Abstract: For a sheet circulating transfer route that includes a sheet transfer portion of a printing mechanism provided with a transfer belt for transfer of a sheet as positioned thereto, a transfer section provided with drive rollers for transfer of a sheet as image-formed by an image former of the printing mechanism, and a sheet invert portion operable for inversion of the sheet as image-formed, there is a drive controller adapted, in conformity to a condition that a sheet to be positioned in the printing mechanism is equal in length to or longer than a path distance from the image former to the drive rollers, to set a transfer speed of the sheet as image-formed by the drive rollers up as an identical speed to a transfer speed of the sheet as positioned by the transfer belt, and in non-conformity to the condition, to set it up as a greater speed than the transfer speed by the transfer belt.

Abstract: In a printing apparatus, even when the measured paper size differs from the scheduled size, it is possible to reduce the frequency of requiring a recovery procedure, and prevent the productivity from decreasing by continuing the operation of the printing apparatus as much as possible. The printing apparatus includes a paper feeding unit for feeding a print sheet from a paper feed tray 120, 130a, 130b, 130c or 130d to a transportation route CR through a paper feed route FR, in-tray sensors 182, 183a, 183b . . . for measuring the paper size in the paper feed trays; a transportation sensor 181 for measuring the paper size on the transportation route, a transportation operation adjusting unit 332 for adjusting the transportation operation on the transportation or paper feed route according to the measurement result of the transportation sensor 181 when the measurement results of the transportation sensor 181 and in-tray sensors mismatch.

Abstract: For a sheet circulating transfer route that includes a sheet transfer portion of a printing mechanism provided with a transfer belt for transfer of a sheet as positioned thereto, a transfer section provided with drive rollers for transfer of a sheet as image-formed by an image former of the printing mechanism, and a sheet invert portion operable for inversion of the sheet as image-formed, there is a drive controller adapted, in conformity to a condition that a sheet to be positioned in the printing mechanism is equal in length to or longer than a path distance from the image former to the drive rollers, to set a transfer speed of the sheet as image-formed by the drive rollers up as an identical speed to a transfer speed of the sheet as positioned by the transfer belt, and in non-conformity to the condition, to set it up as a greater speed than the transfer speed by the transfer belt.

Abstract: In a printing apparatus, even when the measured paper size differs from the scheduled size, it is possible to reduce the frequency of requiring a recovery procedure, and prevent the productivity from decreasing by continuing the operation of the printing apparatus as much as possible. The printing apparatus includes a paper feeding unit for feeding a print sheet from a paper feed tray 120, 130a, 130b, 130c or 130d to a transportation route CR through a paper feed route FR, in-tray sensors 182, 183a, 183b . . . for measuring the paper size in the paper feed trays; a transportation sensor 181 for measuring the paper size on the transportation route, a transportation operation adjusting unit 332 for adjusting the transportation operation on the transportation or paper feed route according to the measurement result of the transportation sensor 181 when the measurement results of the transportation sensor 181 and in-tray sensors mismatch.

Abstract: An image forming apparatus capable of performing a double-side printing process is described. The transportation efficiency and the productivity can be improved by narrowing the distance between adjacent print sheets for use in absorbing the disparity in the transportation of print sheets.