Printer ReviewPrinter Review

Six Steps of Laser PrintingSix Steps of Laser Printing

1.1. CleaningCleaning

2.2. ConditioningConditioning

3.3. WritingWriting

4.4. DevelopingDeveloping

5.5. TransferringTransferring

6.6. FusingFusing

Take place inside toner Take place inside toner cartridgecartridge

Use components that Use components that undergo the most wearundergo the most wear

Side ViewSide View

Step 1: CleaningStep 1: Cleaning

Step 1 Mind-Numbing DetailStep 1 Mind-Numbing Detail

Sweeper strip cleans Sweeper strip cleans the drumthe drum

Remove/swept away Remove/swept away by Sweeping bladeby Sweeping blade

Cleaning Blade Cleaning Blade finishes physical finishes physical cleaningcleaning

Erase lamps remove Erase lamps remove electrical chargeelectrical charge

Step 2: ConditioningStep 2: Conditioning Primary Charging Roller conditions drum to Primary Charging Roller conditions drum to

contain a contain a Uniform Uniform high electrical charge (-600 V)high electrical charge (-600 V)

Step 3: WritingStep 3: Writing

Laser beam discharges a lower Laser beam discharges a lower charge to only those places where charge to only those places where toner is to gotoner is to go

Writing Mind-numbing Writing Mind-numbing DetailDetail

Uniform charge is discharged only where the Uniform charge is discharged only where the laser beam hits (due to photosensitivity)laser beam hits (due to photosensitivity)

Mirrors reflect the laser beam onto the DrumMirrors reflect the laser beam onto the Drum Scanning Mirror directs beam across the pageScanning Mirror directs beam across the page Main mirror(as wide as the page) reflects beam onto Main mirror(as wide as the page) reflects beam onto

drum through a slitdrum through a slit Focusing lens sharpens the imageFocusing lens sharpens the image Beam detect causes DC controller to step the Beam detect causes DC controller to step the

drum and start a new scandrum and start a new scan

Step 4: DevelopingStep 4: Developing

Toner is placed onto the drum where Toner is placed onto the drum where the charge has been reducedthe charge has been reduced

Developing Mind-numbing Developing Mind-numbing DetailDetail

Charged (~-300V) Toner (resin coated Charged (~-300V) Toner (resin coated iron) is attracted to the developing iron) is attracted to the developing cylinder magneticallycylinder magnetically

Control blade creates even distributionControl blade creates even distribution Charged Toner is pulled off developing Charged Toner is pulled off developing

cylinder onto drumcylinder onto drum Toner is charged by DC bias on Dev.Cyl. Toner is charged by DC bias on Dev.Cyl.

The amount of bias controls densityThe amount of bias controls density

Step 5: TransferringStep 5: Transferring

Strong electrical charge draws toner Strong electrical charge draws toner off drum onto paper; takes place off drum onto paper; takes place outside the cartridgeoutside the cartridge

TransferingTransfering

As paper is feed to roller a transfer As paper is feed to roller a transfer charging roller creates a positive chargecharging roller creates a positive charge

As paper passes by drum, the toner is As paper passes by drum, the toner is drawn to the positively charged paperdrawn to the positively charged paper

After paper passes roller the static After paper passes roller the static charge eliminator reduces the charge charge eliminator reduces the charge on the paper and the drumon the paper and the drum

Step 6: FusingStep 6: Fusing

Heat and pressure fuse toner to Heat and pressure fuse toner to paperpaper

Fusing Mind-numbing detailFusing Mind-numbing detail

Fusing roller apply heat and Fusing roller apply heat and pressure.pressure.

Toner melts into paperToner melts into paper If temperature exceeds 410 degrees If temperature exceeds 410 degrees

F the fusing system shuts downF the fusing system shuts down