Blue Ray Disc Technology

Posted by : Unknown Saturday, June 29, 2013

Abstract

Blu-ray, also known as Blu-ray Disc (BD), is the name of a next-generation optical disc format jointly developed by the Blu-ray Disc Association (BDA), a group of the world's leading consumer electronics.

Blu-ray, also known as Blu-ray Disc (BD) is the name of a next-generation optical disc format. The format was developed to enable recording, rewriting and playback of high-definition video (HD).

Applications of Blu-ray Disc

High Definition Television Recording:

High Definition Video Distribution:

High Definition Camcorder Archiving:

Mass Data Storage:

Digital Asset Management and Professional Storage:

Advantages of BD (Blu-ray Disc)

v Random access,

v Searching , quickly browse and preview recorded programs in real-time.

v Large data storage .

v Automatically find an empty space to avoid recording over programs.

v Simultaneous recording and playback of video .

v Enhanced interactively, enables more advanced programs and games.

Contents

· Introduction to Blu-ray.

· What is Blu-ray? & Why the name Blu-ray? Who

developed Blu-ray?

· Blu-ray formats.

· How much data & video can fit in the Blu-ray disc.

· Cost of Blu-ray Products.

· Difference between Blu-ray & DVD.

· Working of Blu-ray & Building a Blu-ray.

· Applications of Blu-ray disc.

· Advantages & Disadvantages of Blu-ray disc.

· Competitors of Blu-ray disc.

· Conclusion.

INTRODUCTION

Blu-ray, also known as Blu-ray Disc (BD), is the name of a next-generation optical disc format jointly developed by the Blu-ray Disc Association (BDA), a group of the world's leading consumer electronics, personal computer and media manufacturers (including Apple, Dell, Hitachi, HP, JVC, LG, Mitsubishi, Panasonic, Pioneer, Philips, Samsung, Sharp, Sony, TDK and Thomson). The format was developed to enable recording, rewriting and playback of high-definition video (HD), as well as storing large amounts of data. The format offers more than five times the storage capacity of traditional DVDs and can hold up to 25GB on a single-layer disc and 50GB on a dual-layer disc. This extra capacity combined with the use of advanced video and audio codecs will offer consumers an unprecedented HD Experience.

Blu-ray 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. Seven of the eight major movie studios have already announced titles for the Blu-ray launch, including Warner, Paramount, Fox, Disney, Sony, MGM and Lionsgate.

Developments in technologies

Blu-Ray discs are one of the newcomers on the optical disc scene. The first optical discs available to consumers were the large video laser discs that were marketed during the early 1970s. By the familiar CD became available. One compact disc was able to hold about 700MB (megabytes) of data. The first CDs were used for audio albums.

In the 1990s DVD (digital video discs) became popular. DVDs are the identical form factor of a CD but are able to hold much more data. The format was agreed upon because one DVD can hold a standard-length movie.

Blu-Ray is the next iteration on the optical disc timeline. The Blu-Ray standard was established to hold on standard-length movie in HDTV format, or high-definition television. Such movies are displayed in significantly higher resolution and therefore they require much more storage space. A standard Blu-Ray disc holds 27GB (gigabytes) of information which is about 40 times the amount of data that a CD can hold.

Although the technology is identical to CDs and DVDs, the fundamental difference with Blu-Ray is the laser that is used to read the discs. A blue laser (hence the name Blu-Ray) is used instead of the red lasers that are used on earlier discs. Blue lasers have a shorter wavelength (405 nanometers) than red lasers (650 nanometers), and therefore the beam can be focused on a smaller area which means that you can cram more data on an identically sized disc.

The new laser means that Blu-Ray discs are not readable on standard CD and DVD players and readers. Many Blu-Ray drives, however, will be backwards-compatible so they will be able to playback the older disc formats. The growth of Blu-Ray is expected to parallel the increasing popularity of HDTV and overtake legacy systems.

What is Blu-Ray?

