Do we really need more capacity?

Cynics amongst us may say that its just another way for the computer and consumer electronics industry to sell us all something new. While there is an element of truth in this, as not everyone needs the additional capacity but computers, software and applications do continue to be increasingly data hungry.

Many users will welcome the additional amount of storage that both formats offer, as they are getting to full capacity with DVD and are starting to need multi-disc sets. The new formats will be the equivalent to five and ten times the size of a DVD. In addition to this, faster broadband speeds are allowing users to download increasingly larger amounts of data.

High definition television will begin broadcasting throughout Europe in 2006 and will allow consumers the best possible television experience in both watching and recording. In the United States over seven million digital televisions have already been sold and Europe is not far behind. In Europe, it is expected that broadcasting the World Cup in 2006 in high definition and will be a major factor for many to make their first purchase of a high definition digital television.

The fast transfer rate of blue laser disc - coupled with the larger capacity on a disc - also makes it ideal for archive applications, medical records and high resolution assets that need instant access or retrieval.

First of all, lets take a quick look at the differences between the two formats that both utilise blue laser disc recording:

Blu-ray

Blu-ray is backed by over 100 companies who are members of the Blu-ray Disc Association (http://www.blu-raydisc.com). The key members include; Sony, Pioneer, HP, Dell, Philips, Mitsubishi Chemical, Walt Disney, TDK, Hitachi, 20th Century Fox and Apple.

Initial storage capacity of a Blu-ray disc will be 25GB (or 135 minutes of high definition film and two hours of bonus features in standard definition quality) for a single layer and 50GB with dual layer (or three hours of film and nine hours of bonus materials). Prototypes have already been developed by TDK that will take this to 100GB on a single side. The Blu-ray group estimate the technology will be viable as a format standard for 10-15 years.

Similar to CD and DVD, Blu-ray discs will be available as once only recordable (BD-R), re-writable (BD-E) and in a pre-recorded disc format (BD-ROM). There will also be two other types of Blu-ray disc that are contained in cartridges for specific use in the broadcast and data archiving industries. These are called PD and PDD respectively.

Blu-ray disc products will be launched to cover three major application areas: 1. Desktop computer use and home video applications.
2. Professional broadcasting.
3. Professional data backup applications.

Blu-ray discs are manufactured using a single disc substrate, with the recording layer very close to the disc surface. This should result in less potential distortion, higher precision and shorter production times and costs.

In terms of backward compatibility, it is likely that Blu-ray disc products will play both DVD and CD formats. It is also expected that Blu-ray PC and Mac recorders will also be able to record onto CD and DVD discs. Sony have recently announced that their next generation Playstation 3 console will have Blu-ray capability.

High Density DVD

There are fewer companies in the HD-DVD Promotion Group (http://www.hddvdprg.com), but still some significant ones none the less. Companies include; NEC, Toshiba, Sanyo, Thomson and Universal Pictures. The format is also supported by the DVD Forum.

Initial storage capacity is around 15/20GB, 30/32GB and 45 GB as a maximum with dual layer. In its present shape, the capacity is unable to go beyond that due to the position of the recording layer, which is further away from the disc surface.

Disc manufacturers will be able to transition over to HD-DVD more easily as it is a similar disc structure to DVD. However, the limited capacity could see it end up as an interim solution and manufacturers will inevitably need to invest in Blu-ray production lines.

Like DVD, HD-DVD disc is manufactured by bonding two surfaces (substrates) together. It is likely that HD-DVD devices will also be able to play DVD and CD content. Discs will be available in a recordable (HD-DVD-R), re-writable (HD-DVD-RW) and pre-recorded version (HD-DVD-ROM).

89 film titles will be introduced in late 2005.

Why can blue laser expand capacity?

With the same disc surface size as both CD and DVD a blue laser disc can record and store more information by using a laser beam with a much smaller focus than CD or DVD. This laser can record smaller and higher density pits, enabling more data storage.

