Paper Size Change And Detection - Ricoh FT5540 Service Manual

5.2 PAPER SIZE CHANGE AND DETECTION

Three paper guide posts [A] at the front and rear sides of the large capacity tray align the
paper in the tray. The two sets of guide posts are connected by a rack and pinion system
which keeps the guide posts equidistant from the center of the tray.
The guide posts move as the paper size dial [B] turns. As the dial is rotated, the size lever
tracks a cam groove [C] on the surface of the dial. Movement of the size lever is transferred to
the front post rack of the rack and pinion system. Any movement of the front post rack [D] is
transferred by the pinion to the rear post rack [E].
Paper Size Detection
The paper size detection system of the large capacity tray is similar to that of the cassette.
Both systems use the same data bus, signals, and type of sensor. However, the mechanism
of paper size detection in the large capacity tray is different.
When the paper size dial is rotated to a standard paper size, one of the actuator plates [F]
enters the paper size sensor [G]. At the same time, the pin on the leaf spring [H] drops into a
notch on the inside rim of the dial and the positioning switch [I] becomes de-actuated. This
signal allows the copier CPU to monitor data from the paper size sensor. The paper size of the
tray is then displayed on the indicator screen where the size of the lower cassette is usually
displayed.
When the paper size dial is positioned at a non-standard paper size, the positioning switch is
actuated. At this time, the Load Paper indicator lights and no paper size is displayed on the
indicator screen.
10-7
31 August 1989