US Patent 7382442 Object detector of vehicle

A polygon mirror of an object detector of a vehicle includes first faces for projecting a laser to a first predetermined area and a second face for projecting the laser to a second predetermined area higher than the first predetermined area. The polygon mirror is rotated to project the laser to the first and second predetermined areas through a projection window. Thus, the laser can be projected not only to an area at normal height in front of the vehicle but also to an area higher than the normal height in front of the vehicle. Thus, even if a reflection object of an obstacle is positioned at a high position, probe light can be projected to the reflection object. As a result, object detection or distance measurement can be performed correctly.