A light guide (11) includes: an incident surface (18), an exit surface (17) and two reflective surfaces (1501, 1502). The incident surface (18) allows light emitted from a light source (12) to be incident thereon. The exit surface (17) extends in a main scanning direction and allows the incident light to exit the light guide (11) therethrough. Two reflective surfaces (1501, 1502) are located opposite to the exit surface (17) to extend in the main scanning direction and are configured to reflect the incident light toward the exit surface (17). One (1501) of the reflective surfaces includes a plurality of light reflecting patterns (16) formed integrally therewith and having an oval hemispherical prism shape. The other reflective surface (1502) is a separate surface from the one reflective surface (1501) and is formed in a planar shape that enables attachment of a reflective member (1521) allowing the incident light to be reflected thereon toward the exit surface (17).