17
The differences of CD-R/CD-RW discs and General CD-ROM
1. Recording Layer
Recordable CD has a wobbled pre-groove on the surface of disc for laser beam to follow track.
2. Disc Specification
Read-only Disc
CD-R and CD-RW Disc
3~1
1T
1.6um
0.4~0.5 um
(Pit)Groove
Land
Track pitch(p)
Radial Direction
Iw
A
O
a
a
Groove
Land
Radial Error Signal
The Groove wobble
Average center
Actual center
CD-ROM (READ-ONLY DISC)
a=30nm
ITEM
CD-ROM
CD-R
CD-RW
Standard
Yellow Book
Orange Book II
Orange Book III
Record
Not available
Write once
Re-Writeable
Tracking Signal I11/Itop
> 0.6
> 0.6
0.55 > M
11
> 0.70
(HF Modulation)
Read Laser Power(mW)
< 0.5 mW
< 0.7 mW
< 1.0 mW
Jitter
< 35 nsec
< 35 nsec
< 35 nsec
Reflectivity (R
top
)
70 %
65 %
15 % ~ 25 %
Remark)
Write Laser Power(mW)
14-65 mW
6-45 mW
