Abstract: A print head protection system is used in connection with an inkjet printer having a print head adapted for elevating, and a belt moving over a platen. A plurality of acoustic sensors is arrayed transversely to the process direction. The acoustic sensors measure a combined thickness of the belt, the platen, and the media sheet. An analyzer will detect if the media sheet is in contact with the media transport. An error signal is created when the thickness is below a predetermined value, indicating the media sheet is not in contact with the media transport. A mitigation control is operative to mitigate print head damage in response to the signal. Printing is halted in response to the signal to preclude damage to the print head. The sheet is discarded.

Abstract: A print head protection system is used in connection with an inkjet printer having a print head adapted for elevating, and a belt moving over a platen. A plurality of acoustic sensors is arrayed transversely to the process direction. The acoustic sensors measure a combined thickness of the belt, the platen, and the media sheet. An analyzer will detect if the media sheet is in contact with the media transport. An error signal is created when the thickness is below a predetermined value, indicating the media sheet is not in contact with the media transport. A mitigation control is operative to mitigate print head damage in response to the signal. Printing is halted in response to the signal to preclude damage to the print head. The sheet is discarded.

Abstract: A sheet-receiving surface comprises retractable bars movable between a first position and a second position. The first position is a first distance away from a mounting support. The second position is a second distance away from the mounting support. The first distance is greater than the second distance. Pivot arms, having a first end and a second end opposite the first end, are rotationally attached at the first end to the retractable bars and rotationally attached at the second end to the mounting support. Bias elements, operatively connected to the pivot arms, bias the retractable bars to the first position. A link is operatively connected to the retractable bars and an actuator. The sheet-receiving surface accumulates sheets of media into sets of sheets. Responsive to operation of the actuator, the link applies a force to move the retractable bars to the second position, forming an opening to allow the sets of sheets to drop, forming a stack of sets of sheets.

Abstract: A print head protection system is used in connection with an inkjet printer having a print head adapted for elevating. A projector upstream of the print head projects a reference pattern onto the media sheet. An imaging camera captures a digital image of the projected pattern. An analyzer compares the digital image of the projected pattern with the reference pattern. If moiré fringes are detected, the moiré fringes are analyzed for media sheet curl. An error signal is created when the sheet curl exceeds a predetermined distance above the process path. A mitigation control raises the print head to preclude damage in response to the signal. Alternately, the sheet can be discarded.

Abstract: An exemplary apparatus herein includes a registration item positioned at the end of a shelf. Further, tamper elements contact the sides of sheets of media on the shelf to align them and push them toward the registration item. In addition, a frame element is connected to each of the tamper elements and a biased member is connected to the frame element. A motor is connected to the biased member. Rotation of the motor moves the tamper elements in a closed curve path motion relative to the shelf and the registration item. With increasing speed of the rotation of the motor, the biased member expands, and this increases the distance of the closed curve path motion and increases the force applied by the tamper elements against the sheets of media being moved toward the registration item along the shelf.

Abstract: An exemplary apparatus herein includes a registration item positioned at the end of a shelf. Further, tamper elements contact the sides of sheets of media on the shelf to align them and push them toward the registration item. In addition, a frame element is connected to each of the tamper elements and a biased member is connected to the frame element. A motor is connected to the biased member. Rotation of the motor moves the tamper elements in a closed curve path motion relative to the shelf and the registration item. With increasing speed of the rotation of the motor, the biased member expands, and this increases the distance of the closed curve path motion and increases the force applied by the tamper elements against the sheets of media being moved toward the registration item along the shelf.

Abstract: A sheet-receiving surface comprises retractable bars movable between a first position and a second position. The first position is a first distance away from a mounting support. The second position is a second distance away from the mounting support. The first distance is greater than the second distance. Pivot arms, having a first end and a second end opposite the first end, are rotationally attached at the first end to the retractable bars and rotationally attached at the second end to the mounting support. Bias elements, operatively connected to the pivot arms, bias the retractable bars to the first position. A link is operatively connected to the retractable bars and an actuator. The sheet-receiving surface accumulates sheets of media into sets of sheets. Responsive to operation of the actuator, the link applies a force to move the retractable bars to the second position, forming an opening to allow the sets of sheets to drop, forming a stack of sets of sheets.

Abstract: Sheet stacking apparatus examples herein include a clamp receiving at least two sheets (e.g., a set of sheets). The clamp aligns and holds the set of sheets. The sheet stacking apparatus also includes an ejector device, an elevator platform, and a registration wall. The ejector device moves the set of sheets held by the clamp in a first direction to move the set of sheets to the elevator platform. The ejector device moves the set of sheets held by the clamp in a second direction to move the set of sheets to contact either the elevator platform or a previously stacked set of sheets. The ejector device moves the set of sheets held by the clamp in a third direction, opposite the first direction, to position the set of sheets against the registration wall. The clamp then releases the set of sheets so that they remain against the registration wall.

Abstract: An apparatus includes a compiler surface that receives sheets of media, and a registration surface positioned at one end of the compiler surface. The leading edges of the sheets of media contact and are aligned by the registration surface. A rotatable cam is positioned at the other end of the compiler surface. The rotatable cam has a lobe, and the surface of the lobe is a high-friction surface. When the rotatable cam is at a “first” rotation position, this causes the lobe to contact the bottom sheet as the sheets of media are received onto the compiler surface. When the rotatable cam is at a “second” rotation position, this causes the lobe to move out of the way and avoid contacting any of the sheets of media as the sheets of media are ejected from the compiler surface.