A cardboard conveyor device forms sub negative pressure regions communicative to a main negative pressure region by using wind shield structures of a plate body structure, thus saving power consumption of an aspirator. The plate body structure is for example formed by three plate bodies, the plate body of a middle layer has air holes, the plate body of an upper layer has first interval spaces penetrating the plate body of the upper layer, and the plate body of a lower layer has second interval spaces penetrating the plate body of the lower layer. Each of the first interval spaces is communicative to the corresponding second interval space via the corresponding air holes, and the second interval spaces are communicative to the main negative pressure region. Thus, the sub negative pressure regions can provide a negative pressure to the cardboard being conveyed.

A sheet 200 for an array of vacuum apertures 152 in a substrate support unit 150 of a printer is provided. The sheet 200 comprises a plurality of valves 202 formed into the sheet 200. The sheet 200 is made from a resilient material. Each valve 202 comprises a valve head 204 for sealing a vacuum aperture 152 in the substrate support unit 150, and a valve lever arm 206 for permitting movement of the valve head 204 towards and away from the vacuum aperture 152 in order to open and close the valve 202.

A medium processing apparatus includes a liquid applier and a post-processing device. The liquid applier applies liquid onto a medium. The post-processing device performs a process on a media bundle including the medium with the liquid applied by the liquid applier. The liquid applier includes a liquid application member, a liquid storage, a movement mechanism, and a compression support. The liquid application member has an end portion to contact with the medium to apply the liquid onto the medium. The liquid storage stores the liquid to be supplied to the liquid application member. The movement mechanism moves the liquid application member toward or away from the medium to bring the end portion into contact with the medium or separate the end portion from the medium as an approaching operation. The compression support compresses the liquid application member according to the approaching operation of the movement mechanism.

A suction cup gripping system has suction cup gripping devices each provided with a gripping suction cup having an internal cavity, a Venturi vacuum generator connectable to a compressed air line and connected to the internal cavity to generate therein a partial vacuum, a release valve connected to the internal cavity and operable to connect the internal cavity to an external environment or the compressed air line to eliminate the partial vacuum in the internal cavity, and a check valve interposed between Venturi vacuum generator and internal cavity. The gripping system includes a valve system connected to the Venturi vacuum generators and the release valves, a manifold connected to the internal cavities, a vacuum sensor connected to the manifold, and a control unit configured to control the valve system.