Output Devices

Output Devices

1. Visual output- Screens and monitors

   • VDU- Visual display unit is used to describe any device used with computers to display images
   • TFT- Thin film transistor are known for crisp sharp colours because they are made up of thousands of light sources. However the accuracy isn't as good because the static resolution can't be changed
   • CRT- Cathode ray tube is the most affordable and has the best overall picture quality. However they are heavy and bulky and have a size limit.
   • LCD- Liquid Crystal Displays offer high quality colour resolution but at a more expensive cost.

2. Undestanding resolution

   • Jobs that require resolution quality to be high are photographers because they need the photo to be highest possible quality to edit it.
   • Pixelation means an image which conmtains a low overall number of pixels. This can happen because the resolution for the image is incorrect.

3. Large displays

   • A lumen is a measurement of the light intensity radiating in the air from a light source.
   • Projectors have high colour reproduction and take up a lot less space than other products. However the user three CRT tubes which makes them more confusing to understand.
   • A Light emitting diode (LED) is a technology that gives a bright and colourful image. An (OLED) is the organic version uses lower input.

4. Small Displays

   • The average resolution is 320 x 240
   • Smaller screens have a smaller resolution because as the resolution increases the items on screen become sharper but smaller.
   • When content is downloaded to a device, the file size is smaller and as a result the quality decreases significantly because they have a limited storage.

5. Speakers, Headphones and earphones

   • Speakers are either peripherals or built into numerous systems such as laptops and computers, if they are built into the system the quality will be limited so the output of sound will be worse.
   • Headphones are useful for numerous scenarios. They could be used in numerous jobs such as call centres. This is because the sound directly enters the the ear because the sound is concentrated.
   • Headphones have miniature speakers and are mainly used to listen to music. They are worn over the outside of the ear. An earphone is a tiny speaker that fits in your ear, this is less safe as there is no air circulation retained and it attacks the ear.

6. Special purpose

   • The built in features of microsoft ease of use allow access to things such as magnifier, keyboard and narrator as these shortcuts give assistance to the user if they need the special requirements.
   • A virtual signing system is used to help deaf people understand whats being said through a virtual human communicating with the user
   • Special braille printers are available for the blind and they emboss the braille into heavyweight paper.

7. Internet access

   • Most businesses offer both website and mobile versions of the same website as this allows the customers to access the websites and use it in simpler layout.
   • Businesses put disclaimers on websites in terms of resolutions so that the users know what size is most suitable and which one isn't as effective or good a quality.

8. Printers

   • Laser printers function by ink being transferred to paper then fused with heat and pressure. It comes either monochrome or in colour with the four colours being cyan, magneta, yellow and black. They are faster printers and are cheaper to maintain over a long period of time.
   • Inkjet and multifunctional printers. Inkjet printers are very popular in places such as homes due to the fact that they're cheaper. However they're expensive to run and slower than others. A multi-purpose printer allows the user to print colour and plain, and also scan items into a computer.
   • Dot matrix printers are the fastest printers but low quality, they aren't as popular and due to this are expensive to buy.
   • Thermal printer. Thermal is fine heated points which form characters on the paper. There are no moving parts in the thermal printer. Used on receipts.
   • Is the process of printing 3D objects with a digital file. Tiny slices formed by the point forms layers in which cool together to become solid.