Sony DVP-S7000 (serv.man2) Service Manual ▷ View online
– 106 –
5-3-4.
Tilt Control
At CD playing, the tilt control is made using the tilt sensor of optical pickup in a period from
the start of play (start of spindle rotation) to the completion of TOC data reading.
The tilt control in this case is same as tilt servo control by tilt sensor during DVD playing.
The tilt servo is turned off after the completion of TOC data reading.
The tilt servo mode ON/OFF control is done with the tilt servo amplifier in the IC001
(SSI33P3720) on the TT-701 board.
– 107 –
5-4.
Disc Loading and Chucking
Disc loading, unloading, and chucking operations are performed with one DC motor. Its block
diagram is shown in Figure 5-22.
Figure 5-22.
Loading block diagram
5-4-1.
Motor Driver
The motor driver IC (IC891) determines the output potential (voltage level to drive the
motor) according to the voltage applied to the input (!¶P). When input is +2.5V, namely
when the potential is same as reference voltage applied to the IC891@£P, its outputs OUT+
(!™P) and OUT– (!£P) become both +6V, and consequently, the motor does not rotate and
the tray stands still (braking status).
If higher voltage than +2.5V is applied to the input, the voltage at !™P is higher than +6V,
and voltage at !£P is lower than +6V, then the motor rotates forward and the tray moves in
the loading direction. On the contrary, if lower voltage than +2.5V is applied, the voltage is
lower than +6V at !™P and higher than +6V at !£P, then the motor reverses and the tray
moves in the unloading direction.
Also, if “H” signal is applied to the MUTE pin (@™P), the motor brake is open regardless of
input level.
IC891
Loading/Tilt Driver
MB-75 BOARD
TT-701 BOARD
IC136
Drive Control
IC145
IC722
D/A Converter
IC149
IC140
CHUCK
TRAY
12
OUT+
11
CN885
10
11
CN007
Loading
Motor
Motor
LDMT+
LDMT–
10
22
CN980
22
+5V
CN005
23
23
S001
TRAY OUT
Sensor
TRAY OUT
Sensor
PH001
5
13
IC983
4053
LOAD/UNLOAD
14
LOADCNTR
11
+2.5V
LOADON
LT-MUTE
13
OUT–
23
+2.5V
VREF
17 IN
22 MUTE
M
1
CN004
2
12
Buffer
Extended
Output
Port
12
100
SRAM
IC151
Extended
Input
Port
4
3
+5V
R074
1K
D601
+5V
R121
100K
100K
R147
100K
100K
IC090
System Control
IC021
Interface Micom
85
AD1
11
CN980
FP-411 BOARD
R064
10K
CHUCKING
Sensor
+5V
R063
100
R065
10K
10
CN101
AD1
S109
O/C
– 108 –
5-4-2.
Tray Position Detection
The tray position is detected with a chucking sensor PH001 and a tray out sensor S001 on
the TT-701 board. These signals are entered from TT-701 board to the MB-75 board through
a flexible flat cable, and converted into the data by IC151, 140, then entered to the drive
control (IC136).
The relation between tray position and sensor signals is as shown below:
Mode
<TRAY OUT (CN005@£)>
<CHUCKING (CN005@™)>
Tray out position
H
L
Tray operating
L
L
Chucking position
L
H
– 109 –
5-4-3.
Each Operation
The tray operation is controlled with LOAD/UNLOAD, LOADON, and LT MUTE signals
output from the drive control. The contents of respective signals are as follows:
• LOAD/UNLOAD signals : Determine the speed and direction of loading and unloading.
• LOADON signal
: Turns on/off tray operation.
• LT MUTE signal
: Opens the motor brake.
Also, the OPEN/CLOSE command is entered from S109 on the FP-411board, and based on
its data line (AD1) level, the interface microcomputer on the MB-75 board makes judgment.
(1) Loading
LOAD/
<LOADING operation>
UNLOAD
LOADON
LT MUTE AD1
• OPEN/CLOSE button is pressed
about +2.5V
L
H
GND
↓
• Loading
about +4.3V
H
L
+5V
↓
Tray IN
• Chucking sensor (PH001) active
about +4.3V
H
L
+5V
↓
Chattering elimination (about 10msec)
• Brake
about +4.3V
L
L
+5V
↓
Braking
• Stand still
about +2.5V
L
L
+5V
(Brake kept applied)
(2) Unloading
LOAD/
<UNLOADING operation>
UNLOAD
LOADON
LT MUTE AD1
• OPEN/CLOSE button is pressed
about +2.5V
L
L
GND
↓
• Unloading
about +0.9V
H
L
+5V
↓
Tray OUT (about 100msec)
• Unloading (PWM operation)
about +0.9V
H/L
L
+5V
↓
Tray OUT (about 200msec)
repeat
• Tray out sensor (S001) active
about +0.9V
H
L
+5V
↓
Chattering elimination (about 10msec)
• Brake
about +0.9V
L
L
+5V
↓
Braking (about 500msec)
• Stand still
about +2.5V
L
H
+5V
(Motor is released)
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