Abstract: Provided is a sheet thickness measurement device capable of increasing measurement density and measurement accuracy over the entirety of a sheet to be measured. Based of a difference between a sheet thickness signal at a position of a backup roll where the sheet exists, and a sheet thickness signal at a position of the backup roll where the sheet does not exist, the sheet thickness signals from the plurality of sheet thickness sensors are zero-adjusted in association with the position of the surface of the backup roll. Based on an output signal from a magnetic sensor in a state in which the sheet is not present on the backup roll, the sheet thickness signals from the plurality of sheet thickness sensors in a state in which the sheet is present on the backup roll are corrected in association with the position of the surface of the backup roll. This enables high-density and accurate sheet thickness measurement.

Abstract: Provided is a sheet thickness measurement device capable of increasing measurement density and measurement accuracy over the entirety of a sheet to be measured. Based of a difference between a sheet thickness signal at a position of a backup roll where the sheet exists, and a sheet thickness signal at a position of the backup roll where the sheet does not exist, the sheet thickness signals from the plurality of sheet thickness sensors are zero-adjusted in association with the position of the surface of the backup roll. Based on an output signal from a magnetic sensor in a state in which the sheet is not present on the backup roll, the sheet thickness signals from the plurality of sheet thickness sensors in a state in which the sheet is present on the backup roll are corrected in association with the position of the surface of the backup roll. This enables high-density and accurate sheet thickness measurement.

Abstract: A touch roller is pressed to the surface of a sheet being conveyed in a space and the amount of displacement of the touch roller is measured to evaluate the sag of the sheet at the position at which the touch roller is pressed against the sheet. The method enables the sag of a sheet to be accurately evaluated with the use of a device having a relatively simple structure and easily maintained.

Abstract: A touch roller is pressed to the surface of a sheet being conveyed in a space and the amount of displacement of the touch roller is measured to evaluate the sag of the sheet at the position at which the touch roller is pressed against the sheet. The method enables the sag of a sheet to be accurately evaluated with the use of a device having a relatively simple structure and easily maintained.