19-07-2012, 10:29 AM
Blu ray
bluraydisc-.ppt (Size: 583 KB / Downloads: 30)
HISTORY
1 GENERATION:
Compact Disc (CD) :- capacity 650/700MB
Wave length of laser which reads data : 780nm
Colour of laser : Red
2 GENERATION:
Digital Versatile Disc (DVD) :- capacity 4.7GB
Wavelength of laser which reads data : 650nm
Colour of laser : Red
THE NAME
The Blu ray name is a combination of “Blue” for the colour of the laser is used and the “ray” for optical ray.
TYPES OF BD
SINGLE LAYER:
Can hold data upto 25/27 GB that means 2hrs of HD video or about 13hrs of standard video.
DOUBLE LAYER:
Can hold data upto 50GB that means 4.5hrs of HD video or more than 20hrs of standard video.
FORMATS OF BD
It comes in 4 different formats:
BD ROM (read only):- for reading recorded content.
BD – R (recordable):- for PC data storage.
BD – RW (rewritable):- for PC data storage.
BD – RE (rewritable):- for HDTV (High Definition Television) recording.
ADVANTAGES:
Hard coating technologies make Blu ray Disc most durable and family- friendly.
Hard coating technology provides resistance to:-
Finger prints
Marks
Scratches
Dust
Much more ROBUST than today’s polycarbonate – based CD/DVD (and HD DVD’s)
ON GUARD
It uses Data Encryption Standard (DES) that has a key length of 56bits.
A key block and disc ID are written into the ROM area to prevent illegal copying.
BDA Blu ray Disc Association)
This association develops and licences Blu ray Disc technology. (in 2002)
FEATURES OF BD:
With BD we can :-
Record HDTV without any quality loss.
Instantly skip to any spot on disc.
Record on one program while watching other on the disc.
Create play list.
Automatically search for an empty space on the
disc to avoid recording over a program.