Patent ID: 6639695
Filing Date: 2003-10-28
Classification: H04N

Abstract:
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.