Double 66.8GB: Sony, Toshiba developed large-capacity Blu-ray technology
Although the large-capacity Blu-ray technology frequently appears, it is very difficult to become a true standard specifications. Sony and Toshiba recently proposed a new technology to the Blu-ray Disc Association (BDA) ,it can increase single-layer Blu-ray disc capacity from 25GB to 33.4GB, double is the 66.8GB.
The single-layer 33.4GB ’s realization of reading and writing benefits from the use of PRML signal processing technology, but it also can be used on existing Blu-ray device: 405nm wavelength blue-violet laser, numerical aperture 0.85 objective lens .
Prior to this, the use of PRML where the media is not appropriate for the 33.4GB evaluation techniques. PRML will lead to inter-symbol crosstalk, it is difficult to control the time-base error (jitter).For this, Sony and Toshiba developed the maximum likelihood sequence estimation (i-MLSE) evaluation index, with a strong error correction, it also can be relatively simple to estimate the reading error rate.
However, the biggest problem of i-MLSE technology is the too complex calculation . According to Sony’s statement, maybe only the latest hardware device cano real-time process, which means the early Blu-ray devices will not be able to support this new high-capacity CD-ROM.
As a core member of BDA, Sony plans to use BDA and other organizations to promote large-scale i-MLSE technology to eventually make it be adopted as a standard technologies, thus promoting the realization of the standard capacity of 66.8GB.