pctechguide.com

  • Home
  • Guides
  • Tutorials
  • Articles
  • Reviews
  • Glossary
  • Contact

DVD+R

The first DVD+RW drives had no capability to write to write-once DVD media. However, in early 2002 Verbatim became the first media maker to offer DVD+RW technology in both the ReWritable and Write-once formats. Like their DVD+RW media, the new DVD+Recordable discs were certified for 2.4x recording speed (equivalent to 3.32MBps or 22x CD-R performance).

That spring second-generation DVD+RW drives – capable of handling both types of media – began to emerge. Philips were the first off the mark, with a drive that was capable of being upgraded to read the new format via a firmware patch. Other DVD+RW Alliance optical drive manufacturers were soon to follow suit.

In October 2003, Philips Electronics and Mitsubishi Kagaku Media (better known by its Verbatim brand name) demonstrated its new dual-layer DVD recordable technology at the Ceatec Japan 2003 exhibition. The new technology virtually doubles data storage capacity on DVD+R recordable discs from 4.7GB to 8.5GB, while remaining compatible with existing DVD Video players and DVD-ROM drives.

The dual-layer DVD+R system uses two thin embedded organic dye films for data storage separated by a spacer layer. Heating with a focused laser beam irreversibly modifies the physical and chemical structure of each layer such that the modified areas have different optical properties to those of their unmodified surroundings. This causes a variation in reflectivity as the disc rotates to provide a read-out signal as with commercially pressed read-only discs.

Dual-Layer

A major challenge during development – which started in 2001 – was to maintain compatibility with the DVD-ROM standard to ensure that the new dual-layer discs would be playable on commercially available DVD players. This has been achieved through the use of a thin silver-alloy as reflector material in the upper layer giving a reflectivity from the layer of at least 18% in compliance with the dual-layer DVD-ROM standard. In addition, the transmission of the upper recording layer is greater than 50% to allow for read-out and recording of the lower recording layer. This layer has high power sensitivity since the upper layer absorbs and reflects part of the incoming light. It also has a much higher reflectivity (> 50%) which after double transmission through the upper layer also results in an apparent layer reflectivity (at the disc surface) of at least 18%. These high transmission and reflectivity values have been achieved through careful optimization of the dye material and deposition, groove shapes and silver deposition. In addition to optimizing reflectivity, other parameters such as signal amplitude and tracking signals were also optimized to ensure full compatibility with current DVD standards.

The DVD+RW Alliance finalized its specification for dual-layer DVD+R media in the autumn of 2003. Dual-layer recordable technology represents an important milestone in the drive to continually improve and expand the optical data storage options available to consumers, enabling users to record 4 hours of DVD-quality video or 16 hours of VHS-quality video, without the need to turn over the disc.

With dual-layer burners, the top layer is written in the same way as by traditional single-layer burners; an organic dye film is heated by a red laser to cause fluctuations in its optical response which can then be read back as data. The second layer is written by refocusing the laser beam so that it passes through the first layer, through the partially reflective metal layer, down to the lower dye layer. The alterations in both the wavelength and the power of the laser are such as to leave the upper layer unaffected.

Using this dye-recording-film layer method, the new dual-layer DVD-R technology, shows almost the same performance as that for dual-layer DVD-ROM discs, realizing a 9.34% jitter with a 17.3% reflection rate on the first layer (L0) of a disc, and an 8.08% jitter with a 19.5% reflection rate for the second layer (L1). This means that it will be possible to play back dual-layer DVD-R discs on most existing DVD players, and that DVD recorders supporting the technology will be easily developed.

The first dual-layer burners reached the market in the summer of 2004. The principal downside of these early devices was that the added complications of dual-layer recording meant that write speeds were limited to a speed of 2.4x. This compared unfavorably with the 8x single-layer burners available at the time and the 12x and 16x burners on the horizon. A second issue was that the standard for dual-layer media requires that the same amount of data be recorded on each layer. This can result in additional time having to be spent in writing superfluous dummy data on a disc’s second layer.

  • History of DVD development and birth of the DVD Forum
  • DVD Formats
  • DVDs – digital versatile disks – how they’re made and how they work
  • DVD OSTA
  • DVD File Systems
  • CDR-RW Compatibility Issues
  • DVD Encoding
  • DVD Content Protection
  • Regional codes for DVDs
  • DVD-ROM
  • DVD-Vdeo
  • DVD DivX Codec
  • DVD-Audio
  • DVD Recordable Formats
  • DVD-R – write once recordable DVDs
  • DVD-RAM
  • DVD+RW
  • DVD-RW
  • DVD+R
  • DVD Multi-Writers

Share this:

  • Click to share on Twitter (Opens in new window)
  • Click to share on Facebook (Opens in new window)

Related

Filed Under: DVD

Latest Articles

Guide to Kensington Slot (K-lock, Kensington Lock, Universal Security Lock) mobile device security

A Kensington Security Slot (or Kensington Slot, Kensington Lock or simply K-Slot) is a common device with which a laptop, notebook, monitor, or other movable piece of equipment can be securely attached to something less mobile. Kensington slots, conceived by their namesake … [Read More...]

Differences with Reverse Image Search on Desktop and Mobile Devices

Searches with images are a Google functionality with which users can find similar images, source of photographs or until the date in which an image was uploaded to the Internet. This functionality of Google Images is part of the advanced search options and allows users to use images to use the … [Read More...]

Bridges

Bridges became commercially available in the early 1980s. At the time of their introduction their function was to connect separate homogeneous networks. Subsequently, bridging between different networks - for example, Ethernet and Token Ring - has … [Read More...]

2021 PC Hardware Releases to Bolster Your Gaming

If you are a PC gamer, then chances are you are looking to upgrade your kit over the coming year. However, a lot of money can go into building the … [Read More...]

New Transfer Feature in Dropbox Enable Sharing files with Third Parties

Dropbox has been a popular P2P sharing platform for many years. They don't announce new features as often as other applications, since they have a … [Read More...]

Ransomware Operators Find Data Theft Profitable

How valuable is your data? That’s not a question that organizations or individuals have to ask themselves all that often. You might know the market … [Read More...]

Engineers Encounter the Quantum Challenge with Computers Running a Hundred Million Times Faster

Quantum computers have been a subject of discussion for many years. They have probably been something that philosophers and technology pundits have … [Read More...]

Transferring Image Files from Your Cell Phone Without Cables or Email

You don't have a cable available to transfer the photos from your cell phone to your computer? You don't feel comfortable sending them through your … [Read More...]

Why Drupal Accessibility is Vital for Your Website

Drupal may not be as popular as WordPress, but it is still used in over 1 million websites. The Internet might be more conducive to our needs if more … [Read More...]

Guides

  • Computer Communications
  • Mobile Computing
  • PC Components
  • PC Data Storage
  • PC Input-Output
  • PC Multimedia
  • Processors (CPUs)

Recent Posts

Protect Business From Cyber Attacks

A company is only as safe as its computer network and, though it's hard to admit, many businesses are frightfully unprotected when it comes to … [Read More...]

Pentium P5 microarchitecture – superscalar and 64 bit data

First introduced in 1993, the Pentium was the successor to Intel's 486 line of CPUs and the defining processor of the fifth generation. The … [Read More...]

CD-ROM Purple Book – What is Purple Book?

The informal name for specification produced by Philips and Sony in 2000 to describe their double-density compact disk … [Read More...]

[footer_backtotop]

Copyright © 2021 About | Privacy | Contact Information | Wrtie For Us | Disclaimer | Copyright License | Authors