What’s the Blu-ray Disc

Comparison of laser beam wavelengths,
NA and cover layer thicknesses

These are the ultimate requirements for producing a practical laser, optical pickup, and disc. Optical disc engineers combined their efforts to optimize these specifications, and created the Blu-ray format as a mainstream, high-density recording media for the years ahead.

Blu-ray is a next-generation disc format. The single-side, dual-layer disc structure is also an important factor for enabling the immense data storage capacity of 50 GB. Next, a Panasonic specialist in this field will describe this structure in detail.


Blu-ray Benefits

1. HD Image Quality Video

In addition to the MPEG-2 format used by DVD-Video, the BD-Video disc uses video codes, such as MPEG-4 AVC and VC-1, which deliver high image quality using high compression rates. The data transfer speed is 48 Mbps, which is about five 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.


2. High Quality Surround Sound
T he BD-Video disc optionally supports next-generation surround sound formats like Dolby Digital Plus. Connecting a BD-Video player to an AV center 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.
* HDMI Ver. 1.1 and newer.


3. The High storage Capacity
The BD-Video disc boasts a data storage capacity of 25GB* in a single layer and 50GB* in 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 100 GB* and even 200 GB*. One BD-Video 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.
*1GB=1 Billion bytes. Useable capacity will be less.