A vortex generating apparatus has the capability of attracting and removably adhering one or more solid objects. The lamp is used as a headlamp in a vehicle, and the second optical member emits the light from the fluorescent material to the outside of the lamp, so that the second optical member form sat least one of a part of a cut line that defines a boundary between a bright region and a dark region of the headlamp. The current flows to the lower and upper probes are compared to determine a level of ink in the ink reservoir.