Patent ID: 7905564

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, comprising: an ink jet head for ejecting a plurality of ink droplets, including an image forming droplet and a smoothing droplet, a single nozzle based on 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 a prescribed recording medium; a smoother for performing a smoothing process using the smoothing droplet to form a smoothing dot, wherein the distance between a center of the smoothing dot and a center of the image forming dot is smaller than the pitch of the image forming dot, and a controller for controlling the smoother, thereby changing the speed of ejection of the ink droplet forming the smoothing dot in accordance with the size of the ink droplet forming the smoothing dot and not changing the timing of ejection of the ink droplet forming the smoothing dot; 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.