Output Devices | Computer for GCSE/IGCSE - Year 11 PDF Download

Introduction

• Output devices present processed results in a format understandable to humans.
• Within a general-purpose computer system, the primary output device is the monitor or screen.
• Additional output devices encompass projectors, printers, speakers, and actuators.

Actuators

• Actuators work alongside motors to convert energy (such as electrical, air, or hydraulic) into physical movement of objects.
• They are manufactured in various sizes, each tailored for specific functions.
• Examples of applications include rotating a wheel, opening/closing doors, managing conveyor belts, operating machinery, controlling robotic arms, inducing vibrations, starting/stopping pumps, and regulating valves.
• Actuators are commonly paired with sensors. These sensors compare their input with preset values. If the input falls within a specific range, actuators are activated to move physical objects.

Light projectors

• Light projectors are devices used to display computer outputs on a large screen.
• They are commonly utilized for delivering presentations in various settings, including business and education.
• There exist two main types of light projectors: Digital Light Processing (DLP) and Liquid Crystal Display (LCD) projectors.
• DLP projectors employ millions of micro-mirrors on a microprocessor to manipulate light intensity through color filters.
• On the other hand, LCD projectors utilize three mirror filters to break down an image into red, green, and blue wavelengths, which are then combined to produce a full-color image.

Laser and Inkjet Printers

Both types of printers create physical copies of digital documents. This is essential when electronic devices are not available.

Laser Printers

• Are highly efficient for producing multiple copies quickly
• Suitable for high-volume print jobs like creating leaflets
• Offer cost-effective printing on a per-page basis
• Commonly utilized in business and educational environments
• Feature large toner cartridges and paper trays
• Utilize electrostatic charges to transfer and bond toner particles onto paper

Inkjet Printers

• Excel at producing high-quality images and graphics
• Ideal for low to moderate volume printing needs
• Can be more cost-efficient for color printing compared to laser printers
• Versatile and commonly found in home and small office settings

3D Printers

• Creation of 3D Models: 3D printers build 3D objects by adding layers of material on top of each other based on a digital model. This process enables the production of precise objects.
• Medical Applications: These printers have significant medical uses such as crafting prosthetics and blood vessels with great precision to enhance healthcare.
• Rapid Prototyping: They are valuable for quickly creating prototype models for various industries, allowing for swift product development and testing.
• Global Accessibility: Models can be shared digitally and printed worldwide, showcasing the widespread reach and impact of this technology.

Liquid Crystal Display screens

• LCD screens consist of numerous tiny liquid crystals.
• The display is structured with pixels organized in a matrix formation.
• Illumination from a backlight is necessary for the display.
• LCD screens find applications in TVs, monitors, tablets, and phones.
• These screens demonstrate low power consumption and operate at a cool temperature.
• They are not prone to image burn or flicker problems.
• LCD screens offer vivid images and colors.
• Production costs for LCD screens are lower compared to LED screens.

Organic light emitting diode (OLED) screen

• Much thinner and lighter than traditional LCD screens
• Use organic light emitting diodes (OLEDs)
• They use organic carbon compound to create semiconductors
• No form of backlighting is required
• You can have very thin, flexible screens

Speakers

• Speakers are devices that convert digital audio signals into sound waves that are audible to humans. This transformation is achieved by passing the digital data through a digital-to-analog converter (DAC), which converts the data into an electric current.
• The electric current is then amplified to a level that can drive the loudspeaker effectively. This amplification process ensures that the sound produced is of sufficient volume for listening.
• Once the amplified current reaches the loudspeaker, it is converted back into sound waves, which are then emitted into the surrounding environment, allowing us to hear the audio content.
• Common applications of speakers include listening to music, watching videos with sound, making phone calls, and receiving alerts or alarms for notifications.