A printing device for printing substrates, such as circuit boards, wafers, or solar cells, has at least one movably mounted printing unit with a working surface on which the substrate to be printed can be placed. The printing unit is paired with a transport belt device, which has a supply roller with a transport belt wound thereon, a collection roller for winding up the transport belt, and two deflecting surfaces, in particular deflecting rollers, which are paired with the working surface. The transport belt is guided by the supply roller over one deflecting surface and onto the working surface in order to form a contact surface for the substrates, and by the working surface over the other deflecting surface to the collection roller. The deflecting surfaces can be moved together with the respective printing unit. The supply and collection rollers are held on the printing device in a stationary manner.

A gas collection device of a printing press includes an organic compound treatment system (33) including a gas chamber (34). The device includes a cover (3) configured to cover a print unit (2) of a printing press. The device includes a gas transfer device (4) configured to suck a gas of a volatile organic compound produced in the print unit (2) from the inside of the cover 3 and transfer the gas to the gas chamber (34). It is possible to provide a gas collection device of a printing press, which can prevent a work environment in which the printing press is installed from being deteriorated by the gas of the volatile organic compound.

A printing device for printing substrates, such as circuit boards, wafers, or solar cells, has at least one movably mounted printing unit with a working surface on which the substrate to be printed can be placed. The printing unit is paired with a transport belt device, which has a supply roller with a transport belt wound thereon, a collection roller for winding up the transport belt, and two deflecting surfaces, in particular deflecting rollers, which are paired with the working surface. The transport belt is guided by the supply roller over one deflecting surface and onto the working surface in order to form a contact surface for the substrates, and by the working surface over the other deflecting surface to the collection roller. The deflecting surfaces can be moved together with the respective printing unit. The supply and collection rollers are held on the printing device in a stationary manner.

A self-advancing cleaner and a method of operating the self-advancing cleaner. In an embodiment, a rotatable member can engage a transport belt, wherein the rotatable member includes a cleaning surface comprising a surface sufficiently rough to collect and take away ink debris from the transport belt. During a cleaning operation the cleaning surface remains stationary while the transport belt moves in a sliding relative motion with respect to the cleaning surface, which allows the ink debris to be collected on the cleaning surface. Once an ink contamination level associated with the ink debris attains a threshold and a set friction exceeds the threshold, the self-advancing cleaner advances.