Detection Of The Ink Tank; Outline; Method Of Detecting The Ink Tank - Canon BJ-W3000 Service Manual

CHAPTER 2. BASIC OPERATION
E. Detection of the Ink Tank

1. Outline

The printer has an ink tank detection function. When an ink tank is not installed, an error
message appears on the message display and the ink and head condition is indicated by a blink-
ing hyphen ("–").

2. Method of detecting the ink tank

The presence of the ink tank is detected by the ink tank detection sensor (PS4) installed on the
purge unit when the carriage returns to the home position, in the order of yellow, magenta, cyan,
and black. The ink tank detection sensor uses a reflective type photo sensor. The existence of
the ink tank is detected by whether or not light is reflected from the bottom surface of the tank.
When the ink tank is installed, light from the sensor is reflected from the bottom surface of the
tank and returns to the light receiving unit, causing the ink tank detection signal (TANK) to be
"0". When no ink tank is installed, light is not reflected back to the light receiving unit, and the
ink tank detection signal (TANK) becomes "1".
Figure 2-213 is a flow chart of the ink tank detection and remaining ink detection process.
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Figure 2-211