Disclosed in a communication device including a light source over a substrate and a liquid crystal element over the light source. The light source includes first to third light-emitting elements and first to third light-guide plates. The first light-emitting element is configured to emit first light. The second light-emitting element is configured to emit second light different in wavelength from the first light. The third light-emitting element is configured to emit third light different in wavelength from the first light and the second light. The first to third light-guide plates are arranged in a stripe shape and is configured so that the first light to the third light are respectively incident thereon. The liquid crystal element overlaps the first to third light-guide plates. The liquid crystal element is configured to independently control irradiation regions of the first to third lights incident through the first to third light-guide plates.