Circuit Descriptions
Samsung Electronics
7-25
Circuit Descriptions
7-24
Samsung Electronics
1) FOCUSING SERVO
(1). FOCUS INPUT
The focus loop is changed from open loop to closed loop, and the triangular waveform moves the object lens up
and down (at pin 48 of SIC7 during Focus SERVO ON.) At that time, S curve is input to pin 43 of SIC7.
SBAD (pin 44 of SIC7) signal, summing signal of PD 1, B, C, D, is generated, and zero cross(2.1V) point
occurs when S curve is focused and SBAD signal exceeds a preset,constant value. The focus loop is changed to
closed loop, and the object lens follows the disc movement, maintaining a constant distance from the disc.
(these operations are same in CD and DVD).
Fig. 7-43
(2). PLAY
When focus loop closes the loop during focus servo on, both pin 43 and pin 48 of SIC7 are controlled by VREF volt-
age(approx. 2.1V), and pin 1, 2 of SIC4 are approximately 4.5V.
2) TRACKING SERVO
(1). NORMAL PLAY MODE
(1) For DVD
Composite : The signal output from PD A, B, C, D of Pick-up, the tracking error signal (RIC2 pin 14) uses the
phase difference of A+C and B+D in RIC2, and inputs to terminal 8 of RIC1. The signal is output to RIC1 pin 21,
and input to SIC7 pin46(TEI). Then, it is output to SIC7 pin 49 via digital equalizer, and applied to the tracking
actuator through SIC4. Pins 46, 49 of SIC7 are controlled by VREF(approx. 2.1V) during normal play.
Meanwhile, DVD repeats the track jump from 1 to 4 in inner direction at normal play ( because data- read speed
from disc is faster than data output speed on screen).
Vref
Vref
1.5V
Pin48 of SIC17 (FOO)
Pin43 of SIC7 (FEI)
Pin44 of SIC7 (SBAD)
7-6-3 Operation
7-6-2 Block diagram
Fig. 7-42
DISC
SLED M/T
HALL
PCB
LD
PD
SPINDLE M/T
CN1
HA1+
HA1–
HA2–
HA2+
SLED+
SLED–
AO
DO
CO
BO
FO
EO
PD
LD
F–
T+
T–
F+
SPINDLE
FOCUSING
TRACKING
SIC2
SSC9502D
RIC1
TA1236F
MIC1
TMP 93CS41F
SIC7
TA942ØF
DIC1
TA90A19F
SIC4
BA5924
SIC5
BA6840
RIC2
TA1253F
+
+
12
2
1
23
22
17
18
12
11
2
7
23
22
7
34
34
55
12
51
52
1
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 ...