Patent ID: 7488104

Claim:
A backlight unit comprising: a discrete light source section, a reflecting section, a light guide section, a first optical mixing section, and a second optical mixing section; wherein the reflecting section, the light guide section, the first optical mixing section, and the second optical mixing section are overlaid in this order; the discrete light source section includes individual light sources having different spectra or different light emission quantities arranged near an incident plane of the light guide section; a light drawing section configured to take a light propagating through the light guide section out on a reflecting section side or on a first optical mixing section side is provided on a surface of the light guide section facing the reflecting section or a surface facing the first optical mixing section; the first optical mixing section is configured to mix color lights of different spectra or lights of different light quantities substantially in an in-plane direction to make the light uniform; and the second optical mixing section is configured to mix lights at different angles in a same point in a plane to angularly realign the light to make a luminous light color and a luminous light quantity uniform in the plane.