A light source device includes: a light source; a driving signal generating unit that supplies a driving signal to the light source; a light amount measuring unit that measures the amount of light of the light source; and a light amount correcting unit that calculates as a light amount error a difference between a target light amount corresponding to a gray-scale value indicated by gray-scale data input from the outside and the amount of light measured by the light amount measuring unit, corrects a differential efficiency by an integrated value of a product of the light amount error and the gray-scale value, corrects a threshold value of the driving signal, and outputs to the driving signal generating unit a command signal for generating a driving signal having a differential efficiency and a threshold value after the correction.