Illumination device

An illumination device comprising:

• a first lenticular lens sheet in which a plurality of first plano-convex cylindrical lenses which extends in a first direction is arranged in a direction perpendicular to the first direction;
• a second lenticular lens sheet in which a plurality of second plano-convex cylindrical lenses which extends in a second direction is arranged in a direction perpendicular to the second direction;
• a third lenticular lens sheet in which a plurality of third plano-convex cylindrical lenses which extends in a third direction is arranged in a direction perpendicular to the third direction;
• and
• at least one point light source that emits illumination light rays through the first to third lenticular lens sheets,
• wherein the second lenticular lens sheet is laminated on the first lenticular lens sheet such that an angle formed by the first direction and the second direction falls within a first angle range,
• the third lenticular lens sheet is laminated on the first and second lenticular lens sheets such that each of an angle formed by the first direction and the third direction and an angle formed by the second direction and the third direction falls within a second angle range,
• a lower limit of the second angle range is greater than an upper limit of the first angle range,
• the third lenticular lens sheet renders point-shaped illumination light rays emitted from the point light source to line-shaped illumination light rays extending in a direction perpendicular to the third direction, and
• the first and second lenticular lens sheets diffuse the line-shaped illumination light rays extending in the direction perpendicular to the third direction by the third lenticular lens sheet in a direction substantially perpendicular to the first direction and the second direction, to generate streak illumination light rays along a diffusion direction of the illumination light rays diffused by the first and second lenticular lens sheets.