Detecting The Paper Level - Kyocera Mita KM-4530 Service Manual

2BC/D

(1-1) Detecting the paper level

The mechanism of paper level detection is same for drawers 1 and 2, so only drawer 1 is explained here.
The drawer operating plate for making paper in the drawer come into contact with the forwarding pulley is activated by
raising the lift operating plate. The lift operating plate is attached on the lift shaft to which the upper lift motor (LM-U) is
connected. When the drawer is set to the copier or the lift limit switch 1 (LILSW1) is turned off as the paper on the lift is
used for copying, the upper lift motor (LM-U) will operate until the leading edge of the paper on the drawer operating
plate turns lift limit switch 1 (LILSW1) on. The tilting up angle of the lift operating plate (lift motor drive shaft angle) is
therefore small when the paper level is low, and large when the paper level is high. The upper lift motor (LM-U) includes
a circuit that converts the tilting up angle into 2-bit digital data by dividing the angle into four levels and outputs the data
as paper level detection signals (UPLESW1, UPLESW2). The engine PCB (EPCB) judges the amount of paper
remaining with four levels of full, 3/4, 1/2, and 1/4 based of the UPLESW1 and UPLESW2 signals and judges also
exhaustion of paper when paper switch 1 (PSW1) is not turned on even if the lift limit switch (LILSW1) is turned on. The
PCB, therefore, detects five levels of the amount of paper remaining in total.
Lift motor upper drive
shaft angle
57.17 to 80.0°
41.35 to 57.17°
28.54 to 41.35°
0 to 28.54°
2-1-2
Drawer 1
Lift operating plate
Paper level detection
output signal level
UPLESW1 UPLESW2
H
L
L
H
Figure 2-1-2 Paper level detection
UPLESW1
CN17-3
UPLESW2
CN17-1
LM-U REM
CN17-5
PSW1
CN7-9
LILSW1
CN7-6
EPCB
UPLESW1
CN17-8
UPLESW2
CN17-6
LM-L REM
CN17-10
PSW2
CN7-25
LILSW2
CN7-22
Figure 2-1-3 Paper level detection section block diagram
Lift limit switch 1
Drawer operating plate
Lift shaft (lift motor upper drive shaft)
Amount of
paper
remaining
1/4
L
1/2
L
3/4
H
H Full
LILSW1
LM-U
LILSW2
LM-L
Paper switch 1
PSW1
PSW2