Patent ID: 8251600

Claim:
A mechanical shutter, comprising: a base comprising a first through hole defined therein; a connecting shaft extending from the base; a cover comprising a second through hole and a connecting hole, the connecting shaft of the base extending through the connecting hole to secure the base to the cover, the base and the cover cooperatively forming a housing, the first through hole and the second through hole aligned with each other and cooperatively defining a light passage; a primary blade defining a shaft hole, the connecting shaft extending through the shaft hole, the primary blade being rotatably secured to the base, the primary blade being capable of rotating around the connecting shaft relative to the base; and a secondary blade movable relative to the primary blade; wherein the mechanical shutter further comprises a first slot and a first post extending through the first slot, the first slot is defined in the secondary blade, the first post is fixed on the cover, and the first post is slidable in and along the first slot; the primary blade being rotatable around the connecting shaft relative to the base, so as to carry the secondary blade to move and rotate about the first post, the shape of the primary blade and the shape of the secondary blade remaining the same during the rotations, and thereby the primary blade and the secondary blade cooperatively totally covering or opening the light passage.