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 – Output Devices (Cambridge IGCSE ICT 0417)

This section covers all output devices listed in the syllabus. For each device the following sub‑sections are provided:

• Characteristics – key features required by the syllabus (type, resolution/precision, power use, connectivity, output medium).
• Typical classroom / office use – realistic examples for IGCSE learners.
• Advantages
• Disadvantages
• Key points – 2‑3 short statements to remember.

2.1 Monitor (Display Screen)

Characteristics

• Type: CRT, LCD, LED, OLED, QLED.
• Resolution (grid of tiny dots): e.g. 1920 × 1080 px (Full HD), 3840 × 2160 px (4K).
• Colour depth: 8‑bit (16 M colours) or 10‑bit (1 B colours).
• Refresh rate: 60 Hz (standard) – 120 Hz (gaming).
• Response time: 1‑5 ms (lower = less motion blur).
• Aspect ratio: 4:3, 16:9, 16:10.
• Power use: high for CRT, low for LCD/LED.
• Connectivity: VGA, DVI, HDMI, DisplayPort, USB‑C.

Typical classroom / office use

• Viewing documents, spreadsheets and web pages.
• Playing educational videos or interactive simulations.
• Design work where colour accuracy is important (e.g., photo editing).

Advantages

• Immediate visual feedback.
• Wide range of sizes and resolutions to match the task.
• LCD/LED models consume little electricity.
• OLED/QLED give very high contrast and vivid colours.

Disadvantages

• CRT monitors are bulky, heavy and power‑hungry.
• LCD/LED screens can show colour shift when viewed from an angle.
• High‑resolution or OLED displays are relatively expensive.
• Bright screens increase classroom power consumption.

Key points

• Resolution = number of dots (pixels) that form the picture.
• LCD/LED monitors are the most common in schools because they are light and energy‑efficient.
• Higher refresh rates give smoother motion, useful for games and video.

2.2 Touch Screen (as an Output Device)

Characteristics

• Display type: usually LCD or LED.
• Touch technology: Resistive (pressure), Capacitive (finger), Infrared, Surface‑Acoustic‑Wave.
• Multi‑touch capability: 2‑point, 5‑point, 10‑point etc.
• Resolution & colour: same as the underlying monitor.
• Power use: similar to a standard monitor plus a small amount for the touch sensor.
• Connectivity: HDMI/DVI for video, USB for touch input.

Typical classroom / office use

• Interactive whiteboards for group activities.
• Student tablets for digital textbooks.
• Point‑of‑sale terminals in a school canteen.

Advantages

• Combines visual output and input on one surface – saves desk space.
• Direct manipulation (drag, pinch, swipe) is intuitive for learners.
• Supports collaborative work when several users touch the screen at once.

Disadvantages

• Higher purchase price than a separate monitor + mouse/keyboard.
• Surface attracts fingerprints, smudges and can be scratched.
• Resistive screens need pressure; capacitive screens may not work with gloves or wet hands.

Key points

• Touch screens are mainly output devices because they display the visual information.
• Capacitive technology is the most common in modern tablets and phones.
• Regular cleaning with a soft, dry cloth helps maintain readability.

2.3 Multimedia Projector

Characteristics

• Technology: LCD, DLP, LED, Laser.
• Resolution standards: SVGA (800 × 600), XGA (1024 × 768), WXGA (1280 × 800), Full HD (1920 × 1080), 4K UHD (3840 × 2160).
• Brightness: 1 500 – 5 000 lumens (typical classroom); > 3 000 lm for larger halls.
• Contrast ratio: e.g. 10 000 : 1.
• Throw distance: short‑throw (≤ 1 m), standard, long‑throw.
• Power use: LED and laser models are more energy‑efficient than lamp‑based units.
• Connectivity: HDMI, VGA, USB, wireless (Wi‑Fi, Bluetooth).

Typical classroom / office use

• Projecting slides for a lesson or a business presentation.
• Showing educational videos to a whole class.
• Displaying interactive whiteboard content from a teacher’s laptop.

Advantages

• Can create very large images (up to 300 inches or more).
• Portable models are easy to move between rooms.
• All viewers see the same content at once.
• Laser and LED projectors have long light‑source life and low maintenance.

