According to one embodiment, a light emission controller has a light-value-change detector and a lighting controller. The lighting-value-change detector is configured to detect a change in a lighting value of a plurality of light sources. The lighting controller is configured to turn on the plurality of light sources at a plurality of lighting timings within a lighting period defined between an initial lighting timing and a final lighting timing of the plurality of lighting timings by pulse width modulation in accordance with the change in the lighting value, a number of the lighting timings in a later lighting period of the lighting period being greater than a number of the lighting timings in an earlier lighting period of the lighting period.