Image Number 4 for United States Patent #6386690.
A present invention provides an ink jet printing apparatus comprising an ink replenishing system which prevents ink leakage when a power supply from a main power source is cut off due to a power failure or the like while an ink reserving section of a print head of the ink jet printing apparatus is replenished with ink. The ink replenishing system is capable of properly managing the amount of ink in the ink reserving section. In the ink jet printing apparatus, when a power supply from a main power source is cut off after the start of an ink replenishing operation, power is supplied from a secondary power source so that ink replenishing control is executed depending on the power state of the secondary power source. If the ink replenishing operation has not been completed, after the main power source is recovered, the ink replenishing operation is performed again.