Non-impact printing methods are known in which visual information is printed on moving paper webs or other materials as desired using a device which directs coloring matter towards the web surface under the influence of electrical signal control circuitry. Non-impact printing devices include the well-known so called jet printers, such as disclosed in U.S. Pat. Nos. 3,060,429 of C. R. Winston, 3,577,198 of D. R. Beam, 3,416,153 of C. H. Hertz et al, 3,562,757 of V. E. Bischoff, 3,769,624 of C. H. Lee et al, 3,769,627 of J. J. Stone and others. In addition, electrokinetic methods are known in which the printing head is positioned in virtual contact with the web surface such as is disclosed in U.S. Pat. No. 3,750,564 of H. Bettin.
The jet printing mechanisms of the aforementioned U.S. Patents generally disclose the generation of a stream of ink droplets at least portion of which are electrostatically charged. Signal controlled deflector means cause selected droplets to contact the moving web surface whereas droplets not forming part of the information are prevented from contacting the surface by the use of a catcher or the like, from which the unused droplets of ink are returned to the reservoir. The disclosure of Bettin in U.S. Pat. No. 3,750,564 and of J. P. Arndt in U.S. Pat. No. 3,832,579 each reveal non-impact printing methods in which a signal is employed to form droplets of finite quantity of recording material without the need for return of excess ink to the system reservoir.
It is also known to produce latent images on dielectric surfaces by pressure contact of such dielectric surfaces in patterned form with ion or electron or molecular donor material, where such latent images can be developed or rendered visible by attraction thereto of electroscopic marking particles. Such methods are useful for manifolding as disclosed in Great Britian Pat. No. 1,347,529, and also for duplicating as disclosed in U.S. Pat. No. 3,857,722.