Reference Information; Introduction To Dvd - Samsung DVD-R157 Service Manual

14. Reference Information

14-1 Introduction to DVD

14-1-1 The Definition of DVD
DVD is the next generation medium and is the acronym of the Digital Versatile Disc or thr Digital Video Disc,
which maximizes the saving density of the disk surface using the MPEG-2 compression technology to enable the
storage of 17G bytes of data on the same size CD.
1) 7 times the storage capacity of the conventional CD
- Minimized the track pitch and pit size to 1/2 of conventional CD.
- Uses red laser with short-wavelenght of 650nm (635nm).
DVD Vs. CD-ROM
Disc Thickness
Lens NA
Laser wavelenght
Track pitch
Capacity
Track structure
2) Disc Formats
DVD consists of two 0.6mm discs attached together, enabling access to the upper and lower side of the disk,
and 4 sides could be used at maximum.
Samsung Electronics
CD-ROM CD-R/RW
1.2mm 1.2mm
0.45 0.45(0.5)
780um 780um
1.6pm 1.6pm
0.65GB 0.65GB
Pit train Groove
DVD-ROM DVD-R/RW
0.6*2mm 0.6*2mm
0.6
650um
0.74pm 0.74pm
4.7GB
Pit train
DVD-RAM
0.6*2mm
0.6 0.6
650um 650um
0.615pm
4.7GB 4.7GB
Groove Land/Groove
14-1