Know and understand characteristics, uses, advantages and disadvantages of output devices including monitors, touch screen (as an output device), multimedia projector, laser printer, inkjet printer, dot matrix printer, plotter, 3D printers, speaker,

2. Input and Output Devices – Output Devices

This section covers the characteristics, typical uses, advantages and disadvantages of the main output devices studied in the Cambridge IGCSE ICT (0417) syllabus.

2.1 Monitor (Display Screen)

A monitor converts electronic signals from the computer into visual information that can be read by the user.

• Types: CRT, LCD, LED, OLED, and newer QLED panels.
• Key characteristics: resolution, refresh rate, response time, colour depth, aspect ratio.

Uses

• Viewing documents, spreadsheets and web pages.
• Playing video games and multimedia content.
• Graphic design, CAD and video editing where colour accuracy is critical.

Advantages

• Immediate visual feedback.
• Wide range of sizes and resolutions to suit different tasks.
• Low power consumption for LCD/LED models.

Disadvantages

• CRT monitors are bulky and consume more power.
• LCD/LED screens can suffer from limited viewing angles and colour shift.
• High‑resolution monitors are more expensive.

2.2 Touch Screen (as an Output Device)

Although primarily an input device, a touch screen also functions as an output device by displaying visual information directly on the surface that can be touched.

• Technology: Resistive, capacitive, infrared and surface acoustic wave.
• Characteristics: Touch sensitivity, multi‑touch capability, display type (often LCD/LED).

Uses

• Smartphones, tablets and kiosks.
• Point‑of‑sale (POS) terminals.
• Interactive whiteboards in education.

Advantages

• Combines input and output, saving space.
• Intuitive interaction – direct manipulation of objects on screen.
• Supports multi‑user collaboration.

Disadvantages

• Higher cost than separate monitor + mouse/keyboard.
• Surface can be prone to fingerprints and scratches.
• Some technologies (e.g., resistive) are less responsive to light touches.

2.3 Multimedia Projector

A projector displays computer output onto a large screen or wall, making it suitable for presentations and classroom use.

• Types: LCD, DLP, LED, laser.
• Key specifications: lumens (brightness), resolution, contrast ratio, throw distance.

Uses

• Classroom teaching and seminars.
• Business presentations.
• Home cinema.

Advantages

• Can display very large images (up to 300 inches).
• Portable models are easy to move between rooms.
• Allows multiple viewers to see the same content simultaneously.

Disadvantages

• Requires a darkened environment for optimal image quality.
• Bulb‑based models have limited lamp life and replacement cost.
• Setup can be time‑consuming (alignment, focus, keystone correction).

2.4 Laser Printer

A laser printer uses a laser beam to produce an electrostatic image on a drum, which then attracts toner and transfers it onto paper.

Uses

• High‑volume office printing (reports, invoices).
• Printing of sharp text and line art.
• Colour laser printers for marketing material.

Advantages

• Fast printing speed.
• High-quality text and graphics.
• Low running cost for black‑and‑white output.

Disadvantages

• Higher initial purchase price than inkjet.
• Colour models are more expensive to run.
• Large and heavy – not ideal for very small spaces.

2.5 Inkjet Printer

Inkjet printers spray microscopic droplets of liquid ink onto paper to create images and text.

Uses

• Home printing of documents and photos.
• Small‑business marketing flyers and colour brochures.
• Printing on a variety of media (photo paper, labels).

Advantages

• Good colour reproduction, especially for photos.
• Lower upfront cost.
• Can print on many different media types.

Disadvantages

• Slower than laser printers.
• Ink cartridges can be expensive; ink may dry out.
• Prints can be smudged if wet.

2.6 Dot Matrix Printer

A dot matrix printer creates characters and graphics by striking an ink‑ribbon against paper with a matrix of pins.

• Print quality: Low (typically 9‑dot or 24‑dot per character).
• Speed: 100–200 cpm (characters per minute).

Uses

• Printing multi‑part carbon copies (e.g., invoices).
• Industrial environments where dust and heat are concerns.

Advantages

• Very durable; can operate in harsh conditions.
• Can print through multiple layers of paper.

Disadvantages

• Noisy operation.
• Poor print quality for graphics or high‑resolution text.
• Generally slower than modern printers.

2.7 Plotter

Plotters draw continuous lines on paper using pens or cutting tools, ideal for vector graphics.

• Types: Pen plotter, cutting plotter, inkjet plotter.
• Resolution: Measured in DPI or line width (e.g., 0.025 mm).

Uses

• Architectural and engineering drawings.
• Large‑format graphics and banners.
• Cutting vinyl for signage.

Advantages

• Produces high‑quality, scalable vector output.
• Can handle very large media sizes.

Disadvantages

• Slow for raster images.
• Higher maintenance (pen replacement, cleaning).
• More expensive than standard printers.

2.8 3‑D Printer

3‑D printers create physical objects by depositing material layer‑by‑layer according to a digital model.

• Common technologies: Fused Deposition Modeling (FDM), Stereolithography (SLA), Selective Laser Sintering (SLS).
• Materials: PLA, ABS, resin, nylon, metal powders.

Uses

• Prototyping in engineering and product design.
• Educational models (e.g., anatomical parts).
• Custom jewellery, art and hobbyist projects.

Advantages

• Enables rapid creation of complex geometries.
• Reduces need for tooling and inventory.
• Supports customization and small‑batch production.

Disadvantages

• Print speed can be slow for large objects.
• Surface finish may require post‑processing.
• Material costs and printer maintenance can be high.

2.9 Speaker (Audio Output)

Speakers convert electrical audio signals into sound waves that can be heard by the user.

• Types: Dynamic (cone), electrostatic, planar magnetic, piezoelectric.
• Key specs: Frequency response, power handling (watts), impedance (ohms), sensitivity (dB).

Uses

• Multimedia playback (music, video).
• Computer alerts and system sounds.
• Public address systems and conference rooms.

Advantages

• Provides an essential sensory output for multimedia.
• Wide range of sizes from tiny laptop speakers to large studio monitors.

Disadvantages

• Sound quality varies greatly with design and enclosure.
• High‑power speakers require amplifiers.
• Potential for acoustic feedback in poorly designed setups.

2.10 Actuator (Mechanical Output Device)

An actuator converts electrical signals into mechanical motion, enabling computers to interact with the physical world.

• Common types: Electric motor (DC, stepper, servo), pneumatic, hydraulic.
• Key parameters: Torque, speed (rpm), stroke length, power consumption.

Uses

• Robotic arms and automation equipment.
• Hard‑disk drive read/write heads.
• Automated doors, printers (paper feed), and CNC machines.

Advantages

• Enables precise control of physical processes.
• Can be programmed for repeatable actions.

Disadvantages

• Mechanical wear reduces lifespan.
• Requires power and sometimes complex control circuitry.
• Noise and vibration may be undesirable in some environments.

Summary Table – Comparison of Output Devices

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