| 摘要 |
An ionizer includes a polarity output unit that can selectively output, to a discharge unit, one of a first polarity pattern where the polarity output unit applies a positive direct-current voltage to a first group of discharge needles and applies a negative direct-current voltage to a second group of discharge needles and a second polarity pattern where the polarity output unit applies a negative direct-current voltage to the first group of discharge needles and applies a positive direct-current voltage to the second group of discharge needles and a polarity control unit configured to control the first and second polarity patterns. The polarity control unit includes a current detection unit configured to detect respective direct currents passing through the first group of discharge needles and the second group of discharge needles. When the difference between the current values of the first group of discharge needles and the second group of discharge needles detected by the current detection unit becomes greater than a predetermined value, the polarity control unit switches between the first and second polarity patterns. |
