| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve alignment accuracy of a sheet in a post-processing device, while preventing damage on a fixing roller caused by an edge of a sheet. <P>SOLUTION: A control unit obtains basis weight of sheets that is detected by a registration sensor, and recognizes (classifies) the basis weight of each of the obtained sheets. For example, the control unit classifies the sheets in terms of to which basis weights the sheet belongs: less than 100 g/m<SP POS="POST">2</SP>, 100 g/m<SP POS="POST">2</SP>to 250 g/m<SP POS="POST">2</SP>, and more than 250 g/m<SP POS="POST">2</SP>, and obtains and sets a shift amount corresponding to the classified basis weight from a memory unit (S104 to S116). The control unit adds and subtracts a shift amount set to a previous reference position to calculate a current reference position (S118, S120), and subtracts the calculated current reference position from a passing position of a sheet to be conveyed that is detected by a deviation detection sensor to calculate an oscillation amount ΔL of a registration oscillation unit (S122). The control unit then shifts the sheet in an orthogonal direction that is orthogonal to a conveying direction by the calculated oscillation amount ΔL to deviate the reference position (S124). <P>COPYRIGHT: (C)2013,JPO&INPIT |
