Punch Unit; Adjusting Punching Positions - Lexmark X850e Service Manual

Punch unit

This section describes the media punching operation of the punch.
Two types of punch are provided: the 2/3-hole type and the 2/4-hole type.
The following explains the 2/3-hole type (2-hole/3-hole auto-switching).
Every type has the same construction, except for the sensor (punch hole select) that is provided for the 2-hole
type and 3-hole type only.

Adjusting punching positions

The punching positions from the media edge in the direction of feed are determined by gently pressing the
media against the three punch media stopper assemblies.
The three punching positions from the media edge in the direction of media width are determined by the
following method.
• Activate the punch carriage shift motor assembly, and move the punch to the front side until the sensor
(punch carriage shift HP) turns low.
• Reversely rotate the motor, and move the punch to the rear side until the sensor turns high to determine the
home position.
• The punch carriage shift motor assembly is activated to move the punch to the front until the sensor (punch
unit side registration 1) and the sensor (punch unit side registration 2) detects the media edge, and then the
punch is further moved to the front according to the pulse-number determined by the media size. (The
punch carriage shift motor assembly stops at this position.)
Sensor (punch cam front)
Sensor (punch
hole select)
Sensor (punch unit HP)
Sensor (punch unit motor encoder)
Sensor (punch carriage shift HP)
Punch unit motor
Punch carriage shift motor assembly
Sensor (punch unit side
registration 2)
Sensor (punch unit side
registration 1)
7500-XXX
1-13
General information