59
YPM-MG2196ZF
2) Tracking servo system
The main equalizer of tracking servo is located in the
UPD63702AGF. Fig. 11 shows block diagram of the
tracking servo.
a) Track jump
Track jump is automatically performed by the auto
sequence function in LSI when the LSI accepts com-
mand. The system has six types of jump (1, 4, 10, 32,
32x2, and 32x3) for track jump during searching. In Test
mode, the system can select and check these jump
types and CRG move by selecting a mode. The micro-
computer sets half of the total number of track jumps
(two tracks if the total number of tracks are four), and
counts the set number of tracks by using TEC signal.
The system outputs brake pulse for a specified time (set
by the microcomputer) from the point of time when the
set number is counted, and stops the lens. Thus, track-
ing is closed, and the system can continue normal play-
back.
To improve servo withdrawal during track jump, the
system sets the brake circuit to ON for 60 ms after
brake pulse so that gain of the tracking servo can be
increased.
FF/REV in normal mode is made by continuously per-
forming single jump approximately ten times faster
than in normal playback.
TRACKING
ERROR
D/A
TD
TIN
DRIVER
TOP
TOM
IC301
BA5986FM
LENS
IC 201 UPD63702AGF
77
11
12
JUMP
PARAMETERS
DAC
DIGITAL
EQUALIZER
CONTROL
A/D
5
7
6
R303
10k
Ω
R304
27k
Ω
63
t1
t2
GAIN NORMAL
TIN
KICK
BRAKE
TEC
T. BRAKE
EQUALIZER
T. SERVO
CLOSED
OPEN
NORMAL
GAIN UP
OFF
ON
t1
TIN
TEC
(10 TRACK)
EQUALIZER
T. BRAKE
SERVO
CIN
2.8mS (4.10 TRACK JUMP)
5.8mS (32 TRACK JUMP)
GAIN UP
NORMAL
ON
OFF
OPEN
CLOSED
t2
60mS
t
Fig. 11 Tracking servo block diagram
Fig. 12 Single track jump
Fig. 13 Multi track jump
Содержание YPM-MG2196ZF
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Страница 4: ...4 YPM MG2196ZF 2 EXPLODED VIEWS AND PARTS LIST 2 1 CD MECHANISM ...
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Страница 20: ...20 YPM MG2196ZF 1 2 3 4 1 2 3 4 D C B A CN801 PU UNIT A C D 4 2 SIDE PCB B SIDE PCB SIDE A B ...
Страница 22: ...22 YPM MG2196ZF 1 2 3 4 1 2 3 4 D C B A D 4 4 MOTOR PCB B SPINDLE MOTOR M5 MOTOR PCB B D ...
Страница 23: ...23 YPM MG2196ZF 1 2 3 4 1 2 3 4 D C B A D M M4 CARRIAGE 1 12 B CN864 ...
Страница 25: ...25 YPM MG2196ZF 1 2 3 4 1 2 3 4 D C B A M M2 LOADING 1 1 4 2 I M 4 6 LOAD MOTOR PCB LOAD MOTOR PCB G H J G ...
Страница 28: ...28 YPM MG2196ZF 1 2 3 4 1 2 3 4 D C B A LOAD DOOR MODE E 4 9 FORDSW PCB I FORDSW PCB I SIDE A ...
Страница 29: ...29 YPM MG2196ZF 5 6 7 8 5 6 7 8 D C B A I FORDSW PCB I SIDE B ...
Страница 35: ...35 YPM MG2196ZF Grating waveform Ech Xch 20mV div AC Fch Ych 20mV div AC 45 0 75 60 30 90 ...