Patent ID: 7551326

Claim:
An image reading apparatus comprising: a plurality of line sensors arranged to be mutually spaced in a sub scanning direction to scan an original in the sub scanning direction; a platen arranged between the original and said plurality of line sensors; a mover moving said platen at a rate relative to said plurality of line sensors, said rate being different from that of the original relative to said plurality of line sensors; a noise pixel detector detecting a noise pixel from each of a plurality of data output from said plurality of line sensors; a determination unit determining the order in which the noise pixel is detected from the data output from said plurality of line sensors, based on the order in which said plurality of line sensors are arranged and the direction in which said platen is moved; a noise length predictor predicting the length of noise in the sub scanning direction, in response to detection of the noise pixel by said noise pixel detector from the data output from one of said plurality of line sensors that precedes in the order determined by said determination unit, said length being predicted based on the number of detected noise pixels successive in a main scanning direction, the rate of said original relative to said plurality of line sensors, the rate of said platen relative to said plurality of line sensors, and the distance between said plurality of arranged line sensors; and a determiner determining as effective the noise pixel detected from the data output from one of said line sensors that follows said line sensor preceding in the order determined by said determination unit, in the period from the time at which the noise pixel is detected from the data output from said line sensor preceding in the order to the time at which said predicted length of noise is reached.