BLU-RAY DISCBy : HARSH PATEL09IT056

HISTORY1st GENERATION:Compact disc (CD): --- 650/700 MBIt is with us for over 20 years.Wavelength of laser which reads data: 780 nmColor of laser: Red2nd 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

HISTORY3rd 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 bySHUJI NAKAMURA at NICHIA CORPORATION

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.

FORMAT OF BD

It 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.

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.

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.--------------------------------

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

COMPARISON IN BUILDING BD AND DVDBDData is placed on top of a 1.1 mm thick polycarbonate layer

Doesnt suffer from BIREFRINGENCE

Doesnt suffer from DISC TILTHard coating is placed outside to protect from scratches or fingerprintsDVDData is sandwiched b/w two polycarbonate layers, each 0.6 mm thick

Suffer from BIREFRINGENCE

Suffer from DISC TILT

No such hard coating is placed

BLU RAY S DURABILITY ADVANTAGEVarious hard coating technologies make Bly ray disc most durable and family -friendlyHard-coating technology provides resistance to:- Finger prints- Marks- Scratches- DustMuch more ROBUST than todays polycarbonate-based CD/DVDs

FEATURES OF BDWith BD we can:Record HDTV without any quality lossInstantly skip to any spot on discRecord one program while watching other on the discCreate playlistsEdit or reorder programs recorded on discAutomatically search for an empty space on the disc to avoid recording over a programAccess to web to download subtitles and other extra featuresAnd many more

BLY-RAYS DENSITY ADVANTAGEHigher density enables better data seek timesShorter to travel for same amount of data results in faster data seekBetter for random access of data

On GAURDBlu-ray discs are better armed than current DVDs. They come equipped with a secure encryption system a unique ID that protects against video piracy and copyright infringement.

DO MORE WITH BLUMore capacity, Density and PerformanceMore Industry Support/Consumer Reach (BDA has 140+ members)More DurableMore Interactive User ExperienceMore Flexible Content Protection: AAC, BD+ Renewability Technology and ROM Mark

Thank You

Cd-2.11um dvd-1.32um bd-0.58um*Birefringence, or double refraction, is the decomposition of a ray of light (and other electromagnetic radiation) into two rays (the ordinary ray and the extraordinary ray) when it passes through certain types of material, such as calcite crystals or boron nitride, depending on the polarization of the light*AAC- advanced auto coding.*