Patent ID: 7712861

Claim:
An image forming apparatus, comprising: an image forming device which has a plurality of nozzles performing droplet ejection of ink to deposit droplets of the ink to form an image onto a prescribed medium; an image reading device which acquires read image data by reading in the image on the medium; a deviation amount calculation device which, for each of the nozzles, calculates a deviation amount in the droplet ejection with respect to a prescribed central value according to the read image data; a droplet ejection correction device which corrects the droplet ejection of each of the nozzles according to the deviation amount of the nozzle; a storage device which stores a maximum tolerable value for a temporal variation in the deviation amount of each of the nozzles; and a control device which, for each of the nozzles, compares the temporal variation in the deviation amount with the maximum tolerable value stored in the storage device, and implements control which discards the deviation amount relating to a period where the temporal variation in the deviation amount exceeds the maximum tolerable value, in such a manner that that deviation amount is not used in correcting the droplet ejection of the nozzle.