Sensing apparatus for robot cleaner and sensing mtehod thereof

PURPOSE: A sensor and a sensing method of robot cleaners are provided to correctly recognize the position of the robot cleaners regardless of surface material of a cleaning area. CONSTITUTION: A sensor (100) of robot cleaners comprises a light emitting unit (10), a lens unit, a holder (30), a light receiving unit (40), and a body (50). The light emitting unit emits light to the surface of a cleaning area. The lens unit concentrates the light reflected on the surface of the cleaning area and includes lenses having a different view angle. The holder accommodates the lens unit. The light receiving unit receives the light passing through the lens unit. The light emitting unit, the holder, and the light receiving unit are combined in the body.