Abstract: An inkjet printer and a method for controlling an inkjet printer are disclosed. The inkjet printer is provided with an endless transport belt for transporting a medium to be printed; at least one roller for driving the transport belt and at least one additional roller for driving and/or suspending the transport belt; a detection system configured to detect a deformation of the transport belt including at least an in-plane bending deformation of at least a stretch of the transport belt and to generate at least one deformation signal indicating the detected deformation; an actuator assembly configured to change a position and/or orientation of at least one of the rollers of the inkjet printer; and a controller configured to control the actuator assembly based on the at least one deformation signal.

Abstract: A sheet printer includes a sheet conveyor assembly including a first conveyor with a first holding device configured for exerting a holding force on a sheet proportional to a coverage of the sheet on the first conveyor and a second conveyor upstream of the first conveyor including a second holding device configured for holding and releasing the sheet, a print head assembly positioned over the first conveyor, a detector assembly for sensing the transport of the first conveyor, a controller storing on its memory a sheet media catalogue and configured to control a release timing of the second holding device for releasing the sheet partially engaged by the first conveyor based on a media type parameter selected from the media catalogue and to control the print head assembly to commence printing the sheet based on transport information from the detector assembly.

Abstract: The invention relates to a print system comprising at least two page-wide arrays of ink jet print heads, positioned in a frame over a conveyor belt for transporting a substrate underneath the arrays, three sensors for reading markers on the conveyor belt and a control unit that is configured to derive control signals from encoder signals of the three sensors. Two sensors are directly connected to the frame and a third sensor is connected to one of the said two sensors by an element with virtually no thermal expansion, extending in transport direction. The control signals, comprising signals for controlling a transport speed of the conveyor belt and line pulses for the at least two print heads, are derived in such a way that an amount of thermal expansion of the frame is determined and an absolute print resolution is maintained.

Abstract: A sheet transport system for moving a sheet in a transport direction while adjusting a position of the sheet in a lateral direction normal to the transport direction to a target position, includes first and second pinch roller sets spaced apart from one another in the transport direction, each pinch roller set including two pairs of pinch rollers spaced apart from one another in the lateral direction, each pair forming a nip for pinching and driving the sheet with an individually controllable speed; a detection system for detecting a position of the sheet in the lateral direction while the sheet is pinched by the first pinch roller set; and a control system configured for carrying out the following actions: by controlling the speeds of the pinch rollers of the first pinch roller set before the sheet has reached the second pinch roller set, rotating the sheet by a first rotation angle for adjusting a given reference point on a leading part of the sheet to its target position; and when the sheet has left the fi

Abstract: A sheet transport system for moving a sheet in a transport direction while adjusting a position of the sheet in a lateral direction normal to the transport direction to a target position, includes first and second pinch roller sets spaced apart from one another in the transport direction, each pinch roller set including two pairs of pinch rollers spaced apart from one another in the lateral direction, each pair forming a nip for pinching and driving the sheet with an individually controllable speed; a detection system for detecting a position of the sheet in the lateral direction while the sheet is pinched by the first pinch roller set; and a control system configured for carrying out the following actions: by controlling the speeds of the pinch rollers of the first pinch roller set before the sheet has reached the second pinch roller set, rotating the sheet by a first rotation angle for adjusting a given reference point on a leading part of the sheet to its target position; and when the sheet has left the fi

Abstract: An inkjet printer and a method for controlling an inkjet printer are disclosed. The inkjet printer is provided with an endless transport belt for transporting a medium to be printed; at least one roller for driving the transport belt and at least one additional roller for driving and/or suspending the transport belt; a detection system configured to detect a deformation of the transport belt including at least an in-plane bending deformation of at least a stretch of the transport belt and to generate at least one deformation signal indicating the detected deformation; an actuator assembly configured to change a position and/or orientation of at least one of the rollers of the inkjet printer; and a controller configured to control the actuator assembly based on the at least one deformation signal.

Abstract: A method for accurately controlling a medium displacement in an inkjet printer is provided by accurately determining a relation between an actuation signal for a drive motor and a medium displacement. The method comprises the steps of establishing a set of calibration actuation signals each corresponding to a nominal calibration step and determining an achieved medium displacement step for each calibration actuation signal in the set. The set comprises at least one calibration actuation signal for actuating the drive motor to make one full revolution and at least one calibration actuation signal for actuating the drive motor to make a rotation larger than one full revolution, but smaller than two full revolutions. Both a cyclic deviation and a local deviation of the nominal displacement relation is determined based on a finite series of basis functions.

Abstract: A method for accurately controlling a medium displacement in an inkjet printer is provided by accurately determining a relation between an actuation signal for a drive motor and a medium displacement. The method comprises the steps of establishing a set of calibration actuation signals each corresponding to a nominal calibration step and determining an achieved medium displacement step for each calibration actuation signal in the set. The set comprises at least one calibration actuation signal for actuating the drive motor to make one full revolution and at least one calibration actuation signal for actuating the drive motor to make a rotation larger than one full revolution, but smaller than two full revolutions. Both a cyclic deviation and a local deviation of the nominal displacement relation is determined based on a finite series of basis functions.