Miscellaneous Detection Functions; Waste-Ink Amount Detection; Bj Cartridge Detection; Ink-Out Detection - Canon QY8-1360-000 Service Manual

Part 4: Technical Reference

5.2 Miscellaneous Detection Functions

In addition to sensor-based detection functions, the BJC-7100 printer also has the
following detection functions.

5.2.1 Waste-ink amount detection

This function processes the amount of waste ink (and ink optimizer) in the waste ink
absorbers.
The printer stores the total waste ink amount absorbed by the waste ink absorbers
from cleaning and maintenance jet operations in the EEPROM on the logic board.
Post-absorption evaporation is taken into account when calculating the amount. The
total waste ink amount is updated when the power is turned off, on completion of
cleaning operations, and when a page is output. When the waste ink amount
approaches the absorber's capacity, the printer stops printing.

5.2.2 BJ cartridge detection

The detection signals from the index unit in the print head heater board are used to
detect the presence and type of BJ cartridge.
For details, see Part 4, section 3.2.6, "BJ cartridge detection" (page 4-28) .

5.2.3 Ink-out detection

1) Detection operation
An ink-out detection pulse is output to the ink paths in the ink room in the head
holder. The pulse is transmitted via the ink path to the ink sponges and received by
the electrode on the carriage. It is then amplified by the carriage board and read by
the AD board of the MPU, and converted from analog to digital to detect the
existence of ink.
The electrode is located opposite the ink room in the head holder.
2) Timing processing
Ink-out detection is performed for all inks in a single sweep in the following order:
ink optimizer, black ink, color ink, and photo ink.
In the case of the color and photo inks, detection proceeds from yellow through
magenta to cyan. Post ink-out detection processing differs according to the timing.
Detection timing
• When power turned on using
POWER button
• After page is output
• After all cleaning operations
• When head overheat is detected
*: The cleaning operation differs according to which ink has run out.
See Part 4, section 3.3.1, "Function of purge unit" (page 4-29) for details.
When the waste ink amount (or ink optimizer amount) reaches 95% of the
waste ink absorber capacity, the printer generates a waste ink alarm (operator
call). You can press the RESUME button to continue operating the printer.
When the waste ink amount (or ink optimizer amount) subsequently
reaches 100% absorber capacity, the printer outputs a waste-ink full error
(service call) to prevent ink leaks.
TABLE 4-9 INK-OUT DETECTION TIMING
Post ink-out detection processing
Cleaning *
Cleaning *
Transition to ink-out error (operator call)
See Part 4, section 2.5, "Head Overheat
Protection" (page 4-12) for details.
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BJC-7100