LG RH1777 Service Manual page 82

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
Po
Pb
Ttop
Po
Pe
Pb
Tmp
Tmp
Tcl
4-20
Twd (3T )
Ttop
Ttop
Tmp
Tcl