Media handling system for duplex printing

A media sheet handling system for enabling printing to a first side and a second side of a media sheet, comprising:

• a first roller which feeds the media sheet along a first path toward a print zone, the media sheet having a first edge and a second edge opposite the first edge;
• a second roller located along the first path between the first roller and the print zone, the second roller receiving a lead edge of the media sheet as the media sheet progresses along the first path from the first roller to the second roller;
• a media sheet edge sensor which generates a first signal when a lead edge of the media sheet is detected and which generates a second signal when a trail edge of the media sheet is detected;
• wherein during printing to the first side of the media sheet during a duplex printing operation, the second roller rotates in a first direction to advance the media sheet into the print zone, the second roller discontinuing rotation in the first direction after printing to the first side is complete and while a portion of the media sheet remains in contact with the second roller, and wherein the first edge of the media sheet serves as the lead edge during printing to the first side;
• a refeed guide located along the first path between the first roller and the second roller, the refeed guide movable between a first position and a second position, the refeed guide biased toward the first position, wherein action of the media sheet passing over the refeed guide along the first path moves the refeed guide into the second position;
• a controller which receives the first signal and second signal and derives a trigger signal based upon an interval between receiving the first signal and second signal, the trigger signal triggering the second roller to change direction to rotate in a second direction opposite the first direction while the portion of the media sheet remains in contact with the second roller, wherein the second roller moves the media sheet back toward the refeed guide while rotating in the second direction, the second edge of the media sheet being the lead edge during movement of the media sheet back toward the refeed guide, and wherein the refeed guide is positioned in the first position blocking the first path when the second edge serving as the lead edge contacts the refeed guide during the movement of the media sheet back toward the refeed guide, the refeed guide directing the media sheet along a second path toward the first roller;
• and
• wherein the media sheet is re-fed around the first roller along the first path to the second roller and through the print zone to receive print onto the media sheet second side.

A media sheet handling method for printing to two sides of a media sheet, comprising the steps of:

• feeding the media sheet with a first roller along a first path onto a second roller;
• rotating the second roller in a first direction to advance at least a portion of the media sheet through a print zone, wherein a first edge of the media sheet is a lead edge during said feeding and rotating steps;
• printing to a first side of the media sheet within the print zone during the rotating step;
• after the step of printing to the first side, discontinuing rotation of the second roller in the first direction while a portion of the media sheet remains in contact with the second roller;
• moving a refeed guide into the first path to block the first path in a region between the first roller and the second roller;
• rotating the second roller in a second direction opposite the first direction to move the media sheet back toward the refeed guide, wherein the refeed guide directs the media sheet along a second path to be repicked by the first roller;
• refeeding the media sheet from the first roller to the second roller and through the print zone, wherein a second edge opposite the first edge of the media sheet is the lead edge during said refeeding step;
• after the media sheet clears the second roller during said step of rotating the second roller in the second direction, reversing the direction of the second roller to rotate in the first direction, wherein said reversing direction of the second roller to the first direction occurs before the media sheet second edge is fed onto the second roller from the first roller;
• and
• printing to a second side of the media sheet within the print zone during the refeeding step.

A media sheet handling method for printing to two sides of a media sheet, comprising the steps of:

• feeding the media sheet with a first roller along a first path onto a second roller;
• rotating the second roller in a first direction to advance at least a portion of the media sheet through a print zone, wherein a first edge of the media sheet is a lead edge and a second edge of the media sheet is a trail edge during said feeding and rotating steps;
• sensing the first edge of the media sheet as the lead edge with a sensor;
• printing to a first side of the media sheet within the print zone during the rotating step;
• sensing the second edge of the media sheet as the trail edge with the sensor;
• after the step of sensing the trail edge, determining based upon the lead edge sensing and trail edge sensing when the media sheet first side printing is complete;
• after said first side printing is complete, discontinuing rotation of the second roller in the first direction while a portion of the media sheet remains in contact with the second roller;
• moving a refeed guide into the first path to block the first path in a region between the first roller and the second roller;
• rotating the second roller in a second direction opposite the first direction to move the media sheet back toward the refeed guide, wherein the refeed guide directs the media sheet along a second path to be repicked by the first roller;
• feeding the media sheet along the first roller;
• sensing the second edge of the media sheet as the lead edge with the sensor;
• based upon the sensing of the second edge as the lead edge determining when the first edge as the trail edge is in a desired position clear of the second roller;
• and
• after the media sheet reaches the desired position, reversing the direction of the second roller to rotate in the first direction, wherein said reversing direction of the second roller occurs before the media sheet second edge as lead edge is fed onto the second roller from the first roller for second side printing;
• and
• refeeding the media sheet from the first roller to the second roller and through the print zone;
• printing to a second side of the media sheet within the print zone during the refeeding step.

