Patent ID: 7182470

Claim:
A light amount control apparatus comprising: at least one pair of light amount control plates facing each other and arranged at side edge portions of a light path of a light source; a pair of rotating support shafts arranged substantially parallel to each other for supporting the pair of light amount control plates so that the pair of the light amount control plates rotates relative to the light path; a driving device having a drive rotating shaft, said drive rotating shaft being arranged substantially parallel to the pair of the rotating support shafts; and a transmitting member for transmitting rotation of the drive rotating shaft to the pair of light amount control plates, said transmitting member including a first gear assembly arranged perpendicular to the drive rotating shaft and connected thereto to rotate in a first direction, and a second gear assembly associated with the first gear assembly and rotating in a second direction opposite to the first direction, said first gear assembly supporting one of the pair of light amount control plates and said second gear assembly supporting the other of the pair of light amount control plates; wherein said first gear assembly includes one first spur gear with first teeth, and said second gear assembly includes two second spur gears with second teeth rotatably supported on a same axis for meshing with the one first spur gear, said two second spur gears being urged in a direction that the two second spur gears are pulled each other in a rotational direction thereof, said second teeth being held at positions shifted from each other, said first teeth meshing with a portion between the second teeth.