| 摘要 |
PURPOSE:To enable maintaining a good recording state, even if the unevenness of density is generated in a printing head, by detecting the unevenness of density of a plurality of recording elements with a specified timing and by regulating a driving signal to be given to a recording head on the basis of results of the detection. CONSTITUTION:A correction table 27 for the unevenness of density has a correction line differing in gradient by 0.01 at a time from Y=0.70X to Y=1.30X and changes the correction line according to a correction selection signal 26 outputted from a correction RAM 25 for the unevenness of density. As the correction table for the unevenness of density, a straight line with a gradient '1.0' is selected for all nozzles to obtain an output image 42. While the image is moved in the direction of the arrow A by CCD 43, it is converted into a digital density signal by a non-recording density converter to generate a density unevenness pattern. CPU 24 operates a difference between the density at each nozzle of the pattern and a preset value and selects 'Y=1.20X' as the correction line of a nozzle, of which density becomes the same as its set point if it is raised e.g. by 20%. |
