NOZZLE CLEANING METHOD OF INK JET PRINTER

PROBLEM TO BE SOLVED: To provide a method for cleaning nozzles which wastes ink less in an ink jet printer of a multi-nozzle head. SOLUTION: A counter starts counting at a printing start (step E). A less frequently used nozzle group is cleaned when a count value (t) corresponds to a cleaning cycle T1 (steps G and H). A frequently used nozzle group is cleaned when the count value (t) corresponds to a cleaning cycle T2 (steps I and J). The cycle T1 is set to be shorter than the cycle T2. In other words, the cleaning cycle for nozzles is set in accordance with the frequency of use of the nozzles and, the number of cleaning times is restricted for nozzles that require less cleaning. In comparison with the conventional case where all nozzles are simultaneously cleaned at one time, a consumption amount of ink can be reduced and a life of an ink cartridge is increased. Moreover, a discharge amount of ink is also reduced, whereby a waste ink cartridge can be made small and a life can be extended.