Image Creation; Printing Process Overview - Samsung ML-451 Series Service Manual

2.2.6. Image Creation

This section describes the image creation process used by the printer.

2.2.6.1. Printing Process Overview

The printing system of this product includes the LSU with 2 laser beams, the imaging unit, the toner cartridge and the
transfer unit.
The Imaging unit consists of a Drum unit and Development unit. The Drum unit has an OPC drum, Charge roller, and
Cleaning blade.
The OPC drum [C] is charged with a negative voltage by the Charge roller and is exposed by the light from the LSU (Laser
Scanning unit) [A]. The light produced by the laser creates a latent image by discharging on the surface of the OPC drum.
The negatively charged toner is attracted to the latent drum image due to an electric field. The toner (visible image) on the
OPC drum is transferred to the paper by the positive bias applied to the first transfer roller [C]. The toner cartridge [D]
supplies with the toner to the development unit.
Process Steps
1) OPC drum charge: The Charge roller gives the drum a negative charge.
2) Laser Exposure : Light produced by a laser diode is projected on the charged OPC through the lens and mirrors.
3) Development: This machine uses a dual-component development system . The magnetic roller carries negatively
charged toner to the latent image on the drum surface.
4) Transfer: The transfer roller opposite the OPC drums transfers toner from the drums to the transfer media (e.g.
paper, OHP film, etc).
5) Cleaning for OPC drum: The cleaning blade removes remaining toners on the drum surface after image transfer
to the paper.
6) Quenching for OPC drum: Discharging the drum is done by illuminating the whole area of the drum with the
LED lamps at the end of every job.
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2. Product Specifications and Description
A : Laser Scanning Unit (LSU)
•
B : Transfer Roller
•
C : OPC Drum
•
• D : Toner Cartridge
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