A surface light source device which illuminates a transmission-type liquid
crystal display unit from the back surface includes P.times.Q surface
light source units with individually controlled light sources. Each of
the light sources includes a plurality of light-emitting element units.
Each of the light-emitting element units includes at least one red
light-emitting element that emits red light, at least one green
light-emitting element that emits green light, and at least one blue
light-emitting element that emits blue light. The center of mass of a
luminance profile based on each of a plurality of red light-emitting
elements, a plurality of green light-emitting elements, and a plurality
of blue light-emitting elements in each surface light source unit
substantially coincides with the center of mass of the surface light
source unit.