(1) Focus Error Signal
(A-B)
•
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)
(E-F)
•
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
(A+B+2C)
•
In case of CD Disc
This signal is converted to DATA signal in DSP IC (IC301 : TC9461F).
2. Structure of the Photo Diode (CD)
Infrared laser
Pick-Up module
Photo Diode
Tracking
Focusing
10
E
F
C
B
A
(As seen from light
receiving side)