Fundamentals of CD-RW Recording and Playback

Playback is performed by directing a weak laser beamat the groove section, and changes in reflection off the recording layer are read.When the laser beam strikes unrecorded or erased portions,a strong reflection is given off.When it strikes a recorded portion,a weak reflectionis given off.The portions that give off a change in the reflectance ratio are treated as a "1." Any other portions are treated as "0." In other words, the portions between recorded and unrecorded/erased are "1" and others, as long as they continue in the same condition, are treated as "0."