IT’S the next big thing—allegedly. A super-dense fluorescent disc
designed to “replace DVDs, CDs and VHS videotape” will be played in public for
the first time next week at the swish Claridges hotel in London—if it
works that is. Last month, at a private demo, a prototype played only audio and
the sound stuttered and was distorted.
However, Constellation 3D of Concord, Massachusetts, is confident that its
new Fluorescent Multilayer Video Disc (FMVD) system will knock spots off
DVD.
The new discs look just like transparent CDs. They are made by first pressing
10 plastic films, each 15 micrometres thick. The films are then laminated onto a
tough substrate to provide a multilayered “data sandwich” with a capacity of
over 40 gigabytes. The company reckons future 100-layer versions of FMVD will be
able to hold 1000 gigabytes—a terabyte. DVDs hold just 4.7 gigabytes.
Advertisement
Although the new discs won’t work on existing CD and DVD players, FMVD
players could be made to play today’s discs. Constellation says FMVDs will be
ideal for memory-hungry high-definition TV recordings and will easily fit a
standard movie onto a single disc (several DVDs are needed for HDTV).
Constellation is also planning a 20-layer credit card.
The company is not the first to try multiple layers to boost storage. Ten
years ago, IBM tried to make CDs with many thin layers—each layer had pits
like a CD. But it gave up because the adjacent layers soaked up too much of the
laser light as it passed through.
Constellation’s answer is to fill the pits with fluorescent dye, which emits
light when struck by a laser beam tightly focussed into a powerful spot. Pits in
the adjacent layers above and below do not fluoresce because they are struck by
unfocused and therefore much weaker light. The light emitted by the fluorescent
dye is of a slightly different wavelength to the laser, so a sensor can pick it
up. To read the different layers, one after the other, the laser in the player
simply switches its focus.
The company is developing recordable blank discs, with dyed pits that change
colour during recording. Despite the complex lamination, Constellation says
FMVDs won’t cost any more than DVDs.
Next week’s press demonstration should be interesting. Last month’s prototype
played only audio and had difficulty switching between its six layers: the sound
distorted until the focus control was adjusted manually. But Constellation
promises that next week’s demonstration will show colour video with sound from a
fluorescent disc. Company executive John Ellis admits that spectators will only
be seeing analogue video—Constellation won’t have a digital prototype
until August.
Computer firm Dell is guardedly encouraging of the idea. Tom Pratt, Dell’s
storage technology expert, has studied all the practical methods of increasing
storage densities. “FMVD technology could provide an eight-fold increase in
current optical disc storage capacity,” he wrote in a recent technical paper.
