Blu-ray Disc uses a blue laser to achieve a storage capacity of around 25G bytes or around five times that of current DVD discs. It is one of a number of new optical disc storage formats that are being targeted at applications such as storage of high-definition video.
In a Blu-ray Disc the recording layer on which the data is stored lies under a 0.1mm protective layer and on top of a 1.1mm thick substrate. The substrate, or basic surface on which a material adheres, is usually made of a polycarbonate plastic but the new prototype disc replaces this with paper. The result is a disc of which paper makes up approximately 51 percent of its weight, Sony.
By replacing plastic with paper the companies hope to produce a more environmentally friendly, as well as a more secure disc, said Taro Takamine, a spokesman for Sony in Tokyo.
"Oil is a limited resource but paper can be recycled," he said. "One of the initial advantages of the paper disc will be a decrease in the amount of raw material needed to produce a disc."
By replacing most of the plastic in a disc with paper it could also aid recycling of products such as magazines bundled with discs, Takamine said.
The paper disc can also be more easily cut with a pair of scissors and that will make it much easier for users to destroy discs, and thus protect their data, when disposing of unneeded discs, he said.
The next step for the two companies is to investigate mass production techniques and possibly realize another goal of the project: a cheaper Blu-ray Disc. Sony currently sells blank Blu-ray Discs for around ¥3,500 (£18).