Patent ID: 8147149

Claim:
A barrier unit, which is designed to be attached to a camera in order to protect the lens of the camera and which is ready to open or close as needed, the barrier unit comprising: a base with a cylindrical portion; a first ring, which is arranged so as to rotate around the cylindrical portion; first and second blades, which are interlocked with the first ring and which are gradually opened and closed as the first ring rotates, and a second ring, which is arranged so as to rotate around the cylindrical portion, wherein when one of the first and second blades is fully opened, the first ring is further movable to turn the other blade in an opening direction, wherein a first elastic member is arranged between the first and second rings in order to bias the first ring to a direction in which the first and second blades are closed, and wherein a second elastic member is arranged between the base and the second ring in order to bias the first ring to a direction in which the first and second blades are opened.