In a case where a cleaning member is reciprocated in a longitudinal direction of a transmissive member in cleaning operation, the time necessary for the cleaning operation is lengthened. A movement unit is controlled to move the cleaning member in a first direction from a first position in response to a cleaning start signal and then to stop the cleaning member at a second position, and to move the cleaning member in a second direction opposite to the first direction from the second position in response to a next cleaning start signal and then to stop the cleaning member at the first position.