Input and Output Devises
By Rana Zaki
Scanners are used to transfer images or text from paper into a digital format that the computer can use. It can then be edited, printed, or uploaded to the Internet.
There are two main types of scanner:
PRO: Good for scanning bulky items - You don't want to be lifting bulky items up and down just for scanning, so a hand held bar code scanner is a must for safely tracking these items.
Inexpensive and flexible
CON: Short reading zone - When you want to scan items that are far away, such as 20 feet high up in warehouse storage, these items will not work well. There are other scanners that can scan at distance that you'd be better off using.
Touch screen - OUTPUT (but when touched INPUT)
PRO: Takes up less space
CON: Needs calibarting
Interactive whitebourd -OUTPUT (but when touched INPUT)
An interactive whiteboard can take what is being shown on the computer screen and display it for all the class to see. Students and teachers can interact with the screen by tapping it to select items or menus. They can also drag windows around just as you would with a mouse.
PRO: Helpful for students to learn
CON: There are a lot of schools that don’t have the money for this newer way of teaching.
Motion sensor - INPUT
A device which detects or measures a physical property and records, indicates, or otherwise responds to it.
PRO: Most wireless motion sensor alarms have advanced features, such as automatically dialing 911 when it detects unwanted entry, or a load sound.
CON: you need to regularly check and replace the batteries in order for your motion sensor alarm to work.
OMR (optical mark reader) -INPUT
The form is scanned into the computer and the OMR software is used to recognise and record where the marks appear on the paper.
PRO: The machine can then read the data very reliably and rapidly.
CON: If a mark is too light, the optical mark reader would be unable to read it.
Optical Character Recognition (OCR) -
PRO: Instead of sending an actual PDF to a customer or employee beyond your firewall, you can attach the PDF from the cloud and send it as a downloadable link, rather than the actual document ─ totally removing size constraints.
CON: You cant send any Ebook formats.
Graphics Tablet - INPUT
PRO: Helpful for graphics designers and illustrators.
CON: The computer must be running an application that can deal with the graphics tablet. For example Photoshop or CAD (Computer Aided Design) software.
FOR MASS PRODUCTION
Laser printers work through electronically charging a piece of paper with the digital images selected for printing. They use a type of powdered ink called toner, which sticks to the paper where it has an electronic charge and is permanently melted to the paper using a hot fusing wire.
Laser printers are much more efficient than ink-jet printers, capable of producing several thousand prints from one toner cartridge.
PRO: Laser printers produce amongst the highest quality printouts when compared to other types of printers.
CON: The disadvantage is that colour laser printers are very expensive and tend to produce images that have a shiny, artificial look. They are more suited to printing text than graphics.
FOR HOME USE
An ink-jet printer works through spraying minute dots of ink onto paper to create an image. The dots use a combination of different colours to create photo-realistic images.
PRO: they offer excellent colour output and are cheaper than laser printers.
CON: they are much slower than laser printers, particularly when printing text, and the ink cartridges have to be replaced quite frequently.
FOR ENGINEERS/ DESIGNERS/ ARCHITECTS
A plotter will draw an image according to the instructions given from a connected computer.
PRO: Good quality and useful for posters and work.
CON: Very slow printing.
A buzzer is a sound device often used to signal the start or end of something.
It can be controlled from a computer through a hardware interface that converts a digital computer signal into a signal that can drive the buzzer.
A buzzer is also an example of a 'transducer'. A transducer is a physical device that converts one form of energy into another - in this case a buzzer converts electrical energy into acoustic / sound energy.
PRO: It tells you if you are being burgled.
CON: It might sound annoying.
Robotic Arm -OUTPUT
PRO: can work very fast, cheaper and more officiant.
CON: It could starngle you
A plotter can be used to produce high quality, accurate, A3 size or bigger drawings. They are usually used for Computer Aided Design (CAD) and Computer Aided Manufacture (CAM) applications, such as printing out plans for houses or car parts.
Other output devices
Many other types of output device exist including:
mechanical devices, eg a robot arm