Paper Feed Sensor, Paper Eject Sensor - Brother MP-21C Service Manual

3.5.2

Paper Feed Sensor, Paper Eject sensor

The Paper feed/eject sensor actuator and a photo sensor detect whether there is paper
or not. The Paper feed/eject sensor actuator has a paper a sensing arm and the photo
sensor operating arm. When paper hits the paper sensing part as paper is ejected the
photo actuator arm goes up and detects the paper.
When the paper has ejected out of the printer, the Paper eject sensor actuator returns to
the former status and detects that there is no paper.
The Paper feed sensor detects;
•
If a paper is inserted into the Straight paper path slot or the Paper feeding guide.
•
The top edge of the paper which is fed from the ACSF
•
The bottom edge of the paper
The Paper eject sensor detects;
•
The top edge of the paper which is fed from the Straight paper path slot or the Paper
feeding guide
•
The bottom edge of the paper
Pressure roller ASSY
Paper hold ASSY
Platen cover
Paper eject
sensor actuator
Paper feeding can be from the Straight paper path slot or the Paper feeding guide. (Manual
feeding)
Paper feeding starts when the Paper feed sensor turns into ON. In a manual feeding, the paper is
fed until it hits the sensing point of the Paper eject sensor. If the Paper eject sensor turns ON, the
paper is continuously fed further to the print starting position. If not, a paper mis-pick error will be
detected.
Paper feeding from the ACSF
After the ACSF starts to pick-up the paper and the Paper feed sensor turns ON, the printer starts
the feeding operation. If the Paper eject sensor does not turn ON, the ACSF repeats the paper
pick-up operation twice more. If the Paper eject sensor stays in the OFF status after theses
additional retries, a paper miss-pick error will be detected.
Paper feed sensor
Paper eject sensor
Main PCB
Fig. 2.18
II-17
Paper