Hitachi Maxell unveils 940GB cartridge using ultrathin DVDs

Hitachi
Maxell Ltd. has developed an ultrathin DVD, with a thickness of just 92 micrometers or about 1/13th the thickness of of conventional DVD media.  Each disc is double-sided and features a native capacity of 9.4GB.  The purpose of this optical media is for their specially made 100-layer cartridges.  These are known as stacked volumetric optical discs (SVOD).  A 100-disc SVOD cartridge features a capacity of 940GB and has dimensions of 65mm x 133mm x 161mm (2.56" x 5.23" x 6.34").

This
optical disc based cartridge has a significant advantage over both DVD libraries due to its huge space saving as well as random-read access, which magnetic tapes cannot perform.  The data cartridge will also offer support for next-generation blue-violet laser optical discs, which would bring the capacity up to 5 TB (using Blu-ray media).  Hitachi Maxell expects to start commercialising SVOD as early as from the start of 2007, with a 940GB cartridge costing about Â¥40,000 (~US$340).  The SVOD drive will be targeted at corporate users, hospitals as well as other professional users who need to store a vast amount of data.

Hitachi Maxell Ltd. said Wednesday it has developed an ultrathin DVD, just one-13th the thickness of a conventional DVD, that can be stacked to create a compact storage device capable of accommodating nearly one terabyte of data. The new DVD is only 92 micrometers in thickness, compared with 1.2 millimeters for conventional DVDs, and has a data storage  capacity of 4.7 gigabytes, the same as an ordinary DVD. When the disc is mounted on a special 100-layer cartridge, the cartridge boasts a data storage capacity of 940 GB. Some further info can be found on engadget here.

With the low cost in making DVDs, it is quite surprising that it is not until know that this technique of using a large number of optical discs in a cartridge has not developed until now.  So far, companies have been trying all sorts of other techniques including holographic, smaller pit and multiple layer technology.  Even though it is possible to build a low cost raid array with a capacity of over 1 Terabyte, this SVOD technology does have the advantage in that if one disc fails, the whole cartridge does not suddenly becomes corrupt or unreadable.  If write-once media is used, this would also eliminate accidental erasure, much like WORM media. 

Source: Sci-Tech Today