Illumination system, control device, and control method

The invention provides a lighting system, a control device and a control method, which can improve a relaxing effect. A lighting system (1) is provided with a light-emitting unit (21) and a control unit (11). The control unit controls the light emitting unit. A first period in which the light intensity of the light emitting section is controlled by the control section includes a second period in which the light intensity of the light emitting section is controlled based on the light output pattern. For the light intensity of the light emitting unit controlled by the control unit, during the second period, the component intensity of a light component having a frequency greater than 1 Hz is 5% or less of the maximum value of the component intensity of a light component having a frequency of 1 Hz or less. The second period at least comprises a third period. The maximum value (Lmax) of the light intensity of the light-emitting part in the third period and the minimum value (Lmin) of the light intensity of the lig