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Blu-Ray
set to take the world by storm! |
by:
Paul
Colbert |
The
Blu-ray Disc belongs to a new generation
of optical discs capable of staging high
density data. Blu-Ray technology is based
on a blue-violet coloured laser. The blue
laser operates at a wave length of 405 nm,
while older technology such as DVDs and
CDs are based on red and infrared lasers
that works at 650 and 780 nm. Since the
wave length is shorter with a blue laser,
the new Blu-ray technology makes is possible
to store much more information
The advantage with the Blu-ray technology
is that the laser beam can be focused much
more tightly at the surface of the disc.
Tight focus means that a smaller spot will
be produced on the surface on the disc,
and when the spots become smaller there
will naturally be room for more information
on each disc. The minimum spot size of any
laser depends on a naturally accruing phenomenon
called diffraction. The narrow beam of light
sent out from a laser will always diverge
into a wider beam eventually, due to the
natural diffraction of waves. Diffraction
will also occur the waves meet an obstruction.
By reducing the wavelength of a laser, we
can affect the diffraction.
In Blu-ray technology, the diffractions
is also affected by the fact that the lens
used to focus the light has a higher numerical
aperture than the lenses found in ordinary
DVDs - 0.85 instead of 0.6. Blu-ray technology
based appliances are also equipped with
a dual-lens system of supreme quality, and
the cover layer has been made thinner in
order to prevent unwanted optical effects.
All this makes it possible for a Blu-ray
laser to focus on much smaller spots. The
optical improvements are accompanied with
a new method for encoding data which makes
it possible to store even more data on the
Blu-ray disc.
The standard for Blu-ray technology has
been developed as a joint venture between
several major manufacturers of PCs and consumer
electronics, including Sony and Philips.
The group is called the Blu-ray Disc Association
(BDA). The first Blu-ray recorder was launched
in Japan in 2003, by Sony. Today, Samsung,
JVC, Matsushita (Panasonic) and LG Electronics
are all examples of companies using Blu-ray
technology in their products. Hewlett Packard
has announced that they will release desktop
PCs equipped with Blu-ray technology in
late 2005.
The main competitor for the Blu-ray technology
is the HD DVD format which is also capable
of storing more information than a normal
DVD. The Blu-ray technology does however
allow for more information per layer than
the HD DVD format - 25 GB compared to 15
GB. The Blu-ray technology will on the other
hand most likely be more expensive to support,
at least initially, which can make the HD
DVD a tempting alternative. In a Blu-ray
disc, the data is stored extremely close
to the surface. This made the first Blu-ray
discs extremely vulnerable to scratching
and many users preferred the tougher HD
DVD discs. Since 2004, all Blu-ray discs
are coated with a clear polymer called "Durabis"
which makes them much more durable. According
to the developers of Durabis, the TDK Corporation,
a coated Blu-ray disc will work even after
being attacked with a screwdriver.
About the author:
Paul Colbert of http://www.blu-ray-world.comis
an author of various articles relating to
new technology and innovations. All content
may be used freely but may not be altered
in anyway without prior written consent
by webcashflow LLC and a link back to Blu-Ray-World.com
must be given.
Circulated by Bandoni
Media
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