HOLODISCS FIGHT PIRACY
Printing holograms on the data side of CDs and DVDs promises to make them not only snazzier but also more difficult to copy. Martin Richardson, a physicist at De Montfort University in Leicester, UK, who invented the technique, says the holograms do not affect playback.
Richardson created the discs by modifying the normal process for making DVDs. He embossed a holographic pattern on a disc of reflective metal film, which he then attached to the plastic layer on which the data is normally burnt. To a laser reading the disc, the signal reflected from the data is…
