INFO 1 Output Devices

Types of output devices are:

Screens

Printers

Projectors

Speakers

Headset

A monitor (or screen) is the most commonly used output device.They come in many different shapes, sizes and forms.

The quality and detail of the picture depends on the number of pixels that the monitor can display.The higher the number of pixels, the better quality the output. 

Larger monitors make working at the computer much easier on the eyes, but the larger the monitor, the more money it costs. A typical monitor size is a 19 inch diagonal.

Modern operating systems can easily handle a dual monitor setup, (as long as the graphics card also has dual sockets).There are 4 different types of screen

• Laptop Screen
• Touchscreen
• Computer Screen 
• Television Screen

Advantages

• Very large screen size
• Thin profile, sometimes only an inch depth.
• Large viewing angle (160 degrees) compared to LCD screens (40 degrees)
• Brighter display than rear projection TVs
• Unaffected by magnetism (unlike old CRTs)
• Can be mounted on a wall or free standing - more flexibility than other screens

Disadvantages

• Standard 720p resolution not good for displaying text compared to 1080p
• Has to be viewed from a distance compared to a standard computer monitor
• Large TVs need a lot of room around it for comfortable viewing
• More expensive than a standard computer monitor

Liquid Crystal Display (LCD)
Advantages

• Better quality

Disadvantages

• More expensive
• Harder to fix

Cathode Ray Tube (CRT)

Older technology so it takes up more space

Plasma Display Panal (PDP) 

Darker imag then LCD

Printers are another common output device. They are used to create a 'hard' copy of your work i.e. something that you can hold, hand to someone else or file away. Most printers produce their output on paper.

There are 5 different types of printer which are:

• Dot Matrix
• Inkjet
• Laser Printer Thermal Transfer
• Dye- Sublimation printer 

Type of computer printing which uses a print head that moves back and forth, or in an up and down motion, on the page and prints by impact, striking an ink-soaked cloth ribbon against the paper.

Speed - 50 to 550 cps (Characters per second)

Advantages

• Easy to use
• Cheap to maintain

Disadvantages

• Noisy 
• Poor quality

Squirts ink onto the paper and form letters from tiny dots. 

Spped - 41-55 ppm (pages per minuets)

Advantages

• Quiet
• Good quality
• Can colour print
• Cheap

Disadvantages

• High cost of cartridges

Similar to the way a photocopier works, uses heat to input on paper

Speed - 215 ppm

Advantages

• Can produce colour prints
• Good quality print outs

Disadvantages

• Expensive 

Is a non impact printer that uses heat to make an impression on the paper.

Advantages

• Quiet
• Used for bar codes, price tages and labels
• Can also be portable, moblie point of sale, receipt or ticket printing. Runs off battery, used in bars when customers make a payment by credit card 

Disadvantages

• Only one colour printing 

Used to produce high quality graphical images. The printer head heats up as it passes over the film, causing the dye to vapourise and infuse the glossy surface of the paper before they return to solid form.

Speed - 7 second per 4x6 print

Advantages

• Produce images excellent colour reprodcution

Disadvantages

• Expensive

A digital projector is a device which connects to a computer and is used to project the video output from the computer onto a wall or screen.Projector in classrooms they are often used with electronic whiteboards.The projector can be portable and placed on a stand or it can be permanently fixed to the ceiling.

Advantages

• Good quality on adequate size screen
• Project the output froma laptop computer onto a larger screen

Disadvantages 

• Expensive

Most computers are fitted with a small internal speaker which can produce beeping sounds to alert you if you make an error.Computers can also be fitted with a sound card (or chip) which will enable sound to be output through external speakers. These usually produce a much higher quality sound than the internal speaker.

Common Device used to output sound. A speaker converts electrical signal into acoustical energy

Advantages

• Everyone can hear the sound playing 
• They can help create an atmosphere or ambiance to accompany a presentation
• They help blind people to use the computer because text can be converted into sound

Disadvantages

• Can be expensive 
• The output from speakers can disturb others who are trying to work

Combine an Input device (microphone) and an output device (loudspeakers).VoIP ( Voice over Internet Protoco) millions of computers users can make free telephone calls to other users over the internet.

Headphones and earphones consist of a pair of small loudspeakers which are worn over or in the ears.They are connected either by cable or wirelessly to a device such as a computer, radio or MP3 player. A transducer converts the electronic signals from the device into sounds which can then be heard by the user via the phones.

Advantages

• You can use your hands for other tasks
• The sound can only be heard by the user 
• Portability - lightweight and easy to carry around
• Can listen to music on the move

Disadvantages

• Costs extra 
• Often not aware of surrounding noises such as cars in traffic or people talking