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.
(S-Door)
ADF Cover Sensor
PNL CPU
IC1
+5V
Shutter
A
K
Shutter
Read Point
A
Sensor
K
+5VP
Shutter
A
K
ADF
Sensor
PNL1 PC Board
PC2
+5V
nBPNT
PC3
+5VP
PC1
GND
195
CPU
(IC1)
GND
SC PC Board