The thin, flexible substrate enables the disc to rotate at 15,000 rpm, which is fast enough for recording and reproduction at 250 Mbps (a rate equivalent to an HDTV VCR for broadcasting).
Current optical disc systems are speed-capped at about 10,000 rpm. Faster rotating speeds may physically disintegrate the disc.
In cooperation with the with Nagaoka University of Technology, Engineers at the Science and Technical Research Laboratories (STRL) of Japan's public broadcaster have managed to accurately control the optical beam tracking servo operation at the 15,000 rpm. The new control method is based on a feed-forward scheme that determines the position of optical beam by using positioning data from the previous track.
The disc can be used to store and reproduce broadcast quality HDTV signals at 250 Mbps. For comparison, a 1x Blu-ray Disc records at 36Mbps.
The thin profile of the disc would also make it feasible to install multiple disks in a cartridge to make a large-capacity storage medium.
NHK plans to further increase the data transfer rate and capacity of the optical disk for HDTV video archiving and to replace magnetic tape as the video recording medium at broadcasting stations.
The results of the ultra-thin optical disc research will be showcased at the Open House 2008 show in Tokyo, Japan, May 22~25.