ALL ABOUT LASER PRINTER

ALL ABOUT LASER PRINTER

This printer is also known as page printer because they receive their print job one page at a type.  There are two major types of laser printer

1)      The first use a laser to scan the image on two a organic photo conductive drum (OPC)

2)      The second use an array of led to create the image on the drum.  Xerox invented this printer in 1971 but the first laser printer was introduced y hp in 1984.

BASIC COMPONENTS

Tonner cartridge :Tonner is a black carbon substance mixed with polyster resin to make it flow better and iron oxide particles to make it sensitive to electrical charge.  Tonner contain a medium called developer which carries the tonner until it is used by the EP(Electro photography) process.

The tonner also contains the opc drum.  The drum is coated with a photo sensitive material that hold a static charge unless it is exposed to light.  The drum also contains a cleaning blade known as doctor blade. That continuously scraps the unused tonner from the drum.

Load Scanner Assembly:The laser scanning assembly contains a laser LED and a scanning mirror that shines  on the particular area of an OPC drum.  When it does that the drum discharges the charge onlyu to the areas that was scanned.

High voltage Power Supply :The EP process require high voltage electricity hvps provides high voltages to the primary and transfer corona.  This component converts 240 VAC into plus +600 VDC and -600 VDC.

DC power supply : The Hpvs Cannot Provide Power To Together Components Which Runs At A Lower Voltage  The Pc Power Supply Provides 3 Voltages +5 Volt Dc, -5vdc, Used By Logic Circuit Board +24v Used By Paper Transport Motor And Cooling Fans

Paper Transport Assembly : This assembly is responsible for moving the paper into the printer. It consist of a motor and several rubber roller.  The first is the paper feed roller or paper pickup roller, which rub against the paper and pushes one sheet into the printer.  The second is registration roller. 

This roller moves the paper while the opc drum prints.  The third is the fuser roller it moves the paper in very small increments while the fuser assembly makes the print permanent.

Corona Assembly : The first is primary corona, which is a electrical coil now becomes a roller which charges the opc drum with -600v.  The second one is transferred corona,  which charges the paper with +600vdc.  

This two corona assemblies are powered by hvps.  There is a static charges eleminator strip that discharge the static charge from the paper otherwise paper jam will frequently occur.

Fusing Assembly : The Assembly Contains A Halogen Lamp Which Generate Heat Upto 200 Centigrade It Also Contains A Teflon Coated Aluminium Roller For Fusing And A Rubber Pressure Roller .

 As  The  Paper Passes Between The Two Roller, The Pressure Roller Pushes The Paper Against The Fusing Roller Which Melts The Tonner Into Paper

Control Circuit Board : It is a motherboard of a ;printer i.e. Mounted under the printer it converts signals from the computer or that various assemblies can understand the board has connector for each type of interface and coils for each assembly.

Ozone Filter : High Voltage Create Ozone Gas It Is A Chemical Reactive Gas That Effects And Reduce The Life Of Laser Printer Components Every Printer  Contains An Ozone Filter Which Reduce the Ozone Gas While Maintenance Of printer This Filter Must Be Clean.