LG RH200MH/HDRF899X Service Manual page 81

Hdd/dvd recorder

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To make recordings, it is necessary to modulate the write pulse, which is called "Write Strategy".

There can be many types in Write Strategy. Typically Write Strategy for DVD ±R has NMP(Non Multi-Pulse) type and

MP(Multi-Pulse) type. In NMP type each single mark is created by subsequent separated short pulses. In MP type each

single mark is created by one continuous pulse.

Write Strategy for DVD ±RW has Type 1 and Type2. In Type 1 the mark with nT width is created by one top pulse and (n-2)

multi-pulses. Thus mark 3T is made by one top pulse and one multi-pulse. In Type 2 the mark with nT width is created by

one top pulse and (n-3) multi-pulses. Thus mark 3T is made by one top pulse only.

RL-02A uses MP type Write Strategy for DVD ±R and Type 1 for DVD ±RW as shown below.

Recording data

Write pulse

for DVD R

Zero Level

Write pulse

for DVD RW

Zero Level

Po :Write Power (Peak Power)

Pe :Erase Power

Pb :Bias Power

Twd ( 8T )

Ttop

Tmp

Tcl

4-20

Twd (3T )

Ttop

Tmp

Tcl

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