A blade driving device includes an opening forming member forming an opening portion, a pivotal member pivoting about the opening portion, blades configured to enter or exit from the opening portion upon receiving power transmitted from the pivotal member, a cover member arranged so that the pivotal member and the plurality of blades are located between the cover and the opening forming member, and engaging portions engaging the of blades with the opening forming member. The pivotal member comes into slidable contact with the engaging portions in a process of pivoting. A pivotal position of the pivotal member with respect to the opening forming member is defined by the engaging portions.

A light shielding blade including a laminate in which a resin layer is sandwiched between two metal base materials, wherein the two metal base materials each have a specific rigidity of 2010.sup.6 [Pa.Math.m.sup.3/kg] or more and a specific bending rigidity of 1.0 [Pa.sup.1/3.Math.m.sup.3/kg] or more, and wherein the resin layer has an elastic modulus of 1 GPa or more and a thickness of 65 m or less.

A light shielding blade including a laminate in which a resin layer is sandwiched between two metal base materials, wherein the two metal base materials each have a specific rigidity of 2010.sup.6 [Pa.Math.m.sup.3/kg] or more and a specific bending rigidity of 1.0 [Pa.sup.1/3.Math.m.sup.3/kg] or more, and wherein the resin layer has an elastic modulus of 1 GPa or more and a thickness of 65 m or less.

An aperture module is provided. The aperture module includes a blade unit including a plurality of blades configured to form an incidence hole through which light passes, the plurality of blades being provided in (2M1) layers in an optical axis direction, the plurality of blades disposed in each layer being provided in (2N+1) members, where M and N are natural numbers, a rotator on which the plurality of blades are rotatably seated, and an aperture driver configured to rotate the rotator and change a size of the incidence hole. In the plurality of blades, blades disposed on different layers of the (2M1) layers overlap at least partially in the optical axis direction, and blades disposed on a same layer of the (2M1) layers do not overlap each other in the optical axis direction.

An aperture module is provided. The aperture module includes a blade unit including a plurality of blades configured to form an incidence hole through which light passes, the plurality of blades being provided in (2M1) layers in an optical axis direction, the plurality of blades disposed in each layer being provided in (2N+1) members, where M and N are natural numbers, a rotator on which the plurality of blades are rotatably seated, and an aperture driver configured to rotate the rotator and change a size of the incidence hole. In the plurality of blades, blades disposed on different layers of the (2M1) layers overlap at least partially in the optical axis direction, and blades disposed on a same layer of the (2M1) layers do not overlap each other in the optical axis direction.

An aperture module is provided. The aperture module includes a plurality of blades configured to interlock with each other to form a through-hole, a rotator on which the plurality of blades are disposed, a first base on which the rotator is disposed, a second base connected to the first base, and a driving unit disposed on the second base and configured to provide a driving force to move the rotator in a direction that intersects an optical axis direction. The first base is configured to move in an optical axis direction with respect to the second base.

An aperture module is provided. The aperture module includes a plurality of blades configured to interlock with each other to form a through-hole, a rotator on which the plurality of blades are disposed, a first base on which the rotator is disposed, a second base connected to the first base, and a driving unit disposed on the second base and configured to provide a driving force to move the rotator in a direction that intersects an optical axis direction. The first base is configured to move in an optical axis direction with respect to the second base.

A light pass aperture module, in order along a central axis, includes a blade assembly and a cap. The blade assembly includes a plurality of blades. The blades form a light pass aperture, and the light pass aperture is variable in size with the central axis as a center. The cap covers the blade assembly. The cap has a through hole, and the through hole is disposed corresponding to the light pass aperture. The cap includes a surface level down structure. The surface level down structure is disposed corresponding to one of the blades, and the surface level down structure is closer to the one blade than the through hole.

A light pass aperture module, in order along a central axis, includes a blade assembly and a cap. The blade assembly includes a plurality of blades. The blades form a light pass aperture, and the light pass aperture is variable in size with the central axis as a center. The cap covers the blade assembly. The cap has a through hole, and the through hole is disposed corresponding to the light pass aperture. The cap includes a surface level down structure. The surface level down structure is disposed corresponding to one of the blades, and the surface level down structure is closer to the one blade than the through hole.

A shutter assembly comprises a plurality of shutter blades movable between an open position and a closed position, and a plurality of drive mechanisms arranged circumferentially about the plurality of shutter blades for moving the plurality of shutter blades, wherein each of said drive mechanisms is stable in at least a first position and a second position.