INFO1 – Practical problem solving in the digital world

Getting information from a computer

Monitor Printer

Speakers Lights

Visual:◦ Text◦ Images

Audible:◦ Sound

Visual output

◦ Most computer information is viewed as an output on a monitor or screen

Audible (sound) output

Most common output device. Allow you to see what’s happening as you work or

view. Allow viewing of moving images unlike a printer. Images quality depends on size and resolution Resolution is measured in pixels. You can set the resolution to how you want to

view the information. High resolution and a large screen give better

quality images.

CRT (cathode ray tubes) Fire electrons at the

screen to make the pixels glow the correct colour

Length of the tubes cause this monitor to be deep and take up lots of space.

These are good quality image at a low cost.

TFT (thin film transistor) Much flatter and take up

less room. Use liquid crystals to form

the image Also called LCD. Preferred to CRT even

though image quality may not be as good in equivalent CRT size.

Also use less energy and don’t flicker so are better for your eyes.

http://savepower.co.za/tips/replace-crt-computer-screens-with-tft-lcd-screens/

Project a large version of the monitor output onto a screen.

Used for a larger audience. Can be portable, but often mounted to

ceiling. The brighter or larger the room the brighter

the bulb needs to be. Quite costly and can overheat.

Touch sensitive computer displays used in schools.

You can draw and operate the computer using either a stylus or finger depending on the type of board.

Combines input and output. Can use handwriting

recognition software

Often used as TV’s, but can be used instead or normal monitor.

Often used in shopping centres and reception areas of businesses.

Work by illuminating tiny fluorescent lights to make the image.

Available in very large sizes. Lots can be linked together to form one

massive display.

Increased in use as mobiles are now used to view internet, check mail, chat, video etc.

3G phones can display live video, so require good quality image that refreshes quickly.

A 2 inch TFT screen can display 16 million colours at 320 x 240 pixel resolution, much better than older versions.

Make challenges for web designers to design web content that can be viewed correctly on a small screen.

Generally have larger screens than mobiles. Need to be able to run application software

e.g. Word, spreadsheets. Need to allow scrolling. Part of the screen is usually a virtual

keyboard to allow typing.

Printers

Print full page at a time so are faster than inkjet.

Uses a laser beam on a light sensitive drum that uses electrostatic charges to attract toner particles.

Page is heated to melt toner onto page.

Monochrome (black) used in offices for good quality documents quickly.

Colour uses 3 toners (magenta, cyan & yellow).

Good quality images and text.

Not as good as high quality inkjet for photographs as they use lower resolution and less colours.

Have now become cheaper so are used more commonly.

Very popular for home use as they tend to be cheaper than lasers.

Can be expensive to run, and are slower than lasers.

Use 3 ink colours plus black and spray ink onto page.

Can have a high resolution and more colours. Can also use a variety of glossy papers to

produce almost professional looking photos. Ink can run if not allowed to dry.

Includes a built in scanner so can be used as a photocopier.

Suitable for home and small office use. Some also have fax facility. Usually inkjet rather than laser,

Mainly used for printing on multipart stationary.

Can print several copies very quickly, where quality is not important. They tend to fade.

Usually used in industry. Used less now as there are faster, cheaper

methods. Also used in shop tills for receipts.

Is made up of several layers, usually in different colours.

When they are fed through a dot-matrix printer, several copies are printed at once.

Flatbed plotters use pens which move across paper to produce an accurate image.

Can be used for large size technical drawings and graphs.

Some can be fitted with a small blade to cut out letters and shapes.

Engineers and architects now use large (up to A0) inkjet plotters as they can print in colour, but they are very expensive.

Found in many towns and over the internet. Files can be sent (usually adobe acrobat or

jpeg) and photos can be posted or collected. Uses offset litho printing onto huge roles of

paper and cut to size using cutting tool. Can be more cost effective for small

businesses. Using such a service saves time, produce

excellent results and reduces wear and tear on office printers.

Some offer design services which can reduce design time in the office.

Found in many towns and over the internet. Can be more cost effective for small

businesses. Files can be sent (usually adobe acrobat or

jpeg) and photos can be posted or collected.

Uses offset litho printing onto huge roles of paper and cut to size using cutting tool.

If you own a digital camera its likely that you will want to print your own photos:

Small specialist photo printers are available, they are portable and can print up to 6 x 4 inch photos.

Can be connected to camera using cable or Bluetooth. Or print from memory card taken out of camera.

Decent quality photos, but are expensive to run.

Photo Printing – Portable Printers

Photo Printing – Inkjet Printers Most inkjet printers can print good quality

photos. Quality will vary depending on type of ink

and printer resolution. Photo quality ink is more expensive. This type of printer can be expensive to run

for printing documents.

Photo Printing – Dye Sublimation Printers People like photos to last a long time. Some domestic photo printers cannot

produce this. Dye sublimation printers use a wax based

ink which can last a much longer time. They are gradually becoming available for

domestic use.

Photo Printing - Professional Can still be more cost effective than running

your own photo printer. Becoming easier and cheaper with many

supermarkets and chemists offering this service.

Can print from CD, memory card or Bluetooth connection to a camera.

Internet companies offer the same service, but in addition offer specialist printing such as books, albums, mugs, montage posters etc

Digital Photo Frame This can provide a way to show many more

photos than you would ever print. They contain a screen that displays a

slideshow of photos from a USB device.

External speakers can be connected to the computer via the sound card.

They vary in size and quality. Some monitors and laptops have built in speakers,

but have poor quality, not good enough for music or gaming.

Headphones are good so that others around cannot hear the sound, but can cause ear problems.

Often used for mp3’s and in call centres. Wireless headsets use Bluetooth and can be more

convenient than ones with cables. Often used as hands free kits for mobile phones.

Visual:

Used for people with disabilities. Usually large monitors that can be adjusted by:

Increased font size Adjusting screen resolution Magnifying the display using a zoom function

(can cause the need for lots of scrolling) Adjusting colour contrast (certain colours are

easier for people to see)

Audible:

Sound can be useful rather than a visual output. Text can be read out as it is typed, and spell

check set to audible rather than visual. Websites can use key words to describe graphics,

these are read out as the page loads.

Printers: Braille printers can be used for blind people. Raised dots represent text and numbers and can

be read by touch, using the fingers. Reading Braille is difficult however.

http://www.teach-ict.com/gcse/hardware/output/miniweb/index.htm