According to a news published at TechOn, Ricoh exhibits an optical device compatible with CD, DVD, Blu-ray Disc and HD DVD.
Ricoh's Multiple Format Compatible Plate (MFCP) comes in three main models, one that supports four formats of CD/DVD/Blu-ray Disc/HD DVD, one that is compatible with three formats of CD/DVD/Blu-ray Disc or CD/DVD/HD DVD, and one that works with both Blu-ray Disc and HD DVD.
At present, the new optical device can only be applied to read-only applications. The company intends to further promote development, aiming at prices lower than $1 (USD).
Some more technical details about how the device works can be found in the original article.
