue laser and red laser diodes as light sources. However, the lasers share the same object lens. Newly developed ICs handle the physical difference between DVD and HD DVD.
NEC said the single optical head structure enables production of smaller and thinner HD DVDs at lower cost. Using the single head, NEC developed prototypes of full- and half-height drives that achieved 15 Gbytes for a single-layer ROM disk, 30 Gbytes for a double-layer ROM disk and 20 Gbytes for rewritable disks.
These HD DVD drives are planned to go mainstream in 2005, and NEC plans to demonstrate a few prototypes at the International Consumer Electronics Show next month in Las Vegas.