Holographic Versatile Disc(HVD) Presented By:
CSE(IV year) CONTENTS : CONTENTS Need Of HVD
What is HVD ?
Holographic Versatile Disc Structure
HVD Write System
HVD Read System
How HVD compares Others ?
Conclusion HVD Alliance : HVD Alliance Need Of HVD : Need Of HVD Multimedia - a single minute of compressed video takes up to 12 Mbytes
Data Warehouses - large corporations’ warehouses now taking more than 2 Tbytes
World Wide Web - one vendor’s high-end Web server packs 128 Gbytes of disk
In Hospitals Multi slice CAT scan: 500MB Cardiac video: 3GB : What is next ? 0.7 GB 9 GB 30~50 GB Optical Disc Technology The Answer is: : The Answer is: Holographic Versatile disc What is HVD ? : What is HVD ? Holographic Versatile Disc (HVD) is an optical disc technology which would hold up to 3.9 terabytes (TB) of information .
An HVD is an advanced optical disk that’s presently in the development stage. Polaroid scientist J van Heerden was the first to come up with the idea for holographic three-dimensional storage in 1960.
Holographic memory systems have been around for decades. They offer far more storage capacity than CDs and DVDs -- even "next-generation" DVDs like Blu-ray -- and their transfer rates leave conventional discs in the dust. Basics of Holographic Disk : Basics of Holographic Disk The first step in understanding holographic disk is to understand what "holographic" means. Holography is a method of recording patterns of light to produce a three-dimensional object.
The recorded patterns of light are called a hologram. HVD Structure : HVD Structure Green writing/reading laser (532 nm)
Red positioning/addressing laser (650 nm)
Photo polymeric layer (data-containing layer)
Dichotic layer (reflecting green light)
Aluminum reflective layer (reflecting red light) Dimension of HVD : Dimension of HVD Working Principle : Working Principle HVD uses a technology called 'collinear holography,' in which two laser rays, one is blue-green and another 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 disc while the red laser is used as the reference beam and to read servo information from a regular CD-style aluminium 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. Slide 13: Reference: http://electronics.howstuffworks.com/hvd.html HVD Write System : HVD Write System A simplified HVD system consists of the following main components:
Blue or green laser (532-nm wavelength in the test system)
Spatial light modulator (SLM)
Polymer recording medium Cont….. : Cont….. The process of writing information onto an HVD begins with encoding the information into binary data to be stored in the SLM. These data are turned into ones and zeroes represented as opaque or translucent areas on a "page" -- this page is the image that the information beam is going to pass through. Slide 16: Data image Collinear Holography : Collinear Holography Recording Process Media Lens SLM Information Pattern Reference Pattern Collinear Holography : Collinear Holography Reconstructing Process Media Reconstructed SLM BS Lens Reference Pattern Reflective Layer How Collinear Holography works : How Collinear Holography works SLM Objective Lens Cover Layer Recording Layer Reflective Layer Inner :Information
Outer :Reference Slide 21: Page data (left) stored as hologram (right) HVD Read System : HVD Read System To read the data from an HVD, you need to retrieve the light pattern stored in the hologram.
In the HVD read system, the laser projects a light beam onto the hologram -- a light beam -- a light beam that is identical to the reference beam. Cont…. : Cont…. An advantage of a holographic memory system is that an entire page of data can be retrieved quickly and at one time. In order to retrieve and reconstruct the holographic page of data stored in the crystal, the reference beam is shined into the crystal at exactly the same angle at which it entered to store that page of data. Each page of data is stored in a different area of the crystal, based on the angle at which the reference beam strikes it.
The key component of any holographic data storage system is the angle at which the reference beam is fired at the crystal to retrieve a page of data. It must match the original reference beam angle exactly. A difference of just a thousandth of a millimeter will result in failure to retrieve that page of data. Cont… : Cont… During reconstruction, the beam will be diffracted by the crystal to allow the recreation of the original page that was stored. This reconstructed page is then projected onto the CMOS, which interprets and forwards the digital information to a computer. Slide 26: Page data stored in an HVD (left) and recreated by CMOS sensor (right) Advantages : Advantages High Storage capacity of 3.9 terabyte(TB) enables user to store large amount of data.
Records one program while watching another on the disc.
Edit or reorder programs recorded on the disc.
Automatically search for an empty space on the disc to avoid recording over a program. Slide 28: Users will be able to connect to the Internet and instantly download subtitles and other interactive movie features
Backward compatible: Supports CDs and DVDs also.
The transfer rate of HVD is up to 1 gigabyte (GB) per second which is 40 times faster than DVD .
An HVD stores and retrieves an entire page of data, approximately 60,000 bits of information, in one pulse of light, while a DVD stores and retrieves one bit of data in one pulse of light. Continued…………. Comparison : Comparison How HVD compares Others ? : How HVD compares Others ? While HVD is attempting to revolutionize data storage, other discs are trying to improve upon current systems. Two such discs are Blu-ray and HD-DVD, deemed the next-generation of digital storage. Slide 31: Video-On-Demand Portable Computing Multimedia Consumer Audio/Video Applications Conclusion : Conclusion HVD will soon replace previous DVDs.
It is currently supported by more than 170 of the world's leading consumer electronics, personal computer, recording media, video game and music companies.
The format also has broad support from the major movie studios as a successor to today's DVD format. Slide 33: Thank You Any Query? : Any Query?