Will write-once BD-R discs from TDK be a lot better
for long time archiving ?
While reading all what is published about the so called Â«format warÂ» Blu-Ray vs HD-DVD,
among all the arguments about capacity, costs and copy protection for movies
I found far more interesting the following things about the sensitive material that is going to be used for recording in the new formats.
My surprise was that TDK says that they use 2 non-organic layers
for manufacturing their write once BD-R discs.
I donâ€™t know if others companies that have already announced Blu-Ray discs (like Sony for example) are going to use a similar technique for their BD-R discs or not ?
Press release from TDK about manufacturing of their BD-R discs
published on January the 5th 2006:
Here is the interesting part about how the data are written and protected in the BD-R format:
Fig. 6 Recording process with write-once type BD-R media
[b]1. When the recording laser makes contact, its heat melts the Si and Cu alloy, which become mixed.
- When the mixture cools, the hardened Si and Cu alloy become a composite, in which the recording mark is formed[/b]
Comparison with HD DVD still using organic dye:
The new dye used for the discs 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. Development of the new dye by Hayashibara, Mitsubishi Kagaku Media/Verbatim and Toshiba is a breakthrough for HD DVD-R. 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.
The organic dye is highly sensitive to blue laser light, has the uncompromised readout stability essential for practical use, and the solubility in organic solvent required for easy production of the dye recording layer by a spin-coating process.
As the HD DVD-R disc is based on the same disc structure as DVD discs, back-to-back bonding of two 0.6 millimeter-thick substrates, already installed DVD-Recordable manufacturing lines can utilize the new dye in efficient production of HD DVD-R