Patent ID: 6412927
Filing Date: 2002-07-02
Classification: B41J

Abstract:
An ink ejection device, comprising:a nozzle plate formed with nozzles from which ink is ejected; walls including side walls, a ceiling wall and a bottom wall, the walls defining an ink channel having a volume filled with ink and having a length defined by two ends, said nozzle plate being attached to one of the two ends of the ink channel, ink being supplied to the ink channel from another one of the two ends of the ink channel; an actuator that applies pressure wave vibrations to the ink in the ink channel; and a control unit that drives said actuator in response to a one-dot printing command commanding to print a one dot image on a recording medium, wherein said actuator successively ejects a plurality of ink droplets that are non-joinable during their flight time toward the recording medium to print a dot image on the recording medium, said actuator being driven to eject the plurality of ink droplets, wherein said actuator is driven for a first duration of time to eject an n-th ink droplet of the plurality of ink droplets, and for a second duration of time to eject an (n+1)th ink droplet following the n-th ink droplet, the (n+1) h ink droplet being ejected after an interval of a time from the ejection of the n-th ink droplet, the droplets being deposited on the recording medium in a partially overlapping manner, wherein at least one of the first duration of time, the second duration of time, and the interval of the time is unequal to a duration of time T corresponding to a time required for the ink pressure wave vibrations to propagate one way through the ink channel.