Blu-ray discs can store significantly more data than traditional DVDs due to their use of a blue laser instead of red, allowing for smaller data pits. A single-layer Blu-ray disc can hold up to 25GB of data, enough for over 2 hours of high-definition video. Blu-ray discs are also more durable than DVDs due to their stronger protective coating that makes them more resistant to scratches, fingerprints, and dust. The Blu-ray format was developed to enable recording, playback and rewriting of high-definition video as well as storing large amounts of computer data.

1. Blu-ray
Discs
-Debraj Das
130370111011

2. Introduction
O Blu-ray, also known as Blu-ray Disc (BD) is the
name of a next-generation optical disc format.
The format was developed to enable recording,
rewriting and playback of high-definition video
(HD), as well as storing large amounts of data.
O The format was developed to enable recording,
rewriting and playback of high-definition video
(HD), as well as storing large amounts of data.
O The format offers more than five times the storage
capacity of traditional DVDs & can hold upto
25GB on a single-layer disc and 50GB on a dual-
layer disc.

3. Introduction
O A single-layer Blu-ray disc, which is roughly the
same size as a DVD, can hold up to 25GB of data --
that's more than two hours of high-definition video or
about 13 hours of standard video.
O A double-layer Blu-ray disc can store up to 50 GB,
enough to hold about 4.5 hours of high-definition
video or more than 20 hours of standard video.
O Blu-ray is the next-generation digital video disc. It
can record, store & play back high-definition video &
digital audio, as well as computer data. The
advantage to Blu-ray is the sheer amount of
information it can hold.

4.  Blu-ray disc (BD) is appropriately named after the
blue laser used to write the data
 The first blue laser was developed in 1996 by Shuji
Nakamura (Nichia Corporation).
 In 2002, an alliance was formed, called the Blu-ray Disc
Association, including the likes of Sony, Samsung, Sharp,
Hewlett-Packard, Royal Phillips, Hitachi, LG, Matsushitha
Electrical Industrial Co. Ltd, Mitsubishi, Pioneer &
Thomson.
 The name Blu-ray is derived from the blue-violet
laser it uses to read and write to the disc.
 The “e” was intentionally left out of the name due
to trademark restrictions

5. HISTORY OF DISCS

9. COMPARISON OF CD,DVD AND B D
SPECIFICATION
Parameter CD DVD BD .
Disk diameter 120 mm 120 mm 120 mm
Disk thickness 1.2 mm 1.2 mm 1.2 mm
Laser wavelength 780 nm 650 nm 405 nm
Numerical aperture 0.45 0.60 0.85
Minimum pit length 0.83 um 0.4 um 0.138 um
Data rate 1.2 Mb/sec 11 Mb/sec 36 Mb/sec
Number of sides one One or two one or two
Number of data layers One One or two One or two
Data capacity ~680 MB 4.7 GB (1L) 27 GB
8.5 GB (2L)
1 7 GB (2L/2S)

12. It comes in four different formats:
 BD-ROM(read only) : for reading recordedcontent.
 BD-R (recordable) :for PC data storage.
 BD-RW (rewritable) :for PC data storage.
 BD-RE (rewritable) : for HDTV (high definition television) recording.

13. CHARACTERISTICS OF
BLU-RAY
Life Span
Content Protection
Cost
Capacity
Robustness of disc
Compatible

14. LIFE SPAN
In the caseof ordinarydiscs,the disclifeisless.
In the rewritableversions,asre-writingisdone repeatedlyto one area of
the discmostprobably, theinnerperimeterlimitingthe disclife.
BDFS(Blu-rayDiscFileStructure is designedsoas to avoidthisproblem,
by usinga systemthat usesfreediscspaceswithequal frequency.

15. CONTENT PROTECTION
Strongestcontent and copy protection schemeseverdeveloped
IncorporationofRobustcopymechanism
COST
Long termProfitabilitymodelfor content Providers
CheapestProduction cost

16. CAPACITY
The Blu-raydisc enablesthe recording, rewritingand playbackof HD videoup
to 27 GB of dataon asinglesidedsinglelayer.Itisenough to put 2.5 hours of
HDTV recordingon it.It alsocan record over 13 hours of standardTV
broadcasting.Adouble-layerBlu-raydisccan storeup to 50 GB, enough to
hold about 4.5 hoursof high-definitionvideoor more than 20 hours of
standardvideo.

