| 摘要 |
PURPOSE:To eliminate the need for an additional mechanism for cutting off light by rotating a reflecting mirror which constitutes the writing mechanism for a photosensitive body and changing the optical path, and thus cutting off the light. CONSTITUTION:When the cover of a housing is closed, a stopper 17 is pressed up to bring the external-diameter surface of the stopper 17 into contact with the tip part of the cam surface 19 of a lower holder 11 and an upper holder 12 abuts on a rotary stopper 14b, so the rotation of the reflecting mirror 3 is locked and laser light L is reflected by the reflecting mirror 3, travels along an optical path S, and is made incident on a polygon mirror. When the cover is opened, the stopper 17 is pressed down by a spring 15 and the reflecting mirror 3 is rotated with the spring force T of a torsion spring 13, so that the light L travels along an optical path S' different from the optical path S and is reflected. |
