Samsung SV-DVD50 Service Manual page 149

7-14 DVD Servo
(1) Outline
SERVO system of DVD is Compoced of Focusing SERVO, Tracking SERVO, SLED Linked SERVO and CLV
SERVO (DISC Motor Control SERVO).
1) Focusing SERVO : Focuses the optical spot output from object lens onto the disc surface. Maintains a uniform
distance between object lens of Pick-up and disc (for surface vibration of disc).
2) Tracking SERVO : Make the object lens follow the disc track in use of tracking error signal (created from Pick-up).
3) SLED Linked SERVO : When the tracking actuator inclines outwardly as the object lens follows the track during
play, the SLED motor moves slightly (and counteracts the incline).
4) CLV SERVO (DISC Motor Control SERVO) : Controls the disc motor to maintain a constant linear velocity
(necessary for RF signal).
(2) Block Diagram
DECK
DISC
DCN3
4
5
DCN1
13
14
LDCD
9
PDCD
7
24
18
2
22
20
19
23
5
3
12
11
DCN2
11
12
10
8
4
3
5
7
9
1
2
RIC1 (S5L1463)
4
5
2
3
17
18
14
11
12
13
22 23 24 25
to ZIC1 (Vaddis5E)
6
30 29 32 33 35 34
28
27
5
36
6
SIC3 (FAN8728)
37
4
18
2
21
14
25
13
46
15
1
3
Fig. 7-44
Circuit Operating Descriptions
71
31
29
8
From
ZIC 124/25
SIC1 (S5L1455)
VREF
26
28
13
14
3
152
7-47