Scanning Optical System And Radar

A scanning optical system, comprising:

• a rotatable mirror unit including a first mirror surface and a second mirror surface each inclining relative to a rotation axis;
• and
• a light projecting system including at least one light source which emits a light flux toward an object through the mirror unit;
• wherein a light flux emitted from the light source is reflected on the first mirror surface of the mirror unit, then, proceeds to the second mirror surface, further is reflected on the second mirror surface, and is projected so as to scan on the object correspondingly to rotation of the mirror unit,
• wherein the mirror unit includes multiples pairs of the first mirror surfaces and the second mirror surfaces, and the respective intersection angles of the multiples pairs are different from each other,
• wherein in one rotation of the mirror unit, the light flux emitted from the light source is reflected on the second mirror surfaces in the respective pairs which construct the multiples pairs, and is projected sequentially, thereby to scan a measurement range in which the object is measured, and
• wherein a length in a sub scanning direction of the light flux emitted from the light source and the intersection angles of the multiples pairs are set so as to correspond to a length in a sub scanning direction of the measurement range.