A driver circuit applies a voltage such that clarity of a light control sheet is 83% or less to bring the light control sheet into a first state, and applies a voltage such that haze of the light control sheet according to JIS K 7136 is 15% or less to bring the light control sheet into a second state. The clarity is calculated from the following Formula (1): 100×(LC−LR)/(LC+LR) . . . (1) where LC is an intensity of straight light traveling straight along a traveling direction of parallel light entering the light control sheet, and LR is an intensity of narrow-angle scattered light having an angle within ±2.5° relative to the traveling direction of the parallel light, in light that has passed through the light control sheet.