News and Reviews....

Birth of the Blues ....... February 2002

By Robert Lieto

Just released ...... Nine companies gathered in Tokyo last week (Feb 18-22) to announce the successor to the DVD technology, the Blu-ray Disc. A far denser, blue-violet laser based medium that is NOT compatible with its wildly successful red laser DVD medium. While the red laser medium has an average of 4.7 gigabytes of storage space, the Blu-ray laser with its groove-track recording techniques yield a density of 27 gigabytes of storage space. It would allow more then 2 hours of High Definition recording and 13 hours of standard recording.

Conspicuously absent from the Blu-ray roster is DVD Forum leader and DVD format pioneer Toshiba Corporation, which reportedly had been invited to join but chose not to attend, asserting that the work in regard to the Blu-ray ought to be conducted under the auspices of the DVD forum.

The nine (9) companies in attendance, out of seventeen (17) that make up the steering committee DVD forum, could lock horns in the up and coming annual meeting, scheduled at months end. It is possible that the focus could shift to Blu-ray by majority vote.

Specifications:    

Recording Capacity                    23.3Gbytes/ 25Gbytes/ 27Gbytes

Laser Wavelength                        405 nm (Blue-Violet laser)

Lense Numerical Aperture (NA)    0.85

Data Transfer Rate                        36 Mbits/second

Disc Diameter                                120mm

Disk Thickness                                1.2mm

Recording format                             Phase change recording

Track Format                                    Groove Recording

Tracking Pitch                                    .32 micron

Shortest Pit length                            0.160/ 0.149/ 0.138 microns

Video recording Format                    MPEG-2 Video

Audio Recording Format                AC3, MPEG-1, Layer2, etc.

Video & Audio Multiplexing            MPEG-2 transport stream

In closing, while the format itself is not compatible with DVD systems of today,  the technology is said to be manageable in that it could be made compatible with in some way although no specifics were mentioned.