Input Devices

QWERTY Keyboard
1. The standard desktop and laptop keyboard.
2. It is used in most countries in Europe and on tablet computers and mobile phones
3. The device works by pressing the keys that you want and then it creates characters on the page.
4. Advantages - It is the same on every computer which means that it is recognisable.
5. Disadvantages - Can’t use if you are blind or partially sighted.
6. Manual device
Concept Keyboard
1. A concept keyboard is a flat board that contains a grid of buttons.
2. These are used at checkout tills at McDonalds, fast food tills, pubs and skating.
3. To work them you press each button as it can be programmed to do whatever you want.
4. Disadvantages - Poor for text or numeric input - although some keyboards do include a numeric keypad so the operator can enter the amount sold. Limited to the options shown on the keyboard.
5. Advantages - Much faster for making non-text selections such as menu choices on the till of a fast-food outlet. The keyboard is waterproof which can be useful where there is dirt or the risk of splashes.
6. Manual
Mouse
1. A pointing device that are a common form of input to a computer.
2. It uses sensors to track movement and translates this to a moving pointer on the screen.
3. Advantages - The pointer can be used to select items to open, move or edit.
4. Disadvantages - Sensors don’t always detect all movement and can become old and broken.
5. Manual
6. Tracker Ball
  1. Variation of a mouse. A pointing device. Essentially, a trackball is a mouse lying on its back.
  2. To move the pointer, you rotate the ball with your thumb, your fingers, or the palm of your hand. There are usually one to three buttons next to the ball, which you use just like mouse buttons.
  3. Used on computers and laptops
  4. Advantages of trackballs over mice is that the trackball is stationary so it does not require much space to use it. In addition, you can place a trackball on any type of surface, including your lap.
  5. The sensors don’t always detect all movement and can become old and broken.
  6. Manual
Graphics tablet
1. A graphics tablet or digitizer is a computer input device that enables a user to hand-draw images, animations and graphics, similar to the way a person draws images with a pencil and paper.
2. Examples are graphic tablets, some electronic white boards.
3. You trace an image from a piece of paper that is taped or otherwise secured to the surface and store it.
4. Advantages - Can replace the mouse which people can find to be too jerky, and repetitive stress injuries like carpal tunnel syndrome are less likely when using this tool.
5. Disadvantages - Can become broken and the sensors can become old and not react as quickly so your image may not be created successfully.
6. Manual
Scanner
1. Scans barcodes, characters etc. to receive information. Bar code scanners
2. E.g. Bar code scanners
3. It is a pattern of different thickness lines that can be scanned to identify an item. A light is then reflected back to the scanner which detects the pattern of thick and thin lines that represent a number. This number is then used to identify an item.
4. Advantages - Flatbed scanners are very accurate and can produce reasonably high quality images. Any image which is digitised by the scanner can then be included on electronic documents. Images once digitised can be enhanced with a graphics application. Specialist scanners can convert old material such as 35mm negatives into digital files. Can accurately capture an image, but the original source may be more important than the scanned image.
5. Disadvantages - Images produced by the scanner can take up a lot of memory space. Images lose some quality in the scanning and digitising process. The quality of the final image is dependent on the quality of the original image.
6. Manual
Digital Camera
1. Takes pictures
2. E.g. Iris or facial recognition or Skype or social networking
3. You take a picture or show your face for facial recognition and then it stores it in its memory.
4. The big advantage of digital cameras is that making photos is both inexpensive and fast because there is no film processing. Interestingly, one of the biggest boosters of digital photography is Kodak, the largest producer of film. Kodak developed the Kodak PhotoCD format, which has become the de facto standard for storing digital photographs.
5. The digital cameras can be limited by the memory.
6. Manual
Touch Screen
1. Used in tablet computers, kiosks, mobile phones, supermarkets checkouts.
2. The user touches an icon or symbol to select it directly on the screen.
3. Advantages - It is easy and quick to use.
4. Disadvantages - Easy to click an incorrect button and hard to use with greasy fingers or gloves on.
5. Manual
OMR
1. Optical mark recognition. The technology of electronically extracting intended data from marked fields, such as checkboxes and fill-infields, on printed forms
2. E.g - National lottery tickets, multi-choice papers
3. OMR technology scans a printed form and reads predefined positions and records where marks are made on the form.
4. Advantages - A fast method of inputting large amounts of data - up to 10,000 forms can be read per hour depending on the quality of the machine used. Only one computer needed to collect and process the data. OMR is much more accurate than data being keyed in by a person.
