A system is disclosed. The system comprises a roller with a spindle to wind and/or unwind a roll of media, a media advancement sensor to measure the advancement of the media, and a controller. The controller is to control the spindle to rotate an angular displacement, and to determine a calculated media advancement based on the angular displacement and a radius of the roll of media. The controller is also to receive from the media advancement sensor a measured media advancement. The controller is further to detect that a displacement difference between the measured media advancement and the determined media advancement exceeds a predetermined threshold. If the displacement difference exceeds the predetermined threshold a slippage condition is detected.

A liquid ejection apparatus includes a conveying unit, a winding unit, a printing unit, and a rotation control unit. The conveying unit is configured to intermittently convey a printing medium by a predetermined feed amount. The winding unit is configured to wind the printing medium conveyed by the conveying unit. The printing unit is configured to perform printing on the conveyed printing medium. The rotation control unit is configured to control the winding unit to rotate in a winding direction at a predetermined timing after the conveying unit has started to convey the printing medium intermittently, and then cause the winding unit to rotate in a reverse direction opposite to the winding direction.

A liquid ejection apparatus includes a conveying unit, a winding unit, a printing unit, and a rotation control unit. The conveying unit is configured to intermittently convey a printing medium by a predetermined feed amount. The winding unit is configured to wind the printing medium conveyed by the conveying unit. The printing unit is configured to perform printing on the conveyed printing medium. The rotation control unit is configured to control the winding unit to rotate in a winding direction at a predetermined timing after the conveying unit has started to convey the printing medium intermittently, and then cause the winding unit to rotate in a reverse direction opposite to the winding direction.

A tension applying device is attached to a sheet conveyance device. The sheet conveyance device includes a feeding roller for feeding a continuous-form sheet and a winding roller for winding the continuous-form sheet fed from the feeding roller. The tension applying device applies tension to the continuous-form sheet between the feeding roller and the winding roller. The tension applying device includes a guide rail, a slider, a tension bar, and an angle adjustment mechanism. The guide rail is inclined downward toward a continuous-form sheet. The slider slides along the guide rail. The tension bar is supported by the slider and brought into pressure contact with the continuous-form sheet by weight of the slider. The angle adjustment mechanism adjusts an inclination angle of the guide rail with respect to a horizontal direction.

A tension applying device is attached to a sheet conveyance device. The sheet conveyance device includes a feeding roller for feeding a continuous-form sheet and a winding roller for winding the continuous-form sheet fed from the feeding roller. The tension applying device applies tension to the continuous-form sheet between the feeding roller and the winding roller. The tension applying device includes a guide rail, a slider, a tension bar, and an angle adjustment mechanism. The guide rail is inclined downward toward a continuous-form sheet. The slider slides along the guide rail. The tension bar is supported by the slider and brought into pressure contact with the continuous-form sheet by weight of the slider. The angle adjustment mechanism adjusts an inclination angle of the guide rail with respect to a horizontal direction.

An example method comprises operating a drive unit to advance a substrate in a substrate advance direction toward a printing station. At the printing station, a first line is printed onto the substrate. A drive unit is instructed to advance the substrate in the substrate advance direction by a target amount, and a second line is printed onto the substrate. The distance between the first and second lines in a direction perpendicular to the substrate advance direction is calculated and, based on the calculated difference, a tension of the substrate is modified.

An example method comprises operating a drive unit to advance a substrate in a substrate advance direction toward a printing station. At the printing station, a first line is printed onto the substrate. A drive unit is instructed to advance the substrate in the substrate advance direction by a target amount, and a second line is printed onto the substrate. The distance between the first and second lines in a direction perpendicular to the substrate advance direction is calculated and, based on the calculated difference, a tension of the substrate is modified.

A mounting apparatus (10) serves to place a film between an electronic component and a bottom surface of a mounting head and mount the electronic component. The mounting apparatus includes: a film winding mechanism (18) that rotates a winding reel (26) to wind in a film spanning from a dispensing reel to the winding reel (26), the film winding mechanism (18) executing the winding so that a new film is disposed on the bottom surface of the mounting head each time when an electronic component is mounted; a tension detecting part (38) that detects the tension of the film after the same is wound by the film winding mechanism (18); and a control part (20) that rotates the winding reel (26) by a winding motor (30) to adjust the tension on the basis of the tension detected by the tension detecting part (38). A film supply apparatus is also provided.

A conveying device includes a sheet conveyor configured to convey a medium in a conveyance direction of the medium, a sheet winder including a winding roller and a winding motor, and circuitry to control the sheet conveyor and the sheet winder. The circuitry is configured to convey the medium intermittently while repeating: causing the sheet conveyor and the sheet winder to convey the loosened medium by a predetermined conveyance amount; rotating the winding motor in a normal direction by a predetermined torque according to an outer winding diameter of the medium to apply a predetermined tension force to the medium; and rotating the winding motor in a reverse direction to loosen the medium by a predetermined slack amount. The circuitry is configured to determine the predetermined tension force according to the width of the medium intersecting with the conveyance direction of the medium.

A conveying device includes a sheet conveyor configured to convey a medium in a conveyance direction of the medium, a sheet winder including a winding roller and a winding motor, and circuitry to control the sheet conveyor and the sheet winder. The circuitry is configured to convey the medium intermittently while repeating: causing the sheet conveyor and the sheet winder to convey the loosened medium by a predetermined conveyance amount; rotating the winding motor in a normal direction by a predetermined torque according to an outer winding diameter of the medium to apply a predetermined tension force to the medium; and rotating the winding motor in a reverse direction to loosen the medium by a predetermined slack amount. The circuitry is configured to determine the predetermined tension force according to the width of the medium intersecting with the conveyance direction of the medium.