Hitachi had a prototype of their new 4 layer 100GB BD-R disc on display at CEATEC
JAPAN 2007. Unlike the 100GB discs being developed by TDK and Panasonic, Hitachi believes that, by modifying the firmware, theirs can be
read back by most existing drives.
Hitachi has developed a prototype four layer Blu-Ray disc capable of holding
100GB of data.
While companies such as TDK and Panasonic have previously mooted 100GB discs, they have always needed a specially
developed optical head in the player to read the disc.
Hitachi, however, claims to have used a standard Blu-Ray drive optical head
that's only slightly modified to allow it to read and write data across the four 25GB layers. It's believed this will only require a
firmware update to make existing drives compatible.
Hitachi is also working on an 8 layer disc that can hold 200GB of
data. However, they've had problems with reflections decreasing the signal strength across the eight layers. If you'd like to read
more, the entire article can be found here.
