Canon W6400 Series Service Manual page 76

Chapter 2
Valve cam sensor
The photo inerrupter-based valve cam sensor detects the status of the valve cam on the ink tank unit.
The sensor determines that the ink supplyer valve is opened when the rotary flag, which operates in conjunction with the valve cam, cuts off the sensor light.
<Operation when ink supply valve (all colors) is open>
<Operation when ink supply valve (Bk) is open>
Head management sensor
The photo transmission sensor detects whether the printhead is discharging ink.
When the carriage arrives at the location for detection, it stops and the ink is discharged from one nozzle of the nozzle array at a time until all the nozzles
are checked for their normal ink discharging operations. This process is repeated for the rest of the 5 nozzle arrays of the printhead.
If the sensor light is blocked by the ink discharged from a nozzle and the voltage measured by the sensor changes, that nozzle is proved to work correctly.
2-32
* Homeposition
Sensor
Rotary flag
* Close * Ink supply valve
(all colors) open
* Close * Ink supply valve
(all colors) open
* Homeposition
* During suction
F-2-37
* Close * Ink supply valve
(Bk) open
* Close
* Ink supply valve
(Bk) open
F-2-38
Printhead
Nozzle unit
Head management
sensor unit
F-2-39
* Close
Sensor
Rotary flag
Ink supply valve
(all colors)
Ink supply valve (Bk)
* Close
Sensor
Rotary flag
Ink supply valve
(all colors)
Ink supply valve (Bk)