Patent ID: 8123325

Claim:
A non-ejecting nozzle detecting method used in an inkjet recording method of depositing transparent processing liquid and colored ink from processing liquid nozzles and ink nozzles, respectively, onto a recording medium one on top of another to form an image and fixing and recording the colored inks, the non-ejecting nozzle detecting method comprising: setting a processing liquid deposited pattern so that, by processing liquid nozzles selected not to be adjacent to one another as non-ejection detection targets, linear non-ejection detection target areas are formed in which the processing liquid is continuously deposited for a predetermined number of dots while gradually changing density of the processing liquid to be deposited to one of increase and decrease in one direction, and, by remaining processing liquid nozzles not selected as the non-ejection detection targets, the processing liquid is continuously deposited while the density of the processing liquid is changed in a direction opposite to the one direction of the linear non-ejection detection target areas; ejecting the processing liquid from the processing liquid nozzles onto the recording medium to form the processing liquid deposited pattern on the recording medium according to the set processing liquid deposited pattern; ejecting the colored ink from the ink nozzles corresponding to the processing liquid nozzles selected as the non-ejection detection targets onto the processing liquid deposited pattern, and recording linear colored ink images on the recording medium to thereby form a processing liquid non-ejection detection pattern on the recording medium; scanning the processing liquid non-ejection detection pattern with a detection sensor; detecting the linear colored ink images in the processing liquid non-ejection detection pattern scanned by the detection sensor; measuring densities and line widths of the detected linear colored ink images; and detecting, based on changes in the measured densities and line widths of the linear colored ink images, a non-ejecting processing liquid nozzle from the processing liquid nozzles selected as the non-ejection detection targets.