US Patent 9778452 Sighting device

A sighting device, including an optical element having a concave reflection surface and an aiming light source and forming in a visual field frame, comprises a main-body housing section that houses the optical element and the aiming light source and has an opening on an upper surface side, a cover member that covers the upper surface side of the main-body housing section, and a link mechanism that couples the main-body housing section and the cover member and moves the cover member with respect to the main-body housing section. The cover member is moved by the link mechanism between a closed position where the cover member covers the opening of the main-body housing section and an open position where the cover member is disposed in a position separated from the opening of the main-body housing section and forms an optical path of the aiming light.