8
CX-692
1.5.2 TRACKING SERVO SYSTEM
The main equalizer for the tracking servo system is being provided
inside the TC9461F(IC401). Fig. 9 shows the block diagram of the
tracking servo system.
Tracking closing and tracking jumping movements are being made
automatically by the auto-sequencing function incorporated inside
the servo DSP (IC401:TC9461F) after the LSI receives the command
from the microcomputer(IC501:PD5511A). This system is being
equipped with the lens kick mode which is to be used for jumping
of 255 tracks or less and the feed kick mode which is to be used for
jumping of 512 tracks or more as the track jumping means to use
for searching. Also, tracking closing movements are being
realized by the zero-track jumping command under the lens kick
mode. Under the test mode, 14 types of jumps, namely, 1, 4, 8,
16, 32, 64, 100, 255, 512, 1,000, 4,095, 4,096, 16,384 and 32760 can
be used for checking by making the mode selection accordingly.
Under the normal mode, jumps of:
CD: 1, 2, 4, 8, 10, 16, 32, 64 and 100
DVD: 1, 2, 3, 4, 8, 12, 16, 32, 64, 100 and 255
are available for lens kicks.
2
3
1
T.BAL
CIRCUIT
T ACT.
26
27
25
DRIVER
IC304
BA6797FM
SERVO DSP
IC401
TC9461F
44
TRO
TEI
41
6
5
7
RF AMP
IC103
TA1254AF
20
46
47
TEO
P1TN
P1TP
VR21
VR21
VR25
VR21
IC108
NJM3404AM
47
TE IC
IC107
PA0065AM
B1
B2
B3
B4
RFA
IC106,109
TC7WU04FU
19
Fig. 9