Disadvantages

• Image quality drops in bright rooms; a dimmed environment is often needed.
• Lamp‑based projectors require periodic lamp replacement, which adds cost.
• Setup can be time‑consuming (focus, keystone correction, alignment).
• Higher power consumption for very bright models.

Key points

• Brightness (lumens) determines how well the picture can be seen in daylight.
• Laser projectors are more expensive upfront but have lower running costs.
• Short‑throw projectors can be placed close to the screen, saving space.

2.4 Laser Printer

Characteristics

Typical classroom / office use

• Printing worksheets, exams and reports.
• Producing crisp black‑and‑white charts for science lessons.
• Colour brochures for school events (using a colour laser model).

Advantages

• Fast printing, especially for text‑heavy jobs.
• Sharp, high‑quality output.
• Low running cost per black‑and‑white page.
• Durable – designed for heavy daily use.

Disadvantages

• Higher initial purchase price than ink‑jet printers.
• Colour toner cartridges are expensive.
• Unit is larger and heavier – needs a dedicated space.
• Noise from the drum and rollers can be noticeable.

Key points

• Laser printers are ideal for large volumes of text.
• Colour laser printers are useful for marketing‑type material but cost more per page.
• Regularly replace toner cartridges and keep the printer clean to maintain quality.

2.5 Ink‑Jet Printer

Characteristics

Typical classroom / office use

• Printing colour photographs for art projects.
• Creating small batches of flyers or newsletters.
• Printing on specialised media such as stickers or printable CDs.

Advantages

• Excellent colour reproduction – good for photos and graphics.
• Low upfront cost.
• Can print on many different types of paper and media.

Disadvantages

• Slower than laser printers for large text jobs.
• Ink cartridges can be pricey; ink may dry out if not used regularly.
• Printed pages can be smudged if handled while still wet.
• Higher power use when printing at high quality.

Key points

• Best choice when high‑quality colour images are required.
• Keep the printer used at least once a week to avoid clogged nozzles.
• Consider refillable ink tanks for lower long‑term cost.

2.6 Dot‑Matrix Printer

Characteristics

• Print quality: 9‑dot (low) or 24‑dot (higher) per character; approx. 60 × 60 dpi.
• Speed: 100 – 200 characters /min (≈ 5‑10 pages /min for simple text).
• Impact printing: pins strike an ink‑ribbon, allowing printing through multi‑part carbon forms.
• Power use: 30‑50 W.
• Connectivity: Parallel (legacy) or USB.

Typical classroom / office use

• Printing multi‑part invoices, receipts or delivery notes.
• Environments with dust, heat or vibration where non‑impact printers would fail.

Advantages

• Very durable; works in harsh conditions.
• Can produce several copies in one pass (carbon‑paper forms).
• Low consumable cost – inexpensive ink ribbons.
• Quiet when idle; only the print head makes noise.

Disadvantages

• Noisy during operation (mechanical pin striking).
• Low print quality – unsuitable for graphics or high‑resolution text.
• Slower than modern non‑impact printers for large jobs.

Key points

• Ideal for forms that need several copies at once.
• Not suitable for printing photos or detailed diagrams.
• Maintenance is simple – replace the ribbon when colour fades.

2.7 Plotter

Characteristics

• Type: Pen plotter (coloured pens), Cutting plotter (vinyl cutter), Ink‑jet plotter (large‑format).
• Output mode: Vector (mathematical lines) – excellent for CAD drawings.
• Resolution / line width: Pen width as low as 0.025 mm; ink‑jet plotters up to 1200 dpi.
• Media size: Up to 1.2 m (≈ 48 in) wide or larger.
• Power use: 100‑250 W.
• Connectivity: USB, Ethernet, Wi‑Fi.

Typical classroom / office use

• Printing architectural or engineering drawings from CAD software.
• Creating large‑format posters or banners.
• Cutting vinyl for school signage or club T‑shirts.

Advantages

• Produces high‑precision, scalable vector output.
• Can handle very large sheets of paper or vinyl.
• Cutting plotters quickly create custom shapes and lettering.

Disadvantages

• Slow when printing raster images or photographs.
• Higher maintenance – pens need replacement, blades need sharpening.
• More expensive than a standard desktop printer.
• Noise from the moving carriage can be noticeable.

