Developemnt of Electrostatic paper Separation and Feed Mechanism

A new paper separation and feed mechanism is proposed to realize a highly reliable paper handling system for printers and copiers. The paper-separation system consisted of a pair of parallel electrodes and a paper pile between the electrodes. Electrostatic separation of a piece of paper was realized always at the top of the pile when the applied voltage exceeded a threshold to generate electrostatic force larger than the weight of the paper. The threshold voltage was about several kilovolts, and it agreed with the numerical value calculated by the FEM for the electrostatic field. Based on these basic investigations, a prototype paper separation and feed mechanism was constructed. It consisted of a roller-type separation electrode coated with an insulating film, a biased charger roller in contact with the separation roller to charge the insulating film on the separation roller, a ground electrode, and a paper pile between the electrodes. When electrostatic field was applied between the biased charger roller and a ground electrode on which the paper pile was mounted, it was confirmed that only a top paper was separated, adhered electrostatically to the roller, and then fed by the rotation of the separation roller. In this system, reliable paper separation and feed was realized and a feed speed over 600 mm/s was demonstrated.

Experimental set-up of electrostatic paper-separation mechanism.

Motion of paper after voltage application between separation electrode and ground electrode. The applied voltage was increased gradually. (movie)

Experimental set-up of new electrostatic paper separation and feed mechanism with charger roller.

Motion of electrostatic paper-feed after electrostatic paper separation in experimental observation. (initial air gap: 0.5 mm, 1.3 kV applied voltage, paper feed speed: 30 A4-prints per minute) (movie)