Printing technology on organic photoconductor drum (OPC Drum) is summarized by the following 6 steps:
STEP1:The OPC drum must be charged with a negative charge, (electrons)
the primery charge roller apply a hight voltage to the drum.Note:if this step missing, (poor contact in the high voltage) the page will be printed all black)
the charge roller is located on the drum.
The laser beam reach the drum surface to discharge the zone of text that will be printed on the paper. Note: if the laser beam don't reach the drum,( the interlock switch is not actuated when the front cover is closed) the image will not be formed on the drum.
the laser unit is showing on this picture:
the developping cylinder prepare the toner to be taken by the drum, the surface that was touched by the laser beam are positive, they attract the toner by electrostatic force, the other zone push the toner because they have the same charge (both negative, coulomb law). the image will be formed on the drum surface.the developping roller is located on the cartridge.
the transfer roller attract the image formed on the drum surface to the paper.Note:
if the high voltage not reach the transfer roller, the paper comes out blank (poor contact), or if the transfert roller is dirty the quality of printing is bad. these is the picture of the transfert roller and the paper pickup roller :
the image was transfered to the paper, and must be fixed by temperature, and pressure. the fixing unit or fusing unit is composed of :the hot roller and a pressure roller.
the clean blade or cleaning roller remove the residuel toner on the drum surface, to prepare for a new print operation. Note :if the cleaning step was not performed the page comes out with the trace of the last print page.