Patent ID: 8141871
Filing Date: 2012-03-27
Classification: B65H

Abstract:
1. An image forming apparatus comprising: an image forming unit configured to form an image on a recording medium; a conveyance unit configured to convey the recording medium passing through the image forming unit; a motor configured to activate the conveyance unit; a stop order unit configured to order stoppage of the motor; a detection unit, configured to detect a rotated number of the motor or a conveyance distance during a post-order period, and the post-order period being a period from when the stop order unit ordered stoppage of the motor, which rotate at a constant speed rotation, until when the motor stops; a storage unit, configured to store the rotated number or the conveyance distance detected by the detection unit; a sensor, disposed in a conveyance path of the recording medium, and configured to detect passage of the recording medium; a timing determination unit, configured to determine a pre-order period as a appropriate order timing for stoppage of the recording medium at a target stop position, the pre-order period is calculated from dividing a difference between a first distance and a second distance by a conveyance speed during the constant speed rotation of the motor, the first distance being one of either the conveyance distance stored in the storage unit or a second conveyance distance corresponding to the rotated number stored in the storage unit, and the second distance being a distance between a position where the sensor detects passage of the recording medium and the target stoppage position for the recording medium, an initialization processing unit, configured to drive the motor without conveying the recording medium, and perform initialization processing that activates the image forming unit and the conveyance unit, and an anomaly determination unit, configured to determine an anomaly state when the second distance is smaller than the first distance; wherein the detection unit detects the rotated number or the conveyance distance, when the stop order unit orders the stoppage of driving of the motor after a completion of initialization processing by the initialization processing unit.