| 摘要 |
PURPOSE:To use the driving section of a light reflecting means with small torque by measuring the distance from the reference plane of an original mounted on an original platen with the copied face facing upward before exposure scanning and keeping the length of light path from the copied face to a photosensitive body constant, and at the same time, making acceleration of the light-reflecting means small in an area in which the rate of change of the distance from the reference plane of image forming of the original to the copied face is large and copying is not necessary. CONSTITUTION:The distance from the reference plane of image forming of an original to a copied face facing upward is measured before exposure scanning, and the length of light path from the copied face to a photosensitive body is kept constant. In this case, acceleration of a light reflecting means is made small and controlled not to maintain the length of light path constant in an area in which the rate of change of the distance from the reference plane of image forming of the original to the copied face is large and copying is not necessary. That is, in the case where the rate of change is larger than a value, mirrors 9, 9 are not made to follow up movement of a book 1, and not moved at high acceleration required to correct the length of light path, and moved with small acceleration. |
