Yamaha CRW-2100E Series Owner's Manual - page 11

Introduction

2

*1 Pure-Phase Laser System (patent applied for)

Technology that reduces phase interference of the laser beam, so that it shines accurately on the disc.

*2 Jitter value

An important measure of recording quality. This has been improved 25% compared with Yamaha models

not using this technology.

*3 Running OPC (Optimum Power Control)

CD-R/RW discs vary by manufacturer in their recording characteristics, and the laser output required to

write data differs by disc. Running OPC is technology that solves this problem by automatically adjusting

the output of the laser according to the material of the disc on which data is being written.

*4 If you attempt to write at 16X or 12X speed but the CRW2100E drive detects that the quality of a target

CD-R disc is inappropriate for such speeds, the drive will automatically slow down the writing speed

optimally for the disc.

About Partial CAV (Constant Angular Velocity)

Writing to a CD-R disc is normally done using CLV (Constant Linear

Velocity) method.  In this method, the disc rotation speed will be so adjusted

as to keep a constant data transfer rate at any portion of the disc.  In other

words, the disc rotation speed will vary in CLV writing.

In contrast, CAV (Constant Angular Velocity) method uses a constant disc

rotation speed at any portion of the disc whereas the data transfer rate will

vary.  Because CAV method has an advantage to largely increase the data

transfer rate with a minimum load to the drive’s mechanism (compared to

CLV’s rotation speed adjustment), many of current CD-ROM drives use CAV

method.

CD formats define the constant linear density of written data (data should be

written onto the disc track in the constant pitch) so that amount of recorded

data per disc rotation will increase as the writing point moves from the inner

to the outer.  In other words, in CAV writing the outer portion has an

increased data transfer rate.

The CRW2100E drive uses CAV method in the inner portions as well as CLV

method in the outer portions (Partial CAV) in order to enable up to 16X-

speed writing.  The drive will control the disc rotation speed to start writing

at 12X speed in the inner portions, gradually accelerating up to 16X speed

and maintaining 16X speed in the outer portions.