New Double Layer DVD+R technology developed by Philips in cooperation with MKM increases DVD recordable capacity to 8.5 Gbytes

Philips will demonstrate its new Double Layer DVD recordable technology at the DVD+RW Alliance booth at the CEATEC* JAPAN 2003 exhibition in Makuhari (Chiba, Japan) from October 7 to 11. Developed by Philips Research in cooperation with MKM (Mitsubishi Kagaku Media)/Verbatim, the technology virtually doubles data storage capacity on DVD recordable discs from 4.7 Gbyte to 8.5 Gbyte while remaining compatible with existing DVD Video players and DVD-ROM drives.

Both Philips and MKM regard the introduction of Double Layer DVD+R technology as the next important milestone in the drive to continually improve and expand the optical data storage options available to consumers. Users will benefit from the additional storage capacity of the DVD+R disc as it will enable them to record 4 hours of DVD-quality video or 16 hours of VHS-quality video, without the need to turn over the disc. PC users will be able to archive up to 8.5 Gbytes of computer files on a single disc, which almost doubles the storage capacity compared with the 4.7Gbytes for the single-layer DVD+R discs currently available.

The Double Layer DVD+R system uses two thin embedded organic dye films for data storage separated by a spacer layer (see figure). 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.

Initial investigations were started by Philips Research around 2 years ago at a time when there was general scepticism throughout the optical storage industry that compatible Double Layer DVD recordable would ever be possible. Developments since then, initially by Philips and later in cooperation with media manufacturer MKM, have dispelled this scepticism and the new Double Layer DVD+R technology is now fully endorsed by the DVD+RW Alliance.

“Very soon after the initial developments by Philips, MKM recognized the potential of this new technology and contributed its media expertise to help drive the technology forward,” says Dr Yoshimitsu Kobayashi, CEO of Mitsubishi Kagaku Media. “The technology is in line with the strategy of the DVD+RW Alliance which is currently active in finalizing the new format to bring backward-compatible Double Layer DVD recording to the consumer.”

A major challenge during development was to maintain compatibility with the DVD-ROM standard to ensure that the new Double Layer discs would be playable on commercially available DVD players. “Compatibility with the installed base of DVD Video players was the key factor in our research for a Double Layer DVD+R disc,” explains Dr Frans Greidanus, Senior Vice President of Philips Research. “Although Double Layer concepts have been proposed before, our team here at Philips Research was the first to be able to record on both layers of the dual layer DVD+R disc and play it back in a standard DVD video player.”

Compatibility 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 Double 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 is setting an aggressive feature and performance roadmap, and the Double Layer DVD+R format book is expected to be ready within this year. Recorders for both the PC and consumer electronics markets are expected to become available during the course of 2004.

Cross-section of a Double Layer DVD+R disc


Laboratory set-up for investigating the read and write characteristics of
Double Layer DVD+R discs.

Both pictures are available in high resolution format from http://www.extra.research.philips.com/pressmedia/pictures/stor-dvdr9.html

More information:

See also the press release “The DVD+RW demonstrates dual layer DVD+R, nearly doubling the capacity of recordable DVDs.” to be issued by the DVD+RW Alliance on October 7, 2003

Background information on the Double Layer DVD+R technology is available from:


Double Layer DVD+R:
Doubling the data storage capacity of recordable DVD to 8.5 Gbyte

Double Layer DVD+R Presentation


About Royal Philips Electronics
Royal Philips Electronics of the Netherlands is one of the world's biggest electronics companies and Europe's largest, with sales of EUR 31.8 billion in 2002. It is a global leader in color television sets, lighting, electric shavers, medical diagnostic imaging and patient monitoring, and one-chip TV products. Its 164,000 employees in more than 60 countries are active in the areas of lighting, consumer electronics, domestic appliances, semiconductors, and medical systems. Philips is quoted on the NYSE (symbol: PHG), London, Frankfurt, Amsterdam and other stock exchanges. News from Philips is located at www.philips.com/newscenter

About Mitsubishi Kagaku Media
Mitsubishi Chemical Corporation (MCC), parent company of Mitsubishi Kagaku Media, is Japan's largest chemical company and one of the world's leading manufacturers of information storage products. In a line-up of data and image storage media, MCC holds a strong market share in markets such as Recordable and Rewritable DVD discs, CD-R and CD-RW discs, 90 mm and 130 mm MO discs, 130 mm WORM discs. Many of these products are marketed through Mitsubishi Kagaku Media/Verbatim Corporation, which is a wholly owned subsidiary of MCC. Mitsubishi Chemical Corporation has approximately 10 000 employees, and on a consolidated basis recorded revenues of approximately US$ 16 billion for the year ended March 31, 2003.

For further information, please contact:

Koen Joosse, Philips Research

World wide: Shigeru Tamura, Mitsubishi Kagaku Media
US: Tim Clatterbuck , Verbatim Corporation

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