SS 1 First Term

Learning Objectives

• Describe monitors and soft copy output.
• Identify printers, speakers and projectors.
• Describe plotters and choose the right output device.
• Distinguish between soft copy and hard copy.

Monitors and Soft Copy

An output device presents the results of processing to the user. Output can be visual (text, images), audio (sound), or physical (printed paper). The monitor, printer, speakers, projector, and plotter are all output devices because they deliver processed information to humans.

The monitor is the main visual output device. It displays soft copy. Modern monitors are flat screens such as LCD and LED panels, while older models used bulky cathode-ray tubes (CRT). Screen quality depends on resolution (the number of pixels), refresh rate (how often the image updates), and colour range. A higher resolution, for example 1920 by 1080, shows sharper text and finer detail.

Soft copy is output presented on a screen, not printed. Hard copy is output printed on paper or another physical medium. The email PDF and the on-screen marksheet are soft copy. The printed paper is hard copy. Both are output from the same data.

Printers, Speakers, and Projectors

A printer produces hard copy. Two main technologies are common. Inkjet printers spray fine drops of ink onto paper. They are good at colour and cheap to buy, but slow and ink is costly. They are best for photos and posters. Laser printers use toner and a laser drum. They are fast, sharp, and cheap per page, but have an expensive initial cost. They are best for office documents and exams. Other printers include thermal printers (used for receipts in POS and banks) and dot-matrix printers (used for multi-part forms in some businesses).

Speakers and headphones convert digital audio into sound, the audio form of output. Schools use speakers for lessons and assemblies; headphone use helps learners avoid disturbing others in a computer lab.

A projector enlarges the computer screen and displays it on a wall or a projection screen. It is the clear choice for classrooms and presentations because many people can see the same content at once. A projector turns the computer's visual output into a large shared image.

Plotters and Choosing the Right Output Device

A plotter draws images using pens (or cutters) as it moves across paper, producing very precise, large drawings. It is used in architecture, engineering, and cartography for blueprints, maps, and circuit designs. Plotters are slower than printers for ordinary text but excel at line accuracy and continuous large-format output such as a 6-metre banner.

Choosing an output device depends on the audience (one person or many), the medium (screen, paper, sound), the quality needed, and the running cost. For daily class fact sheets, a laser printer is best because it is fast and cheap per page for text. For large business banners, a plotter or wide-format printer is best because it handles long continuous media. For teaching a class of 40, a projector is best because it provides one shared large image for everyone. For music during assembly, speakers are best because they provide wide audio reach. For photo prints for an event, an Inkjet printer is best because it has good colour reproduction.

Output Systems Overview

A computer processes data internally, but that work is only useful when it is presented to people in a form they can understand. The four main output systems are the monitor, the printer, the speaker and the projector.

The monitor presents soft copy output as text, images and video on a screen. The printer produces hard copy by printing text and images on paper.

The speaker converts digital audio into sound so people can hear music, speech and other audio content. The projector enlarges the image from the computer and throws it onto a wall or screen so many people can view it at once.

Choosing the right output system depends on the task. A report meant to be filed uses a printer, a presentation for a large audience uses a projector, and everyday work uses the monitor.

Printing Technologies

Impact printers strike a ribbon against the paper using physical force. Dot-matrix printers are the common impact type, still used where multi-part carbon forms are needed.

Non-impact printers form images without any physical striking. Inkjet printers spray tiny droplets of liquid ink onto the paper, producing rich colour. Laser printers use a beam of light and powdered toner to create sharp, fast text.

3D printing builds a physical object layer by layer from plastic, resin or metal. A 3D printer is an output device because it turns digital models into real three-dimensional objects.

DPI, dots per inch, describes how detailed a printed image is. PPM, pages per minute, measures how fast a printer works. These two figures let buyers compare printers.

Voice and Audio Output

Voice and audio output deliver information through sound. Speakers play music and announcements while headphones let one person listen privately. Voice output features read text aloud so users can receive information without looking at a screen.

Voice assistants like Google Assistant and Siri rely heavily on audio output. When you ask a question, the assistant answers with a spoken response generated from digital audio.

Audio output is also central to the entertainment industry. Video editors review soundtracks through studio monitors, and musicians mix their songs using speakers.

Industrial output describes how computers control physical machines. A CNC machine follows a computer program to cut, drill or carve materials with high precision.

An actuator is a component that converts an electrical signal from a computer into movement. Actuators power robotic arms, automated doors and conveyor belts.

Practical Work

1. Draw a table of five output devices and their uses.
2. Compare inkjet, laser and thermal printers.
3. Choose an output device for a large engineering drawing.
4. Explain the difference between soft copy and hard copy.

Scenario-Based Questions

1. A principal wants the whole school to watch a results presentation and also to hear the announcements. Which two output devices should the school set up, and what reasons from your note support each choice?
2. A school office must print 400 daily fact sheets every morning. Compare the inkjet and laser printers on buying cost, speed, and cost per page, then recommend one for the office with justification.
3. An architecture firm must print a precise six metre long building plan. Explain why a plotter is the better choice than an ordinary printer, and name what the plotter draws with.
4. A teacher emails a PDF of the timetable to parents instead of printing piles of paper. Distinguish soft copy and hard copy, and give one advantage of the soft copy and one advantage of keeping a hard copy in the office.
5. A graphic designer needs to print colour photos for an event, and a fuel station needs to print small receipts for customers. Identify the printer best suited to each task and justify each recommendation.
6. A student's monitor shows blurry text at low resolution. Explain which feature of the monitor controls sharpness of the display, and what the student should check when the school buys a replacement.
7. In a computer laboratory of 25 students, why would a school choose headphones rather than speakers for individual work, while choosing speakers for a whole school assembly? Justify both choices.