an automatic razor blade sharpener simultaneously sharpens and sanitizes multiple edges of a spring - loaded disposable razor blade cartridge without edge overheating by lubricated gentle contact of the blade edges with a moving rubber or polymeric compliant belt that is motor driven . the disposable razor blade handle is set in a cradle aperture , which is spring loaded against the moving belt . a sanitizing and lubricating liquid is dispersed from a container between the razor blade edges and the moving belt forms a thin liquid layer on the belt surface . the liquid layer is illuminated by transversely located light illuminator and the reflected light is received by a transversely located sensor . deep grooves in the blade cutting edge reduce this reflection , indicating an overly worn blade . the absence of reflection actuates an led , informing the user that the thin liquid film has evaporated or spilled out , or that the container lacks a sufficient quantity of sanitizing and lubricating liquid .