Indirect Electro Copying Machine

A machine which applies a uniform positive charge to a selenium coated drum and then exposes the charged surface to the image of the original by projecting the image through a lens system. Light reflected off the original strikes the drum dissipating the static charge. The charge on the drum corresponding to the image of the original is retained. The drum is sprinkled with black powder that adheres to the charged area of the drum. The adhering powder on the drum transfers the image to the paper. The powder image is then fused to the paper by heat.