A driving device that includes a temperature monitoring circuit, a headroom voltage monitoring circuit, a power supply voltage monitoring circuit, and a control unit. The temperature monitoring circuit detects a temperature of a drive circuit that drives a light emitting element in a test light emission period of the light emitting element. The headroom voltage monitoring circuit detects a headroom voltage of the drive circuit in the test light emission period. The power supply voltage monitoring circuit detects a power supply voltage supplied to the light emitting element in the test light emission period. The control unit adjusts the power supply voltage in the test light emission period according to an input/output potential difference of the light emitting element varying depending on the temperature of drive circuit so as to obtain a headroom voltage necessary and sufficient for causing a prescribed drive current to flow through the light emitting element.