LG Electronics GSA-4168B Signal detection of the P/U, Track Center, Tp/2, Main, Sub2, kF+H - E+G

3. Signal detection of the P/U

Pick-Up module

Photo Diode

1) Focus Error Signal ==> (A+C)-(B+D)

Infrared Iaser

Focusing

Tracking

This signal is generated in RF IC (IC101 : R2S35002) 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 (IC101 : R2S35002) 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 (IC301 : R8J32007).

Track Center

Tp/2 Sub1

F,E

	Main	D,C
		A,B
Sub2		H,G

	Tp
	k[(F+H) - (E+G)]
Offset
	(A+D) - (B+C)
TE	(A+D) - (B+C) - k[(F+H) - (E+G)]

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