A control device can stably control the quantity of the emitted light of a backlight unit by means of a simple arrangement. The control device comprises an electric current supply section for supplying a predetermined drive current to a group of light emitting elements, a quantity of emitted light detecting section for detecting the quantity of light emitted from the group of light emitting elements, a temperature detecting section for detecting the temperature of the backlight unit, a reference quantity of light outputting section for outputting a reference quantity of light for the light emitting elements of each color and a control section for controlling the electric current supply section so as to make it supply a constant drive current to the light emitting elements of blue color according to the quantity of emitted light detected by the quantity of emitted light detecting section, the temperature detected by the temperature detecting section, and the reference quantity of light output from the reference quantity of light outputting section and supply a predetermined drive current to the light emitting elements of red color and those of green color according to the constant drive current supplied to the light emitting elements of blue color.