| 摘要 |
PURPOSE:To shorten the period when a laser beam is eclipsed by the ridge lines of a polygon mirror and a reflecting means and to obtain a large effective deflection angle by switching and wobbling the optical paths of the laser beam between the two optical paths parallel with each other by an optical path switching means at a high speed. CONSTITUTION:The two optical paths parallel with each; other are provided by using the optical path switching means 13 and, for example, a prism 14. The two optical paths are switched and wobbled at the high sped by the optical path switching means 13 near the side where the reflecting points of the laser beam at the rotary polygon mirror 8 and the reflecting means 16 approximate to the ridge lines BO of the rotary polygon mirror 8 and the reflecting mirror 16. The period when the laser beam is eclipsed by the ridge lines of the polygon mirror and the reflecting mirror is shortened by the simple constitution in this way and the large effective deflection angle is obtd. The display images of the high image degree are thus obtd. |
