Samsung DVD-V940K Training Manual page 70

Circuit Operating Descriptions
(16) Fast Forward Mode
Tape fast forward operation using capstan motor.
• State input ; Press the rewind button in the stop or fast forward modes.
• Indication output ; First digit rotates in LED display.
• Output at ;
IC601 Pin 25 (CAP F/R)
(17) Rewind Mode
Tape rewind operation using the capstan motor.
• State input ; Press the rewind button in the stop or fast forward modes.
• Indication output ; First digit rotates in LED display.
• Output at ;
IC601 Pin 25 (CAP F/R)
(18) Rewind Shut-Off Mode
Tape rewind operation then power off mode.
• State input ; Press the power button in the rewind mode.
(19) VISS (VHS Index Search System)
• Index search ;
Find a certain point of the tape using high speed REW/FF and start playback. (Fig. 7-14). The detection is
obtained by adjusting the width of the control pulse. (duty cycle) When recording starts, the duty cycle of
control pulse will change and then record on the control track of the tape for 2 seconds.
REC CTL
PB CTL
• Index Detection Process
The detector block in IC601 detects the duty cycle of the control pulse input at Pin 85, 86.
When detecting the index mark, the Micom controls the next operation such as scan play.
• Intro Scan
Continues FF or REW then playback at the index mark point for about 5 seconds and repeats the operation the
end of the tape or the start sensor is detected during intro forward scan or intro reverse scan.
7-12
: Hi
: Low
100%
60 5%
(NORMAL RECORD)
Fig. 7-14 Index Recording
100%
27.5 2.5%
(INDEX RECORD)