Illumination device and display device

An illumination device comprising:

• a light guide including a first main surface which emits light, a second main surface on an opposite side to the first main surface, a first side surface and a second side surface on an opposite side to the first side surface;
• a plurality of convex portions provided on the second main surface of the light guide;
• and
• a first light source element and a second light source element which respectively oppose the first side surface and the second side surface of the light guide, wherein
• light emitted from each of the first light source element and the second light source element enters inside the light guide from the first side surface and the second side surface, and the entering light propagates inside the light guide while being reflected on the first main surface and the second main surface, and
• when an incident angle of a main ray of the propagating light is expressed by θ, a diffusion angle of the light is expressed by δ, an angle of the convex portion of the light guide is expressed by α, a critical angle of the light guide is expressed by θc, and an angle which satisfies (90°−θc) is expressed by β0, a relationship:
• ((β0+δ)/3)<θ<((β0−δ)/2) is satisfied.