An ink jet recording apparatus, comprising: an ink head configured to discharge an ink; a conveying unit arranged to face the ink head, the conveying unit conveying a sheet to allow the ink to be discharged onto the sheet while carrying the sheet; and a control unit; wherein: the conveying unit includes: a conveyor belt configured to carry the sheet, the conveyor belt turning and moving along a predetermined turning direction; a drive roller configured to drive the conveyor belt in the turning direction by being held in contact with an inner peripheral surface of the conveyor belt; a driving unit configured to generate a rotational drive force for rotating the drive roller; a driven roller configured to rotate, following the conveyor belt, by being held in contact with the inner peripheral surface of the conveyor belt at a position different from the drive roller; and an encoder configured to output pulse signals corresponding to an angular velocity of the driven roller, characterized in that the control unit includes: a storage configured to store outer diameter information on an outer diameter of the driven roller; a filter configured to attenuate frequency components of a target frequency in the pulse signals output from the encoder, using a frequency corresponding to a pulse number of the pulse signals output from the encoder during one turn of the driven roller as the target frequency, and output the attenuated pulse signals; a drive roller controller configured to control a rotation speed of the drive roller by controlling the driving unit based on the pulse signals output from the encoder and the outer diameter information of the driven roller stored in the storage; and a discharge timing controller configured to control a discharge timing of the ink in the ink head based on output signals of the filter and the outer diameter information of the driven roller stored in the storage. an ink head configured to discharge an ink; a conveying unit arranged to face the ink head, the conveying unit conveying a sheet to allow the ink to be discharged onto the sheet while carrying the sheet; and a control unit; wherein: the conveying unit includes: a conveyor belt configured to carry the sheet, the conveyor belt turning and moving along a predetermined turning direction; a drive roller configured to drive the conveyor belt in the turning direction by being held in contact with an inner peripheral surface of the conveyor belt; a driving unit configured to generate a rotational drive force for rotating the drive roller; a driven roller configured to rotate, following the conveyor belt, by being held in contact with the inner peripheral surface of the conveyor belt at a position different from the drive roller; and an encoder configured to output pulse signals corresponding to an angular velocity of the driven roller, a conveyor belt configured to carry the sheet, the conveyor belt turning and moving along a predetermined turning direction; a drive roller configured to drive the conveyor belt in the turning direction by being held in contact with an inner peripheral surface of the conveyor belt; a driving unit configured to generate a rotational drive force for rotating the drive roller; a driven roller configured to rotate, following the conveyor belt, by being held in contact with the inner peripheral surface of the conveyor belt at a position different from the drive roller; and an encoder configured to output pulse signals corresponding to an angular velocity of the driven roller, characterized in that the control unit includes: a storage configured to store outer diameter information on an outer diameter of the driven roller; a filter configured to attenuate frequency components of a target frequency in the pulse signals output from the encoder, using a frequency corresponding to a pulse number of the pulse signals output from the encoder during one turn of the driven roller as the target frequency, and output the attenuated pulse signals; a drive roller controller configured to control a rotation speed of the drive roller by controlling the driving unit based on the pulse signals output from the encoder and the outer diameter information of the driven roller stored in the storage; and a discharge timing controller configured to control a discharge timing of the ink in the ink head based on output signals of the filter and the outer diameter information of the driven roller stored in the storage. a storage configured to store outer diameter information on an outer diameter of the driven roller; a filter configured to attenuate frequency components of a target frequency in the pulse signals output from the encoder, using a frequency corresponding to a pulse number of the pulse signals output from the encoder during one turn of the driven roller as the target frequency, and output the attenuated pulse signals; a drive roller controller configured to control a rotation speed of the drive roller by controlling the driving unit based on the pulse signals output from the encoder and the outer diameter information of the driven roller stored in the storage; and a discharge timing controller configured to control a discharge timing of the ink in the ink head based on output signals of the filter and the outer diameter information of the driven roller stored in the storage.