An ATM includes a sheet driving system with a sheet path along which sheets travel, and sheet sensors and sheet drive mechanisms adjacent the sheet path. One sheet drive mechanism is disposed apart from another sheet drive mechanism in a direction relative to the sheet path, and each sheet drive mechanism is selectively operative to change relative speed and direction of movement of disposed areas of a sheet as the sheet travels adjacent to the sheet drive mechanisms along the sheet path. A control system is responsive to sensing a sheet with a sensor to selectively actuate a sheet drive mechanism to change the position of the sheet relative to the sheet path.

The roller-to-roller conveyance control apparatus includes an amplitude target setting unit that sets an amplitude target value of the tension deviation; an adjustment execution command generation unit that provides a command to adjust the control gain; an adjustment manipulated-variable output unit that outputs an adjustment manipulated variable; a manipulated-variable amplitude determination unit that increases the amplitude of the adjustment manipulated variable until the amplitude of the tension deviation becomes larger than the amplitude target value; and a control-gain calculation device that calculates the control gain from the amplitude and the vibration period of the tension deviation. A tension-shaft speed controller controls a tension-control-shaft motor on the basis of the line speed reference and the adjustment manipulated variable during the adjustment of the control gain.

A medium wind-up apparatus includes a reel-out motor, which is a driving source that winds up a medium, a control portion that controls the reel-out motor on the basis of a torque limit value, which regulates an upper limit of an output torque of the reel-out motor, and a reel-out side detection portion that detects a rotation speed of the reel-out motor, in which the control portion changes the torque limit value on the basis of the detected rotation speed. In this case, it is preferable that the control portion increase the torque limit value in a case in which the detected rotation speed falls below a first threshold value, and that the control portion reduce the torque limit value in a case in which the detected rotation speed exceeds a second threshold value, which is larger than the first threshold value.

A sheet conveying apparatus includes a second conveying roller adjoining a motor driven first conveying roller, a phase determiner to determine a rotational phase of a rotor of the motor, a controller, and a discriminator. The controller controls a drive current flowing through a winding of the motor to reduce phase deviation. The discriminator executes a discrimination regarding one of whether a front end of a sheet has reached a nip portion and whether a rear end of the sheet has passed through a nip portion. The controller controls such that the first conveying roller rotates at a first conveying roller peripheral velocity which is different from a peripheral velocity of the second conveying roller. The discriminator executes the discrimination based on a value of a parameter corresponding to a load torque applied to the rotor where the first conveying roller rotates at the first conveying roller peripheral velocity.

A transport control method for use in transporting a medium in a predetermined direction by an upstream drive roller and a downstream drive roller, to operate the downstream drive roller by using PID control based on a detection value of a tension sensor disposed downstream of the upstream drive roller and upstream of the downstream drive roller for detecting tension. The transport control method includes a stable state determining step for determining, at time of the operation, whether a difference between the detection value of the tension sensors and a target value is within a stable width to make a stable state which maintains a stability time; and a gain decreasing step for decreasing a gain of the PID control to be less than an initial value when the difference is determined to be in the stable state.

A medium feeding apparatus includes a detection tension acquiring unit that acquires a detection tension which is a tension applied during an (n1)-th feeding operation in a plurality of feeding operations in which the medium is fed, a corrected tension calculating unit that calculates a corrected tension obtained by correcting a target tension which is a target value of a tension to be applied during a n-th feeding operation based on the detection tension, and a driving controlling unit that controls a roll motor during the n-th feeding operation based on the corrected tension.

An apparatus for controlling conveyance between rollers includes: a tension-control-amount-detector; a speed-shaft-speed-controller; a tension-shaft-speed-controller; a synchronous-speed-command-generation-unit synchronizing the speed-shaft speed command with a tension-shaft reference speed command; a tension-control-calculation-unit outputting a tension-control correction value based on proportional compensation based on a proportional gain, and integral compensation based on an integral gain; an adjustment-execution-command-generation-unit outputting an adjustment execution command during an automatic adjustment period; a binary-output-unit outputting one of positive and negative values of the additional-value amplitude as an additional value in adjustment during the automatic adjustment period; a tension-shaft-speed-command-generation-unit outputting a tension-shaft speed command based on the tension-shaft reference speed command, the tension-control correction value and the additional value in adjustment; and a gain-calculation-unit calculating a proportional gain and an integral gain based on a period and an amplitude of the tension control deviation for the automatic adjustment period.