  1. Disadvantages - If the marks don't fill the space completely, or aren't in a dark enough pencil, they may not be read correctly. Only suitable for recording one out of a selection of answers, not suitable for text inpu The OMR reader needs the answers to be on the prepared forms which will all be identical to one another. You can't just pick up a blank sheet of paper and mark your answers on it.
5. Automatic
OCR
1. Optical character recognition
2. E.g. companies and libraries taking physical copies of books, magazines, or other old printed material and using OCR to put them onto computers.
3. An OCR system consists of a normal scanner and some special software. The scanner is used to scan text on a document or piece of paper into the computer. The OCR software then examines the page and changes the letters into a form that can be edited or processed by a normal word processing package.
4. Advantages - Cheaper than paying someone to manually enter large amounts of text. Much faster than someone manually entering large amounts of text. The latest software can recreate tables and the original layout.
5. Disadvantages - All documents need to be checked over carefully and then manually corrected. If the original document is of poor quality or the handwriting difficult to read, more mistakes will occur. Not worth doing for small amounts of text.
6. Automatic
MICR
1. Magnetic Ink Character Recognition
2. E.g. - Check numbers, bank or building society sort codes, and customers’ account number.
3. These numbers are written in a special ink which contains iron particles. This ink is magnetised and commonly called 'magnetic ink'. It can be read by a special machine called a Magnetic Ink Character reader.
4. The advantages of a MICR scanner is that it can read the magnetic characters through ink and other things that can normally obscure reading the data visually and it can be done quickly with high accuracy.
5. The disadvantages are that the MICR characters are very limited to only 14 characters, any damage to the MICR characters or any printing out of the precise format specifications will cause a failure of the MICR print to be read properly, MICR scanners are also very precisely designed machines that are relatively expensive and need constant maintenance to maintain their reliability.
6. Automatic
Barcode Reader
1. Barcodes are also used on books to show the book's ISBN number - have a look at any textbook that you have in your bag. They are also used on library tickets so that when your ticket is scanned, the database brings up your account and any books which you still have out on loan are displayed.
2. A barcode reader is an automatic input device which is used to scan or 'read' the barcode by using a visible red light. The reflected light is translated into digital data that is interpreted by the computer to identify the product and price from the database.
3. The main advantage of using a barcode system is that any price change only needs to be made to the database and not every single product package.
4. System Failure may cost more delays. Scratched or crumpled barcodes may cause problems. Data must be coded in the barcode in laser scanning.
5. Automatic
Magnetic Strip(e) reader
1. Used on credit cards for swiping to pay for item(s).
2. The user swipes their card on a device to pay for their item(s)
3. Advantages - The magnetic strip can hold personal details such as account number and name. The strip can contain up to 60 characters, stored magnetically.
4. Disadvantages - To read the data on the card, it is 'swiped' through a Magnetic Stripe Reader machine and the data is read and fed back to the computer.
5. Automatic
Microphone
1. Measuring paper blueprints, tracing paper drawings into a digital software program, CAD menu template. The pen (Digitizer Stylus supplied models)
2. You use the pen to control the screen and work the digitizer stylus.
3. One of the biggest advantages of any video digitizer is ease of playback. Video digitizers give video editors a huge advantage. Using a computer-based non-linear editing program to manipulate digital files is the standard for the professional film and video industry. It is also common on home computers where software that comes with new computers or digital video cameras lets users make basic cuts and edits.
4. To project correctly, the tablet must be placed in landscape mode instead of the more comfortable portrait mode. Electromagnetic resonation based tablets are troubled with “jitter” and when around the metal at the edges of the screen may change the properties of the reflected signal. In some digitizer technology a battery powered pen is used; they usually suffer from the lack of support in many graphics applications. Right clicking is sometime tricky using a digital pen.
