Optical element and optical system having the same

摘要

An optical element formed from a transparent optical material includes two refraction surfaces, a first reflection surface group having a plurality of internal reflection surfaces arrayed in a predetermined direction, a second reflection surface group opposing said first reflection surface group and having at least one internal reflection surface and two side surfaces opposing each other in parallel to the predetermined direction. Light incident from one of the refraction surface is alternately reflected by the internal reflection surfaces of the first reflection surface group and the internal reflection surface of the second reflection surface group and guided to the other refraction surface. A width of at least one of the plurality of internal reflection surfaces of the first reflection surface group and at least one internal reflection surface of the second reflection surface group in a direction in which the two side surfaces oppose is smaller than a distance between the two side surfaces in the direction in which the side surfaces oppose.