Philips DVDR630VR Service Manual page 129

2) Recording format using organic dye material
( DVD-R / DVD+R )
The format that records data through the creation of recorded marks by changing the organic dye material with a
laser beam.
G
Disc structure
G Recording principles
[ Recording ]
Recording is done by changing the organic dye layer and the substrate with a laser When a strong laser is applied
to a disc, the temperature of the organic dye material goes up, the dye is decomposed and the substrate changes
at the same time. At this time, a durable bit is created as is the case with a CD-ROM.
[ Playback ]
Signals are read with the differences of the reflection of a laser from pits.
3-148