Industry Patents

An illumination device includes a light source and a first light guide. The first light guide includes a first light guide portion and a second light guide portion, and the second light guide portion includes a light-emitting surface. Light emitted by the light source couplingly enters the first light guide portion, and is emitted from the light-emitting surface of the second light guide portion. The cross-sectional area of the second light guide portion is perpendicular to the center line of the first light guide and gradually decreases along the optical axis direction of the light source. The light-emitting surface does not have rotational symmetry. By means of the illumination device, light rays emitted from the light-emitting surface are distributed unevenly in a space. Modifying the distribution of light emitted by the illumination device helps to reduce light loss and increase the utilization of the light.