Samsung Electronics
7-23
Circuit Descriptions
7-22
Samsung Electronics
7-6 SERVO
7-6-1 Outline
SERVO system of DVD is divided into 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).
7-5-3. Low pass filter VF1, VF2
VF1 and VF2 remove quantization noise occurring in the course of D/A conversion as low pass filter with
cut-off frequency of 6.75MHz. VR5 and VR6 are input impedances and convert the level of subcarrier.
Fig. 7-40 Frequency features of VF1,VF2
7-5-4 Amplifier
VQ1 is buffer and the gain is amplified through VQ2, VQ3. The main factors which determine the gain are VR10
and VR11, and the gain is 1+VR11/VR10. VR12 is the main factor that determines the offset of output signal of
amplifier unit and the rate is approx. VR 12/(VR10+VR11)
Fig. 7-41 Amplifier
7-6-5 Buffer
VQ4, VQ5, and VQ6 are buffer unit and circuit that double the drive power so as to output without signal conver-
sion when connected with exterior devices. VC11 is an AC coupling capacitor, VR19 is an essential impediance at
video signal interface and being matched with the impediance in the input block of exterior devices determines the
level of video signal.
0(dB)
-3(dB)
6.75MHz
Frequency
GAIN(dB)
Video input
Video output
+8V
VR9
VR12
-8V
+8V
VR11
VR10
VQ2
C1623
VQ3
A812
Содержание DVD-907
Страница 11: ...Precautions 2 4 Samsung Electronics MEMO ...
Страница 53: ...Disassembly and Reassembly 5 6 Samsung Electronics 5 1 2 PCB Locations Fig 5 6 PCB MAIN PCB SMPS PCB FRONT ...
Страница 60: ...Disassembly and Reassembly Samsung Electronics 5 13 PCB MAIN PCB SMPS PCB FRONT Fig 5 13 5 2 2 PCB Locations ...
Страница 67: ...Disassembly and Reassembly 5 20 Samsung Electronics MEMO ...
Страница 83: ...Circuit Descriptions 7 30 Samsung Electronics MEMO ...
Страница 114: ...Samsung Electronics 10 1 10 Packing Diagram ...
Страница 115: ...Samsung Electronics 10 2 Packing Diagram MEMO ...
Страница 118: ...13 2 Samsung Electronics 13 1 MAIN PLAY B D SILK COMP 13 1 1 COMPONENT SIDE ...
Страница 119: ...13 3 Samsung Electronics 13 1 2 SOLDER SIDE PLAY B D SILK SOLD PCB Diagrams ...
Страница 120: ...13 4 Samsung Electronics 13 2 FRONT DVD 907 ...
Страница 121: ...13 5 Samsung Electronics 13 3 FRONT DVD 927 ...
Страница 122: ...13 6 Samsung Electronics 13 4 SMPS ...
Страница 123: ...13 7 Samsung Electronics 13 5 DECK ...
Страница 124: ...13 10 Samsung Electronics 13 7 SCART JACK ...
Страница 125: ...14 1 Samsung Electronics 14 Wiring Diagram ...
Страница 127: ...15 2 Samsung Electronics 15 1 1 MICOM 15 1 MAIN Rev 1 ...
Страница 128: ...15 3 Samsung Electronics Schematic Diagrams 15 1 2 SERVO ...
Страница 129: ...15 4 Samsung Electronics Schematic Diagrams 15 1 3 DATA PROCESSOR ...
Страница 130: ...15 5 Samsung Electronics Schematic Diagrams 15 1 4 A V DECODER ...
Страница 131: ...15 6 Samsung Electronics Schematic Diagrams 15 1 5 AUDIO ...
Страница 132: ...15 7 Samsung Electronics Schematic Diagrams 15 1 6 VIDEO ...
Страница 133: ...15 8 Samsung Electronics Schematic Diagrams 15 1 7 CONNECTOR ...
Страница 134: ...15 9 Samsung Electronics 15 2 1 DVD 907 15 2 FRONT ...
Страница 135: ...15 10 Samsung Electronics Schematic Diagrams 15 2 2 DVD 927 ...
Страница 136: ...15 11 Samsung Electronics 15 3 SMPS ...
Страница 137: ...15 12 Samsung Electronics 15 4 PICK UP DECK ...
Страница 138: ...15 13 Samsung Electronics 15 5 MAIN Rev 2 15 5 1 MICOM ...
Страница 139: ...15 14 Samsung Electronics Schematic Diagrams 15 5 2 SERVO ...
Страница 140: ...15 15 Samsung Electronics Schematic Diagrams 15 5 3 DATA PROCESSOR ...
Страница 141: ...15 16 Samsung Electronics Schematic Diagrams 15 5 4 A V DECODER ...
Страница 142: ...15 17 Samsung Electronics Schematic Diagrams 15 5 5 AUDIO ...
Страница 143: ...15 18 Samsung Electronics Schematic Diagrams 15 5 6 VIDEO ...
Страница 144: ...15 19 Samsung Electronics Schematic Diagrams 15 5 7 CONNCTOR ...
Страница 145: ...15 20 Samsung Electronics 15 6 SCART JACK ...
Страница 146: ...ELECTRONICS Samsung Electronics Co Ltd May 1998 Printed in Korea AH68 20198A ...