Brother MFC9100C Service Manual page 28

2.3 Sensors and Actuators
This equipment has the following sensors and thermistor.
Sensor name
Document front sensor
Document rear sensor
Cover sensor
CCD HP sensor
Registration sensor
Paper width sensor
Paper ejection sensor
Cassette sensor
Ink cartridge sensors
Black ink empty sensor
Carriage encoder
Head thermistor
Head property EEPROM
Purge cam HP switch
• Document front sensor which detects the presence of documents.
• Document rear sensor which detects the leading and trailing edges of pages to tell the control
circuitry when the leading edge of a new page has reached the starting position and when the
scan for that page is over.
• Cover sensor which detects whether the scanner unit is closed.
• CCD HP sensor which detects whether the CCD unit is in the home position.
• Registration sensor which detects the leading and trailing edges of paper, which allows the
controller to determine the registration timing.
• Paper width sensor which detects whether the paper width is A4-size or wider.
• Paper ejection sensor which detects whether the paper goes out of the equipment.
• Cassette sensor which detects whether the paper cassette is loaded.
• Ink cartridge sensors, each of which detects whether an ink cartridge is loaded.
• Black ink empty sensor which detects whether the black ink cartridge is empty.
• Carriage encoder which detects the current carriage position and carriage travel speed. If the
carriage travel speed varies abnormally, the controller regards it as a paper jam.
Type
Photosensor
Photosensor
Photosensor
Photosensor
Photosensor
Mechanical switches
Photosensor
Photosensor
Thermistor

Mechanical switch
III - 12
Located on
Document sensor PCB
Cover sensor PCB on the scanner base
Scanner base
Paper width/registration sensor PCB on the
upper paper chute
Paper ejection/cassette sensor PCB on the
lower paper chute
Carriage PCB
Carriage PCB
Carriage PCB
Carriage PCB
Print head unit (Head PCB)
Purge cam (→Main PCB)