| 摘要 |
PURPOSE:To obtain excellent surface tilt correction effect, to reduce curvature of field, and to improve distortion characteristics for realizing a constant speed scanning. CONSTITUTION:This scanning optical system is provided with a light source part 1, a cylindrical lens 2 as a 1st image formation system which linearly images nearly parallel luminous flux from the light source part 1, a deflector 3 consisting of a rotary polygon mirror arranged nearby the position of image formation by the cylindrical lens 2, the deflecting surface 4 of the deflector 3, 2nd image formation optical system 5 and 6 which image the luminous flux deflected by the deflector 3 on a scanned surface 7, and a scanning surface 8. The image formation optical systems 5 and 6 consist of a 1st single lens 5 which has a toric surface and positive refracting power in the scanning surface 8 and a 2nd single lens 6 which has an aspherical surface and negative refracting power in the scanning surface 8. |
