Pioneer YPM-MG2196ZF Service Manual page 60

YPM-MG2196ZF
b) Brake circuit
Servo withdrawal will deteriorate during setting and
track jump. Thus, the system uses the brake circuit to
provide stable withdrawal to servo loop.
The brake circuit detects the direction of lens move-
ment, and outputs only drive signal in the opposite
direction from the lens movement. Thus, the system
delays the speed of the lens movement to stabilize
withdrawal of the tracking servo.
The system judges sliding direction of track from TEC
and MIRR signals, as well as the relationship of their
phase.
TEC
TZC
(TEC "SQUARED UP" )
(INTERNAL SIGNAL )
MIRR
MIRR LATCHED AT
TZC EDGES
SWITCHING PULSE
EQUALIZER OUTPUT
(SWITCHED)
DRIVE DIRECTION
Note: In the illustration, the phase of equalizer output is shown as the same as with that of TEC.
60
LENS MOVING FORWARDS
(INNER TRACK TO OUTER)
REVERSE
Fig. 14 Tracking Brake Circuit
LENS MOVING BACKWARDS
FORWARD
Time