A sheet stacker includes a sheet conveyor arrangement and a stacker platform. The sheets are fed in a sheet feeding direction on the stacker platform, to form stacks of sheets thereon. The stacker platform supports a stack conveyor configured and controlled to move in a conveyor direction to move the stack under formation such that sequentially piled up jobs are placed in an approximately centered position one with respect to the other according to the sheet feeding direction.

A sheet stacker includes a sheet conveyor arrangement and a stacker platform. The sheets are fed in a sheet feeding direction on the stacker platform, to form stacks of sheets thereon. The stacker platform supports a stack conveyor configured and controlled to move in a conveyor direction to move the stack under formation such that sequentially piled up jobs are placed in an approximately centered position one with respect to the other according to the sheet feeding direction.

A discharge unit includes a first discharge guide which guides the sheet conveyed by the conveyance guide, a second discharge guide which includes the discharge opening, and guides the sheet guided by the first discharge guide toward the discharge tray, and a discharge roller and a discharge pinch roller which are provided in the second discharge guide. The first discharge guide is rotatable around a first axis which is parallel with an axial direction of the discharge roller. The second discharge guide is connected to the first discharge guide to be rotatable around a second axis which is parallel with the first axis. An angle at which the second discharge guide is inclined with respect to a sheet supporting surface in the discharge tray is constant while the discharge unit is moving from the third position up to the fourth position.

The sheet stacker includes a sheet conveyor arrangement, configured for feeding a plurality of sheets and having a sheet discharge end, and a stacking bay. In the stacking bay sheets delivered by the sheet conveyor arrangement are formed into stacks. A stack conveyor is provided in the stacking bay and is movable in a conveyor direction parallel to a sheet feeding direction, according to which the sheets are fed from the sheet discharge end onto the stack conveyor. The sheet discharge end is configured and controlled such that it is gradually lifted during sheet stacking, in order to accommodate a growing stack of sheets being formed on the stack conveyor. A stop plate is positioned in the stacking bay above the stack conveyor and in front of the sheet discharge end of the sheet conveyor arrangement. The stop plate is configured and controlled to be gradually lifted from the stack conveyor as the sheet stack grows, to be withdrawn upon completion of the stack thus allowing removal of the stack in an evacuation direction substantially parallel to the conveyor direction, and to be lowered towards the stack conveyor again.

The sheet stacker includes a sheet conveyor arrangement, configured for feeding a plurality of sheets and having a sheet discharge end, and a stacking bay. In the stacking bay sheets delivered by the sheet conveyor arrangement are formed into stacks. A stack conveyor is provided in the stacking bay and is movable in a conveyor direction parallel to a sheet feeding direction, according to which the sheets are fed from the sheet discharge end onto the stack conveyor. The sheet discharge end is configured and controlled such that it is gradually lifted during sheet stacking, in order to accommodate a growing stack of sheets being formed on the stack conveyor. A stop plate is positioned in the stacking bay above the stack conveyor and in front of the sheet discharge end of the sheet conveyor arrangement. The stop plate is configured and controlled to be gradually lifted from the stack conveyor as the sheet stack grows, to be withdrawn upon completion of the stack thus allowing removal of the stack in an evacuation direction substantially parallel to the conveyor direction, and to be lowered towards the stack conveyor again.

An image reading apparatus, includes: a supply tray; a discharge tray; a conveyance guide; a reading sensor; a discharge unit, which includes a discharge opening to discharge the sheet conveyed by the conveyance guide to the discharge tray and is configured to move from a third position to a fourth as the document supported by the paper feed tray is decreased, the fourth position being higher than the third position; a first drive source, which generates a drive force; a first rotation body, which moves the movable plate by transmitting the drive force from the first drive source to the movable plate; and a second rotation body, which moves the discharge unit by transmitting the drive force from the first drive source to the discharge unit, wherein a diameter of the first rotation body and a diameter of the second rotation body are different from each other.

An image reading apparatus includes a supply tray which supports sheets and includes a movable plate configured to move in correspondence to reduction in a number of the sheets, a discharge tray which is located below the supply tray; a discharge unit which has a discharge opening for discharging the sheet and moves from a lower position and a higher position in correspondence to reduction in the number of the sheets supported on the supply tray, a controller which controls movements of the movable plate and the discharge unit, and a sheet detection unit which detects whether the sheets supported on the discharge tray is lower than a predetermined height. The controller determines a timing to move the discharge unit from the higher position toward the lower position based on a detection result of the sheet detection unit.

An image reading device includes: a supply tray including a movable plate which moves from a first position to a second position according to a decrease in the number of sheet to be supported by a supply tray; a discharge guide including a discharge opening for discharging the sheet conveyed by a conveyance guide to a discharge tray, and moves from a third position to a fourth position according to the decrease in the number of the sheets to be supported by the supply tray; a first drive source and a first drive train that transmits a drive force from the first drive source to a discharge roller. The discharge roller discharges a sheet through a discharge opening by receiving the drive force from the first drive source.

An image reading apparatus includes a supply tray which support sheets and includes a movable plate configured to move in correspondence to reduction in a number of the sheets supported on the supply tray, a discharge tray which is located below the supply tray and supports discharged sheets, a conveyance guide which guides a sheet conveyed from the supply tray toward the discharge tray, a reading sensor which reads an image on the sheet conveyed along the conveyance guide, and a discharge unit having a discharge opening for discharging the sheet to the discharge tray and moves from a third position to a fourth position in correspondence to reduction in the number of the sheets supported on the supply tray. A first timing for which the movable plate is to move and a second timing for which the discharge unit is to move are different.

An image reading apparatus includes: a supply tray; a discharge tray, which is positioned below the supply tray to support the sheet; a conveyance guide, which conveys the sheet from the supply tray to the discharge tray; a reading sensor, which reads an image on the sheet conveyed on the conveyance guide; a discharge unit, which includes a discharge port to discharge the sheet conveyed by the conveyance guide to the discharge tray and is configured to move from a third position to a fourth position, the fourth position being higher than the third position; a first drive source, which generates a drive force; and a second drive source, which generates a drive force, wherein the movable plate is moved by the drive force from the first drive source, and the discharge unit is moved by the drive force from the second drive source.