Service manual

Part 4: Technical Reference
BJC-4300
2.6 Ink Smear Control
Immediately after the printed sheet is ejected from the printer, the ink dries naturally
on the paper output tray. If the next printed sheet is ejected before the ink has enough
time to try on the preceding sheet on the paper output tray, the ink may be smeared
when the sheet slides over the preceding one. To prevent this, a wait period is applied
during printing so that the sheet is delayed being ejected, giving more time for the ink
on the preceding sheet to dry.
When a black BJ cartridge is used (whose printing speed is faster) and. high duty
printing is completed, the printer automatically detects the high duty printing position
and the time elapsed from the start of printing.
There is no need to execute ink smear control when a color BJ cartridge is used.
2.7 Head Overheating Protection Control
If the ink has run out and the printing operation is continued, the bubble jet head can
get extremely hot. If the head temperature sensor in the bubble jet head detects a
temperature above the temperature limit, head overheating control is executed.
Protection level 1:
This level prevents the user from touching the bubble jet head’s hot aluminum plate
when the bubble jet head is replaced. When the user tries to manually move the
carriage to the cartridge replacement position, the beeper will sound three times and
the cartridge cannot be replaced. Depending on the protection level, the user may even
be prevented from replacing the cartridge until a set period of time passes.
Protection level 2:
If a still higher temperature is detected, the carriage is returned to the home position
for 3.5 seconds to bring down the temperature. After the resting period, printing will
resume. This continues for over 20 seconds to lower the bubble jet head’s
temperature.
Protection level 3:
If the temperature continues to Increase, a head temperature error occurs. This stops
the printing operation.
If this still does not lower the head temperature, the sensor is
deemed faulty and a head temperature sensor error will be indicated.
2.6 Auto Power On/Off
This printer is turned on with print signals sent from the host computer, and is
automatically turned off when print signals are not received after a specified period of
time. These settings can be made separately from the printer driver or BJ setup utility
program.
When the auto-power on function is set as valid, the STROBE signal is sent three times
in succession turning the printer on. Therefore the interface is constantly valid even
when the power is off.
With the auto-power off set as valid, the printer is turned off if print data is not
received for a set period of time.
The valid times are 1, 10, 30 and 60 minutes.
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