Sns Pc Board - Panasonic DF-1100 Service Manual

Panasonic DF–1100

6.2.9 SNS PC Board

Each sensor consists of an LED and phototransistor. When documents are placed on the ADF tray or are
moving, a shutter in the document sensor closes. The light path from the LED is blocked turning the
phototransistor "OFF", and the output voltage from the sensor becomes a "High" level. With no document
on the ADF tray, the shutter opens the light path, and output from the sensor is kept at a "Low" level.
Operation of the RP Sensor is opposite to the ADF Sensor. When the leading edge of the document reaches
the RP Sensor, the shutter opens and the output voltage becomes a "Low" level. Then, the shutter closes
and the output becomes a "High" level when the lagging edge of the document clears the RP Sensor. The
Tx Door Sensor operation is the same as the ADF Sensor, the output from the sensor is kept at a "Low" level
when the door is closed and becomes a "High" level when the Tx Door is opened.
+24V
Shutter
Transmitter
A
Door
Sensor
K
Shutter
Read Point
A
Sensor
K
Shutter
A
ADF
Sensor
K
6–28
PC2
pSDOOR
nBPNT
PC4
pAPNT
PC3
GND
SNS PC Board
+5V
+5V
GND
+5V
GND
GND
FCB PC Board
CPU
(IC19)
MPU