Example implementations relate to print media stacks. In some examples, a device may include a sheet channel to guide a sheet of print media within the sheet channel above and separated in a vertical direction from a stack of printed media when the sheet of print media exits a print path of a printer. The device may include a plurality of clamps to control alignment of the sheet of print media on the stack of printed media when the sheet channel moves outboard from the sheet of print media to allow the sheet of print media to fall onto the stack of printed media, wherein the plurality of clamps sequentially pin the sheet of print media to the stack of printed media from a middle portion of the sheet of print media outward.

A post-processing apparatus according to an embodiment includes a processing tray, a post-processing section, a sensor, and a control section. A sheet supplied from an image forming apparatus is led into the processing tray through a lead-in path. The post-processing section applies post-processing to the sheet sent from the processing tray. The sensor detects an object passing a detection space in the lead-in path. The control section controls operation of the post-processing section based on a time in which the sensor detects the object.

An example stacking system comprises a stacking member movable between a first position in which the stacking member is configured to partially support a first stack of printed substrates, and a second position in which the stacking member is disengaged from the first stack. A receptacle positioned below the stacking member is configured to hold a second stack of printed substrates. A controller is configured to cause the stacking member to move between the first position and the second position when the first stack satisfies a criterion, thereby depositing the first stack into the receptacle on top of the second stack.

An example stacking system comprises a stacking member movable between a first position in which the stacking member is configured to partially support a first stack of printed substrates, and a second position in which the stacking member is disengaged from the first stack. A receptacle positioned below the stacking member is configured to hold a second stack of printed substrates. A controller is configured to cause the stacking member to move between the first position and the second position when the first stack satisfies a criterion, thereby depositing the first stack into the receptacle on top of the second stack.

A paper stacking device includes: a stacker on which paper is stacked; a paper ejector that ejects the paper; an aligning plate that is provided on a side of the paper, and aligns a side end of the paper; a paper floating member that is provided in the aligning plate, and supports, from below, the side end of the paper; and a blower that is provided on the side of the paper across the aligning plate, and blows air, wherein the aligning plate includes a blowing opening through which air from the blower is blown, the paper floating member is switched between: a paper floating position; and a retreat position, when the paper floating member is located in the paper floating position, the blowing opening is opened, and when the paper floating member is located in the retreat position, the blowing opening is shielded.

Example implementations relate to print media stacks. In some examples, a device may include a sheet channel to guide a sheet of print media within the sheet channel above and separated in a vertical direction from a stack of printed media when the sheet of print media exits a print path of a printer. The device may include a plurality of clamps to control alignment of the sheet of print media on the stack of printed media when the sheet channel moves outboard from the sheet of print media to allow the sheet of print media to fall onto the stack of printed media, wherein the plurality of clamps sequentially pin the sheet of print media to the stack of printed media from a middle portion of the sheet of print media outward.

Example implementations relate to print media stacks. In some examples, a device may include a sheet channel to guide a sheet of print media within the sheet channel above and separated in a vertical direction from a stack of printed media when the sheet of print media exits a print path of a printer. The device may include a plurality of clamps to control alignment of the sheet of print media on the stack of printed media when the sheet channel moves outboard from the sheet of print media to allow the sheet of print media to fall onto the stack of printed media, wherein the plurality of clamps sequentially pin the sheet of print media to the stack of printed media from a middle portion of the sheet of print media outward.

An example print medium loading device includes a loading unit on which a print medium is loadable, a transporting roller unit to transport a print medium toward the loading unit, and a moving gate between the loading unit and the transporting roller unit. The loading gate moves according to locations to which the print medium is transported. In an example, when a first print medium is loaded on the loading unit and the transporting roller unit transports a second print medium toward the loading unit, the moving gate is positioned at the first location to overlap a trailing end of the first print medium toward the moving gate. When the leading end of the second print medium is past the moving gate and the second print medium is loaded on the loading unit, the moving gate sequentially moves through the first through fourth positions.

An example print medium loading device includes a loading unit on which a print medium is loadable, a transporting roller unit to transport a print medium toward the loading unit, and a moving gate between the loading unit and the transporting roller unit. The loading gate moves according to locations to which the print medium is transported. In an example, when a first print medium is loaded on the loading unit and the transporting roller unit transports a second print medium toward the loading unit, the moving gate is positioned at the first location to overlap a trailing end of the first print medium toward the moving gate. When the leading end of the second print medium is past the moving gate and the second print medium is loaded on the loading unit, the moving gate sequentially moves through the first through fourth positions.

An example stacking system comprises a stacking member movable between a first position in which the stacking member is configured to partially support a first stack of printed substrates, and a second position in which the stacking member is disengaged from the first stack. A receptacle positioned below the stacking member is configured to hold a second stack of printed substrates. A controller is configured to cause the stacking member to move between the first position and the second position when the first stack satisfies a criterion, thereby depositing the first stack into the receptacle on top of the second stack.