CyberLink's Double Layer Technology

DVD burners are hotter than ever. More and more computer buyers want a DVD burner built-in. The reasons are simple: DVD discs offer higher capacity, prices for burners are dropping, and DVD discs are getting cheaper. It is no wonder that DVDs and DVD burners are replacing traditional CDs and CD burners. With the latest introduction of Double Layer technology, DVDs can now store up to four hours or 8.7 GB of data, almost twice as much as before.

Even though double-layer discs and drives have just hit the stores, it is not a new technology. In fact, the original DVD design enabled multiple configurations for storage capacities. Movie studios have long been using Double Layer technology; this is why they can fit a 2-hour movie onto one disc. The movies are burned onto a double-layer disc, also known as DVD9.

A disc has two layers or sides. Data are burned and stored in little indents called "pits." A red laser light reads the data on the discs. The minimum pit length for a one-sided disc is 0.4 um. For a double-layer disc, the pits are enlarged to 0.44 um for better accuracy because the laser has to penetrate through the first layer to reach the second layer. As a result of the larger pit size, fewer of the 0.44 um pits can fit onto one layer of the disc. Hence, a double-layer disc can hold 8.5 GB of data, and not 9.5 GB, which is twice the amount of a single-sided disc (2 x 4.7GB). However, a double-sided disc can hold up to 9.5 GB of data, but the disc has to be flipped over when being used or the disc has to be played in a drive that can read both sides

The introduction of Double Layer technology to the market duplicates the pleasure for consumers. Users can now burn a 120-minute, high-quality video, music, or data onto a DVD9 disc in one swoop, giving users more room to create menus, background music, transitions, etc. whenmaking their discs.