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 & TFT Monitors  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.

 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.

Laser Printer  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

 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.

 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.

 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

 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. Special Purpose Output Devices

 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. Special Purpose Output Devices

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