2. High Definifon DVD(HDDVD)
It is the next generation DVD developed by
TOSHIBA & NEC.
The disc has a capacity of 15GB in single
layer,&
30GB capacity in dual layer.
The technology used in HDDVD is almost
similar
to the existing CD,DVD technology.
3. • CD
The CD ROM was introduced in 1982,The storage
capacity of a CD is almost 650MB.CD’s are of
different type ROM,R,RW.
The disc is of 1.2mm thickness & 120mm diameter
.it consists of polycarbonate substrates, a
reflective layer ,a data storage layer.
The data is stored as 1’s& 0’s,In conventional CDs,
these 1s and 0s are represented by millions of pits
s and land.
The discs are read using red lasers( 780nm
wavelenth)
Data is encoded in the CD's in acontinuous
spiraltrack, from the inside to the outside, about 1.6
to 2.2microns wide (a micron is 1/1000 of a
4. technology : read
The pits and smooth areas (the smooth areas are
called lands) are read by a laser when the disc is
played.
Pits and lands reflect the light from the laser
differently,
and that difference is encoded as binary data: the
light
hitting a land reflects back directly to a photodiode,
whichgenerates an electrical pulse, while the light
hitting a pit is refracted (deflected from a straight
path, or scattered),and, consequently, reduced
below the level needed to activate the photodiode.
5. write
a layer of organic polymer dye between
the polycarbonate and metal layers
serves as the recording medium.
Thecomposition of the dye is permanently
transformed by exposure to a specific
frequency of light.
While in the rotation by making the laser
ON or OFF the the data is writing.
6. DVD
DVD is a relatively new optical disc technology that
uses denser recording techniques
The original DVD format was launched in Japan in
1996.
A DVD is very similar to a CD, but it has a much
larger data capacity. A standard DVD holds about
seven times more data than a CD does(4.7GB).
The original purpose of DVD was to hold video data
in particular - DVD once was said to stand for Digital
Video Disk. However, as the number of DVD
applications grew, the variety of data stored on
DVD
7. Basic technology
The wave length of the laser beam used to read
the DVD disc is shorter than that used for
standard CDs
ie,650nm wavelenth.
There are more tracks per disc on DVDs,
because they are placed closer together than on
CDs. The track pitch has been reduced to 0.74
microns.
Data pits are considerably smaller, which allows a
greater number per track than on CDs.
10. HD DVD(High Definition DVD)
The HD-DVD format, developed and proposed by
Toshiba & NEC was introduced to the DVD Forum in
November of 2003 and approved as the next-
generation DVD format.
It was developed to store highdefintion videos to get
its full effect for HDTV.
This is the only high definition format which is
approved
by the DVD forum
12. In HDDVD we are using Blue Violet laser
(405nm) thus reducing the track pitch to 0.4
microns, Which increases the data capacity. The
size of the pits is also reduced.
It holds a data rate of maximum 36.55 Mbps.
13.
14. Blue Violet Laser
Shuji Nakamura, a Japanese
researcher working in a small
chemical company, Nichia
Chemical Industries, built the first
blue laser diode.
This uses the GaN(gallium nitride)
, in the earlier time blue lasers
were large and expensive gas
laser instruments and needed high
currents and strong cooling.
16. The disc of diameter 12cm & thickness
1.2mm
The disc contains polycarbonate subtrate
layer in both sides .
There’s one reflective layer made of
alumnium.
& a protective layer of lacquer
The recording layer is of organic dye, is
highly sensitive to blue laser light, has the
uncompromised readout stability essential
for practical use.
20. Dual layer HDDVD
DVD media has two dye layers for data recording.
Each dye layer is separated by a spacer and a
metal reflector.
The first reflector (positioned after the first dye
layer) is semi-transparent; when the laser is
focused a certain way, it will pass through this
reflector and continue through to the second dye
layer and can read the data
in the second dye layer.
The second reflector is completely opaque and will
24. Appetite For HD Content Increasing
HDTV
Gap between “US HDTV households” (US HHs) and current
cable/satellite offerings is great market opportunity
6.1 10.0 15.7 23.3 32.5 41.9 50.4 57.3
0
10
20
30
40
2003 2004 2005 2006 2007 2008 2009 2010
US
HHs
(MMs)
HD Dig Cable
HD Satellite
Source: Forrester Research – HDTV & the Coming Bandwidth Crunch, 2/17/2005
US HHs
25. HDDVD in high definition
media
HDDVD helps to view the high definition
movies in its full effect.
It supports all the high definition formats such
as MPEG-2,VC-1,MPEG-4,AVC.MPEG-2
needs 19.3Mbps. It can give up to data rate
36.55Mbps.
It supports video formats up to 1080i,1080p.
&HDTV video resolution 1920-1080.
26. High definition images offer a considerably richer colour palette with greater subtlety of colour transition
and enhanced contrast. The result is greater precision, incredible detail and breathtaking realism.
27. advantages
Cheaper to produce in the short term when
compare to blueray.
The only high definition format approved by the
DVD forum.
The name itself, HD-DVD, is more consumer-
friendly
HD-DVDs carry the same basic structure as
current DVDs, so converting existing DVD
manufacturing lines into HD-DVD lines is
supposedly simple.
Backed by Microsoft.
28. disadvantages
HD-DVD simply can't boast the same
storage capacity as Blu-ray.
HDDVD did not have the Hard coating .