A backlight unit includes an anisotropic sheet disposed between a rectangular display panel portion and a light source disposed directly behind the rectangular display panel portion. The anisotropic sheet is a sheet to transmit and diffuse an emitted light of the light source toward the rectangular display panel portion, and has a structure that makes the emitted light more widely diffuse in a direction along a long side of a display surface of the rectangular display panel portion than in a direction along a short side of the display surface of the rectangular display panel portion. The long side and the short side of the display surface are different lengths.