Patent ID: 7931360

Claim:
A priming system for priming an inkjet printhead having an ink inlet, an ink outlet and a plurality of nozzles, said priming system comprising: pressure-regulating ink chamber having an inlet port and an outlet port connected to said ink inlet via an upstream ink line; an ink reservoir in fluid communication with said inlet port, said ink reservoir being positioned above a level of ink in said chamber; a valve positioned between said ink reservoir and said inlet port, an air pump having a pump outlet communicating with a headspace above said ink in said ink chamber; a sensor positioned for sensing ink in a downstream ink line connected to said ink outlet, said sensor cooperating with said pump such that said pump is shut off when said sensor senses any ink; and means for minimizing phantom sensing of ink caused by ink bubbles in said downstream ink line, wherein, in a priming configuration, said valve is configured to be shut and said pump is configured to positively pressurize said headspace until said sensor senses ink.