| 摘要 |
PURPOSE:To obtain the light attenuator which continuously changes the rate of attenuation with a simple constitution by arraying in series the 1st, 2nd, 3rd lenses of the specified lengths and the same axis and turning the 2nd lens about the parallel axis spacially from the optical axis. CONSTITUTION:Lenses 10, 12 of the same optical axis and (nL)/2+L/4, nL+L/2 in length and a lends 14 of the same length as that of the lens 10 are arrayed in series. When the lens 12 is turned together with an eccentrically rotating sleeve 13, the parallel deviation quantity DELTAx of the optical axis of the lens 12 with respect to the optical axis of the lenses 10, 14 changes and the light which has entered from the lens 10, is made to parallel luminous fluxes and emits after having been passed through the lens 12 and been focused by the lens 14 is continuously adjusted of its rate of attenuation. |
