Canon Color Bubble Jet BJC-1000 Series, Service Manual

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Part 4: Technical Reference
4-28
BJC-1000
5. SENSOR FUNCTIONS
The printer has a pick-up roller sensor, paper end sensor, home position sensor (purge
sensor), printer temperature sensor, and head temperature sensor.
Also, the EEPROM counts and records the waste ink absorption amount. When the
waste ink absorber becomes full, the waste ink absorption amount indicates an error.
5.1 Pick-up Roller Sensor
The photo interrupter-type pick-up roller sensor detects the initial position of the sheet
feeder's pick-up roller. When the initial position is detected, the flag interrupts the
sensor.
5.2 Paper End Sensor
The photo interrupter-type paper end sensor detects with the paper sensor arm's flag
when a sheet of paper passes through the paper feeding mechanism. When the flag
interrupts the sensor, the sensor does not detect the paper. When the flag does not
interrupt the sensor, the sensor detects the paper.
5.3 Home Position Sensor (Purge Sensor)
The photo interrupter-type home position sensor senses the home position edge and
detects the carriage position. After the edge is detected, the carriage moves to the right.
At the home position, the maintenance jet is executed.
Also, at the capping position, the on/off of the home position sensor (purge sensor) flag
during the recovery operation is detected.
BJ Cartridge
Paper End
Sensor
Flag
Pick-up Roller Sensor
Temperature Sensor (TH1)
Home Position Sensor
(Purge Sensor)
Figure 4-26 Sensors