01-01-2011, 04:35 PM
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SUBMITTED BY :-
Vivek Chandra Yadav
EC 4th Year
ABSTRACT
Optical discs share a major part among the secondary storage devices. Blu-ray disc is a next generation optical disc format. The technology utilizes a blue laser diode operating at a wavelength of 405nm to read and write data. Because of the blue laser it can store enormous amount of data than was ever possible.
Data is stored on a BD in the form of tiny ridges on the surface of an opaque 1.1mm thick substrate. This lies beneath a transparent .1mm protective layer. With the help of Blu-ray recording devices it is possible to record upto 2.5 hrs of very high quality audio and video on a single BD.
Blu-ray also promises some added security, making ways for copyright protections. Bd can have a unique ID written on them to have copyright protection inside the recorded streams.
Blu-ray Disc takes the DVD technology one step further just by usin g a laser with a nice colour.
Introduction
Tokyo Japan, February 19, 2002: Nine leading companies announced that they have jointly established the basic specifications for a next generation large capacity optical disc video recording format called "Blu-ray Disc". The Blu-ray Disc enables the recording, rewriting and play back of up to 27 gigabytes (GB) of data on a single sided single layer 12cm CD/DVD size disc using a 405nm blue-violet laser.
By employing a short wavelength blue violet laser, the Blu-ray Disc successfully minimizes its beam spot size by making the numerical aperture (NA) on a field lens that converges the laser 0.85. In addition, by using a disc structure with a 0.1mm optical transmittance protection layer, the Blu-ray Disc diminishes aberration caused by disc tilt. This also allows for disc better readout and an increased recording density. The Blu-ray Disc's tracking pitch is reduced to 0.32um, almost half of that of a regular DVD, achieving up to 27 GB high-density recording on a single sided disc.
Because the Blu-ray Disc utilizes global standard "MPEG-2 Transport Stream" compression technology highly compatible with digital broadcasting for video recording, a wide range of content can be recorded. It is possible for the Blu-ray Disc to record digital high definition broadcasting while maintaining high quality and other data simultaneously with video data if they are received together. In addition, the adoption of a unique ID written on a Blu-ray Disc realizes high quality copyright protection functions.
The Blu-ray Disc is a technology platform that can store sound and video while maintaining high quality and also access the stored content in an easy-to-use way. This will be important in the coming broadband era as content distribution becomes increasingly diversified. The nine companies involved in the announcement will respectively develop products that take full advantage of Blu-ray Disc's large capacity and high-speed data transfer rate. They are also aiming to further enhance the appeal of the new format through developing a larger capacity, such as over 30GB on a single sided single layer disc and over 50GB on a single sided double layer disc. Adoption of the Blu-ray Disc in a variety of applications including PC data storage and high definition video software is being considered.
Concept of the format establishment :
To realize the large capacity with 12cm disc
- More than 2-hour high definition video recording
- High capacity of more than 4-hour recording by double layer technology.
To cope with digital broadcasting
- High compatibility with digital broadcasting
- To prevent illegitimate duplication of contents
To enhance the Blu-ray Disc world
- Adoption of the Blu-ray Disc in variety of media and applications
Main Features of physical format:
Large recording capacity up to 27GB:
By adopting a 405nm blue-violet semiconductor laser, with a 0.85NA field lens and a 0.1mm optical transmittance protection disc layer structure, it can record up to 27GB video data on a single sided 12cm phase change disc. It can record over 2 hours of digital high definition video and more than 13 hours of standard TV broadcasting (VHS/standard definition picture quality, 3.8Mbps)
Easy to use disc cartridge:
An easy to use optical disc cartridge protects the optical disc's recording and playback phase from dust and fingerprints
High-speed data transfer rate 36Mbps:
It is possible for the Blu-ray Disc to record digital high definition broadcasts or high definition images from a digital video camera while maintaining the original picture quality. In addition, by fully utilizing an optical disc's random accessing functions, it is possible to easily edit video data captured on a video camera or play back pre-recorded video on the disc while simultaneously recording images being broadcast on TV.
Recording format:
Like the DVD, the Blu-ray disc uses phase change recording. This must be good news for those who plan to make the new format compatible with its wildly popular predecessor. This recording format will also makes a two-sided disc easily realizable because both writing and reading can be executed by a single pickup.
Multiplexing:
Blu-ray disc utilizes global standards like MPEG-2 Transport Stream compression technology for video and audio multiplexing. This makes it possible for a Blu-ray Disc to record high definition broadcasting and other data simultaneously with video data if they are received together. Data captured on a video camera while recording images being broadcast on TV can also be edited simultaneously.
Main Features Of Logical format :
Highly compatible with digital broadcasting :
MPEG2 transport stream compression technology for video recording can record digital broadcasting including HDTV while maintaining its original picture quality.
Best data structure for disc recording
Achieving improvement of searching, easy editing functions and play a list playback functions by adapting logical data structure making the best use of random accessing.
File system for HDTV real time recording
Adapting the file system which can achieve high bit rate recording and playback of HDTV and best use of disc space
History of Blu‐ray Disc
First Generation
When the CD was introduced in the early 80s, it meant an enormous leap from traditional media. Not only did it offer a significant improvement in audio quality, its primary application, but its 650 MB storage capacity also meant a giant leap in data storage and retrieval. For the first time, there was a universal standard for pre‐recorded, recordable and rewritable media, offering the best quality and features consumers could wish for themselves, at very low costs.
Second Generation
Although the CD was a very useful medium for the recording and distribution of audio and some modest data‐applications, demand for a new medium offering higher storage capacities rose in the 90s. These demands lead to the evolution of the DVD specification and a five to ten fold increase in capacity. This enabled high quality, standard definition video distribution and recording. Furthermore, the increased capacity accommodated more demanding data applications. At the same time, the DVD spec used the same form factor as the CD, allowing for seamless migration to the next generation format and offering full backwards compatibility.
Third Generation
Now High Definition video is demanding a new solution. History proved that a significant five to ten time increase in storage capacity and the ability to play previous generation formats are key elements for a new format to succeed. This new format has arrived with the advent of Blu‐ray Disc, the only format that offers a considerable increase in storage capacity with its 25 to 50 GB data capacity. This allows for the next big application of optical media: the distribution and recording of High Definition video in the highest possible quality. In fact, no other proposed format can offer the data capacity of Blu‐ray Disc, and no other format will allow for the same high video quality and Interactive features to create the ultimate user experience. As with DVD, the Blu-ray Disc format is based on the same, bare disc physical form factor, allowing for compatibility with CD and DVD. The Blu‐ray Disc specification was officially announced in February 2002. Blu‐ray Disc recorders were first launched in Japan in 2003.
• 1982 ‐First working CD player developed by Philips. Philips and Sony developed CD standard – 12cm disk, 74 minutes on a single spiral
• 1983 ‐First CD players sold
• 1985 ‐CD‐ROM introduced – not popular at first. More powerful PCs lead
to demand for multimedia, image processing and larger applications. Growth in sales brings prices down.
• 1990’s ‐ CD‐R and CD‐RW introduced – big success.
• 1996 ‐DVD introduced
• 1999 ‐DVD becomes mainstream
• 2003 ‐BD introduce
