TDK has joined efforts to develop a 25GB rewritable optical disc format. It is the first recording media manufacturer to join the Blu-ray Disc Founders group. The announcement came Thursday at the Cebit trade show in Hanover, Germany.

TDK has joined efforts to develop a 25GB rewritable optical disc format. It is the first recording media manufacturer to join the Blu-ray Disc Founders group. The announcement came Thursday at the Cebit trade show in Hanover, Germany.

At 120mm in diameter, Blu-ray discs will be the same size as a CD or DVD, and like CDs, will not require a case or caddy when used in the drive. This could make them vulnerable to scratching or marking, but TDK has solved that problem, according to a company spokesman. TDK Blu-ray disks will be less vulnerable to surface damage thanks to a hard coating which resists scratches, according to a TDK spokesman. The coating also repels deposits of grease and moisture such as fingerprints, causing them to bead into droplets smaller in diameter than the laser beam used to read the disc, ensuring that they do not interfere with the data.

The specification for a rewritable 25GB Blu-ray disc is complete, and specifications for read-only and recordable versions will follow soon, the group said. The other members of the founders' group are: Dell, HP, LG Electronics, Panasonic, Mitsubishi, Pioneer, Philips, Samsung, Sharp, Sony and Thomson.