| 摘要 |
PURPOSE:To increase the image resolution in the secondary scanning direction during the reading of picture information, by giving a prescribed quantity of exposure at all times to an original which has no relation with the fluctuation of the secondary scanning speed. CONSTITUTION:The pulse Pt produced from a shift degree detecting circuit TPG is supplied to a pulse generating circuit PSG. The circuit PSG produces a light source drive pulse Pl having a prescribed width and a rise at a prescribed time position to the time position of the pulse Pt, a start pulse Pr for reading plus a driving clock pulse of image sensor IS respectively. The pulse Pl is applied to a light source drive circuit LD, and the circuit LD applies the amplified pulse to an illuminating light source LS. Thus an original O is illuminated by the source LS and in a prescribed time width. The period T of a picture signal supplied from the sensor IS is always constant regardless of the secondary scanning speed of a reader. |
