US Patent 7184229 Optical switch element

An optical switch element (1) for switching an optical path (2) comprises a fixed reflection element (4), which requires strict preciseness in positioning and angle-setting, and a movable optical path parallel displacement element (3A), which permits relaxed preciseness in positioning and angle-setting. When the movable optical path parallel displacement element is not present in the optical path, light goes straight, and when the optical path displacement element is inserted into the optical path, light running in the optical path is displaced in parallel, inputted into the fixed reflection element, and bent by the fixed reflection element.