Canon NP-70 Service Manual page 58

NP•70
3-17
Block
Actions Occurring
The forward advance of the copyboard releases MS 14 (actuated in STEP 7CH ),
STEP 9CH
and permits the feeding of the copy paper up to the drum for transfer of the
image to the paper. Additionally, C25 begins discharging to hold relay K10
energized until after the next MS3A pulse.
The copy paper exits the machine at this time, if the copier is in the second or
later copy cycle. With this action, the jam detection ckt. resumes its inter-
cycle condition and awaits the next passage of copy paper through the machine.
STEP LOCH
The copyboard advances across MS 10 and signals a change of copyboard drive
motion -clutch CQ2 is energized to drive the copyboard back to the normal
starting position. Capacitor C 16 is held by the change of voltage from D 16 to
D17.
STEP 11CH
As K10 is still ON, the actuation of MS3A by the rotating drum energizes relay
K11 to turn the jam circuit ON. This turn-on occurs in the first copy cycle and
K11 will remain energized until after the last copy exits the machine. Thus,
MS3A actuation in the second or later copy cycles will cause no change in the
jam detection ckt.
STEP 12CH
STEP 13CH
Capacitor C25 finishes the discharging action begun in STEP 9CH and causes
K10 to deenergize. Should this be the last copy, K11 is now set to be turned
OFF when the next MS3A pulse occurs. However, if further copying is being
performed, K10 will again be energized to ensure K11 is held ON for jam de-
tection.
(both
In this step the copyboard motion stops as it returns to the starting position.
If no further copying operation are to be performed, capacitor C 16 will start its
8.0 second discharge time, known as the Second Feed Interval. In the case of
repeat copying, C 16 does not start to discharge but remains held for the next
copy cycle by voltage through D 16.
STEP 14CH
last and
repeat)
In last copy operation, the paper begins to exit the machine. As the use of
varying sizes of paper is possible, this time and drum position is approximate.
However, the paper must start blocking the photocell before the drum reaches
50° in order to prevent jam circuit operation.
STEP 15CH
(last only)
STEP 15CH
The copyboard is released so that the next copy cycle can begin as the drum
reaches 0°. This is the same as STEP 3C
(repeat only)
STEP 16CH
SL7 is enabled for the purpose of jam detection. This is the same as
(last copy)
STEP 6CH .
© CANON INC.
Second Printing-June, 1974