DUST SENSOR FOR VACUUM CLEANER, AND VACUUM CLEANER

PROBLEM TO BE SOLVED: To permit a minimum projection cross-sectional area of dust to be sensed to be freely set, and securely sense dust of the set cross-sectional area. SOLUTION: The dust sensor is structured so as to convert a change in luminous energy to a light receiving means 6 through a lens means 5 capable of setting the area of a received light flux of the light receiving means 6 to an electrical signal, the electrical signal, discriminate a nose component from a signal component of an amplification signal of the electrical signal amplified at an amplification degree set by an amplification degree setting means 7 by an amplification means 8 and output a dust sensing signal in accordance with the dust passing through the suction passage 15 by the output of an S/N characteristic discrimination means 10 which outputs only the signal relating to the sensing of the dust, and set the amplification degree A, the S/N characteristic setting value A of the S/N characteristic discrimination means 10 and an area setting value A of the area of the received light flux of the lens means 5 in accordance with the set value A of a sensing capacity setting means 2 to decide on the minimum dust projection cross-sectional area which can be sensed by having the light receiving means 6 arranged oppositely to the light emitting means 4 in the suction passage 15. COPYRIGHT: (C)2008,JPO&INPIT