Epson DLQ-3000 Service Manual page 72

Table 2-7. Functions of the Paper Feed Sensor
Sensor
Right/left PEW sensors
Left PEW sensor alone
Front/Rear paper
sensors
Rear paper sensor
alone
Front paper sensor
alone
Paper jam sensor
Notes)
1. When the printer is powered on, if any of the right/left PEW sensor and front/rear paper
sensor detects paper, the printer does not detect the leading edge of the paper but the
paper end condition.
2. Left and right margin for cut sheet and continuous paper are switched by the release
sensor.
‰
Black solid mode
This printer is equipped with the black solid print mode. In this mode, the printer prints
regardless of the reflection rate of the paper.
‰
Paper jam detection
The paper jam sensor monitors a signal output for each step (1/216 inch per step). If the
output signal becomes the same as the one for power on time and the following signals
for the specified numbers of steps remain the same, the status is regarded as the paper
jam error, and the CPU indicates the paper jam error.
Rev. A
Detection
Paper width measurement
(detects the left and right
paper edges)
Paper bottom detection
(detects the rear edge.)
Paper end detection
Leading edge detection at
loading paper
(detects the paper top.)
Detects the leading/rear
edge of the paper.
Paper end detection
Detects the leading/rear
edges of the paper
Detects the leading edge of
the paper
Paper jam detection
Operating Principles
Function
Selects the left and right margins.
Depending on o the CR position,
one of the sensors is used.
If one of the sensors detects
paper, it is regarded "Paper is
loaded". If both sensors don't
detect paper, it is regarded "No
paper is loaded".
Ensures the paper feed and paper
eject action.
Determines the top margin.
Determines the top/bottom margin.
Ensures the paper feed and paper
eject action.
Detects the leading edge and
printable area for the black-solid
print paper.
Performs front paper feeding.
Detects paper jam condition in the
front/rear paper feed direction.
2-11