| 摘要 |
PURPOSE:To miniaturize the device and to realize uniform scanning even when wobbling and deviation may occur to the surface of a polygon mirror by using the combination of spherical scanning lens and cylindrical lens together with a beam splitter. CONSTITUTION:When a reflecting mirror 7a of polygon rotating mirror 7 shifted to the position of 7a' because of wobbling or deviation, the light route moves as is shown by dotted line. However, in both cases, the light is made incident upon scanning lens 6 from the distance of f6, namely the focal length of scanning lens 6, any route of optical beam will be refracted in parallel. Then the light through cylindrical lens 5 focuses at A which is distance by its focal length f5, and image is formed at one point of scanned surface 11, resulting in stable and uniform scanning. Also, by making in cident the optical beam vertically on the reflecting mirror using a beam splitter 3, the device can be miniaturized. |
