Patent ID: 8366276
Filing Date: 2013-02-05
Classification: B01D,G03B

Abstract:
1. A filter device comprising: a filter unit including a housing in which a roll filter stretched between a feeding shaft and a take-up shaft is housed, the housing including, between the two shafts, an opening for exposing a part of the filter; a filter installation detection sensor for detecting installation of the filter unit; a filter winding driving unit for taking up or rewinding the installed filter; a control unit for controlling operations of the filter winding driving unit based on a detection signal from the filter installation detection sensor; and a sensor for detecting rewinding of the filter performed by the filter winding driving unit, wherein when the control unit determines based on the detection signal from the filter installation detection sensor that the filter is installed, the control unit causes the filter winding driving unit to rewind the filter by a predetermined amount, and when the sensor does not output a signal corresponding to detection of rewinding of the filter for a certain period of time during the rewinding of the filter by the predetermined amount, the control unit determines that the filter is new.