6 – 1Chapter 6 Principles of OperationChapter 6 Principles of OperationEngine1. Summary of Printing ProcessElectrophotography is used in the printer to print image on paper using a video signalsent from the PWBA ESS to the MCU of the HVPS/MCU. The electrophotography iscomposed of the following 7 steps:(1) Charging - Negative charges are uniformly distributed over the surface of the drumby Bias Charge Roll.(2) Exposure - The laser scanner scans the surface of the drum with a quite thin laserbeam modulated according to the signal from the PWBA ESS (controller), to create aninvisible electrostatic latent image on the drum surface.(3) Development - During development, toner particles are attracted to the electrostaticlatent image on the drum surface. Thus, a visible toner image is created.(4) Transfer - The toner image is transferred from the drum surface to the paper.(5) Peeling - Electric charges on the paper are partially neutralized. As a result, thepaper is peeled off from the drum surface.(6) Fixing - The toner image is permanently fixed to the paper by heat and pressure.(7) Cleaning - The remaining toner is removed from the drum surface.Summary of print process:By rotating the drum, the surface undergoes various steps including charging,exposure, development, transfer, peeling, and cleaning. A toner image is created onthe surface of the drum and transferred to the paper. The paper is subjected to somesteps including transfer, peeling, and fixing by the paper transport mechanism. Whenthe paper is placed in position relative to the image, the toner image is transferred tothe paper from the drum surface, and then fixed.
