Electrostatic Printer

In 1969 the electrostatic printer was invented by Renn Zaphiroplous. 

The simple way of describing the electrostatic printing is the process of taking paper with a coating so fine it is invisible to the eye, and applying and electrical charge so that an image appears. Basically, the paper is coated with a dielectric, which means it doesn't conduct electricity so you can charge it with electric charges. A hoarding head with approximately 400 stylie per inch, puts little dots of electrical charges on the paper which are invisible. Then the paper gets passed through liquid toner, which is a colloidal suspension of particles. These particles get attracted toward charges on the paper and an image appears.

The first machine they made looked like a square garbage can, and the front is where the paper came out. These first machines printed black and white, but as the printers improved they later went to full color. The last machine they made printed on 72-inch wide paper.

When you see trucks or cars drive by with an image on them, it is just a vinal covering. These images are created by an electrostatic printer. An electrostatic printer also created billboards. These images are made of little dots that do not fade. If you take photographic film and use it for these purposes, the film fades in the sunlight. The colors fom an electrostatic printer come from inorganic fast dyes that don't fade so you can put the images anywhere or on anything and it won't ruin in the rain, snow, or sunlight.
Renn came up with the idea for using this process because one day he was working with pen recorders where the pen goes back and forth laying down ink. The problem was that it was hard to feed the ink in the pen when the pen went so fast. Electrostatic printing was a way of solving the problem and being able to create a technique that printed at very high speeds. Renn and the company created a machine that printed 40 pages per second.