Panasonic UF-580 Service Manual page 209

6.2.8 SNS PC Board
Each sensor consists of an LED and photo transistor. When documents are placed on the ADF tray or are
moving, a shutter in the document sensor opens. The light from the LED turns the photo transistor "ON",
and the output voltage from the sensor becomes a "Low" level. With no document on the ADF tray, the
shutter interrupts the light path, and output from the sensor is kept at a "High" level. Operation of the RP
Sensor is exactly the same as the ADF Sensor. The ADF Cover Sensor operation is similar, except that the
output from the sensor is kept at a "Low" level when the cover is closed and becomes a "High" level when
the Printer Cover is opened.
ADF Cover Sensor
(ILS PC Board)
Read Point
Sensor
PNL CPU
IC1
ADF
Sensor
+5V
Shutter
A
PC2
K
Shutter
A
PC3
K
+5VP
Shutter
A
PC1
K
PNL1 PC Board
+5V
nBPNT
+5VP
GND
SC PC Board
209
CPU
(IC1)
GND
MPU