ILLUMINATION DEVICE AND LIGHT GUIDE MEMBER

摘要

PROBLEM TO BE SOLVED: To provide an illumination device and a light guide member capable of efficiently emitting light from an emission surface such that the light arrives at an end portion of a light guide plate without losing transparent feeling.SOLUTION: A light guide unit 10 includes: a curved surface 10c in a region of a rear surface 10b farther than a first position A on the rear surface 10b away from an axis 110 passing through an emission surface 10a and the rear surface 10b by a first distance r; and a rough surface 10d in a region of the emission surface 10a farther than a second position B on the emission surface 10a away from the axis 110 by a second distance rin a direction identical to a direction from the axis 110 to the first position A. Providing that an intersection between the axis 110 and the rear surface 10b serves as an origin and that a direction of the axis 110 from the rear surface 10b toward the emission surface 10a is positive, a normal of the curved surface 10c crosses the axis 110 on a positive side of the axis 110, and an angle on the emission surface 10a at the second position B formed between a normal vector from the rear surface 10b toward the emission surface 10a and a vector from the curved surface 10c toward the second position B is equal to or greater than a critical angle.