Page 2
CX-3150
3
5 678
567
8
C
D
F
A
B
E
-
++
OFFSET ADJ
1+(Pfbal/0x10000)
1+(Pfbal/0x10000)
1-(Pfbal/0x10000)
Analog block
Servo block
FE+
Pfepofs
-
++
OFFSET ADJ
FE-
Pfenofs
1+(Pfbal/0x10000)
1-(Pfbal/0x10000)
1+(Pfbal/0x10000)
1-(Pfbal/0x10000)
+ VIN6
15- 92
+ VIN7
13- 93
+ VIN8
11- 94
+ VIN5
16- 91
CN1101
B4 B3
B2 B1
-
Dfesv
FE x1 or x4
-
++
OFFSET ADJ
Analog block
Servo block
TE+
Pfepofs
-
++
OFFSET ADJ
TE-
Pfenofs
+ VIN2
15- 96
+ VIN3
13- 97
+ VIN4
11- 98
+ VIN1
16- 95
CN1101
B4 B3 B2 B1
-
Dfesv
TE x1 or x4
-+
-+
-+
-+
EQ
EQ
EQ
EQ
PC
PC
-
++
OFFSET DAC
Analog block Servo block
TE+
Pfepofs
-
++
OFFSET DAC
TE-
G
G
Pfenofs
+ VIN9
VREFH20 k-¦
VHALF 17-
CN1101
A
-
Dfesv
TE -6dB 15dB(3dB STEP)
-6dB 15dB(3dB STEP)
30kHz
30kHz 0dB/12dB
0dB/12dB
+ VIN10
VREFH20 k-¦
VHALF 10- C
1.1.2 FE Generation Circuit
Focus Error (FE) Generation Circuit
Each of input signals from B1 to B4 which had been quartered by PU within the analog block is input to IC 1501
passing through the resistance and becomes a signal of FE+=
-(B1+
B3) and FE -=-(B2+
B4) after adding a focus
offset adjustment value. Then, the signal is AD-converted within the servo block and adds an offset cancel value
to become FE, generating a signal of FE=
(FE+
)
-(FE -).
1.1.3 TE Generation Circuit
Trackings Error (TE) Generation Circuit
For DVD, TE is generated, with the application of a phase contrast method, from the phase difference of (B2+
B4)
and (B1+
B3). For CD, TE is generated, with the application of a 3-beam method, by sending the signal to the
variable amp set for the tracking offset adjustment via outer-attached resistance and then by AD-converting it to
make the formula of TE=
A
-C.
DVD (TE from phase difference)
CD (3-beam TE)
