Performance Aspects Of KC-FILM In The Digital Recording Mode

AbstractIn June, 1977 a novel electrophotographic film -- known as KC -Film -- was introduced tothe Graphic Arts Market. This film consists of a very thin layer (3000 thick) of whollyinorganic material sputtered onto a polyester substrate in a proprietary process. Thetiny, vertical crystallites (700 A diameter) function as anisotropic image receptors fea-turing extremely short response times, better than one nanosecond, and they display dis-charge levels proportional to the amount of absorbed energy.Accordingly, it is possible to digitally record pulses at great bandwidth as either bi-nary or intermediate level signals without reciprocity failure and at theoretical resolu-tion levels of 10,000 cycles /mm. These signals can be developed into visible images withelectrostatic toner with great fidelity for storage, reprocessing, viewing, or even print- ing. With especially formulated toners it is possible to print the recording lithographical-ly, i.e., with multiple colors, generating rather esoteric imagery.The daylight handling, infinite storage, and erasability features are expected to leadthis recording material toward many applications in the laser, LED, or electron beam re-cording fields.IntroductionAmong electrophotographic materials KC -Film, a product of Coulter Information Systems,is a relative newcomer. Apart from its newness, this material differs substantially fromother photoreceptors because the coatingis deposited on a flexible substrate by means ofhigh energy particle impact;is wholly inorganic;measures only 1/3 micron in thickness;consists of millions of individual light- sensitivecrystalliteswhose uniformity resembles a monocrystal structureand whose electrical properties outperform all pres-ently known photoconductors.Manufacturing ConsiderationsKC -Film is manufactured with a proprietary radio frequency sputtering process whichyields great uniformity of deposit and excellent morphological /stoichiometric properties.In this process a series of cathodes surround a central anodic cylinder. This cylindertransports the substrate web past the cathodes with the interim space filled with an in-tense and uniform gas plasma. The plasma ions bombard the cathodes, removing from it bykinetic energy molecules of photoconductor material driving it towards the anode, where themolecules impact on the substrate web.