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.

When sheet products 1 are discharged, the sheet products are collided against shutter bars 5 so as to fall and stack on a feed conveyor 4. Then, each of protrusion bodies 7 and 8 are lowered by a first drive 9 so as to nip the sheet products between the protrusion bodies and the feed conveyor. Then, coming products are successively discharged and stacked on the protrusion bodies. And then, a second drive 12 is operated in conjunction with the feed conveyor so as to feed the sheet products nipped between the protrusion bodies and the feed conveyor 4. The shutter bars 5 are elevated and lowered by a third drive for adjusting the height position thereof.

According to one embodiment, a banknote stacking apparatus includes a first weight measurement part, a second weight measurement part, and a controller. The first weight measurement part measures a weight of a first banknote bundle. Banknotes laminated along a thickness direction of the banknotes are bundled as the first banknote bundle. The second weight measurement part measures a weight of a second banknote bundle. A first predetermined number of first banknote bundles laminated are bundled as the second banknote bundle. The controller compares the weight measured by the first weight measurement part with the weight measured by the second weight measurement part, and decides whether the number of first banknote bundles bundled as the second banknote bundle is smaller than the first predetermined number, based on a comparison result of the weight.

According to one embodiment, a banknote stacking apparatus includes a first weight measurement part, a second weight measurement part, and a controller. The first weight measurement part measures a weight of a first banknote bundle. Banknotes laminated along a thickness direction of the banknotes are bundled as the first banknote bundle. The second weight measurement part measures a weight of a second banknote bundle. A first predetermined number of first banknote bundles laminated are bundled as the second banknote bundle. The controller compares the weight measured by the first weight measurement part with the weight measured by the second weight measurement part, and decides whether the number of first banknote bundles bundled as the second banknote bundle is smaller than the first predetermined number, based on a comparison result of the weight.

In accordance with an embodiment, a sheet processing apparatus comprises a processing tray, a longitudinal alignment mechanism, a horizontal alignment mechanism and an interlocking mechanism. The processing tray can stack a sheet. The longitudinal alignment mechanism includes a rotatable paddle. The longitudinal alignment mechanism can align the sheets stacked on the processing tray in a sheet conveyance direction. The horizontal alignment mechanism includes a horizontal alignment plate movable in a sheet width direction orthogonal to the sheet conveyance direction. The horizontal alignment mechanism can align the sheets placed on the processing tray in the sheet width direction. The interlocking mechanism interlocks the paddle in the sheet width direction in synchronization with the movement of the horizontal alignment plate in the sheet width direction.

In accordance with an embodiment, a sheet processing apparatus comprises a processing tray, a longitudinal alignment mechanism, a horizontal alignment mechanism and an interlocking mechanism. The processing tray can stack a sheet. The longitudinal alignment mechanism includes a rotatable paddle. The longitudinal alignment mechanism can align the sheets stacked on the processing tray in a sheet conveyance direction. The horizontal alignment mechanism includes a horizontal alignment plate movable in a sheet width direction orthogonal to the sheet conveyance direction. The horizontal alignment mechanism can align the sheets placed on the processing tray in the sheet width direction. The interlocking mechanism interlocks the paddle in the sheet width direction in synchronization with the movement of the horizontal alignment plate in the sheet width direction.

A sheet stacking system is disclosed that has improved tolerance for sheets that are not flat. Successive sheets are aligned onto a stack by a plurality of registration belts. The heights of the pivoting registration belts are compared with one another to determine the unevenness of the top of the stack. This unevenness is represented by the difference between the heights of the highest and lowest registration belt .sub.stack-height and is monitored to quantify the planarity of the top of the stack. When the unevenness (.sub.stack-height) exceeds a threshold, the system switches to a modified method to control the elevation of the stack. This method may include stopping the machine from stacking before the unevenness is too large for the registration belts to uniformly drive sheets. This invention prevents the stacker from attempting to stack when sheets are expected to skew thereby preventing jams and unusable stacks.

A sheet stacking system is disclosed that has improved tolerance for sheets that are not flat. Successive sheets are aligned onto a stack by a plurality of registration belts. The heights of the pivoting registration belts are compared with one another to determine the unevenness of the top of the stack. This unevenness is represented by the difference between the heights of the highest and lowest registration belt .sub.stack-height and is monitored to quantify the planarity of the top of the stack. When the unevenness (.sub.stack-height) exceeds a threshold, the system switches to a modified method to control the elevation of the stack. This method may include stopping the machine from stacking before the unevenness is too large for the registration belts to uniformly drive sheets. This invention prevents the stacker from attempting to stack when sheets are expected to skew thereby preventing jams and unusable stacks.

The present invention is to provide a sheet conveying device capable of reducing noise. The sheet conveying device includes an endless belt that gives a conveying force to a sheet and a rotating member engaged with an outer peripheral portion of the endless belt. The endless belt has, on its outer peripheral portion, a plurality of convex portions arranged in a peripheral direction thereof, the convex portions each extending in a width direction thereof. The rotating member has a contact portion that contacts the outer peripheral portion of the endless belt and deforms a plurality of points of each of the convex portions in the width direction.

The present invention is to provide a sheet conveying device capable of reducing noise. The sheet conveying device includes an endless belt that gives a conveying force to a sheet and a rotating member engaged with an outer peripheral portion of the endless belt. The endless belt has, on its outer peripheral portion, a plurality of convex portions arranged in a peripheral direction thereof, the convex portions each extending in a width direction thereof. The rotating member has a contact portion that contacts the outer peripheral portion of the endless belt and deforms a plurality of points of each of the convex portions in the width direction.