Blu-ray, also known as Blu-ray Disc (BD) is the name of a next-generation optical disc format. The format was developed to enable recording, rewriting and playback of high-definition video (HD), as well as storing large amounts of data. The format offers more than five times the storage capacity of traditional DVDs and can hold up to 25GB on a single-layer disc and 50GB on a dual-layer disc.

Why the name Blu-Ray?

The name Blu-ray is derived from the underlying technology, which utilizes a blue-violet laser to read and write data. The name is a combination of “Blue" (blue-violet laser) and "Ray" (optical ray). According to the Blu-ray Disc Association the spelling of "Blu-ray" is not a mistake, the character "e" was intentionally left out so the term could be registered as a trademark.
The correct full name is Blu-ray Disc, not Blu-ray Disk (incorrect spelling)
The correct shortened name is Blu-ray, not Blu-Ray (incorrect apitalization) or Blue-ray (incorrect spelling) The correct abbreviation is BD, not BR or BRD (wrong abbreviation) .

Who developed Blu-ray?

The Blu-ray Disc format was developed by the Blu-ray Disc Association (BDA), a group of leading consumer electronics, personal computer and media manufacturers, with more than 170 member companies from all over the world. The Board of Directors currently consists of:

Apple Computer, Inc.
Dell Inc.
Hewlett Packard Company
Hitachi, Ltd.
LG Electronics Inc.
Matsushita Electric Industrial Co., Ltd.
Mitsubishi Electric Corporation
Pioneer Corporation
Royal Philips Electronics
Samsung Electronics Co., Ltd.
Sharp Corporation
Sony Corporation
TDK Corporation
Thomson Multimedia
Twentieth Century Fox
Walt Disney Pictures
Warner Bros. Entertainment

Blu-ray formats:

As with conventional CDs and DVDs, Blu-ray plans to provide a wide range of formats including ROM/R/RW. The following formats are part of the Blu-ray Disc specification:

BD-ROM -- read-only format for HD movies, music, software, games,etc.
BD-R -- recordable format for video recording and PC data storage.
BD-RE -- rewritable format for video recording and PC data storage.

There's also plans for a BD/DVD hybrid format, which combines Blu-ray and DVD on the same disc so that it can be played in both Blu-ray players and DVD players.

How much data can you fit on a Blu-ray disc?

à A single-layer disc can hold 25GB.
à A dual-layer disc can hold 50GB.

To ensure that the Blu-ray Disc format is easily extendable (future-proof) it also includes support for multi-layer discs, which should allow the storage capacity to be increased to 100GB-200GB (25GB per layer) in the future simply by adding more layers to the discs.

How much video can you fit on a Blu-ray disc?

à Over 9 hours of high-definition (HD) video on a 50GB disc.

à About 23 hours of standard-definition (SD) video on a 50GB disc.

Cost of Blu-ray products

As with any new technology the first generation of products will likely be quite expensive due to low production volumes. However, this shouldn't be a problem for long as there is a wide range of Blu-ray related products (players, recorders, drives, writers, media, etc) planned, which should help drive up production volumes and lower overall production costs. Once mass production of components for Blu-ray products begins the prices are expected to fall quickly.

According to the Blu-ray Disc Association, the overall cost of manufacturing Blu-ray Disc media will in the end be no more expensive than producing a DVD. The reduced injection molding costs (one molding machine instead of two, no birefringence problems) offset the additional cost of applying the cover layer and low cost hard-coat, while the techniques used for applying the recording layer remain the same. As production volumes increase the production costs should fall and eventually be comparable to DVDs.

