Patent ID: 7988309

Claim:
An illumination device comprising: a light source that supplies illumination light to an object to be illuminated; a corner cube member comprising a plurality of sheets of corner cubes, the sheets being arranged next to each other and facing different directions, at least one of the sheets being disposed entirely behind the light source with respect to the object to be illuminated, and each of the sheets of the corner cube member including a plurality of corner cubes; and a prism member that guides light from the light source to the object to be illuminated, the prism member being disposed at an opposite side of the light source with respect to the corner cube member, the prism member having a first light incident surface on which light from the light source is incident, a second light incident surface formed as a surface different from the first light incident surface, a first reflecting surface that reflects light incident on the first light incident surface, a second reflecting surface that reflects light incident from the second light incident surface toward the first light reflecting surface and a light emitting surface that emits light reflected by the first reflecting surface.