Современные информационные технологии/ 3. Программное
обеспечение
Bulatova
M.B.
Kostanay
State University named after A. Baitursynov, Kazakhstan
Application of blu-ray technology
Evolution of computer technologies occurs faster than
in any other fields of science. Period of time, when computer
capacity doubles, reduces twice. 1 GHz processors were developed in 22 years,
but 2 GHz ones were developed only in one year and a half. Winchester drives of
160-180 gigabytes are ordinary thing for today. Recently RAID-massifs from
hundreds of hard-drives were created with this purpose. Miniaturization,
increasing operation speed and recording density are questions we deal with
every day. Volumes, speed and frequencies are doubled and quadrupled and nobody
wonders at this. But there is a field where there was no development until
recently. This is field of pluggable data carrier.
In 1960 Theodor Maiman, who worked at research
laboratory of Hews company (California), created the first working laser. As
the rule, new devices are developed for specific tasks solution, specific
functions implementation. It is interesting to know that from the very
beginning laser was put into operation into many fields of human life.
Unusual properties allowed laser penetration into
science and industry, medicine and nuclear technologies, space and our everyday
life. Doubtless lasers are used in computer technologies as well. Recording and
reading data from CD or DVD are possible with the help of
lasers.
In near 2002 world companies such as Hitachi, LG,
Matsushita (Panasonic), Thomson, Philips, Samsung, Sharp, SONY and Pioneer have
intended creation of a new format different from DVD. There was also a split at
this stage: one party has suggested finishing red laser (DVD), and another
undertook working out absolutely new blue – violet technology. Subsequently
format of modified red laser will named HD-DVD, and blue- violet-blue-ray.
Blu-ray Association will be created a little
later. Apple, Dell, Hitachi, HP, JVC, LG, Mitsubishi, Panasonic,
Pioneer, Philips, Samsung, Sharp, Sony, TDK and Thomson.Moreover are members of
this association. Seven of the eight biggest film studios agreed to produce
movies using Blu-ray technology. They are Disney, Fox, Warner, Paramount, Sony,
Lionsgate and MGM, Universal Studio. HD DVD joined Studio Channel, Ocean
Films, Wild Side, DreamWorks. Both formats compatible are Warner and FPE (Fox,
Pathe, Gaumot).
One of the formats developed now is Blu-ray Disc (BD).
It was created for carriers of great volumes of data and video of high resolution.
This technology is developed by the group of companies united in to Blu-ray
Disc Association (BDA). The leading developer of this technology is company
Sony. The competitor of technology Blu-ray is technology HD DVD which main
developer Toshiba is.
Blu-ray has occurred from the base technology in which
blue-violet laser is used for data recording and reading. Blu-ray is
combination of English words “Blue” (blue-violet laser) and “Ray” (an optical
beam). «Dark blue» laser has considerably smaller wave length, than red laser
of DVD-system that also allows writing down data of larger density. Therefore
on Blu-ray disks of 12 sm diameter it is possible to store more information,
than on such one-way single-layer disks. The volume of single-layer disk Blu-ray
approximately corresponds to the volume of 35 compact discs. Laser generates
dispersing beam of light - that means that cross-section size
of the beam increases with distance. Simple demonstration of this phenomenon is
wall illumination by small lamp beam — the more distance to the wall is the
more light is. To reduce stain size a beam is focused. Thus it appears that the
less lens focal length is, the smaller stain is to focus light ray. It is also
used in BD technology- the focusing cone has larger corner - optics of larger
aperture (0,85 in comparison with 0,6 in DVD devices) is used. To be exact,
this is system of two high-quality lenses. As distance from the lens to
focusing point is less, protective layer from the working side is also
necessary to be thinner. Nowadays technology Blu-ray is accessible only in
Japan for recording HDTV (TV of high resolution).
First Blu-ray disks were placed into plastic cards.
Data was placed too close to the surface there. It makes these disks too
sensitive to external actions and scratches. This disadvantage raised doubts
that disks with cartridges would not compete with ordinary CD and DVD disks
Moreover, CD and DVD disks are attractive because of their low price as well,
but they could cause additional expenses on cartridges.
In 2004 development of new polymer covering solved
this problem. This covering protected disks from dust and scratches. It
was worked out by TDK and named "Durabis". It allows Blu-ray
emptying from dust with the help of paper napkins which damage disks of CD and
DVD formats. As disks of CD and DVD formats are produced on the basis of old
optic carriers, they have the same demerits. But Blu-ray with
"Durabis" covering can work even after scratching by screwdriver [1].
BD + is technology which allows changing protection
codes dynamically. This is one of the methods of coding data on BD for content
against copying. It means that constant change of protection code will do
impossible breaking of all BD disks after breaking protection of one of them as
it was with DVD. DVD content was protected using technology CSS. But program
DeCSS released in 1999 allows removing protection from any DVD disks.
BD technology also supports digital water marks.
Digital water marks is a record way of copyrighting latent labels to the
carrier. They should prevent content copying without permission. Protection
technology AACS of association LA should also be used.
Finally, protection (High-bandwidth Digital
Content Protection) HDCP will be also used in BD technology. This is licence
technology which allows reproducing content with the maximum resolution only on
licence players. The players which do not have any HDCP key will not be able to
reproduce content with maximum resolution or will not reproduce it at all.
Nowadays technology Blu-ray provides basic speed of
data transmission in 36 Mbit/seconds. Devices prototypes which can transfer
data with 2x speed are developed. In future it is planned to reach 8x speed.
The numerical aperture 0,85, used in this technology, allows
receiving higher speeds of record and reading. It also means that BD record
mode needs smaller capacity of laser beam and smaller speed of disc rotation to
receive the same speed of data transmission as DVD and HD DVD have [2].
Technology Blu-ray has some advantage. They are larger
volume of carriers, more sophisticated optical system of laser head, as well as
innovative polymeric sheeting. This technology is compatible to earlier
technologies and provides sufficient level of content protection.
Summing up, advantages of Blu-ray Discs are not only
in their enormous capacity, but compatibility with various drives.
Disadvantages of Blu-ray are high price for drives and disks and problems of
backward compatibility with previous data carriers. Price problem will be
settled in the nearest future after development of copying protection system.
Compatibility of Blu-ray depends on several factors. They are mass of putting
into operation, advertisement and future popularity. If there is Blu-ray in
every computer, old formats will be removed and there will be no necessity to
support their compatibility. Mass of putting into operation depends on price of
drives and disks and flexibility of license policy of the leading computer
companies.
Literature
1. "What is
Blu-ray Disc and HD DVD?". http://www.videohelp.com/hd.
Retrieved on 2008-02-16
2. "Blu-ray
profiles, everything you wanted to know". 2007-12-17.
http://www.gizmorepublic.com/media/blu-ray-profiles-everything-you-wanted-know-1270. Retrieved
on 2007-12-19