Patent ID: 7562414

Claim:
A dust sensing unit for use in a vacuum cleaner, comprising: a body having an air flowing passage therein to move air laden with dust or dirt drawn in through a suction nozzle; a detecting sensor disposed on the air flowing passage of the body to detect whether the dust or dirt passes through the air flowing passage; a lamp part to operate according to a signal outputted from the detecting sensor; a rotating part disposed in the body and being configured to rotate by air drawn in through a suction nozzle and through the air flowing passage; and an electric generator rotated by the rotating part to generate an electric power, wherein the body is disposed between the suction nozzle and a cleaner body, and the electric generator supplies the electric power to at least one of the detecting sensor and the lamp part, wherein the rotating part is disposed, so that a portion of the rotating part is disposed to project into the air flowing passage.