Canon QY8-1360-000 Miscellaneous Detection Functions, Waste-ink amount detection, 4-48, BJC-7100

Part 4: Technical Reference BJC-7100

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.

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.

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.

TABLE 4-9 INK-OUT DETECTION TIMING

Detection timing	Post ink-out detection processing
• When power turned on using	Cleaning *
POWER button
• After page is output	Cleaning *
• After all cleaning operations	Transition to ink-out error (operator call)

•When head overheat is detected See Part 4, section 2.5, "Head Overheat Protection" (page 4-12) for details.

*: 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.

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