Patent ID: 7533953
Filing Date: 2009-05-19
Classification: B41J

Abstract:
1. A method of compensating for a defective nozzle in an inkjet image forming apparatus, the method comprising: detecting a defective nozzle of a nozzle unit; checking ejecting statuses of nozzles of the nozzle unit which eject ink at a compensation position on a printing medium corresponding to the defective nozzle and nozzles of the nozzle unit which eject ink at positions adjacent to the compensation position, when the defective nozzle is detected; analyzing image information of the image data to be printed at the compensation position and the image data to be printed at the adjacent positions; detecting whether there is image data corresponding to an area to which ink is not ejected among the image data to be printed at the adjacent positions; and swapping and printing at least three pieces of image data to be printed at the compensation position and the adjacent positions according to the ejecting statuses of the nozzles, wherein the three pieces of image data to be printed at the compensation position, and a first and a second position among the image data to be printed of the adjacent positions are swapped for one another according to the ejecting statuses of the nozzles and the analyzed image information, and wherein the first position comprises at least one of an upper position and a lower position, rather than the compensation position, wherein the image data to be printed at the compensation position is shifted to the second position, the image data to be printed at the second position is shifted to the first position, and the image data to be printed at the first position is shifted to the compensation position when image data corresponding to an area to which ink is not ejected is printed at the second position.