Epson STYLUS 3000 Service Manual page 60

ASF_PQ :Output from the PQ (Paper Quantity) sensor.
The paper quantity sensor uses a sliding potentionmeter. (The maximum resistance:10 ohms) The
sensor ,attached to the right edged guide in the hopper assembly, detects the paper quantity between
the maximum of 15 mm and the minimum of 3 mm. The detected quantity is converted into the
corresponding resistance and the information is transferred to the analog port of the
sensor detects the condition of 3.6 mm which accommodates 25 sheets of 55 kg/m
the signal


GAP : Output from the PG (Platen Gap) sensor.
The sensor determines whether the adjust lever is set to the thin paper side or thick paper side.
The signal is
sensor uses a mechanical switch.


REL : Output from the release sensor.
Release sensor attached to the left and rear side of the printer mechanism determines whether the
release lever is set to friction feed side or tractor side. The signal
on the friction feed side.


CR_PW : Output from the CR PW (Paper Width) sensor.
The sensor, attached to the left side of the
makes 1 return in the paper width seek mode, sensor reads the voltage level of the output signal at
each motor phase change pulse to determine the positions for the both edges of the paper. This
operation prevents printing on the platen. In case no change is detected in paper size from the
previous paper by the
signal output from this sensor is directly sent to the analog port of the
Figure 2-21 shows the sensor circuit block diagram.
Rev. A
.
when the lever is on the thick paper side, and
sensor and ASF PL sensor, the
Figure 2-17. Sensor Circuit Block Diagram
EPSON Stylus COLOR 3000
on the thin paper side. This
is
unit, uses a photo interrupt system. While the
sensor is not activated. The
.
. When the
2
-paper, it outputs
on the tractor side and is
2-19