Abstract: An ion modulator having a bias electrode is capable of producing copies in which the contrast and background are controllable. Such modulator functions in a process which utilizes an adjustable charge density applied to set up uniform fringing fields of the desired magnitude which block ions directed towards background (light) areas. Funneling fields are set up in image (dark) areas in opposition to the original fringing fields by simultaneous imaging and ion projection, decreasing the effect of such fringing fields and permitting ions to pass through the modulator in image areas.

Abstract: A secure property device utilizing radiant energy reflectors applied to a magnetic data member is provided in which the specularity of reflections from the reflectors is enhanced by means of a polymeric primer which is chemically and optically compatible with the reflectors and with the magnetic data member to which it is applied.