The proposed format increases the capacity of read-only discs to 15GB for a single-sided, single-layer disc, and to 30 GB for a single-sided dual-layer disc, and pushes the capacity of read-and-write discs, which currently are single-sided with a single-layer, to 20GB. Today's single-sided dual-layer read-only discs have a capacity of 8.5 GB, while read-and-write discs (single-sided, single-layer only) can store up to 4.7GB of data. The increased capacity of the proposed format is achieved by employing a blue laser, and by utilizing the two companies' new signal-processing and phase-change media recording technologies.
In addition, Toshiba and NEC will shortly propose a 40GB single-sided, dual-layer read-and-write disc to the DVD Forum.
The DVD Forum established two subgroups to study different technical approaches toward the next-generation blue laser DVD format in February this year. One is considering an approach based on a 0.6mm disc substrate, the same method employed in current DVDs, and the other a 0.1mm cover layer. Toshiba and NEC separately promoted research on a 0.6mm disc substrate, the same as that of current DVD discs. After verifying one another's technology they decided to jointly propose a single, unified format to the DVD Forum.
High-definition digital imaging is the wave of the future, an increasingly powerful force in terrestrial and satellite-based broadcasting, the cinema, and in the delivery of games and entertainment and computer applications. The richer data sources and heightened user experience that digital media offer can be seen in the fast penetration of DVD, and in the growing demand for digital media supporting even higher capacities.
Toshiba and NEC support this trend, with a format that provides a cost-effective upgrade path for media vendors, and a backward-compatible solution for the many consumers who have built DVD libraries.
The new formats also meets the needs of the PC-industry-driven optical-drive business, where coming years will see demand for combination drives that can handle both current and next-generation DVD media.
Toshiba and NEC's proposal is based on the following four advantages.
1. It meets manufacturers' needs by enabling use of the same manufacturing infrastructure as current DVD, which minimizes disc production costs.
2. It supports development of backward compatible players that can playback current and next generation DVD.
3. Like the current DVD, it is easy to realize a disc that does not need a cartridge, which allows slim drives that can be integrated into portable equipment.
4. It is easy to realize dual-layer discs, as the back-to-back bonding of 0.6mm-thick discs is the same as for current DVD.
Toshiba and NEC will together submit technical data to the DVD Forum that is necessary for the standardization of the next-generation, high-capacity, blue-laser DVD.
- Outline of proposed format
User data capacity:
File format: UDF
User bit rate: 36Mbps
Disc size: 120mm (diagonal), 1.2mm (thickness: 0.6mm x 2)
Laser diode wavelength: 405nm
Numerical aperture of objective lens: 0.65
Truck structure: Land & groove
Signal processing: PRML
Modulation conversion: 2/3