Carlson Electrophotographic

Carlson electrostatic photocopying process is essentially an electro-optical process. The latent image produced by it is an electrostatic image composed of electrostatic charges. The charge, development and transfer processes are all based on the principle of electrostatic attraction. Since the electrostatic latent image is formed by the charge discharge on the charged film layer caused by the decrease of the photoconductive layer resistance under the illumination, the Carlson electrostatic copying method has the following requirements for the photosensitive drum: it has a very high dark resistivity. In the absence of light, this photoreceptor drum can store these charges for a long time as long as the charge is present on the surface. In the case of light, the resistivity of the photoreceptor drum should drop rapidly, that is, it becomes a good conductor of electricity. The surface charge of the drum is quickly released and disappears. The photosensitive drum used by Carlson electrostatic copying method is mainly composed of selenium and selenium alloy, zinc oxide, organic photoconductive material, etc., and is usually directly coated or evaporated on a conductive substrate (such as aluminum plate or other metal plate). Photoconductive material. Its structure is above the photoconductive layer, below is the conductive matrix.