| 摘要 |
PURPOSE:To attain the reduction of parts in the second image-forming optical system of a light beam scanning optical system and to realize the image exposure of high resolution. CONSTITUTION:This system is provided with a deflection means 4 scanning by reflecting and deflecting light beam 23 from a light source 1, a first and second image-forming optical systems 2, 5 arranged in front and rear sides of the deflection means 4 and image-forming the light beam 23 converged in prior to the deflection means through the deflection means 4 on a surface to be scanned 6. The second image-forming optical system 5 has a correction lens 5 consisting of a toric plane at the side of the deflection means and a toric aspherical surface or non-columnar surface having a hogh-order expansion- term of more than 4th order at the side of the surface to be-scanned. |
