Df Misfeed Check - Ricoh FT7770 Service Manual

5. DF Misfeed Check

The DF has four sensors for misfeed checks: the registration sensor, exit sen-
sor, inverter entrance sensor, and inverter registration sensor. The DF CPU
checks that each sensor has turned on or off within the specific periods
shown above.
reset by sensor activation or deactivation.
If the DF CPU determines that a misfeed condition exists, it stops the DF
motors and informs the copier of the misfeed condition.
displays "Original Misfeed."
To reset the misfeed condition, the feed-in unit safety switch (for feed-in
misfeeds) the inverter unit safety switch (for inversion section misfeeds), or
the lift switch must be actuated after the misfed originals are removed.
CFF Misfeed Check
A misfeed is detected if the CPU does not receive a pulse from the feed hole
sensor within a specified period of time. This time period varies as
follows:
570 msec:
Before the first page of a computer form reaches the exit
sensor. (The form is only being fed by the transport belt.)
420 msec:
The first page has reached the exit sensor (the exit rollers),
but has not yet accelerated to normal speed. This a1so occurs
when each subsequent page starts moving. The form attains
normal speed after moving the distance of two feed holes (one
inch).
160 msec:
The form is moving at normal speed.
A misfeed timer starts at the times specified above and is
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April, '89
The copier then