Patent ID: 8774700

Claim:
An image processing apparatus for a skew correction, comprising: a reading part configured to optically read skew amount measurement patterns and opposite ends of a paper sheet; an image skew amount detecting part configured to detect skew amounts of colors on a color basis based on the skew amount measurement patterns read by the reading part; a paper sheet skew amount detecting part configured to detect a skew amount of the paper sheet based on a displacement between the opposite ends of the paper sheet read by the reading part; a skew correction amount calculating part configured to calculate skew correction amounts of images of the respective colors based on the skew amounts detected by the image skew amount detecting part and the paper sheet skew amount detecting part; and a skew correcting part configured to shift images to correct the skews by recording input image data in plural lines of a line memory, dividing the input image data into plural areas in a main scanning direction, and setting line delay amounts on an area basis based on the skew correction amounts calculated by the skew correction amount calculating part; wherein the skew correcting part includes: multiplexers provided for each line of the line memory; and a controlling part configured to determine, based on data amounts of the respective colors of the input image data, a sharing amount of the line memory and generates control signals of the multiplexers based on the determined sharing amount such that when one of images of the respective colors has the skew correction amount greater than a corresponding line memory capacity allocated to the one image of the color, free space of the line memory, which is initially allocated to another image, is used to perform the skew correction for the one image.