PURPOSE: An ionizer controlling method based on the pollution level and an air purifier using the same are provided to automatically stop the operation of the ionizer as the pollution level decreases by starting the operation of the ionizer automatically as the pollution level of atmosphere increases.CONSTITUTION: An air purifier using an ionizer controlling method based on the pollution level comprises an ionizer(10), the gas sensor(30), and the control unit(20). The gas sensor detects the pollution in atmosphere and produces voltage corresponded to the pollution level. The control unit controls operational time of the ionizer by using the output voltage. The control unit classifies the range of the output voltage, sets weighted value based on the range of output voltage, and calculates the operational time of the ionizer by multiplying pollution sensitive time constant to the weighted value. While the ionizer is operating and the output voltage is lower than the set value, the control unit may stop the operation of the ionizer. The gas sensor controls the output voltage which varies the resistance value depends on toxic gas in the atmosphere.COPYRIGHT KIPO 2013본 발명은 오염도에 따른 이온 발생기의 제어방법 및 상기 제어방법을 이용하는 공기청정기에 관한 것으로서, 본 발명의 일 실시예에 의한 공기청정기는, 이온을 발생시키는 이온발생기 공기 중의 오염도를 측정하여 상기 오염도에 대응하는 출력 전압을 생성하는 가스센서 상기 출력 전압을 이용하여 상기 이온발생기의 동작시간을 조절하는 제어부를 포함할 수 있다.