A closer look at Blu-ray

Within the Blu-ray family there are three types of discs available, which are optimised for specific applications. The main demand and usage will be for the standard Blu-ray product, but there are also two other types of Blu-ray discs available that have been specifically developed for the broadcast and data storage market:

Professional Disc (PD)

PD has been developed specifically for the news gathering and broadcast markets. Products are already being introduced by Sony. These include; a recording and editing system - ENG (Electronic News Gathering) - as well as the XDCAM series of professional camcorders.

PD has a faster data transfer rate, 72 Mpbs as opposed to 36Mbps, than the standard Blu-ray product and is seen as a replacement for traditional tape loaded broadcast cameras. The disc is re-writable and contained in a cartridge for added protection in field use. PD disc media is being manufactured by both Sony and TDK.

Professional Disc for Data (PDD)

PDD has been developed as a replacement for traditional magneto optical (MO) applications, such as data juke boxes for online or archive access and storage. PDD is physically almost identical to Professional disc (PD) and is available as re-writable and recordable. The disc is contained in a cartridge for protection and ease of use by the robotics in any juke box or library system. Typical users will be medical, banking, government and telecom businesses who need fast network access to large amounts of data or information.

Standard Blu-ray

Standard Blu-ray will be the main Blu-ray product for mass use in consumer recorders and players, PC drives and games consoles, such as PlayStation 3. The disc media can be supplied naked and is not contained in a cartridge due to the application at manufacture of a hard coat protective layer. The first manufacturer to introduce this is TDK with their Durabis coating technology.

Dell and HP have committed to begin shipment of their high end PCs with Blu-ray by the end of 2005. Blu-ray will have built-in encryption and copy protection within the hardware and at the media manufacturing level to minimise piracy and illegal copying.

Why the need for a protective layer?

One immediate reason for the protective layer is that by packing more and more data onto the same size disc surface the recorded data can be more susceptible to playback problems caused by damage from handling, scratches and static. Also, in order to obtain the highest capacity from the Blu-ray disc format and to ensure higher precision, the recording layer in a Blu-ray disc is manufactured closer to the disc surface than both DVD and HD-DVD. This means that the Blu-ray disc has a far higher capacity than other blue laser discs such as HD-DVD, but this does mean that the disc needs to be encased in a caddy like PD and PDD or protected by an additional coating layer. By being able to manufacture a disc that can be used in its naked form without a caddy it will ensure a more widespread use and uptake of the Blu-ray format. This is because the disc will be used in a number of different drives and consumer electronic products. Disposing of the caddy will also dramatically reduce the manufacturing and end user unit costs.

Disc Structure Comparison

With the need to have a protective coating on a naked Blu-ray disc, TDK were the first media manufacturer to introduce a scratchproof coating. This has been available for some time as an option on their DVD product range, but recently they have taken this technology even further with the latest version of coating technology called Urbis. The advantages of the Urbis coating mean that discs can be used without a caddy and are far less likely to be damaged by scratches, UV light, fingerprints and dust attracted by static.

And finally....When will it all become available?

Toshiba Corp. has announced a March 2006 commercial launch date for the first HD-DVD player in the United States.

Blu-ray disc recorders were first launched in Japan in 2003. Blu-ray is available in Japan in caddy format and it is expected to be available in the US by summer 2006.

Professional Disc (PD) for broadcasting has limited availability already. It is mainly being tested and trialled in high definition TV projects by the major broadcast companies and authorities.

Professional Disc for Data (PDD), which is used for archiving and back up also has limited availability.

Both the Blu-ray group and HD-DVD group are talking together about a single format to avoid a format clash. However, as each partys proposal appears to be that the other one drops their format, it seems unlikely it will lead to peace in our time.

CD Team, the authors of this article, are a CD and DVD duplication company based in Oxfordshire. CD Team have been specialists in the supply of CD and DVD duplication services and solutions since 1995. In that time they have gained invaluable experience about CD and DVD discs and duplication equipment and how to assess which solution is the best for each of their customers. Please visit their website for more information: http://www.cdteam.co.uk

This article is also available as a PDF at CD Team website: http://www.cdteam.co.uk/blu-ray.htm