A media sheet handling system, comprising:

• a first roller which feeds a media sheet along a first path toward a print zone;
• a second roller located along the first path between the first roller and the print zone, the second roller rotatable in a first direction and a second direction, wherein during rotation in the first direction, the second roller receives the media sheet along the first path from the first roller, and wherein during rotation in the second direction, the second roller feeds the media sheet along a second path;
• and
• a finger guide member located between the first roller and the second roller and movable between a finger guide first position which does not block the first path and a finger guide second position which does block the first path, the finger guide member biased to the finger guide first position, and wherein the finger guide member moves into the finger guide second position during movement of the media sheet along the second path.

A media sheet handling system for enabling printing to two sides of a media sheet, comprising the steps of:

• a first roller for feeding the media sheet along a first path toward a print zone;
• a second roller located between the first roller and the print zone which receives the media sheet from the first roller;
• means for controlling rotational direction of the second roller to rotate in a first direction during printing to each side of the media sheet and to rotate in a second direction to redirect the media sheet toward the first roller between first side printing and second side printing;
• and
• means for blocking the media sheet from moving back along the first path after first side printing and redirecting the media sheet along a second path toward the first roller while the second roller rotates in the second direction.

A media sheet handling system for enabling printing to a first side and a second side of a media sheet, comprising:

• a metering roller which receives the media sheet from a feed path and moves the media sheet toward a print zone, the media sheet having a first edge and a second edge opposite the first edge;
• wherein during printing to the first side of the media sheet during a duplex printing operation, the metering roller rotates in a first direction to advance the media sheet into the print zone, the metering roller discontinuing rotation in the first direction after printing to the first side is complete and while a portion of the media sheet remains in contact with the metering roller, wherein the first edge of the media sheet serves as the lead edge during printing to the first side;
• a feed roller;
• a refeed guide located along the feed path and between the metering roller and the feed roller, the refeed guide movable between a first position and a second position, the refeed guide biased toward the first position, wherein action of the media sheet passing over the refeed guide along the feed path moves the refeed guide into the second position;
• a first signal triggering the metering roller to change direction to rotate in a second direction opposite the first direction while the portion of the media sheet remains in contact with the metering roller, wherein the metering roller moves the media sheet back toward the refeed guide while rotating in the second direction, the second edge of the media sheet being the lead edge during movement of the media sheet back toward the refeed guide, and wherein the refeed guide is positioned in the first position blocking the feed path when the second edge serving as the lead edge contacts the refeed guide during the movement of the media sheet back toward the refeed guide, the refeed guide directing the media sheet along a second path;
• and
• wherein the media sheet is fed along the second path around the feed roller to the metering roller and through the print zone to receive print onto the media sheet second side.

A media sheet handling method for printing to two sides of a media sheet, comprising the steps of:

• receiving the media sheet from a feed path onto a metering roller;
• rotating the metering roller in a first direction to advance at least a portion of the media sheet through a print zone, wherein a first edge of the media sheet is a lead edge during said receiving and rotating steps;
• printing to a first side of the media sheet within the print zone during the rotating step;
• after the step of printing to the first side, discontinuing rotation of the metering roller in the first direction while a portion of the media sheet remains in contact with the metering roller;
• moving a refeed guide into the feed path to block the feed path;
• rotating the metering roller in a second direction opposite the first direction to move the media sheet back toward the refeed guide, wherein the refeed guide directs the media sheet along a second path toward a feed roller;
• refeeding the media sheet from the feed roller to the metering roller and through the print zone, wherein a second edge opposite the first edge of the media sheet is the lead edge during said refeeding step;
• after the media sheet clears the metering roller during said step of rotating the metering roller in the second direction, reversing the direction of the metering roller to rotate in the first direction, wherein said reversing direction of the metering roller to the first direction occurs before the media sheet second edge is fed onto the metering roller from the feed roller;
• and
• printing to a second side of the media sheet within the print zone during the refeeding step.

A media sheet handling system for enabling printing to two sides of a media sheet, wherein printing occurs in a print zone, comprising the steps of:

• a first roller;
• a second roller located between the first roller and the print zone which receives the media sheet along a first path;
• means for controlling rotational direction of the second roller to rotate in a first direction during printing to each side of the media sheet and to rotate in a second direction to redirect the media sheet toward the first roller between first side printing and second side printing;
• and
• means for blocking the media sheet from moving back along the first path after first side printing and redirecting the media sheet along a second path toward the first roller while the second roller rotates in the second direction.