What is Blu-ray Disc? How do they work

New discoveries in the field of optical storage media greatly affect the world film industry. In the early 1990s. CD technology to replace the video tape as the spearhead of penetration into thehome movies.
 

In 1997, when DVD technology was introduced, back in the film industry world revolution occurs. And now, the film industry back getting ready to bring about a revolution continued with the presence of optical storage media of the Blu-ray Disc (BD), which has extra large storage capacity to hold and play audio files and high-definition video.

The name Blu-ray is taken from a combination of the word "blue", color laser that used, and "ray" of the optical ray. The letter "e" on the word "blue" deliberately omitted because generic words can not be used as a trademark.

One-chip single-sided DVD that many in the market today is able to accommodate data of 4.7 GB. Enough to contain two hours of standard-definition movies with the addition of some extra features, such as multiple language subtitles, cup-likan extra films, deleted scenes, etc.

While high-definition movies require bandwidth at least five times greater than standard definition movies, which means also require greater storage media. That is, if you want to watch a movie-quality high-definition movies at home, you need a storage medium with a minimum capacity of 23.5 GB. And Blu-ray Disc is the answer to that need. A piece of Blu-ray Disc can record, store and play high-definition video, digital audio, and other digital data.

The advantage of Blu-ray Disc is a spike in the size of data that can be stored:

• A piece of Blu-ray Disc single-layer, which is roughly as big as the DVD, can store up to 27 GB of data, more than two hours of high-definition movies or about 13 hours of standard-definition video.
• Blu-ray Disc piece of double-layer can store up to 54 GB of data, enough to hold 4.5 hours of high-definition movies or more than 20 hours of standard-definition movies.
• Moreover, Blu-ray Disc not only has a capacity many-fold than the DVD, but also offers a level of interactivity Leaves more. Blu-ray Disc Users can directly connect to the Internet and download the subtitle for the movie is playing and other interactive features

 How Blu-ray Disc Work ?

In optical storage media, digital audio and video data stored in a circular pit-line starting from the middle until you reach the side of the disc. The laser beam read-bejolan lumps contained in the pit of this data and translate it as digital data to be processed by computer.

The more data contained in a disc, the smaller and meeting the existing pit in it. The smaller and pit meeting, and also that there are bumps on it, the more precise (precise) also membacanva laser. In contrast to the current DVD, which uses a red laser to read and write data on the pit. Blu-ray Discs use a blue laser. Blue laser has a wavelength (wavelength) is shorter (450 nanometers) than red laser wavelength (650 nanometers).

The length of the short-wave blue laser has made ​​him a more precise focus. Blue laser to read data stored in the pits with a width of 0.15 micron (uni) (1 micron = 10-6 meters), or two times smaller than the data stored on a DVD pit.

Plus, Blu-ray has reduced the peak track {track pitch) of 0.74 microns to 0.32 microns. All three of the above, pit a leaner, smaller beams, and the top track is shorter, has made ​​Blu-ray Disc can accommodate up to 25 GB of data, or five times the capacity of a piece of the DVD.