Ricoh DD 5450, Field Service Manual, Page: 115 / 403

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113
Chapter 3 Master Making/Master Feed/Ejection Section
(2) End mark sensor
● Reflected light amount
The larger the reflected light amount is, the smaller the output voltage to the main PCB unit is. The
smaller the light amount is, the larger the output voltage is.
The value is checked with HELP-008.
CN9-23
-24
-25
-26
End mark
End mark sensor
*
Sensitivity adjustment of the end mark sensor
Make adjustment in HELP - 008 so that the sensitivity is 150 or more when reading the end
mark printed on the master and 35 or less in the master white part.
(Make sure that the master is not slacked.)
● B4: DD5440 ● A3: DD5450
Description
The end mark is located at a fixed distance relative to the master; as the master is being fed,
the end mark sensor detects master condition and the end mark by means of intensity of reflected
light.
End mark sensor
End mark
Circuit
End mark sensor PCB unit
Blue
Blue
Green
Light green
Green
Light green
Red Red
Main PCB unit
HELP-008 →See page 311
2