LG DRD-820B Manual page 5

2. Structure of the Photo Diode (CD)
(1) Focus Error Signal
• In case of CD Disc
This signal is generated in RF AMP IC (IC201 : TA1254F) and controls the pick-up's up and down to
focus on CD Disc.
(2) Tracking Error Signal (3-Beam Method)
• In case of CD Disc
This signal is generated in RF AMP IC (IC201 : TA1254F) and controls the pick-up's left and right shift to
find the track on CD Disc.
(3) RF Signal
• In case of CD Disc
This signal is converted to DATA signal in DSP IC (IC301 : TC9461F).
10
E
A
(A-B)
(A+B+2C)
Pick-Up module
Photo Diode
C
F
B
(E-F)
Tracking
(As seen from light
receiving side)
Infrared laser
Focusing