Blu-ray format is the most promising technology of data recording on an optical medium.
He has a number of significant advantages that enabled Blu-ray discs take a leading position in the profile segment of the market, displacing competitors.
Optical media first generations
A significant leap forward in the development of storage mediaWe began the so-called optical media, better known as CDs which are almost completely replaced magnetic disk. Conceptually, it is an improved version of the familiar childhood vinyl records, but instead tracks are recorded on the zeros and ones that are not read out a needle and a thin laser beam. Because the laser beam is much thinner needle, it became possible to record on a disc dvenadtsatisantimetrovy to six megabytes of data. The CDs were the first generation of optical storage media. Later in sale device for self recording data on such disks themselves CD rewritable.
The representative of the second generation - DVD possessedsurface structure denser than CDs. The ability to more efficiently use the area of the disc appeared, because the laser beam generator was designed with shorter wavelength, that is more subtle. As a result, the same disk could store space much more information. Even on a single-layer DVD was placed about 4.5 gigabytes of data, and the invention of multi-layer double-sided disc enables you to record up to 16 GB on a single disc.
The next step in the development of optical storage mediaIt was the HD DVD format, ie High Definition DVD. Unlike previous media types when writing and reading HD DVD did not use the red and violet laser whose wavelength was even less so on the single-layer disc with a diameter of 12 centimeters turned out to record about 15 gigabytes of data.
As HD DVD Blu-Ray format refers to the thirdgeneration optical media. It was designed by companies to compete with HD DVD manufacturers. In the case of Blu-Ray to use all the same blue-violet laser, as in HD DVD devices, however, a significant difference was in the drive. All three generations of optical media were a polycarbonate base, which was applied a special layer that is used to record and store data. This layer is resistant to mechanical damage, which often resulted in damage to discs due to scratches or dirt. In 2004, he invented a radically new type of polymer coating, which protected Blu-Ray discs from mechanical influences, making them much stronger and more durable. Furthermore, it made it possible to reduce the thickness of the protective layer is six times, which in turn allowed to record on a single disc of about 25 gigabytes.
These innovations have led to the fact that almost allfilm company by the year 2008 went on Blu-Ray format and HD DVD manufacturer refused to develop the technology in order to avoid a "war of formats". In addition to everything in the Blu-Ray format used by more advanced security technologies from illegal copying, which, of course, was an additional argument for the main consumers of these media - film companies.