Patent ID: 8364071
Filing Date: 2013-01-29
Classification: B65H,G03G

Abstract:
1. A sheet conveying device comprising: a plurality of conveying units each including a drive roller and a driven roller to convey a recording medium while holding the recording medium between the drive roller and the driven roller, the conveying units including a first conveying unit, that conveys the recording medium to an image transfer unit, and a second conveying unit, that transfer an image to the recording medium, the second conveying unit being located more than a sheet length of the recording medium downstream of the first conveying unit in a conveying direction in which the recording medium is conveyed, speed of the drive roller of the second conveying unit being controllable; a first measuring unit attached to a shaft of the drive roller of the first conveying unit that obtains speed information of the first conveying unit; a second measuring unit attached to a shaft of the drive roller of the second conveying unit that obtains speed information of the second conveying unit; a storage unit that stores therein the speed information obtained from the first measuring unit when the recording medium enters the first conveying unit only when the measured speed falls below a threshold speed and the storage unit stores the speed information obtained from first measuring unit when the recording medium exits the first conveying unit only when the measured speed increases above the threshold speed; a calculating unit that calculates a target value based on the speed information stored in the storage unit, and a controller that receives the speed information from the second measuring unit, wherein the speed of the drive roller of the second conveying unit is controlled by the controller based on the target value and the input speed information from the second measuring unit.