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Xerography is electrostatic, not magnetic. Magnetic printers, with magnetic toner, have been built [1] but never really caught on.
It was one of those dead ends from the early years of trying to build a faster printer. Somehow I managed to encounter, early in my career, the first CRT phototypesetter prototype (Harris-Intertype), the first electrostatic liquid printer prototype (Clevite-Brush), the Data Interface Magnetic Printer, the Teletype Inktronic (swept a beam of ink dots with deflection plates, like a CRT), and a Corning Glass display that used photochromic glass (write with UV, view in green, erase with IR). None were successful products, although for a decade or so, electrostatic liquid printers from Versatek [2] were a thing. They used "dark juice", toner particles in a liquid suspension. A row of electrodes charged the paper, which passed over a liquid surface where the paper picked up toner particles. Then a heating station fused the toner and evaporated the liquid. Required special paper. Print quality was mediocre, but the devices were quiet and fast. [1] http://archive.computerhistory.org/resources/text/DataInterf... [2] https://archive.org/details/TNM_Electrostatic_Printers__Plot... |
In classic xerography, yes, the toner is moved around electrostatically. But it also needs to have magnetic properties (either intrinsically or by means of developer) to form a magnetic “brush” which is presented to the drum. Think of iron filings mixed with toner on a piece of paper and a magnet on the other side. The right static charge will be able to pull the toner out while leaving the iron filings behind.