| 摘要 |
PURPOSE:To enhance density detection precision even when detection area is enlarged to a practicable degree by detecting line width of an original in accordance with detection output from a density detector, and correcting this density detection output in accordance with said detected line width. CONSTITUTION:An original density detector 18 is in the second mirror unit 42, and it moves in the horizontal direction rectangular to the arrow direction B at the same time as the unit 42 moves in the direction B. It scans a part of the original 19 on a platen glass 1 in the slant direction during the scanning of an optical system 4 in the direction B. The density signal thus detected is amplified with an amplifier 20, converted into a digital signal with an A/D converter 21, the peak value of each detected density is held with a peak value holder 22, and an the other hand, line width is detected with a line width detector 23. A correction factor K is fed to a calculation part 25 from a correction data part 24, said peak value is multiplied with this factor K, and an exact detection density signal thus corrected is produced. |