Difference between Blu-ray and DVD

Parameters	BD-ROM	DVD-ROM
Storage capacity (single-layer)	25GB	4.7GB
Storage capacity (dual-layer)	50GB	9.4GB
Laser wavelength	405nm	650nm
Numerical aperture (NA)	0.85	0.60
Protection layer	0.1mm	0.6mm
Data transfer rate (1x) Data transfer rate (movie application)	36.0Mbps 54.0Mbps (1.5x)	11.08Mbps 10.08Mbps
Video compression	MPEG-2 MPEG-4 AVC SMPTE VC-1	MPEG-2

Blu-ray for PCs

There are plans for BD-ROM (read-only), BD-R (recordable) and BD-RE (rewritable) drives for PCs, and with the support of the worlds two largest PC manufacturers, HP and Dell, it's very likely that the technology will be adopted as the next-generation optical disc format for PC data storage and replace technologies such as DVD±R, DVD±RW, and DVD-RAM.

Working of Blu-ray Disc

Discs store digitally encoded video and audio information in pits -- spiral grooves that run from the center of the disc to its edges. A laser reads the other side of these pits -- the bumps -- to play the movie or program that is stored on the DVD. The more data that is contained on a disc, the smaller and more closely packed the pits must be. The smaller the pits (and therefore the bumps), the more precise the reading laser must be.

Unlike current DVDs, which use a red laser to read and write data, Blu-ray uses a blue laser (which is where the format gets its name). A blue laser has a shorter wavelength (405 nanometers) than a red laser (650 nanometers). The smaller beam focuses more precisely, enabling it to read information recorded in pits that are only 0.15 microns (µm) (1 micron = 10^-6 meters) long -- this is more than twice as small as the pits on a DVD. Plus, Blu-ray has reduced the track pitch from 0.74 microns to 0.32 microns. The smaller pits, smaller beam and shorter track pitch together enable a single-layer Blu-ray disc to hold more than 25 GB of information -- about five times the amount of information that can be stored on a DVD.

Each Blu-ray disc is about the same thickness (1.2 millimeters) as a DVD. But the two types of discs store data differently. In a DVD, the data is sandwiched between two polycarbonate layers, each 0.6-mm thick. Having a polycarbonate layer on top of the data can cause a problem called birefringence, in which the substrate layer refracts the laser light into two separate beams. If the beam is split too widely, the disc cannot be read. Also, if the DVD surface is not exactly flat, and is therefore not exactly perpendicular to the beam, it can lead to a problem known as disc tilt, in which the laser beam is distorted. All of these issues lead to a very involved manufacturing process.

Building a Blu-ray

The Blu-ray disc overcomes DVD-reading issues by placing the data on top of a 1.1-mm-thick polycarbonate layer. Having the data on top prevents birefringence and therefore prevents readability problems. And, with the recording layer sitting closer to the objective lens of the reading mechanism, the problem of disc tilt is virtually eliminated. Because the data is closer to the surface, a hard coating is placed on the outside of the disc to protect it from scratches and fingerprints.

The design of the Blu-ray discs saves on manufacturing costs. Traditional DVDs are built by injection molding the two 0.6-mm discs between which the recording layer is sandwiched. The process must be done very carefully to prevent birefringence.

1. The two discs are molded.

2. The recording layer is added to one of the discs.

3. The two discs are glued together.

Blu-ray discs only do the injection-molding process on a single 1.1-mm disc, which reduces cost. That savings balances out the cost of adding the protective layer, so the end price is no more than the price of a regular DVD.

Applications of Blu-ray Disc

The Blu-ray Disc format was designed to offer the best performance and features for a wide variety of applications.These are as follows:

High Definition Television Recording:

High Definition broadcasting is vastly expanding in the US and Asia.

Consumers are increasingly making to switch to HDTV sets to enjoy the best possible television experience.The Blu-ray Disc format offers consumers the ability to record their High Definition television broadcasts in their original quality for the first time.

High Definition Video Distribution:

Due to its enormous capacity of 25 to 50 GB per single sided disc,the Blu-ray Disc format can store High Definition video in the highest possible quality.Because of the huge capacity of the disc,there is no need to compromise on picture quality.

