What is Blu-ray?

The Blu-ray Disc™ (BD) is widely used optical disc standard for High Definition video and audio data, named after the short wavelength blue laser which is used to read and write.

Like DVD, there are a number of Blu-ray Disc™ standards, such as read-only BD-ROM, recordable BD-R and rewritable BD-RE. The single largest feature of BD is its high-density data storage capacity of 25GB per layer on one side. This lets you store many hours of content, such as movies with HD resolution and high-quality music with loss-less audio compression. Blu-ray discs also feature a high-performance interactive function that uses Java™*, called Blu-ray Java™, to deliver a new video experience to users not offered by conventional video media.

The structure of a Blu-ray Disc™
The Blu-ray Disc™ is an optical disc with the same dimensions as the DVD disc: 12cm in diameter and 1.2mm in thickness. By using a combination of the 405-nm-wavelength blue-violet laser, which is a shorter wavelength than the red laser used by DVD, and a high-density objective lens with a numerical aperture of 0.85, BD uses a laser beam spot that is only about 1/5 the size used by DVD. Thanks to these technologies, a single-layer Blu-ray Disc™ can store five times more data than a DVD disc.

One Single-Layer Disc equals five DVDs in Data Capacity
The Blu-ray Disc™ boasts a data storage capacity of 25GB in a single layer and 50GB in a dual layer, because it uses the shorter wavelength blue-violet laser and a high-density objective lens to enable higher-density data reading. When a multi-layer system is adopted in the future, the storage capacity can increase to 100GB and even 200GB. One Blu-ray disc can store a huge amount of data so users can enjoy many hours of high-definition content and high-quality surround sound that could not previously be provided by other media.

The Blu-ray Disc™ optionally supports next-generation surround sound formats like 'Dolby® Digital Plus', Dolby True HD or dts-HD. Connecting a Blu-ray player to an AV centre using an HDMI cable enables linear PCM multi-channel data transfer. This makes it possible to reproduce high-quality 7.1-channel surround sound with each channel offering DVD-Audio quality, delivering a surround sound experience that rivals the quality of the master audio source.

HD Image Quality Video
In addition to the MPEG-2 format used by DVD-Video, the Blu-ray disc uses video codicecs, such as MPEG-4 AVC and VC-1, which deliver high image quality using high compression rates. The data transfer speed is 48Mbps, which is about three times faster than DVD. A future plan also calls for a further increase in the data transfer speed. These technologies allow long-time playback of content with high definition image quality.

The Blu-ray Disc™ optionally supports next-generation surround sound formats like 'Dolby® Digital Plus', Dolby True HD or dts-HD. Connecting a Blu-ray player to an AV centre using an HDMI cable enables linear PCM multi-channel data transfer. This makes it possible to reproduce high-quality 7.1-channel surround sound with each channel offering DVD-Audio quality, delivering a surround sound experience that rivals the quality of the master audio source.

Extensive Hardware and Software Support
The Blu-ray Disc™ specifications have been established mainly by leading electronics, PC and gaming manufacturers around the world, including Panasonic. These companies will support Blu-ray promotion by introducing a variety of hardware. A number of major motion picture companies have expressed their support. A large variety of Blu-ray titles are now available! Please visit the Blu-ray.com site here to see a list of movies available.

Films on Blu-ray discs can also be accompanied by a whole range of fantastic extra features that can be accessed on disc and even online. A new hardware profile, called BonusView enables you to enjoy extras which go beyond what was possible on DVD before. For example, the Picture-in-Picture function provides a small second window which can be watched simultaneously as the movie in which actors and directors can give enhanced commentary about the scene you are watching.

Extensive Hardware and Software Support
The even more advanced profile called BD-Live can also connect to the Internet and handle BD movies that have Internet-enabled content, such as interactive multiplayer games, trailers and extra features you can download from the Internet to local storage.



*Java™ and all Java-based trademarks and logos are trademarks or registered trademarks of Sun Microsystems, Inc. in the United States and other countries.