LG HDR676X - Signal Detection of the P;U

4-33
1
) Focus Error Signal ==> (A+C)-(B+D)
This signal is generated in RF IC (LIC121 : AN22113A) and controls the pick-up’s up and down to focus on
Disc.
2
) Tracking Error Signal (DPP Method) ==> {(A+D)-(B+C)}- k x {(EF1+EF4)-(EF2+EF3)}
This signal is generated in RF IC (LIC121 : AN22113A) and controls the pick-up’s left and right shift to find
to track on Disc.
3
) RF Signal ==> (A+B+C+D)
This signal is converted to DATA signal in DSP IC (LIC201 : MN103SA6G).
Pick-Up module
Photo Diode
Tracking
Focusing
Infr
ared Iaser
k[(F+H) - (E+G)]
(A+D) - (B+C)
(A+D) - (B+C) - k[(F+H) - (E+G)]
Offset
TE
Tp
Sub2
Main
Tp/2
Sub1
Track Center
F,E
D,C
A,B
H,G
3. SIGNAL DETECTION OF THE P/U