Contents_______ 1.Holographic Versatile Disc A. Peculiarities B. Working Principle C. Structure of HVD D. Advantages E. HVD- DVD, Blu-ray F. Facts and Future 2.Blu-Ray Disc A. Features B. Applications C. Formats D. Types E. Blu-ray Vs DVD F. Facts and Future
Holographic Versatile DiscHolographic versatile disc (HVD) is aholographic storage format that looks like aDVD but is capable of storing far more data.Prototype HVD devices have been createdwith a capacity of 3.9 terabytes (TB) and atransfer rate of 1 gigabit per second (1 Gbps).At that capacity, an HVD could store as muchinformation as 830 DVDs or 160 Blu-Ray discs.
Peculiarities • Holographic storage uses laser beams to store digital data in three dimensions, rather than in two dimensions as in CD and DVD media. • HVD is, essentially, a holographic layer built on top of a conventional disc. • The HVD process uses a blue-green laser beam, used for reading and writing data, collimated (made parallel) with a red laser beam, which is used for servo and tracking. The above features increase the capacity of the discs.
Working Principle HVD uses a technology called ‘collinear holography’, in which two laser rays, one is blue-green and the other is red, are collimated into a single beam.. The blue-green laser reads data encoded as laser interference fringes from a holographic layer near the top of the disk while the red laser is used as a reference beam and to read servo information from a regular CD-style aluminum layer near the bottom. Servo information is used to monitor the position of the read head over the disc, similar to the head, track and sector information on a conventional hard disk drive.
Structure of HVDThe HVD consist of the followingcomponents:A. Green writing/reading laser(532nm)B. Red positioning/addressing laser(650nm)C. Hologram(Data)D. Polycarbonate layerE. Photo polymeric layer(Data containing layer)F. Distance layersG. Dichoroic layers(reflecting green light)H. Aluminum reflective layer(reflecting red light)I. Transparent base
Advantages High storage capacity of 3.9terabytes(TB) enables users to store large amount of data. Records one program while watching another on the disc. One can edit or reorder programs on the disc. Automatically searches for an empty space on the disc to avoid recording over a program. Backward compatible: Supports CD’s and DVDs also. The transfer rate of HVD is up to 1GB per second, which is 40 times faster than DVD.Disadvantage:HVDs are very expensive compared to othermediums.
HVD compared with HD-DVD and Blue-ray While HVD is attempting to revolutionize data storage, other discs are trying to improve upon current systems. Two such discs are Blue-ray and HD-DVD, deemed the next generation of digital storage. Parameters Blue-Ray HD-DVD HVD Initial cost of Aprox. Rs1000/- Aprox. Rs500/- Aprox. Rs6500/- recordable disc. Initial Storage 54GB 30GB 300GB CapacityRead/Write Speed 36.5Mbps 36.5Mbps 1Gbps
Facts AND FutureProspects•It has been estimated that the books in theU.S Library of Congress, the largest in theworld, could be stored on six HVDs.•The pictures of every landmass on Earth-like the ones shown in Google Earth- can bestored in two HVDs.•With MPEG4 ASP encoding, a HVD can holdanywhere between 4600-11900 hours ofvideo, which is enough for nonstop playingfor a year.•HVDs have tremendous implications inIndustrial, commercial and Dcinema realms.•HVDs will be found widely used for backingup and archiving data in different forms.
Blu-Ray DiscBlu-ray (BD) is a next-generation optical discformat. The format was developed to enable recording,rewriting and playback of high-definition video(HD), as well as storing large amounts of data. Storage capacity of BD is up to 25/50 GB. The blu-ray name is a combination of “blue”, forthe color of the laser that is used and “ray” foroptical ray. The “e” in “blue” was purposefully left off,according to the manufacturers, an everydayword cannot be a trademark.
Features of BD• Broadest Industry Support: Blu-ray Disc is supported by leading hardware manufacturers across the CE and IT fields from the U.S., Europe, Japan and Korea, including Dell, HP, Hitachi, LG Electronics, Matsushita (Panasonic), Mitsubishi, Pioneer, Philips, Sa msung, Sharp, Sony and Thomson/RCA. Finally, major blank media manufacturers including TDK are supporting the Blu-ray Disc format as the successor of DVD. •Life Span: The Blu-ray Disc format is designed to stay relevant for at least 10 to 15 years. Its high storage capacity of 25 to 50 GB allows for the best-possible High Definition video quality and satisfies even the most demanding data storage needs.
Features of BD.. Content Protection: Blu-ray Disc provides some of the strongest copy protection methods ever developed for any consumer format. It makes Blu-ray Disc the best choice for any content publisher wanting assurance that their valuable assets are protected from piracy. Cost: Blu-Ray format is designed to last for a period of at least 10 to 15 years. Due to its enormous capacity, short term replacement of technology is unnecessary. Hence although it requires a nominal investment in advance, it provides greater and longer term profit potential. Capacity: The Blu-ray Disc format offers the highest capacity of any consumer media format to date, also greatly surpassing the capacity of other format proposals. Robustness of Disc: As the result of recent breakthroughs in the development of hard coating for Blu-ray Disc, the discs offer much stronger resistance to scratches and fingerprints than other existing and proposed formats.
Blu-Ray Disc Applications• High Definition Television Recording• High Definition Video Distribution• High Definition Camcorder Archiving• Mass Data Storage• Digital Asset Management and Professional Storage
Formats of Blu-ray Discs• 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 Blu-Ray Discs• SINGLE • DOUBLE LAYERED LAYERED A. It can hold up A. IT can hold to 25/27 GB. up to 50GB. B. 2hrs of HD B. 4.5 Hrs of HD video Video C. 13hrs of C. 20 Hrs of Standard Standard video. video.
Blu-Ray Vs. DVDJust as DVD meant a five to ten time increase instorage capacity compared to CD, Blu-ray Disc willincrease DVD capacity by five to ten times. This isdue, among other reasons, to the usage of a blueinstead of a red laser and improved lensspecifications, allowing for a much smaller focuslaser beam which enables the recording of muchsmaller and higher density pits on the disc.
Due to the fact that the data layer on a Blu-rayDisc is placed much "closer" to the laser lensthan in DVD (or even the HD-DVDproposal), there is less distortion resulting insignificantly improved tolerances. Hence, moreprecision and ultra high storage densities aremade possible.
Facts and Futureprospects 1. Blu-ray is being adopted faster than the DVD format was at a similar period in its development. 2. Blu-ray faces competition from video on demand and from new technologies that allow access to movies on any format or device 3. Quad-layer (128 GB) discs have been demonstrated *********