InkJet and Thermal Printers

Inkjet Introduction

 InkJet Printing came about in the late 1980’s  Have become the replacement printer for the Serial Dot Matrix in the home  Two Main Reasons:  Price  Color capabilities

How it Works

 Produce characters by squirting a precisely controlled amount of ink onto the paper  Dots are extremely small usually 50-60 microns in diameter (Human Hair approx 70 microns)  Dots are placed very precisely on the paper in a pattern up to 1440 x 720 dots per inch  Dots can be different colors and can be of photographic quality



The Printhead

Printhead contains a series of Nozzles that put the ink on the paper

Ink Cartridge

 Variety of cartridges depending on the Manufacturer of the printer  Multi color in one cartridge  Single color in one cartridge  Cyan, Magenta and Yellow  Some cartridges include the printhead

Heat vs Vibration

 Two basic methods of printing using an inkjet printer  Thermal  Piezoelectric

Thermal

 Used mostly by Canon and Hewlett Packard  Also called Bubble Jet  Tiny resistors create heat  The vaporized ink creates a bubble which pushes the ink onto the paper  Typical Bubble Jet has 300-600 nozzles that can fire simultaneously

Piezoelectric

 Patented by Epson  Uses Piezo Crystals at the back of the ink chamber  An electrical charge causes the crystal to vibrate  Crystal vibrates inward forcing ink out of the nozzle  Typically 128 nozzles

Speed

 InkJet printer are NOT known for their speed  May be able to printer up to 16 PPM in black  Usually takes a couple of minutes to print a color page

Thermal Printing

 Two Types  Direct Thermal Printer  Thermal Wax Transfer

Direct Thermal Transfer

 Printhead is a heating element  Special Paper that reacts to heat  Head is passed over paper and heated at the exact moments required to form letters  First Faxes used Direct Thermal Printing  Now used in POS devices

Thermal Wax Transfer

 Utilizes a wax based ink that adheres to the paper during the heating process  Wax Sheet is same size of paper being printed on  A wax sheet for each color  High quality but usually very expensive

Printing Review

 4 Methods of Printing  6 Common parts of Printers  Know which are impact printers  Know the parts of a laser printer  Know specifics of each style of printer  Know history of printing  Know speed of different printers

Printing Review Cont’d

 Know how characters are formed in each method of printing  Know which printers can print graphics  Know quality of print from each printer type