Image reading device

An image reading device comprising:

• a first optical image-forming system receiving light from a first image disposed on a readout surface, and forming a second image of the light received on an image-forming plane;
• a charge coupled device (CCD) sensor comprising pixels arranged in the image-forming plane, parallel to a horizontal scanning direction, to detect the second image formed by said first optical image-forming system, said CCD sensor accumulating, in each pixel, a charge in response to the light detected at the respective pixel;
• scanning means for scanning, in a vertical scanning direction, perpendicular to the horizontal scanning direction, respective horizontal lines of the first image, through said first optical image-forming system and said CCD sensor;
• readout means for reading out, as image data, the charge accumulated in each pixel of said CCD sensor for each horizontal line;
• scanning-position detecting means for detecting scanning position of said scanning means in the vertical scanning direction for each horizontal line;
• and
• means for correcting the image data of each horizontal line read out by said readout means, based on the scanning position detected by said scanning-position detecting means for each horizontal line, wherein
• said scanning-position detecting means comprises
• a position-reading plate having a position-reading pattern located adjacent to said readout surface within a range of horizontal scanning by said scanning means,
• a second optical image-forming system for position-reading, said second optical image-forming system receiving light from said position-reading pattern on an extension of the horizontal line and forming an image of said position-reading pattern, and
• means for detecting amount of light of the image of said position-reading pattern formed by said second optical image-forming system, said detecting means determining the scanning position scanned by said scanning means based on the amount of light detected,
• said first and second optical image-forming systems share optical elements, and
• said means for detecting includes pixels of said CCD sensor not used to detect the light forming the second image formed by said first optical image-forming system.