| 摘要 |
PROBLEM TO BE SOLVED: To provide an air cleaner capable of surely actuating even at an working environment low in air pollution. SOLUTION: The air cleaner is provided with a dust sensor 1a, a gas sensor 1b and an ultraviolet sensor 1c. In each threshold value set circuit 31a-31c, three step threshold value in accordance with the degree of the air pollution are set for each sensor 1a-1c, and the threshold value is lowered when the state in which the detecting signal of each sensor 1a-1c becomes less than a prescribed detecting level continues over a fixed time. Comparator circuits 32a-32c compare respectively the detecting signal of each sensor 1a-1c and the threshold value set by each of threshold value set circuit 31a-31c, and a signal treating circuit 33 generates an output signal in accordance with the degree of the air pollution, and a fan control circuit 34 controls the operation mode of the fan 18 in accordance with the operation of an operation switch SW and the output of the signal processing circuit 33. |
