Canon MultiPASS C530, Service Manual

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2-16
MultiPASS C530/C560 Chapter 2: Technical Reference
Ink empty detection
Ink empty detection during fax operation is performed by firing ink between the light
source and receptor of the ink sensor, located on the left side of the printer. This
function does not work with the BC-22e, only with BC-21e or BC-20.
When ink passes between the source and the receptor, as shown in
Figure 2-10
, the
sensor output will be a pulse waveform. The presence of ink may be determined from
the pulse generation time.
Ink empty detection is performed at the end of each received page of printing. If ink is
not detected on the first detection attempt, the ink nozzle is shifted slightly, and the
detection operation is repeated to double-check the first detection operation. If it is
determined that there is ink remaining, the image data for that page will be erased from
memory. If the cartridge is out of ink, the message
“REPLACE CARTRIDGE”
(with
BC-20)
“BLACK INK EMPTY”/“COLOR INK EMPTY”
(with BC-21) will be
displayed to inform the user that the cartridge is out of ink, and the page will be
“received” to memory again from the image data.
Method of Remaining Color Ink Detection
The method for detection of remaining color ink is the same as that for the detection of
remaining black ink. Sensor output is changed by passing each color (Cyan, Magenta,
Yellow) in front of the ink sensor after the received image is printed. By counting the
time of this change, the presence or absence of ink is detected. The sensor output also
changes according to color, so the threshold value of the sensor is adjusted so that it can
be reliably detected as normal. If one of the CMY colors is detected to be absent,
"COLOR INK EMPTY"
displays, informing the user that there is no more ink. When
color ink has run out, the image is not printed as a BW image, no matter whether there
is black ink available or not.
The timing of the check for remaining volume of color ink is only either after the
cartridge replacement button is pressed, or when a received image is automatically
output. Also, when the BC-22e cartridge is being used, the check for remaining volume
of color ink is not performed when copying is done, when PC printing is done, or in
corresponding circumstances.
The detection level of the ink detection sensor is adjusted automatically by means of a
feedback circuit, and thus requires no manual adjustment. If the sensor output does not
reach a standard level, even after performing feedback control (such as if the receptor is
completely blocked, or if a sensor defect occurs), the ink sensor failure will be reported
with the display of the
“CHECK PRINTER” (error code ##348) message.
NOTE