Abstract: A dynamic aperture module includes a blade set and a driving portion. The blade set includes a plurality of blades, which are disposed around an optical axis to form a light through hole and rotatable for adjusting the light through hole. The driving portion includes a rotating element, at least one magnet and at least one coil. The rotating element corresponds to the blades and is configured to drive the blades to rotate, so that a dimension of the light through hole is variable. The magnet includes four polarities. The polarities of the magnet are relatively distributed along a direction surrounding the optical axis and a direction parallel to the optical axis, respectively. The coil corresponds to the magnet, and one of the magnet and the coil is disposed on the rotating element. The magnet and the coil are disposed along the direction parallel to the optical axis.

Abstract: A multi-layer fluororesin film includes a substrate layer having substantially parallel first and second surfaces, a first fluororesin layer formed on at least one of the first and second surfaces and a second fluororesin layer formed on the first fluororesin layer. The first fluororesin layer has a first fluorine polymer and a first adhesive polymer, and the ratio between the first fluorine polymer and the first adhesive polymer ranges from 0.05 to 0.9. The second fluororesin layer has a second fluorine polymer and a second adhesive polymer, and the ratio between the second fluorine polymer and the second adhesive polymer ranges from 1.2 to 19.