Printers

Objectives :

• Identify the different parts of a printer

• Differentiate between impact printers and non-impact printers

• Explain the working of dot matrix printers

• Explain the working of inkjet printers

• Explain the working of laser printers

• Assembling a printer

• Connect a printer to a computer

• Install a printer driver

• Troubleshoot printers

Printers :

Prints text documents and images on paper

Different types of printer are :

Impact Printers :

Prints documents as well as graphics

Uses a matrix of metal pins on print head to create dots

Physical contact is established between print head, ribbon cartridge and paper

Dot matrix printer is a type of Impact Printer

Uses electromagnet print head and tends to be noisy

Can not produce high quality document or graphics

Best useful in creation of multi-part document like invoices

No. of metal pins in printer head varies form 9 to 24

Speed varies from 30 to 550 cps

Generally connected to LPT port

Can achieve high resolutions by moving print head slowly

Non-impact Printers :

Known for quite operation as physical contact is not established between head, cartridge and paper

Different types of non-impact printers are :

Places extremely minute amount of electrically charged ink on paper to create images or text

Drops of ink are sprayed through a series of nozzles

Uses monochrome as well as color cartridges

Can be connected to LPT or USB port

Provides high quality print

Uses a beam of laser for printing

Uses static electricity to combine ink powder and paper

Consists of a revolving drum/cylinder that is made up of photoconductive material

Drum is charged with the help of a charging wire called the charge corona wire

First, drum is positively charged. thus laser-etched areas will be negatively charged.

Thereafter, a fine ink powder called toner is sprinkled on the paper which has to be positively charged.

As the drum rolls, the toner adheres to the laser-etched area of the drum

After this, the drum rolls over a paper.

The paper is given a negative charge. This negative charge must be stronger than the charge of the laser-etched electric image. This will help the toner to leave the negative area on the drum for the negatively charged paper.

The paper is discharged as it moves out.

The paper is passed through a fuser. As the paper passes through the fuser, the toner melts due to the heat. The toner is thus fixed on the paper.

Attributes of Printer :

Printers are classified on the basis of the following characteristics :

• Speed – Defines speed at which a printer prints the documents. Measured in characters per second (cps) or pages per minute (ppm). Printer speeds vary widely from type to type.

• Dots Per Inch (DPI) – Specifies the number of pixel or dots of ink that the printer uses while printing a image or document. A higher dpi measurement indicates a higher quality printer

Structure of Printer :

Contains parts that accept, support and move paper during the process of printing

• Sensors

• Logic Card

• SMPS

• Cartridge

• Print Head

• Adjustable Lever

• Control Panel

• Cover of Cartridge

Printer Installation :

Assemble the printer – Connect internal and external parts of the printer

Set up printer – Connect printer to the appropriate port on computer

Install Printer Drivers – Install printer driver (software that controls operation of printer) in the computer

Configure the Printer – Set different settings for the printer

Printer Ports :

Standard Parallel Port (SPP) – An obsolete port for printers and was available for the IBM PC and compatible computers built prior to 1995

Enhanced Parallel Port (EPP) – Allows faster data transfer between computer and printer. Also, data can transfer back and forth at the same time. It is about 2 times faster than the SPP interface

Enhanced Capabilities Port (ECP) – Compresses the data and provides faster data transfer between computer and printer compared to EPP

Preventive Maintenance :

Preventive Maintenance ensures that a printer will reach its greatest potential

• Do not place any electronics items near printer

• Do not use bad quality ribbons

• Do not turn the platen head using the knob when the printer is on

• Use the printer regularly otherwise ribbon will dry out

• Turn OFF the printer before cleaning

• Never spray cleaner on the printer itself

• Use compressed air or a vacuum cleaner to remove dust

• Ensure the ink cartridge is secure in the cartridge cradle

• Clean the face of the ink cartridge using a clean swab dipped in isopropyl alcohol

• Use a swab that has isopropyl alcohol and rub on the underside of the cartridge cradle to clean it

• Don’t switch on and off the printer very frequently which results into nozzles clogging

• Turn OFF the printer before cleaning

• Never spray cleaner on the printer itself

• Use a lint-free dry cloth for cleaning the inside of the printer and the Paper feed guide

• Store toner in a cool, dry place

• Clean the corona wire and the roller every time when changing the print cartridge

• Refilled toner cartridges work fine and save money, as long as they have only been refilled once

• Do not use envelopes and address labels in laser printers

Troubleshooting :

You may encounter different problems when working with the printer such as :

• General Troubleshooting

• Printer Driver is not functioning properly

• Troubleshooting Dot Matrix Printers

• Troubleshooting Inkjet Printers

• Troubleshooting Laser Printers