A drive circuit (101, 201, 301, 401, 501, 601, 701, and 801) configured to supply a current to a light emitting element, the drive circuit comprising: a plurality of switching elements (111 and 112) configured to switch between ON/OFF states with a modulation signal; a capacitor connected in parallel with the light emitting element; and a control module configured to control the switching elements (111 and 112) so that a voltage of the capacitor does not become lower than a threshold, wherein the switching elements (111 and 112) include a first switching element configured to switch between ON/OFF states of an electric path connecting a power supply potential with the capacitor, and a second switching element configured to switch between ON/OFF states of an electric path connecting the capacitor with a ground potential, the control module includes a pulse control module configured to control the modulation signal so that the ON/OFF state of the first switching element is contrary to the ON/OFF state of the second switching element, and a stop control module configured to control the modulation signal so that the second switching element is caused to be in the OFF state when the voltage of the capacitor becomes equal to or smaller than the threshold, characterised in that the pulse control module is configured to output a first modulation signal that switches ON/OFF the first switching element, and a second modulation signal that switches ON/OFF the second switching element, and configured to cause the first modulation signal to oscillate with a predetermined pulse width, and cause the second modulation signal to oscillate at a phase reversed from that of the first modulation signal, and the pulse control module is configured to, at the time when the voltage (Vc) of the capacitor is lower than the threshold, cause the first modulation signal to oscillate with a pulse width narrower than the predetermined pulse width while keeping the second modulation signal at an electric potential corresponding to the OFF state. a plurality of switching elements (111 and 112) configured to switch between ON/OFF states with a modulation signal; a capacitor connected in parallel with the light emitting element; and a control module configured to control the switching elements (111 and 112) so that a voltage of the capacitor does not become lower than a threshold, wherein the switching elements (111 and 112) include a first switching element configured to switch between ON/OFF states of an electric path connecting a power supply potential with the capacitor, and a second switching element configured to switch between ON/OFF states of an electric path connecting the capacitor with a ground potential, the control module includes a pulse control module configured to control the modulation signal so that the ON/OFF state of the first switching element is contrary to the ON/OFF state of the second switching element, and a stop control module configured to control the modulation signal so that the second switching element is caused to be in the OFF state when the voltage of the capacitor becomes equal to or smaller than the threshold, characterised in that the pulse control module is configured to output a first modulation signal that switches ON/OFF the first switching element, and a second modulation signal that switches ON/OFF the second switching element, and configured to cause the first modulation signal to oscillate with a predetermined pulse width, and cause the second modulation signal to oscillate at a phase reversed from that of the first modulation signal, and the pulse control module is configured to, at the time when the voltage (Vc) of the capacitor is lower than the threshold, cause the first modulation signal to oscillate with a pulse width narrower than the predetermined pulse width while keeping the second modulation signal at an electric potential corresponding to the OFF state.