| 摘要 |
PURPOSE:To reduce a reactive area in the respective plane mirrors of a rotary polygon mirror and to miniaturize the rotary polygon mirror by wobbling laser beams which pass a turning plane parallel plate and is made incident on the rotary polygon mirror in parallel with each other. CONSTITUTION:After the laser beam emitted from a laser light source 10 is made incident on an optical modulator 12 through a lens 11a and the brightness thereof is modulated by the modulator 12 in accordance with a video signal from a video signal generator 6, it is made incident on the transmission type plane parallel plate 13 through a lens 11b. The plate 13 turns as shown by an arrow and the laser beam is wobbled in a state that respective transmitted light beam li1 and li2 in the case that the plate 13 has inclination shown by a continuous line and a broken line are made parallel with each other, then the light is made incident on the rotary polygon mirror 1 through a lens 14a. The reflected laser beam is reflected by a galvanomirror 17 through a lens 15, a cylindrical lens 14b and a lens 16b and made incident on a screen 18 through the lens 16b. The incident light is allowed to perform horizontal scanning by the polygon mirror 1 and to perform vertical scanning by the mirror 17. |