Key points

• Plotters are the best choice for detailed engineering or architectural drawings.
• Vector output can be scaled without loss of quality.
• Regularly check pen levels and blade condition to avoid print defects.

2.8 3‑D Printer (Emerging Technology)

Characteristics

• Common technologies: Fused Deposition Modeling (FDM), Stereolithography (SLA), Selective Laser Sintering (SLS).
• Materials: Thermoplastic filaments (PLA, ABS), photopolymer resins, nylon, metal powders.
• Resolution (layer thickness): 0.05 mm – 0.30 mm.
• Build volume: Small desktop units (≈ 200 mm³) to large industrial machines (≥ 500 mm³).
• Power use: 100‑300 W (varies with technology).
• Connectivity: USB, SD card, Wi‑Fi.

Typical classroom / office use

• Rapid prototyping of engineering parts for design projects.
• Creating physical models of biological structures (e.g., a heart) for science lessons.
• Producing customised accessories for school clubs (key‑chains, mini‑robots).

Advantages

• Can produce complex shapes that are impossible with traditional manufacturing.
• Supports on‑demand production – no need for large inventories.
• Encourages creativity and problem‑solving in STEM subjects.

Disadvantages

• Printing can be slow, especially for large or high‑resolution objects.
• Finished parts often need post‑processing (sanding, polishing).
• Material costs and maintenance (nozzle cleaning, resin handling) are relatively high.
• Some technologies emit fumes; adequate ventilation is required.

Key points

• FDM printers melt plastic filament to build objects layer by layer.
• SLA printers use a laser to cure liquid resin – they give higher detail but need careful handling.
• 3‑D printing is an emerging skill that complements traditional design and manufacturing lessons.

2.9 Speaker (Audio Output)

Characteristics

• Type: Dynamic (cone), Electrostatic, Planar magnetic, Piezoelectric.
• Frequency response: Typical 20 Hz – 20 kHz (human hearing range).
• Power handling: 5 W – 100 W (depends on size).
• Impedance: 4 Ω, 6 Ω or 8 Ω – matches output of computers or amplifiers.
• Power use: Low when idle; higher when playing loud audio.
• Connectivity: 3.5 mm audio jack, USB, Bluetooth (wireless).

Typical classroom / office use

• Playing instructional videos or language‑learning audio.
• Providing sound for presentations and multimedia projects.
• Assisting students with visual impairments through auditory feedback.

Advantages

• Provides clear audio for multimedia content.
• Portable speakers can be moved between classrooms.
• Bluetooth models reduce cable clutter.

Disadvantages

• Quality varies widely – cheap speakers may distort sound.
• High‑volume use can cause hearing discomfort.
• Wireless speakers need batteries or charging.

Key points

• Speakers convert electrical signals into sound waves that we can hear.
• Check the impedance matches the computer’s audio output to avoid damage.
• For clear speech, choose speakers with a flat frequency response in the 1‑4 kHz range.

2.10 Actuator (Mechanical Output Device)

Characteristics

• Type: Electric motor, pneumatic cylinder, solenoid, servo motor.
• Output form: Rotational or linear motion that performs a physical task.
• Power use: Varies – from a few watts (small servos) to several hundred watts (industrial motors).
• Control: Typically driven by computer signals (e.g., PWM, digital I/O).
• Typical applications: Robotics arms, automated doors, 3‑D printer extruders.

Typical classroom / office use

• Robotics kits where the computer sends commands to move wheels or arms.
• Automatic blinds or projectors that open/close on a timer.
• Lab equipment that positions samples (e.g., motor‑driven microscope stage).

Advantages

• Turns computer commands into real‑world movement.
• Enables automation and interactive projects.
• Wide variety of sizes and strengths to suit any task.

Disadvantages

• Requires power supply and sometimes additional control circuitry.
• Moving parts can wear out and need regular maintenance.
• Noise and vibration may be a concern in quiet classrooms.

Key points

• Actuators are the “muscles” of a computer‑controlled system.
• Simple projects often use hobby‑servo motors that rotate 0‑180°.
• Safety: ensure moving parts are guarded to prevent injury.

End of Section 2 – Output Devices