2. Product Specifications and Description2.5. Image Creation2.5.1. Printing process overviewThis machine uses four imaging units and four laser beams for color printing. Each Imaging unit consists of a Drumunit and Developer unit.Each Drum unit has an OPC drum, Charge roller, Cleaning blade.The OPC drum [A] is charged with a negative voltage and is exposed by the light from the LSU (Laser Scanning unit) [B].The light produced by the laser creates a latent image by discharging on the surface of the OPC drum. The negativelycharged toner is attracted to the latent drum image due to an electric field. The toner (real image) on each OPC drum ismoved to the transfer belt[C] by the positive bias applied to the first transfer roller. All four toners (color image) aretransferred to the paper by a positive charge applied to the second transfer roller[D].1) OPC drum charge : The charge roller gives the drum a negative charge.2) Laser exposure : Light produced by a laser diode hits the charged OPC through the lens and mirrors.3) Development : The developing roller carries negatively charged toner to the latent image on the drum surface. Thismachine uses four independent imaging units (one for each color).4) Transfer :• Image transfer : The first transfer rollers opposite the OPC drums transfer toner from the drums to the transferbelt. Four toner images are super-imposed onto the belt.• Paper transfer : The second transfer roller transfers the toner from the transfer belt to the media.5) Cleaning for OPC drum : The cleaning blade remove remaining toner on the drum surface after image transferto the paper.6) Quenching for OPC drum : Quenching is done by illuminating the whole area of the drum with the laser at the endof every job.7) Cleaning and quenching for transfer belt : The cleaning blade clean the belt surface. The grounding roller inside thetransfer belt unit removes the remaining charge on the belt.Copyright© 1995-2013 SAMSUNG. All rights reserved. 2-37
