Brother HL-4000CN, Service Manual

Page: 104 / 345

III-26
5.2 Paper Feeder
5.2.1 Major functions
•
Switch ASSY size
Switch ASSY size detects paper size and existence or non existence of the paper tray.
•
Sensor photo (No paper sensor)
Detects existence or non existence of paper in the paper tray based on the position of
actuator no paper. (No paper: Sensor beam is intercepted)
•
Sensor photo (Low paper sensor)
The actuator lowers according to how much paper remains in the paper tray. When
the actuator lowers to certain extent, it intercepts the sensor beam to detect low paper
quantity.
As the actuator position can be seen from the front side of paper tray, you can confirm
approximate residual paper quantity.
•
Solenoid feed
Controls operation (rotation/stop) of roll ASSY feed by controlling the rotations of the
gear feed.
•
Clutch ASSY turn
Transmits the drive from the main drive ASSY to roll ASSY turn.
•
Roll ASSY feed
When the solenoid feed operates, the gear feed and gear idler feed are engaged by
the force of the spring feed. Under the drive from the main drive ASSY, the roll ASSY
feed starts rotating and the roll ASSY (pickup ASSY T1) sends paper.
After having rotated one turn, the gear feed and gear idler feed are disengaged at the
notch of the gear feed, no drive is transmitted any more, and the roll ASSY feed stops
rotating. Thus sheets of paper is sent out one by one.
•
Roll ASSY turn
The roll ASSY turn rotates by the drive from the main drive ASSY through the clutch
ASSY turn to feed the paper from the paper tray to chute REGI (REGI roll) ("refer to 5.8
Xerographics").
•
Sensor HUM TEMP
Detects temperature and humidity in the printer.
The printer corrects the charging voltage, the voltage supplied to the transfer rolls, and
the developing bias based on the detected temperature and humidity.