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Rare media
- Thread starter Yo-Yo
- Start date
To review the NO answer to the first question, http://www.pcquest.com/content/technology/2004/104113002.asp There are either single sided dual layered or double sided disks with each side having a single layer. Otherwise they would be too dense to even run in standard players.
"Learn more about the technologies that allows 'more' storage on a single DVD
Links: http://tinyurl.com/4e52y, http://tinyurl.com/5llsr
Enter double layers
If instead of sticking two DVDs back-to-back, you stick them with corresponding sides facing the same way, you get a double-layered disc. So, you have two recordable surfaces with the difference that one layer lies below the other one. But how would you write on the second layer? Simple, when a disc spins inside the drive, it generates heat just like any other fast moving object. When you use special organic material on the disc that softens at this temperature, you achieve transparency. This lets the laser beam that writes/reads the data to pass through the top layer ('L0' in the graphic) and does its work on the second layer ('L1' in the graphic). These recordings have different optical properties compared to their unmodified surroundings and read the same as read-only discs, based on the length of the recordings and unmodified spaces between them. A non-writable 'Spacer' layer, bounded on its L1 side by a semi-transparent reflective metal layer, separates L0 and L1." Read about this at the link provided. http://www.pcquest.com/content/technology/2004/104113002.asp I'll even repost it here again.
Links: http://tinyurl.com/4e52y, http://tinyurl.com/5llsr
Enter double layers
If instead of sticking two DVDs back-to-back, you stick them with corresponding sides facing the same way, you get a double-layered disc. So, you have two recordable surfaces with the difference that one layer lies below the other one. But how would you write on the second layer? Simple, when a disc spins inside the drive, it generates heat just like any other fast moving object. When you use special organic material on the disc that softens at this temperature, you achieve transparency. This lets the laser beam that writes/reads the data to pass through the top layer ('L0' in the graphic) and does its work on the second layer ('L1' in the graphic). These recordings have different optical properties compared to their unmodified surroundings and read the same as read-only discs, based on the length of the recordings and unmodified spaces between them. A non-writable 'Spacer' layer, bounded on its L1 side by a semi-transparent reflective metal layer, separates L0 and L1." Read about this at the link provided. http://www.pcquest.com/content/technology/2004/104113002.asp I'll even repost it here again.