Toshiba crams 45GB onto triple-layer HD DVD

Toshiba today introduced a triple-layer HD DVD-Rom disc which boasts a data capacity of 45GB, enough to record 12 hours of high-definition movies.

The newly unveiled disc is certain to reignite the battle between Toshiba's HD DVD format and rival Sony's Blu-ray technology.

It adds a high-end option to Toshiba's previous HD DVD-Rom line-up, which includes the 15GB (single-layer, single-sided) and 30GB (dual-layer, single-sided) discs.

The process involves the production of a single-layer disc using the same process as for an HD DVD-Rom. The second layer is formed on the first layer using a one-time polycarbonate stamper, and a single-layer 0.6mm disc is then bonded to the dual-layer disc.

Memory-Tech Corporation, Japan's largest independent disc replicator, has confirmed that the new 45GB and hybrid discs can be produced on its existing manufacturing lines and equipment. These are tailored to produce HD DVD discs with only minor additional investment and minimum additional production cost per disc.

Shiroharu Kawasaki, president and chief executive at Memory-Tech, said: "We have already started verification for volume production of triple-layered discs, and we are confident of early verification as they are based on the 0.6mm disc structure and established production technologies."

In a parallel announcement Toshiba also unveiled a double-sided, dual-layer hybrid Rom disc comprising a dual-layer HD DVD-Rom side and dual-layer DVD-Rom side.

Standard definition content from the hybrid disc can be played on existing DVD players. The discs can store 30GB of high-definition content on the HD DVD-Rom side and 8.5GB of standard-definition content on the DVD-Rom dual-layer side.

Toshiba stressed that all its newly developed HD DVD-Rom discs share the same disc structure as previously announced HD DVD formats and today's DVD format of two 0.6-mm thick discs bonded back-to-back.

Full details of the discs will be presented at the HD DVD workshop at Media-Tech Expo 2005 in Las Vegas on 11 May.