LaserJet Printer Demoece638/lectures/19.4... · 2019-09-14 · LaserJet as a brand name identifies the line of dry electrophotography (DEP) laser marketed by the American computer

LaserJet Printer DemoPQTS TEAM

2013-09-16

Background

LaserJet as a brand name identifies the line of dry electrophotography (DEP) laser marketed by the American computer company Hewlett-Packard (HP).

The HP LaserJet was the world's first desktop laser printer.

Electrophotography (xerography) process was invented by Chester Carlson in 1938.

“The creation of a visible image using electrostatic latent image in the form of surface charging patterns on a photoconductive surface. ”

http://en.wikipedia.org/wiki/HP_LaserJethttp://en.wikipedia.org/wiki/Xerography

http://en.wikipedia.org/wiki/Hewlett-Packard

http://en.wikipedia.org/wiki/HP_LaserJet

http://en.wikipedia.org/wiki/Xerography

Host-based printing vs. controller or formatter-based printing

How does xerography work

1. Charging2. Exposure3. Development4. Transfer5. Fusing6. Cleaning

allebach

Stamp

Image Formation Process ( M575)

HP LASERJET ENTERPRISE 500 COLOR MFP M575 Troubleshooting Manual

Step 1 of 10: Pre-exposure

Step 1: Pre-exposureLight from the pre-exposure LED strikes the surface of the photosensitive drum to remove any residualelectrical charges from the drum surface.


Step 2 of 10: Primary charging

Step 2: Primary chargingThe primary-charging roller contacts the photosensitive drum and charges the drum with negative potential.


Step 3 of 10: Laser-beam exposure

Step 3: Laser-beam exposureThe laser beam strikes the surface of the photosensitive drum in the areas where the image will form.The negative charge neutralizes in those areas, which are then ready to accept toner.


Step 4 of 10: Development

Step 4: DevelopmentToner acquires a negative charge as the developing cylinder contacts the developing blade. Becausethe negatively charged surface of the photosensitive drums have been neutralized where they havebeen struck by the laser beam, the toner adheres to those areas on the drums. The latent imagebecomes visible on the surface of each drum.


Step 5 of 10: Primary transfer

Step 5: Primary transferThe positively charged primary-transfer rollers contact the ITB, giving the ITB a positive charge. The ITBattracts the negatively charged toner from the surface of each photosensitive drum, and the completetoner image transfers onto the ITB, beginning with yellow, followed by magenta, cyan, and black.


Step 6 of 10: Secondary transfer

Step 6: Secondary transferThe paper acquires a positive charge from the secondary-transfer roller, and so it attracts the negativelycharged toner from the surface of the ITB. The complete toner image transfers onto the paper.


Step 7 of 10: Separation

Step 7: SeparationThe stiffness of the paper causes it to separate from the ITB as the ITB bends. The static-chargeeliminator removes excess charge from the paper to ensure that the toner fuses correctly.


Step 8 of 10: Fusing

Step 8: FusingTo create the permanent image, the paper passes through heated, pressurized rollers to melt the toner onto the page.


Step 9 of 10: ITB cleaning

Step 9: ITB cleaningThe cleaning blade scrapes the residual toner off the surface of the ITB. The residual-toner-feed screwdeposits residual toner in the toner collection box.


Step 10 of 10: Drum cleaning

Step 10: Drum cleaningInside the toner cartridge, the cleaning blade removes residual toner from the surface of the drum toprepare it for the next image. The waste toner falls into the hopper in the print cartridge.


Step 1 of 10: Pre-exposure ( again in the cycle)

Step 1: Pre-exposureLight from the pre-exposure LED strikes the surface of the photosensitive drum to remove any residualelectrical charges from the drum surface.


Switches and sensors for the pickup, feed, and delivery system( M575)


Laser, electrophotographic print engine architecture

Anatomy of a Toner Cartridge

This is an end view of a laser, electrophotographic toner cartridge. The red lines represent the outer shell of the cartridge.

Some HP LaserJet printers

HP LaserJet Enterprise 500 MFP M575dn

HP Color LaserJet Enterprise CP5525n Printer

Documents

LaserJet Printer Demoece638/lectures/19.4... · 2019-09-14 · LaserJet as a brand name identifies the line of dry electrophotography (DEP) laser marketed by the American computer