Patent ID: 8152164
Filing Date: 2012-04-10
Classification: B65H

Abstract:
1. An image forming apparatus comprising: a first pair of rollers for feeding a print medium; a second pair of rollers for feeding the print medium, the second pair of rollers being disposed downstream in a print medium feeding direction from the first pair of rollers; a first detector for detecting the print medium slack in a specified degree by contact with the print medium, the first detector being disposed between the first pair of rollers and the second pair of rollers; a second detector for detecting either the first pair of rollers or the second pair of rollers need a specified value of driving torque; and a controller for controlling either a feeding speed at which the print medium is fed by the first pair of rollers or a feeding speed at which the print medium is fed by the second pair of rollers based on either outputs from the first detector or outputs from the second detector; wherein if the first detector detects the print medium slack in the specified degree earlier than the second detector detects the first pair of rollers or the second pair of rollers need the specified value of driving torque after feeding of the print medium starts, the controller controls the feeding speed based on outputs from the first detector, and if the second detector detects the first pair of rollers or the second pair of rollers need the specified value of driving torque earlier than the first detector detects the print medium slack in the specified degree after feeding of the print medium starts, the controller controls the feeding speed based on outputs from the second detector.