Canon CLBR 460ps Service Manual page 146

CHAPTER 2
The ON/OFF status of the fixing roller pressure is detected by the fixing unit pressure sensor
(PS6) located outside the fixing unit.
When the fixing roller pressure is turned ON, the pressure detection cam, which is located on
the same shaft as the fixing pressure cam facing the opposite direction, pushes the pressure
sensor flag. As a result, the light of the PS6 is blocked and the FIXING UNIT PRESSURE DETEC-
TION signal (/FXPRS) becomes "L."
When the fixing roller pressure is turned OFF the pressure detection cam makes a half rota-
tion. As a result, the pressure sensor flag is separated from the PS6 and the FIXING PRESSURE
DETECTION signal (/FXPRS) becomes "H." The DC controller determines that the fixing roller
pressure is turned OFF, and stops the printer.
When the /FXPRS signal does not switch from "L" to "H" within a specified period of time after
power-OFF or jam occurrence, or when the signal does not switch from "H" to "L" within a spec-
ified period of time after power-ON or jam clearance, the DC controller stops the printer and
notifies the video controller of a fixing motor failure.
Pressure
detection cam
Pressure sensor flag
Note: The printer cannot turn OFF the fixing roller pressure when the door is open. If the
printer is turned OFF with the door open when the fixing roller pressure is ON, the pres-
sure remains ON. Therefore, make sure to close all the doors and drawers when turn-
ing OFF the power.
2 - 88
Lower fixing roller
Fixing unit pressure sensor (PS6)
< Pressure ON >
Figure 2-5-10
< Pressure OFF >