An illumination system for a vehicle comprising: a light irradiation unit including a light source, a reflecting mirror array, and a projecting portion, the reflecting mirror array including a plurality of reflecting mirrors arranged on a substrate, each of the plurality of reflecting mirrors being configured to be independently driven between an on state and an off state based on control information and reflect light, irradiated from the light source, in a direction corresponding to the on state or the off state, the projecting portion being configured to project the light, reflected by the reflecting mirrors in the on state, toward a predetermined illumination area; an image acquisition unit configured to acquire image information of the illumination area; an object detecting unit configured to detect a shading object based on the image information of the illumination area, acquired by the image acquisition unit; an information generating unit configured to generate the control information for setting each of the plurality of reflecting mirrors to the on state or the off state such that a plurality of irradiation patterns are alternately irradiated, characterized in that each of the plurality of irradiation patterns is a pattern in which a shaded area in combination with dark pixels and light pixels around the shaded area are arranged, the shaded area comprising a plurality of dark pixels that shade the shading object, each of the plurality of irradiation patterns having different arrangement of dark pixels and arrangement of light pixels from each other; and an irradiation control unit configured to control the light irradiation unit based on the generated control information. a light irradiation unit including a light source, a reflecting mirror array, and a projecting portion, the reflecting mirror array including a plurality of reflecting mirrors arranged on a substrate, each of the plurality of reflecting mirrors being configured to be independently driven between an on state and an off state based on control information and reflect light, irradiated from the light source, in a direction corresponding to the on state or the off state, the projecting portion being configured to project the light, reflected by the reflecting mirrors in the on state, toward a predetermined illumination area; an image acquisition unit configured to acquire image information of the illumination area; an object detecting unit configured to detect a shading object based on the image information of the illumination area, acquired by the image acquisition unit; an information generating unit configured to generate the control information for setting each of the plurality of reflecting mirrors to the on state or the off state such that a plurality of irradiation patterns are alternately irradiated, characterized in that each of the plurality of irradiation patterns is a pattern in which a shaded area in combination with dark pixels and light pixels around the shaded area are arranged, the shaded area comprising a plurality of dark pixels that shade the shading object, each of the plurality of irradiation patterns having different arrangement of dark pixels and arrangement of light pixels from each other; and an irradiation control unit configured to control the light irradiation unit based on the generated control information.