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Today you will surprise nobody with the disks DVD, most of users prefer to store information on USB carriers. But nevertheless many prefer to write down movies on Blue-ray, and to that there are strong reasons.
On exterior of Blue-ray it is similar to normal compact disk; the same thickness is 1.2 mm and the same diameter is 12 cm. The main difference from normal CDs and DVD – memory size; on the first single-layer products it is possible to place up to 25 GB of information, on two-layer – to 50. And, if it is about video, then it will be content of high resolution of HD (High Definity). Today there were already Blue-ray with memory size of 100, 128 GB.
For reading of information in the described system not the red laser, but blue is used. Such replacement has been caused by the fact that the blue wave has shorter length that has allowed to increase memory size in comparison with classical DVDs by 5 times. The technology means use of the laser beam having the wavelength of 405 nanometers. It has allowed to narrow recording track to 0.32 microns therefore record density has increased.
The second feature of technology – reduction of protective layer from 0.6 to 0.1 mm that has given the chance to perform operation of reading (record) in more correct mode. Standard diameter of today's disk Blue-ray – the same 120 mm at memory in 27 GB. For portable devices the developers offer products with a diameter of 30 mm and of 1 GB.
The most inexpensive option – the Blue-ray ROM standard available only to reading. The second option – BD-R (Blue-ray recordable) can be used for record only once. It is the most demanded product for players with possibility of record. The main destination of such disks – preservation, dissemination of information. BD-R can be one - or two-layer: production is based on technology of sputtering as well as at RW disks. Top of technology of "blue beam" – the disks of the BD-RE series (Blue-ray Writable) suffering up to 1000 rewritings. In these disks the working layers changing the phases are applied. Similar material has well proved during creation of DVD-RW, CD-RW: in the conditions of new technology it was necessary only to adjust system to the new length of blue wave. BD-RE data carriers, thanks to possibility of repeated rewriting, are economic acquisition. It is obvious what on the player intended for viewing (listening) files on CD, DVDs carriers, Blue-ray will not manage to be reproduced. Therefore today producers offer the universal systems capable to perceive as normal compact disks, and those that are created on Blue-ray technology.