2-45
2.7.3 Tracking Error information
( 0 )( 9 ) ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( 7 ) ( 8 ) ( 9 ) ( 0 ) ( 1 )
Flame Pulse
Track Pulse
(Track reference
Number)
HID
(HEAD SW)
Tape pattern
(Pilot signal)
( f1 ) ( f0 ) ( f2 ) ( f0 ) ( f1 ) ( f0 ) ( f2 ) ( f0 ) ( f1 ) ( f0 ) ( f2 ) ( f0 ) ( f1 )
HEAD
FFh
80h
00h
Tracking Error
Tracking is the
center
Tracking is off (1) Tracking is off (2)
(CH2) (CH1) (CH2) (CH1) (CH2) (CH1) (CH2) (CH1) (CH2) (CH1) (CH2) (CH1) (CH2)
Fig. 2-7-2 Tracking Error explanation (NTSC)
Fig. 2-7-2 shows the tracking error detection method. The DVC multirecords three kinds of pilot signals of
f0 (0), f1 (465 kHz) and f2 (697.5 kHz) on each track. When the CH1 head traces the track on which the f0
pilot signal is recorded in playback, the crosstalk component of the pilot signals of f1 and f2 recorded on
the preceding and following tracks are detected and compared. When the tracking is well controlled, the
error rate is 80h that is the intermediate value between 00h and FFh. When the tracking deviates in the f1
track side, the error rate is lower than 80h. When the tracking deviates in the f2 track side, the error rate is
higher than 80h. When the CH2 head is tracing the track, the error rate is 00h or FFh because only the f1
or f2 component is detected.
Such the tracking error information is digitally processed by the ATF inside the DV-EQ IC and the
processed data is transmitted to the DECK CPU through the 16-bit bus. The DECK CPU controls the
capstan servo according to the data transmitted from the DV-EQ IC.
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