2. HISTORY 1st GENERATION:Compact disc (CD): --- 650/700 MBIt is with us for over 20 years.Wavelength of laser which reads data: 780 nmColor of laser: Red 2nd GENERATION:Digital versatile disc (DVD): --- 4.7 GBIt offers high quality sound and video than CD.Wavelength of laser which reads data: 650 nmColor of laser: Red
3. HISTORY 3rd GENERATION:Blu-ray disc (BD): --- 25/50 GB-Next generation optical disc format.-Developed by blu-ray disc association (which includes Apple, Hitachi, HP, LG, Panasonic, Pioneer, Philips, Samsung, Sharp, Sony)-Wavelength of laser which reads data: 405 nm-Color of laser: Blue-violet which was developed by SHUJI NAKAMURA at NICHIA CORPORATION
4. FORMAT OF BDIt comes in four 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.
5. TYPES OF BD: SINGLE LAYER :- Can hold data up to 25/27 GB that means 2 hrs of HD video or about 13 hrs of standard video. DOUBLE LAYER :- Can hold data up to 50 GB that means 4.5 hrs of HD video or more than 20 hrs of standard video.
6. THE TECHNOLOGYPits : spiral grooves that run from the centre of the disc to its edgesBumps : other sides of these edges.Track pitch : it is the distance between the two tracks (of pits) on the surface.--------------------------------Disc store digitally encoded data in PITS.--------------------------------
7. THE TECHNOLOGYSo, in blu-ray disc:Pit size – 0.15 microns ( more than twice as small as the pits on DVD )Track-pitch is : 0.32 micronsLaser needed : blue-violet laser (405 nm)Data transfer rate : 36 Mbps
8. COMPARISON IN BUILDING BD AND DVD BD DVD Data is placed on top of a  Data is sandwiched b/w 1.1 mm thick two polycarbonate layers, polycarbonate layer each 0.6 mm thick Doesn’t suffer from  Suffer from BIREFRINGENCE BIREFRINGENCE Doesn’t suffer from DISC  Suffer from DISC TILT TILT Hard coating is placed  No such hard coating is outside to protect from placed scratches or fingerprints
9. BLU RAY ‘S DURABILITY ADVANTAGE Various hard coating technologies make Bly 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’s (and HD DVD’s)
10. FEATURES OF BDWith BD we can: Record HDTV without any quality loss Instantly skip to any spot on disc Record one program while watching other on the disc Create playlists Edit or reorder programs recorded on disc Automatically search for an empty space on the disc to avoid recording over a program Access to web to download subtitles and other extra features And many more…
11. BLY-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
12. THE NAMEThe blu-ray name is a combination of “blue”, for the color of the laser that is used and “ray” for optical ray.The “e” in “blue” was purposefully left off, according to the manufacturers, because an everyday word cannot be a trademark.
13. On GAURD• Blu-ray discs are better armed than current DVD’s. They come equipped with a secure encryption system– a unique ID that protects against video piracy and copyright infringement.
14. DO MORE WITH BLU… More capacity, Density and Performance More Industry Support/Consumer Reach (BDA has 140+ members) More Durable More Interactive User Experience More Flexible Content Protection: AAC, BD+ Renewability Technology and ROM Mark