Image forming apparatus and method for controlling the same

摘要

In the invention, an inclination amount of sensors is reflected in positional deviation correction patterns, and for correcting formation positions of images of various colors, the positional deviation correction patterns are formed on a conveying belt. The positional deviation correction patterns are detected by the sensors. A control unit calculates positional deviation correction amounts based on detection results of the positional deviation correction patterns. Based on the calculated positional deviation correction amounts, the control unit performs calculation for correcting the positional deviation correction patterns, and cancels the inclination amount reflected in the calculation results to obtain final positional deviation correction amounts. Skew correction is performed based on the final positional deviation correction amounts, and thus, the positional deviations are corrected.

主权项

1. An image forming apparatus comprising:
a plurality of image formers configured to form a plurality of images having different colors from each other on an image forming medium driven at a predetermined speed in a manner aligning positions of the plurality of images having respective colors; at least two sensors configured to be arranged in a predetermined arrangement direction and detect the plurality of images formed on the image forming medium; an inclination amount calculator configured to calculate an inclination amount of the predetermined arrangement direction relative to a direction perpendicular to a direction of driving; a correction pattern former configured to form, using the plurality of image formers, two correction pattern rows in each of which one or a plurality of correction pattern images are arranged in a row in the driving direction, in positions corresponding to the at least two sensors on the image forming medium, so that the two correction pattern rows differ in position from each other by the inclination amount in the driving direction; and a positional deviation corrector configured to correct, while turning back an inclination by the inclination amount, positional deviations of the plurality of images having the respective colors formed on the image forming medium, based on detection results of the two correction pattern rows detected by the at least two sensors and based on the inclination amount, wherein turning back the inclination by the inclination amount corresponds to applying a negative inclination amount in an amount corresponding to the inclination amount to one of the two correction pattern rows.