Patent ID: 7448713

Claim:
An ink jet printer ejecting a plurality of kinds of ink droplets of different sizes from a single nozzle depending upon data to be printed, thereby forming an image on a prescribed recording medium using dots of sizes corresponding to the sizes of the ink droplets, the ink jet printer comprising: an ink jet head for ejecting an image forming droplet and a smoothing droplet from a single nozzle based on the data to be printed, the smoothing droplet being smaller than the image forming droplet, thereby printing dots of sizes corresponding to the sizes of the ink droplets on the prescribed recording medium; a smoother for performing a smoothing process using the smoothing droplet to form a smoothing dot, wherein a distance between a center of a smoothing dot and a center of an image forming dot is smaller than a pitch of image forming dots, and a controller for controlling the smoother, thereby changing the speed of ejection of the smoothing droplet in accordance with the size of the smoothing droplet and changing the timing of ejection of the smoothing droplet, wherein a position where the center of the smoothing dot is to be printed is changed within one of pixel areas arranged in a matrix form for printing dots therein.