| 摘要 |
PURPOSE:To eliminate the need of securing an area in the width direction of an optical path and to miniaturize a device by constituting a light shielding member so that it can freely move in a direction nearly parallel with the optical path. CONSTITUTION:In the light shielding device provided with the optical path F where the light of specified width passes, and the light shielding members 31 and 32 installed near the optical path F in order to shield the light at the end in the width direction thereof; the members 31 and 32 are constituted to freely move in the direction nearly parallel with the optical path F. A pulse motor 36 is driven, so that the gear parts 31a and 32a of the light shielding blades 31 and 32 are driven to be meshed through an idler gear 35 from a motor gear 34, and the blades 31 and 32 get in the optical path F with turning shafts 37 and 38 as turning fulcrums, thereby shielding both ends in the longitudinal direction of the image light G. The blades 31 and 32 move in a fan shape nearly in parallel with the optical path F to shield both ends of the image light G. Thus, a light shielding unit is miniaturized because the area in the width direction of the optical path F may b e narrow. |
