The present invention discloses a control apparatus. This control apparatus has a modulation circuit, and a control circuit for setting up an amplitude setting signal and/or a pulse width setting signal to be used in the modulation circuit, on the basis of characteristic data representative of characteristics of an input image signal, the amplitude setting signal and/or the pulse width setting signal being used for setting up an amplitude and/or a time width of a pulse signal to be output from the modulation circuit in accordance with a gradient gradation value of the image signal, wherein the modulation circuit is a circuit which uses the time width setting signal and/or the amplitude setting signal as a reference signal for setting up the time width and amplitude of the pulse signal in correspondence with the gradient.