| 摘要 |
PROBLEM TO BE SOLVED: To execute a dust removing mode at an appropriate timing by almost correctly judging the amount of dust attached to a dust collecting electrode. SOLUTION: An air cleaning function comprises a capacity memory 79 for storing a capacity per unit time beforehand depending on each of rotational modes of a fan 30, a timer unit 77 for measuring the operation times of the respective rotation modes of the fan 30 from the operation starting time, a sum total capacity calculating unit 78 for calculating the sum total of the capacity from the operation starting time on the basis of the capacity stored in the capacity memory 79 and the operation time of the individual rotation modes measured by the timer unit 77, and a dust amount judging unit 80 for judging the amount of dust at a dust collector 40 on the basis of the sum total capacity calculated by the sum total capacity calculating unit 78. |
