Minolta Di850 Service Manual page 93

TRAY 3 PAPER FEED UNIT
b) Lowering of up/down plate
When the paper feed tray is pulled out, the
guide lever shown below is disengaged from
the rail, thus releasing the coupling gear that
transmits the drive force of the up drive motor
3 (M21) to the drive pulleys. Then, the up/
down plate falls down mechanically by the
weight of papers.
*2 1st paper feed
To keep constant contact pressure on the paper
by the paper feed roller at the time of paper pick-
up, the weight of the paper feed roller itself is
used. The pick up solenoid 3 (SD10) moves the
paper feed swivel plate down so that the paper
feed roller mounted on the plate falls down to
touch the paper as well. Then, the paper feed
roller picks up a paper and feeds it toward the
paper conveyance unit. The first paper feed sole-
noid moves the paper feed swivel plate down
only when paper is to be fed. Otherwise, it
releases contact.
Paper feed swivel plate
Paper feed roller
Feed roller
Coupling gear
Up drive motor 3
(M21)
Tray
insertion
direction
Guide lever
Pick up solenoid
3 (SD10)
*1 Paper size detection
Length: The rear guide of the tray moves, caus-
ing the paper size detection actuator to move as
well. As a result, the two paper size detection
PS1-3 (PS38), 2-3 (PS39) turn ON and/or OFF.
Thus, the paper size is automatically determined
according to the combination of the ON/OFF
states of these PSs.
Width: The side guide of the tray moves, causing
the side guide (front) rack gear to turn the gear of
the paper size detection VR3. Thus, the paper
size is automatically determined according to the
change in the resistance value of the VR.
Paper size detection
PS1-3 (PS38),
2-3 (PS39)
Side guide (front)
2-K-2
Actuator
Rack gear
Paper size
VR gear