Samsung DVD-V940K Training Manual page 99

7-11 DVD Servo
(1) Outline
SERVO system of DVD is Compoced of Focusing SERVO, Tracking SERVO, SERVO and CLV SERVO
(spindle motor 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
TRINO
DISC
DECK
SP+ SL+
Tr+/-
F+/F-
SP- SL-
CD/DVD
LD select
RIC1
A
B
C
ES6603
D
E
F
MIC1
FAN8004
(TL3472)
MIC2
Checking the spinde
(clockwise or wnhlerwise)
Fig. 7-37
Circuit Operating Descriptions
REAC
TE
FE
U1
Vibratto II
Spindel
Focusing
Tracking
SLED
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