Media Tray Assembly; Front Media Tray Guide And Rear Media Tray Guide; Media Tray End Guide; Bottom Plate - Lexmark W850n Service Manual

4024-110

Media tray assembly

It is necessary to adjust the front side guide, rear side guide and end guide on the media tray assembly to match
the media size.

Front media tray guide and rear media tray guide

The front media tray guide can be adjusted to different media sizes by moving it to the front or rear. These
guides come into contact with the front and rear edges of the media and hold it in position.
The rear side guide moves together with the front side guide.

Media tray end guide

The media tray end guide assembly is designed so that it can adapt to the media length in the media feed
direction by moving the end guide to the left or right.

Bottom plate

The force pushing up the bottom plate is transmitted by the driving force of the media feed lift motor on the
media feed unit assembly to the lift up shaft through the drive gear 13/60T and sector gear 12T. The bottom plate
is pushed up by turning the lift up shaft, which causes the supplied media to get in contact with the pick roll
assembly.

Media feed unit assembly

Since tray 3 and tray 4 are functionally equivalent in terms of the switch (media size), sensor (media out), sensor
(media level) and sensor (pre-feed), only the components of one tray are described here.
The media feed unit assembly is a mechanical unit for supplying media from the media tray assembly to the
printer. The driving force from the media feed lift motor on the media feed unit assembly is transmitted to the
three roll assemblies to feed media.
When the pick roll picks up media and the remaining media decreases, the actuator of the sensor (media level)
lowers accordingly. When the sensor (media level) detects the lowering, the media feed lift motor is activated to
turn the lift up shaft and the bottom plate is lifted accordingly. The remaining media is ready to be fed out.

Media feed lift motor

This motor is activated to feed media and to lift the bottom plate. When feeding media, it rotates forward to drive
the pick roll. When lifting the bottom plate, it rotates in reverse to drive the tray module gears to turn the lift up
shaft.

Switch (media size)

This switch (media size) changes the setting of the size of media supplied from each media tray assembly. A
signal indicating the set size is transmitted as voltage to the printer engine card assembly.

Sensor (media out)

If media runs out in the media tray assembly, the media out actuator lowers and the flag of the media out
actuator that has stayed in the sensor (media out) sensing area leaves there. Thus, the sensor light is
transmitted. When the sensing area is blocked (media is present), the signal is off.

Sensor (media level)

This sensor detects, by the actuator position, whether media in the media tray assembly, is lifted. When the flag
of the actuator leaves the sensor (media level) sensing area, the sensor detects that the media has been lifted.
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General information