Media Level Sensing - Lexmark T650 Service Manual

4062-XXX

Media level sensing

The media level for the media tray assembly is triggered by the actuator flag positioned in the two
photointerrupter sensors in the pick arm bracket assembly. The actuator flag blocks and unblocks the two
sensors in different sequence; it determines whether the paper tray is empty, low, or full.
Note: Media level sensing through sensor blocking sequence
Pick arm assembly
Media out actuator
Sensor (media low)
Pick roll assemblies
Since all media trays are functionally equivalent in terms of the switch (media size), sensor (media empty),
sensor (media low), only the components of one tray are described here.
The pick arm assembly is a mechanical unit supplying media from the media tray assembly to the printer. The
driving force, from the pick arm drive motor on the pick arm assembly, is transmitted to the two pick rolls to
feed media.
When the pick rolls pick up media, the remaining media decreases, and the media out actuator will lower and
interact with the sensor (media low) and sensor (media empty) to determine the amount of media remaining.
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Service Manual
250-sheet tray Sensor A
Tray full unblocked
Tray low blocked
Tray empty blocked
550-sheet tray Sensor A
Tray full unblocked
Tray low blocked
Tray empty blocked
Sensor B
unblocked
unblocked
blocked
Sensor B
blocked
blocked
unblocked
Sensor (media empty)
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