Equipment for printing in black on paper sheets - has electrode, matrix and drive circuits incorporated in unit with paper heated for pigment fixation

摘要

The electrode unit (12) is movable linearly, and its so-called home position is at a short distance beneath a bundle of paper to be printed. The bundle is supported by four small corner plates. The printing process involves a valve (32) being opened to create a powerful suction in a hose (38) to fill a previously evacuated container (33) with air. This suction acts via the electrode unit to the space between the bottom paper sheet in the bundle and the surface of the electrode unit. This causes that a paper sheet be sucked away from the corner plates and the remaining sheets, and adhered to the surface of the electrode unit. A vacuum pump (34) is started and stopped automatically when a pressure gauge records high and low pressures respectively in the container. A control (30) produces signals in series to the electrode unit changeover switch, and a voltage source feeds the unit with voltage and current. The current flows through the matrix electrodes, causing the paper to be heated to a temp. suitable for fixation of pigment particles. At this temp., the linear unit (29) starts to drive the matrix unit laterally beneath a developer (26) which rotates, continuously feeding pigment particles. A picture is thus developed, and the required blackening is produced in the row points activated by the control.