Patent ID: 8934163
Filing Date: 2015-01-13
Classification: G02B,G03B

Abstract:
1. A light quantity control apparatus comprising: a base plate where an opening part is formed; a shutter blade configured to be movable between a closed state where the shutter blade closes the opening part and an open state where the shutter blade opens the opening part; a light quantity adjustment blade configured to be movable between an insertion state where the light quantity adjustment blade is inserted into the opening part and an evacuation state where the light quantity adjustment blade is evacuated from the opening part; an arm member that engages with the light quantity adjustment blade; a link member that is connected with the arm member and engages with the shutter blade; and a stepping motor configured to drive the arm member, wherein the arm member is capable of moving to a first position, a second position, a third position, and a fourth position, in order, by driving the stepping motor in one direction, wherein the shutter blade is in the closed state and the light quantity adjustment blade is in the insertion state when the arm member is at the first position, wherein the shutter blade is in the open state and the light quantity adjustment blade is in the insertion state when the arm member is at the second position, wherein the shutter blade is in the open state and the light quantity adjustment blade is in the evacuation state when the arm member is at the third position, and wherein the shutter blade is in the closed state and the light quantity adjustment blade is in the evacuation state when the arm member is at the fourth position.