Hitachi plays the blues on DVD

Hitachi will use blue laser technology to triple the data capacity of DVD-ROMs and DVD-RAMs by the year 2001, according to a report in Nikkei Byte, a Japanese publication.

The article also outlined Hitachi's DVD-related plans for the next few years.

The company intends to create DVD-ROMs with a single-sided capacity of 14GB on a single-layer disk and 25GB on a double-layer disk. Current DVD-ROMs hold 4.7GB on a single-layer disk and 8.5GB on double-layer disks. CD-ROMs, by comparison, only hold about 640MB of data.

The higher data density will be accompanied by faster access times of 20 ms to 40 ms, as opposed to the current 100 to 200 ms access times. The latest CD-ROM drives can generally read data in 100 to 150 ms.

Using blue light lasers allows for higher data density in optical discs because the shorter wavelength allows for finer resolution of stored data. Much like a magnifying glass might allow for smaller print in a book, the increase in resolution allows for more data to be packed into the same amount of surface area.

Hitachi also projected an increase in the capacity of DVD-RAMs from the current 2.6GB to 4.7GB by the end of 1999, according to the Nikkei Byte report. Capacity and access speed will also be doubled by improving the quality of the disc material.

DVD-RAMs differ from DVD-ROMs in that they can record data. DVD-ROMs allow only for data playback.

The company intends to eventually extend the capacity of DVD-RAMs to 8.4GB by using a blue laser. This improvement will also reduce access time to 5 to 10 ms from the current 50 to 100 ms.

The blue-laser, large-capacity DVD-ROMs and DVD-RAMs Hitachi is planning to ship in 2001 will read current DVD and CD-ROM discs, according to the company.