EET 450 – Advanced Digital

Printers, Plotters and other hard copy output devices

Printers

The object is to get ‘hard copy’ output from the computerOutput is in a variety of forms Letters/numbers Graphics

Printers

The competition is speed versus quality (and price) Speed determined by Characters per

Second (cps) or Pages per Minute (ppm)

Quality is measured by a variety of factors Dots per inch (dpi) ‘Letter Quality’

Printing Engines

Historically, printers were fabricated from typewriter mechanismsDot Matrix Characters are constructed using

‘dots’ of ink or other marks Typically a 5x7 matrix at least

Printing Engines

‘Letter Quality’ Originally used to describe output of

the quality of a professional letter Impact LQ printers use ‘Letter at

once’ technology Laser and Ink Jet printers now have

high enough quality to be determined as LQ

Printing Engines

Line Printer Prints an entire line of print at one

time Used for ‘High Volume’ output

Color versus Monochrome Available in each of the above

technologies +

Printer types

Impact Dot Matrix Uses a set of magnet actuated wires

(pins) which strike a ribbon, leaving the imprint of the character as an array of dots

Ribbons may be in a variety of (primary) colors, allowing color output.

Printer types

Ink Jet (dot matrix) Thermal Inkjet – uses pigment

bearing ink heated to steam – which is emitted to form characters

Piezo Inkjet – uses piezo crystal actuator to ‘spray’ a liquid ink

Printer types

Phase Change Inkjet – wax based inks Electrostatic Inkjet – ink droplets are

charged/propelled by electrostatics

Thermal & electrostatic Printers Use thermally reactive paper darkens

when a very small heating element is activated

Electrostatic discharge into coated paper, burns dots into the surface of electrostatic printers

Printer types

Laser printers Image is ‘written’ using a laser LED, onto an

electro statically charged surface A powdered, pigment bearing, ‘toner’ is

adhered to the surface by the charge The image is transferred to paper, by

pressing the powdered image to the surface The powdered toner is fused (heated) to the

paper by a heating element, at the same time it is pressed into the surface of the paper.

Voila

Laser Printer

Printer Types

Thermal Transfer Pigment is carried on a ribbon, and

melted to the paper by an element – a form of DM

Dye Diffusion/Dye sublimation High quality – photo output Similar to thermal transfer, but using

penetrating dyes

Paper handling

Sheet Feeders Most printers now use some form of

cut sheet feeder to supply paper to the mechanism

Friction feed/continuous paper Use a roller, pressing into the platten

to feed a continuous roll of paper Not very accurate

Paper handling

Pin Feed Generally describes a set of pins, at the

sides of the platten Requires ‘tractor feed’ paper

Tractor Feed Using the holes in ‘tractor feed’ paper,

PULLS the paper from the head area or pushes the paper into the head area

Paper handling

Duplex printing Usually only available in laser printers A complex mechanical mechanism, reverses

the paper from output back to feed into the printer.

Both sides of the paper are used

Form feeders Alternate paper bins Envelope feeders

Consummables

Ink Inkjet cartridges

Refilling Ribbons

Laser printers Toner cartridge

Paper

Quality of paper is measured by Weight - pounds per 500 sheet ream

of uncut C size paper Or per 2000 8.5”x11” sheets

Brightness Ie 84 - % of light reflected from the

surface

Papers

Coating/specialty papers High quality – photo quality Canvas/other surfaces Transparencies Cloth Card stock, etc.

Plotters

Uses x-y control to move paper/pen Draws the image using vectors

Other output devices

Photo plot Photo film image created through

projected light

Other output devices

3D – output Photo lithography

Rapid prototyping technique UV Curable resin used to ‘build’ a 3

dimensional image Milling

Material is removed to leave the 3D image

CAD

Exam

A short review next Tuesday Although not scheduled yet, I thought it would be good to scare the bejesus out of everyone by bringing it up.