| 摘要 |
PURPOSE:To make possible copying of further scale-down magnification without changing the optical system of a predetermined magnification copying system at all by providing an original plane obliquely with respect to the plane rectangular to the optical axis in consideration for the focal depth within the slit width. CONSTITUTION:An original platen 1 is so obliquely provided as to assume an angle of theta with respect to the plane rectangular to the optical axis as compared to the position of the original platen 1' at the unmagnification copying and is so arranged as to move at an equal speed in the obliquely provided direction. The relation between the slit width W of a stationary slit 2 and theta is made 1/2Wtantheta <=DELTAh (DELTAh is the focal depth of a lens 3). If the peripheral speed of a photoreceptor 4 is defined as v0, the component of the moving speed of the original platen 1 in the direction orthogonal to the optical axis is v0, from the unmagnification copying system, and the moving speed of the original platen in its moving speed becomes v0/costheta. Thereby, the copying of further scale-down magnification may be performed without changing predetermined magnification copying optical system at all. |
