What is DVD duplication?

DVD duplication simply involves copying optical media, from one master DVD copy to duplicates of the media on other recordable DVD discs. Similarly DVD replication is identically reproducing a copy of DVD media.

History

In the early 1990s two high density optical storage standards were being developed: one was the MultiMedia Compact Disc (MMCD), backed by Philips and Sony, and the other was the Super Density Disc (SDD), supported by Toshiba, Time-Warner, Matsushita Electric, Hitachi, Mitsubishi Electric, Pioneer, Thomson, and JVC. IBM’s president, Lou Gerstner, acting as a matchmaker, led an effort to unite the two camps behind a single standard, anticipating a repeat of the costly format war between VHS and Betamax in the 1980s.

Philips and Sony abandoned their MMCD format and agreed upon Toshiba’s SD format with two modifications that are both related to the servo tracking technology. The first one was the adoption of a pit geometry that allows “push-pull” tracking, a proprietary Philips/Sony technology. The second modification was the adoption of Philips’ EFMPlus. EFMPlus, created by Kees Immink, who also designed EFM, is 6% less efficient than Toshiba’s SD code, which resulted in a capacity of 4.7GB as opposed to SD’s original 5GB. The great advantage of EFMPlus is its great resilience against disc damage such as scratches and fingerprints. The result was the DVD specification Version 1.5, announced in 1995 and finalized in September 1996. In May 1997, the DVD Consortium was replaced by the DVD Forum , which is open to all companies.

“DVD” was originally an initialism for “Digital Video Disc.” Some members of the DVD Forum believe that it should stand for “Digital Versatile Disc” to reflect its widespread use for non-video applications. Toshiba, which maintains the official DVD Forum site, adheres to the latter interpretation, and indeed this appeared within the copyright warnings on some of the earliest examples. However, the DVD Forum never reached a consensus on the matter, and so today the official name of the format is simply “DVD”; the letters do not officially stand for anything.

The first DVD players and discs were available in November 1996 in Japan, March 1997 in the United States, 1998 in Europe and in 1999 in Australia. The first pressed DVD release was the film Twister in 1996. The film had the first test for 2.1 surround sound. The first titles released in the U.S., on March 19, 1997, by Lumivision, authored by AIX Entertainment, were IMAX adaptations: Africa: The Serengeti, Antarctica: An Adventure of a Different Nature, Tropical Rainforest, and Animation Greats.

By the spring of 1999 the price of a DVD player had dropped below $300 US. At that point Wal-Mart began to offer DVD players for sale, but DVDs represented only a small part of their video inventory; VHS tapes of films made up the remainder. Wal-Mart’s competitors followed suit, and DVDs began to increase in popularity with American consumers.

DVD rentals first topped those of VHS during the week of June 15, 2003 (27.7 M rentals DVD vs. 27.3 M rentals VHS). Major U.S. retailers Circuit City and Best Buy stopped selling VHS tapes in 2002 and 2003, respectively. In June 2005, Wal-Mart and several other retailers announced plans to phase out the VHS format entirely, in favor of the more popular DVD format. However, blank VHS tapes are still widely available since DVD video recorders are significantly less common than DVD players. Many films released to theaters from 2004 onwards are released solely to DVD format and not to VHS format. Consumers have predicted that 2006 would be the final year for new releases on VHS.

According to the Digital Entertainment Group (DEG), all DVD sales and rentals (films, television series, special interests, etc) totaled $21.2 billion in 2004. The sales portion of that was $15.5 billion. In comparison, the total 2004 US box office for theatrical rentals was $9.53 billion (per the National Association of Theater Owners or NATO). While the growth of theatrical films on DVD has cooled recently, that of television programs and music video has increased dramatically.

As of 2006, some retailers, such as Best Buy, no longer offer titles on VHS media, instead concentrating solely on DVDs. The price of a DVD player has dropped to below the level of a typical VCR (although DVD recorders are still usually more expensive than VCRs); a low-end player with reasonable quality can be purchased for under $35 US in many retail stores and many modern computers are sold with DVD-ROM drives. Also popular are units that have integrated a DVD and VHS VCR into a single device; these can be purchased for under $100 US. Most, but not all, movie “sets” or series have been released in boxed sets, as have some entire seasons or selected episode volumes of older and newer television programs.

 

What is cd replication?

First of all, there are two main methods of creating a CD copy. First of them is replication, also known as disc manufacturing, while the second is duplication, aka disc burning.

In this post I’d like to tell you something more about disc replication.

According to Wikipedia, compact disc manufacturing is the process, by which commercial compact discs (CDs) are replicated in mass quantities using a master version created from a source recording.

Probably you are now wondering how it’s done, so lte me tell you:

CD moulding machines are specifically designed high temperature polycarbonate injection moulders. They have a throughput up to 1000 discs per hour, per moulding line.
Clear polycarbonate pellets are first dried at around 130 degrees Celsius for nominally three hours (dependent on which optical grade resin is used). Ten, they are fed via vacuum transport into the one end of the injection moulder’s barrel (called the feed throat) and are transported to the injection chamber via a large screw inside the barrel.
The barrel, wrapped with heater bands ranging in temperature from circa 210 to 320 degrees Celsius melts the polycarbonate. When the mould is closed the screw moves forward to inject molten plastic into the mould cavity. When the mould is full, cool water running through mould halves, outside the cavity, cools the plastic so it solidifies somewhat.
The entire process from the mould closing, injection and opening again takes approximately 3 to 5 seconds.

The moulded “disc” (often called informally ‘green’ disc, i.e. unprocessed) is removed from the mould by vacuum high-speed robots with vacuum suction caps and moved onto the infeed conveyor or cooling station of the finishing line before metallisation.
At this point the discs are clear and contains all the digital information. But because there is no reflective layer, they cannot be played. Yet

Discs then pass, one at a time, into the metaliser. It’s a small chamber operating at approximately 10E-3 Torr vacuum.
This process is called ’sputtering’. The metaliser contains a metal “target” made of an alloy of mostly aluminium and some small amounts of other metals.
There is a system of a load-lock (like an airlock) so that the process chamber can maintain high vacuum as the discs are exchanged. When the disc is rotated into the processing position by the swivel arm in the vacuum chamber, a small dose of argon gas is injected into the process chamber and electrical current is applied to the target. This results in a plasma ignition and the aluminium target evaporates onto the disc (Speaking scientificly it should be called an anode – cathode reaction).
The metal coats the information side of the disc (upper surface) and covers the pits.
This metal layer is the reflective surface that can be seen on the reverse of a CD.
This thin layer of metal is unstable and will oxidise if it is not protected by a lacquer.
That’s the reason why after metalisation the discs pass onto a spin-coater, where UV curable lacquer is dispensed on to the metal layer and spun rapidly to coat the entire disc in a very thin layer (circa 70 nm).
After the lacquer is applied it passes under a high intensity UV lamp which cures the lacquer. The lacquer also provides a surface for the screen printing or offset printing ink to adhere to.

CD technology allows to store up to 800 megabytes of audio, video, and data in various formats which are defined in the Rainbow Books.
A CD  can usually be manufactured with strict manufacturing tolerances for only a few US cents.
If you want to learn more about the prices, visit this CD replication site.

Thank you for reading. Next time I’d like to tell you about  cd/dvd duplication.