Oki B6500 Series, Service Manual

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Chapter 6 Principles of Operation
Chapter 6 Principles of Operation
Engine
1. Summary of Printing Process
Electrophotography is used in the printer to print image on paper using a video signal
sent from the PWBA ESS to the MCU of the HVPS/MCU. The electrophotography is
composed of the following 7 steps:
(1) Charging - Negative charges are uniformly distributed over the surface of the drum
by Bias Charge Roll.
(2) Exposure - The laser scanner scans the surface of the drum with a quite thin laser
beam modulated according to the signal from the PWBA ESS (controller), to create an
invisible electrostatic latent image on the drum surface.
(3) Development - During development, toner particles are attracted to the electrostatic
latent 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, the
paper 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 on
the surface of the drum and transferred to the paper. The paper is subjected to some
steps including transfer, peeling, and fixing by the paper transport mechanism. When
the paper is placed in position relative to the image, the toner image is transferred to
the paper from the drum surface, and then fixed.