Canon BJC-55 User Manual page 318

Determine how long the printer has been in constant operation
Continuous printing for an extended length of time could cause the print head to overheat
and cause it to stop. The print head will stop for a few moments at the end of each pass to
allow it to cool off after it has become overheated.
During heavy duty printing of large areas of dark color, the printer may automatically halt to
protect the print head from damage. In such a case, further printing is not possible until the
print head has completely cooled. Turn off the printer and wait approximately 15 minutes.
Caution
If the print head has overheated, do not touch the print head until it has
cooled.
If you are using the infrared interface, make sure there is not an obstacle between
the printer and the computer
When you use the infrared interface for printing, the area between the printer and the
computer must be free of any obstacle that could interfere with the line-of-sight
communication between the computer and printer. Remove any obstacles.
Problems and Solutions
Troubleshooting 318