| 摘要 |
PURPOSE:To execute anamorphic variable magnification without reducing its resolution by setting up the speed ratio of a scanning system to a photosensitive body and the position of a projection lens so that the magnification in a slit longitudinal direction is different from that in a slit width direction. CONSTITUTION:The projection lens 14 is constituted so as to be moved to a specified magnification position and the 2nd mirror is constituted so as to be deflected to absorb the change of an optical path in accordance with the variable magnification movement of the projection lens 14. Since a prism 10 is arranged close to the photosensitive body, the length of the prism 10 is almost equal to that of the photosensitive body 4 and the prism 10 has no refractive power in the length direction, but has refractive power of B2 in the slit width direction, so that the relative incident angle of light to the prism 10 is changed. The anamorphic magnification beta2 is shown by the formula and a required magnification beta2 can be fixed by setting up the incident angle theta1 to the prism 10, the vertical angle alpha of the prism 10 and the refractive index n of the prism 10 properly. |
