| 摘要 |
In an image reading apparatus having a document feeder adapted to convey an original, an image sensor adapted to read the original conveyed to a platen by the document feeder, and a memory adapted to store image data for each pixel, control is executed to cause the image sensor to execute reading at a predetermined position a plurality of number of times without placing any original on the platen while driving the original convey member of the document feeder, the image data of the original output from the image sensor is compared with the image data of a corresponding pixel, which is stored in the memory, every time the original convey member is read, the image data stored in the memory is updated to data having a larger value, and the presence/absence and position of dust and/or dirt on the platen are detected on the basis of the number of times of reading the original convey member and the image data stored in the memory after the end of a plurality of number of times of reading the original convey member.
|
