| 摘要 |
PURPOSE:To execute horizontal sweep at a high speed without increasing a rotating speed of a polyhedral rotary mirror and without increasing the number of reflection surfaces, by leading incident light to plural reflectors after executing the first deflection by a rotary mirror, and bringing the light reflected by the reflectors to the second deflection by the rotary mirror again. CONSTITUTION:A polyhedral rotary mirror 6 has, for instance, eight reflection surfaces S1-S8, a deflecting mirror 11 for perpendicularly bending a laser beam L from a beam expander 5, for leading it to an incident optical path A and for making said beam incident to the rotary mirror 6 is provided between the rotary mirror 6 and the beam expander 5, and also folded reflectors 12a, 12b are placed so as to be opposed regularly to the polyhedral rotary mirror 6. The laser beam L is led to the rotary mirror from the optical path A through the deflecting mirror 11, and thereafter, is deflected in said mirror, reaches reflectors 12a, 12b by an optical path B, is deflected, and thereafter, is returned to the rotary mirror 6 again through an optical path C, is reflected again, and goes toward an image forming lens 8 through an emitting optical path D. |
