Why Are Movie Discs Called Blu-ray?
The latest innovation for digital video and sound for movies at home came about with the introduction of the Blu-ray disc and the release of the first movies on Blu-ray in 2006. But why are these discs called Blu-ray?
The answer has to do with the laser that is used. They’re simply called Blu-ray because a blue laser (actually blue-violet laser) is used to read and write data as opposed to an infrared or red laser that is used for CDs and DVDs. “Ray” is used because it is an optical ray.
Why is the color of the laser so important for what these discs can do? A blue laser uses a tighter wavelength than its red counterpart, allowing manufacturers to pack more data on a disc that is the same size as a DVD. While a DVD has its data sandwiched between layers on the disc, the Blu-ray disc has its data closer to the surface. This allows it to be read using a smaller beam where the pits of data on the disc are much smaller than on a DVD.
If the Blu-ray’s name is based on the use of a blue laser, then why isn’t it called “Blue-ray”? There’s a simple explanation for that. The “e” was intentionally left out by the Blu-ray Disc Association, the group of companies that developed the format, so the name could be trademarked. A common word like “Blue” cannot be trademarked.