17. ROBUSTNESS OF DISC
Stronger resistance to scratches and fingerprints The protective layer is hard
enough to prevent accidental abrasions and allows fingerprints to beremoved
by wiping the disc with a tissue.
COMPATIBLE
TheBD drives aredesigned to be backwardcompatible, i.e. CDs and DVDs
work equally well with the BD drives.

21. Working
•Discs store digitally encoded video and audio information in pits -- spiral
grooves that run from the center of the disc to its edges.
• A laser reads the other side of these pits -- the bumps -- to play the movie or
program that is stored on the DVD.
•The more data that is contained on a disc, the smaller and more closely
packed the pits must be.
• The smaller the pits , the more precise the reading laser must be.
•Unlike current DVDs, Blu-ray uses a blue laser . A blue laser has a shorter
wavelength (405 nanometers) than a red laser (650 nanometers).
•The smaller beam focuses more precisely, enabling it to read information
recorded in pits that are only 0.15 microns (µm) this is more than twice as
small as the pits on a DVD.
•Blu-ray has reduced the track pitch from 0.74 microns to 0.32 microns. The
smaller pits, smaller beam and shorter track pitch together enable a single-
layer Blu-ray disc to hold more than 25 GB of information

22. THE TECHNOLOGY
22
 Pits : spiral grooves that run
from the centre of the disc to its
edges
 Bumps : other sides of these
edges.
 Track pitch : it is the
distance between the two tracks
(of pits) on the surface.

23. BLU-RAY’S DENSITY
ADVANTAGE
 Higher density
enables better data
seek times
 Shorter to travel
for same amount
of data results in
faster data seek
 Better for random
access of data

24. Laser and Optics
 Blu-ray systems use a blue-violet laser operating at a
wavelength of 405 nm, similar to the one used for HD
DVD, to read and write data. Conventional DVDs and
CDs use red and infrared lasers at 650 nm and 780
nm respectively.
 Blu-ray has two types BD-R and BD-RE with price
$19.99 and $24.99 for 25GB and $47.99 and $59.99
for 50GB respectively.

26. In January 2004 was
introduced a clear
polymer coating that
gives Blu-ray Discs
unprecedented scratch
resistance. The coating
was developed by TDK
Corporation and is called
"Durabis". It allows BDs
to be cleaned safely with
only a tissue.

28.  Various hard coating technologies make Blu -Ray discs more
durable and family-friendly.
 Hard coating technology provides resistance to:
– Fingerprints
– Marks
– Scratches
– Dust
 BD’s are much more Stronger than today’s polycarbonate based
CD’s, DVD’s and HD DVD’s.
 Better for random access of data.
 Faster data seek.

30.  The Blu-ray Disc format offers consumers the ability
to record their High Definition television broadcasts
in their original quality for the first time, preserving
the pure picture and audio level as offered by the
broadcaster.
 Next level in home entertainment, offering an
unsurpassed user experience Since Blu-ray Disc
format incorporates the strongest copy protection
algorithms of any format or proposal to date, the
format allows for recording of digital broadcasts
while meeting the content protection demands of the
broadcast industry.

31.  Blu-ray Disc format can store High Definition video
in the highest possible quality, without need to
compromise on picture quality.
 Depending on the encoding method, there is room for
more than seven hours of the highest HD quality
video. There is even room for additional content such
as special features and other bonus material to
accompany the High Definition movie.
 The Blu-ray Disc movie format greatly expands on
traditional DVD capabilities, by incorporating many
new interactive features allowing content providers to
offer an even more incredible experience to consumers.

32.  With its unprecedented storage capacity, allows for
the HD video recorded with an HD camcorder to be
converted and recorded
 Storage capabilities, without the risk of tape wear

33.  The growing number of broadband connections
allowing consumers to download vast amounts of
data

34. Principal BD Specifications
Capacity 23.3 25 27GB
(single layer)
Wave length of the laser 405nm
Numerical Aperture of the
objective lens
0.85
Data transfer rate 36Mbps
Thickness of the disc 1.2mm
Diameter of the center hole 15mm
Recording method Phase change
Data track Groove recording
Visual data MPEG-2 video

37. Blu-ray discs are better armed than current DVD’s.
They come equipped with a secure encryption system which
consists of a unique ID that prevents video piracy and
copyright infringement.