Lesson Notes By Weeks and Term - Senior Secondary School 1

TERM: 1^st�Term

WEEK: 9

CLASS: S.S. 1

DATE:

SUBJECT: Computer Science
TOPIC: Output devices (Printer)

WHAT IS A PRINTER?

A printer can be defined as an external�output device that facilitates the production of electronic data into hard copy formats. In other words, a printer �will enable you to generate a physical (hard copy) file of your document. In various offices and schools, people print several copies of their work reports and assignments using the computer. Indeed, printers are important computer output devices used for printing several types of documents; mainly texts and pictures. �There are also various types and variants of printers as you shall see shortly.

TYPES OF PRINTERS

In computer science, we have two major types of printers. These are Impact and Non-impact printers. These types of printers shall now be separately defined and discussed below-

Impact Printer:�Impact is a process of printing by which a printer works by banging a needle against an ink ribbon and making marks on the paper in the process. In other words, this type of printers work by hammering strikes against the paper through an ink ribbon. Though its printing quality is fairly good, impact printing has its demerits, chief among which is its excessive noise-making due to the constant banging of needles against the ink ribbons. Examples of Impact Printers are daisy-wheel printers, dot-matrix printers and line printers. These types of printers sharply contrast with laser and ink-jet printers which shall be discussed shortly under Non-impact printers.

Non-Impact Printer:�These are�printers which do not have to strike against a ribbon before texts or images can be printed on papers. Examples of such include �laser printers, ink-jet printer, LED page printer. In this vein, non-impact printers are very much unlike printers like the dot-matrix printer which (although the printing quality is good) makes a lot of noise due to the constant hammering. Most people currently use the non-impact printing system because it is noiseless while producing good quality prints. Above all, it is very fast too.

EXAMPLES OF PRINTERS

• 3D Printer:�A�3D printer�can create physical objects from a digital model of such objects by using materials such as metal alloys, polymers, or plastics. It was created�Created in the year 1984 by a scientist called Charles Hull.

Other examples of printers include the following:

• All-in-one (AIO) printer
• Dot matrix printer
• Inkjet printer
• Laser printer
• LED printer
• Multifunction printer (MFP)
• Plotter
• Thermal printer

ASSESSMENT.

1. Define computer output devices.
2. List and explain the types of output devices.
3. List the examples of output devices.

List and explain the types of printers.