Xerox Paser 7400 Service Manual page 37

The Punch Unit consists of a die and hole punch (punch blade), which is driven by a a
DC motor. The unit attaches to the eccentric cam of the punch shaft. A punch home
position sensor detects the home position of the punch shaft to ensure that the punch
motor stops exactly at its home position, the punch motor stops in relation to the
count of clock pulses from the Punch Motor Clock Sensor. When the punch shaft
rotates 180 degrees from its home position, it initiates a single punch operation.
Punch Unit Components
Component
Punch mechanism
Punch Controller Board
Horizontal Registration
System
Photo sensors
Theory of Operation
Function
When sensor detects proper paper position, the punch blade
punches holes in with paper stack following 180 degree rotation
of the punch shaft.
Receives instructions from the printer and converts them to
control all punch unit operations.
Detects the home position of the punch slide unit to move it to
the appropriate position of the selected paper size.
Five LED's mount over the inlet paper path to detect the leading
and trailing edges of the paper.
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