Patent ID: 7694962
Filing Date: 2010-04-13
Classification: B65H

Abstract:
1. The sheet conveying apparatus comprising: a skew feeding detection unit arranged along a sheet conveying path which detects a skew-feeding state of a conveyed sheet; a skew feeding correction device, arranged along the sheet conveying path, and comprising first and second skew feeding correction rollers that are drivable independently and are arranged respectively at a direction orthogonal to a sheet conveying direction: a drive control unit operable to control driving of the skew feeding correction rollers so as to correct for the skew feeding of the sheet based on a direction by the skew feeding detection unit; and a lag/lead state detection unit which detects whether such a conveyed sheet reaches a reference position disposed at the sheet conveying path in a lag state in which conveyance of the sheet is lagging, or in a lead state in which conveyance of the sheet is leading; wherein the drive control unit are operable to control said driving of the skew feeding correction rollers in dependence upon the detected lag state or lead state such that an amount of the lag or lead of the sheet after such skew feeding correction by the skew feeding correction device becomes smaller than that at the reference position, wherein the drive control unit are operable to control said driving in a first mode when the sheet is detected by the lag/lead state detection unit as having said lag state, and to control said driving in a second mode, different from the first mode, when the sheet is detected as having said lead state, and wherein said first mode involves increasing a rotation speed of one roller of the first and second feeding correction rollers whose contact position is on the side of the conveyed sheet which is lagging from its normal speed and a rotation speed of the other roller of the first and second feeding correction rollers is not decreased from its normal speed, and wherein said second mode involves decreasing a rotation speed of one roller of the first and second feeding correction rollers whose contact position is on the side of the conveyed sheet which is leading from its normal speed and a rotation speed of the other roller of the first and second feeding correction rollers is not increased from its normal speed.