DVD dye

A group of four manufacturers have developed a prototype 15GByte write-once DVD disc that can be easily produced at high volume on standard DVD-Recordable production lines.

Hitachi Maxell and Mitsubishi Kagaku Media/Verbatim, two of Japan's manufacturers of optical disc media, separately tested and verified that the write-once discs, which use a new organic dye specifically developed for blue-laser applications, can be manufactured at high volume.

The new dye is the result of a joint development project by Hayashibara Biochemical Laboratories, a key manufacturer of dyes for DVD-Recordable discs, Mitsubishi Kagaku Media/Verbatim and Toshiba Corporation.

Standard DVD-Recordable discs use a photosensitive organic dye as the data storage medium in their recording layer. In the transition to HD DVD, manufacturers had to meet the challenge of developing a dye for HD DVD-R discs that could be used with the narrow wavelength of a blue laser and offered sufficient readout stability.

As well as meeting the stability criteria, the newly developed organic dye is highly sensitive to blue laser light and is solubility in the organic solvent that is required for the production of the dye recording layer using a spin-coating process.

Hitachi Maxell and Mitsubishi Kagaku Media/Verbatim will commercialise the HD DVD-R discs in spring next year, at the same time that HD DVD recorders and PCs with built-in HD DVD drives are launched by hardware manufacturers such as Toshiba.  

Last month, the German chemical company Degussa said that it had developed a new film forming technique that could help reduce the cost of manufacturing high capacity ‘Blu-ray’ optical data storage disks.

The Blu-ray disk is an alternate format for DVDs that is also being put forward as the 'next-generation' high-density standard. 

In Blu-ray disks, the information layer is just 0.1mm below the surface, and a technique was needed that could apply a layer of plexiglass that was thin enough and had good enough optical qualities without making the disks too expensive for retail pricing.

Degussa has tested its process, which uses a specially-designed film made from its Europlex PC plexiglass grade.

The general manager of Phillips Optical Media, which produces the Blu-ray, is delighted with the development. ‘This cost-effective, high quality 0.1mm layer is the technology the media replication industry was looking for,’ he says. ‘The next step will be mass production of BD-ROM, BD-R and BD-RE based on the Europlex PC film.’