Eric Vanderburg – Core Hardware © 2005

Computer Architecture:Core Hardware

Chapter 13Printers

Eric Vanderburg

Eric Vanderburg – Core Hardware © 2005

Laser Printers1. Cleaning – clean electrical charge from

drum2. Conditioning – applies a uniform charge

(-600v) on the drum3. Writing – Lasers changes the charge on

the drum (-100v) in places where ink should go onto paper. Mirrors sweep the beam across the drum to complete a scanline.

4. Developing – Toner is applied to the drum. It sticks to areas with -100v

5. Transferring – Positively charged paper grabs toner from the drum

6. Fusing – Paper is heated and pressed to attach the toner to the paper

Eric Vanderburg – Core Hardware © 2005

Laser Printers• Print density is adjusted by changing the amount

of charge on the drum• Shake toner cartridge• Economode is great!

Eric Vanderburg – Core Hardware © 2005

Inkjet Printers• Print heads pass over the paper• Ink is boiled and then sprayed with

nozzles onto the paper. • Printers can have as many as 3000

nozzles

Eric Vanderburg – Core Hardware © 2005

InkJet• Some InkJet printers have many

cartridges so you only replace the color you are running out of.

Eric Vanderburg – Core Hardware © 2005

Dot Matrix• Loud• Impact printer• Uses an ink ribbon• Pins hit the ribbon

Eric Vanderburg – Core Hardware © 2005

Other Printers• Thermal Printers

– Heat used to melt wax based ink onto paper

• Solid Ink Printers– Uses sticks of ink –

melted– Long warm up time– Easy maintenance and

refill

Eric Vanderburg – Core Hardware © 2005

Print Drivers• PostScript

– 5 or more PostScript fonts – Developed by Adobe for Macintosh– If your printer does not contain a font, Courier or

Helvetica will be used• PCL (Printer Command Language)

– PCL1 in 1984, PCL6 in 1995– Developed by HP– Provides scalable fonts, font management and storage

of forms and fonts • PJL (Printer Job Language)

– Printer language switching– Job separation– Environment commands– Status feedback– Device attendance– File system commands