High Definition Camcorder Archiving:

As the market penetration of High Definition TV sets continues to grow,so does the demand of consumers to create their own HD recordings.With the advent of the first HD camcorders,consumers can now for the first time record their own home movies in a quality level unlike any before.

Mass Data Storage

In its day ,CD-R/RW meant a huge increase in storage capacity compared to traditional storage media with its 650 MB.Then DVD surpassed this amount by offering 4.7 to 8.5 GB of storage,an impressive 5 to 10 times increase.

Digital Asset Management and Professional Storage:

Due to its high capacity ,low cost per GB and extremely versatile ways of transferring data from one device to another ,the format is optimized for Digital Asset Management and other professional applications that require vast amounts of storage space.

Advantages of BD (Blu-ray Disc)

v Random access, instantly jump to any spot on the disc.

v Searching , quickly browse and preview recorded programs in real-time.

v Large data storage .

v Automatically find an empty space to avoid recording over programs.

v Simultaneous recording and playback of video ( enables Time slip/Chasing playback).

v Enhanced interactively, enables more advanced programs and games.

v Broadband enabled, access web content, download subtitles and extras.

v Improved picture , ability to record high-definition television(HDTV)

v Improved sound ,ability to record surround sound (Dolby Digital , DTS , etc)

Disadvantages of BD (Blu-ray Disc)

Though there are no disadvantages of BDs, there is something negative thing about it i.e., recently the Microsoft declared that it is going to include the software which supports the technology of HD-DVD (which is the most competitive technology of BD) in its latest operating system LONGHORN which may be introduced by the beginning of the next year.

Other Competitors

Blu-ray and HD-DVD are the two major competitors in the market, but there are other contenders, as well. Warner Bros. Pictures has developed its own system, called HD-DVD-9. This system uses a higher compression rate to put more information (about two hours of high-definition video) on a standard DVD. Taiwan has created the Forward Versatile Disc (FVD), an upgraded version of today's DVDs that allows for more data storage capacity (5.4 GB on a single-sided disc and 9.8 GB on a double-sided disc). And China has introduced the Enhanced Video Disc (EVD), another high-definition video disc.

There are also professional versions of the blue laser technology. Sony has developed XDCAM and ProData (Professional Disc for Data). The former is designed for use by broadcasters and AV studios. The latter is primarily for commercial data storage (for example, backing up servers).

When Will Blu-ray Become Available?

Blu-ray recorders are already available in Japan, where more consumers have access to HDTV than in the United States. Outside of Japan, once more TV sets come equipped with a high-definition tuner and more films and television shows are produced in high-definition (which is expected to happen by late 2005 or 2006), Blu-ray movies and TV shows on disc should become widely available. But the format is already available for home recording, professional recording and data storage.

Another important factor is cost. Just as with most new technologies, Blu-ray equipment will be pricey at first. In 2003, Sony released its first Blu-ray recorder in

Japan

with a price tag of around $3,000. The price is expected to drop as the format gains popularity. Blu-ray discs may also be initially more expensive than today's DVDs, but once demand grows and they can be mass-produced, manufacturers say the price will drop to within 10 percent of the price of current DVDs.

Even when the new video standard begins to replace current technologies, consumers won't have to throw away their DVDs, but they will need to invest in a new player. The industry is planning to market backward-compatible drives with both blue and red lasers, which will be able to play traditional DVDs and CDs as well as Blu-ray discs.

In 1997, a new technology emerged that brought digital sound and video into homes all over the world. It was called DVD, and it revolutionized the movie industry.

The industry is set for yet another revolution with the introduction of Blu-ray Discs (BD). With their high storage capacity, Blu-ray discs can hold and playback large quantities of high-definition video and audio, as well as photos, data and other digital content.

Conclusion:

The Blu-ray Disc is the successor of DVD’s with high storage capacity .This can be also useful for storing large volumes of data .Developing Technologies may invent another new storage devices which can be more advantageous; but now Blu-ray Disc is the effective storage device.