Question of the Week
Everybody is rushing to buy blue-ray players these days. What is this blu-ray technology and is it better than DVD?
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Blu-ray technology! Yes, it is blu-ray not the blue-ray. The letter ‘e’ was intentionally avoided to make it suitable for trademarking. And yes, the blu-ray is more advanced and better than a DVD.
Every one was so excited when DVDs came into existence in 1997 which made it possible playing digital audio/video even in our houses. Now, people are talking about the new technology which is even superior to DVDs that came into existence in 2006.
After VCR's and DVDs, advances in technology brought us Blu-ray technology. The name blu-ray is derived from the fact that a blue (actually blue-violet) laser is used for reading and writing Blu-ray disc.
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Blu-ray technology is not an achievement of any single company. A group of prominent companies like Apple, Dell, Sony, Sun Microsystems etc formed Blu-ray Disc Association which developed this technology.
Blu-ray discs are superior to DVDs in the following factors:
(a) More storage capacity
A single-sided standard 12 cm DVD can store 4.7 GB of data whereas the same size single layer blu-ray disc can store 25 GB of data which is almost five times greater than a DVD. A double layer blu-ray disc can store 50 GB of data.
Similar to DVDs we can get mini size blu-ray discs also with the size of 8 cm. This mini disc with single layer capacity can store 7.8 GB and dual layer capacity can store 15.6 GB.
(b) Higher data transfer rate of 36 Mbps and
(c) Audio and video are played with more clarity compared to DVD.
The following are the factors which are responsible to embed more data into a blu-ray disc:
(a) Contrary to DVDs which depend on red lasers operating at 650 nm for reading and writing data, blu-ray discs depend on blue laser that operates at 405 nm. As the blue-ray technology is using the short wavelength laser compared to DVD, it can embed more data into the disc which has the same size of a DVD.
(b) The thickness of cover layer was decreased.
(c) Numerical aperture was increased to 0.85.
Different formats of Blu-ray disc
(a) BD-R: Recordable format for HD video recording and PC data storage.
(b) BD-ROM: Read only format for pre-recorded contents like high definition movies, games.
(c) BD-RW: Rewritable format for PC data storage.
(d) BD-RE: Rewritable format for HD video recording and PC data storage.
The exclusive features of blu-ray players are
You can create the playlists
You can make changes to the recorded video and shuffle their order.
You can record high-definition television (HDTV) with improved sound and picture qualities.
You can record a program while playing another one.
The player automatically searches for the empty space to record new programs on the disc to prevent overlapping of programs.
You can randomly go to any point on the disc.
Backward compatibility
We know that DVDs became very popular when they were introduced and most percent of the people have large collections of movies, music, games and software in the form of DVDs. So, definitely a question arises whether a blu-ray player can support already existing DVDs. Some major companies like Sony, Samsung, Philips, LG are trying to make their blu-ray players which can support CDs, DVDs and blu-ray discs. So, it depends on the companies to decide whether their products should be backward compatible or not.
Issues with blu-ray
Initially there were issues like blu-ray
discs are more vulnerable to scratches than DVDs as the data layer in the blu-ray disc is closer to the disc surface. Later, the companies started hard coating on outside of disc to protect from scratches.
Now many of the world’s prominent studios, consumer electronics manufacturing and marketing companies have announced that they are going to release and market only blu-ray discs.
Although for some more time both DVDs and blu-ray discs exist, slowly all the DVDs will be replaced by blu-ray discs.
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