5. Manual
Chip and Pins
1. E.g. Pin machines
2. A user inserts a card into the machine and then enters a pin number to pay for their goods.
3. Advantages - It is easy to use and it means that you don’t have to find change or cash to pay with. Quick.
4. Disadvantages - They don’t always work as credit cards can get cut off for security reasons.
5. Manual
RFID
1. Radio frequency identification.
2. Used in shops, to track luggage past check points in airports and as tags inside animals.
3. Electronic version of a bar code and it transfers information via radio frequencies to a reader. The number is looked up on a date base and then information is found out about it.
4. Advantages - They don’t require line of sight and can be read at distances of around 10 metres.
5. Disadvantages - RFID systems are often more expensive than barcode systems RFID technology is harder to understand Can be (debatably) less reliable RFID tags are usually larger than barcode labels Tags are application specific. No one tag fits all Possibility of unauthorized reading of passports and credit cards More than one tag can respond at the same time
6. Automatic
Passive sensors
1. One type of remote sensing instrument, a passive sensor picks up radiation reflected or emitted by the Earth. The ETM+, TM, and MSS sensors are all examples of a passive remote sensing system.
2. All objects with a temperature above absolute zero emit heat energy in the form of radiation. Usually this radiation is invisible to the human eye because it radiates at infrared wavelengths, but it can be detected by electronic devices designed for such a purpose.
3. Advantages - lower procurement cost Lower costs of operation and maintenance, due to the lack of transmitter and moving parts Covert operation, including no need for frequency allocations Physically small and hence easily deployed in places where conventional radars cannot be Capabilities against stealth aircraft due to the frequency bands and multistate geometries employed Rapid updates, typically once a second Difficulty of jamming Resilience to anti-radiation missiles.
4. Immaturity Reliance on third-party illuminators Complexity of deployment 2D operation.
5. Automatic
Motion sensors
1. A motion detector is a device that detects moving objects, particularly people. A motion detector is often integrated as a component of a system that automatically performs a task or alerts a user of motion in an area.
2. An automatic door opener is an example of a radar-based motion detector. The box above the door sends out bursts of microwave radio energy (or ultrasonic sound waves), and then waits for the reflected energy to bounce back. If there is nobody in front of the door, the radio energy will bounce back in the same pattern. But if somebody enters the area, the reflection pattern is disturbed. When this happens, the sensor sends a signal and the door opens. In a security system, the sensor sends an alarm signal when the reflection pattern in a room is disturbed.
3. Disadvantages - The light will come on if an animal walks past it.
4. Advantages - You know when someone is walking around your house and the light coming on for you when you get home and it is dark outside.
5. Automatic
Output Devices
1. Laser Printer
  1. Done by powder not ink and the image goes on the drum and collects electrostatics and attracts the powder on and then melts it
  2. E.g. printing text
  3. Cheaper to run (ink)
  4. Expensive to buy
2. Ink Jet Printer
  1. Heats ink and then it squirts it out onto the paper
  2. Marking, coding of products and packages
  3. Output of high quality, quiet, cheap
  4. Ink cartridges are quite expensive and can smudge
3. Dot-Matrix Printer
  1. It hits the ink onto the paper
  2. E.g. continuous stationery
  3. Cheap
  4. Noisy, characters may not be printed clearly
4. Plotter
  1. Uses a series of different-coloured pens. Drum - large sheets of paper. Flatbed - small
  2. Printing graphs, designs, plans and maps
  3. Precise drawings
  4. Flatbed plotters are big
5. Speakers
  1. Electricity moves the speaker to make the air move and create sound waves
  2. In hospitals and hearing sounds or speech off computers
  3. Visually impaired can use them
  4. Takes up space, high quality is expensive
6. 3D Printers
  1. Design something on a computer and using hinges and wheels it creates it in layers from the bottom up
  2. Schools, engineering, medical and prototypes
  3. Easier than building it yourself
  4. Expensive (£1500)
7. Actuators
  1. Computer controlled device that can make a mechanical adjustment to a system
  2. As part of an aeroplane control system
  3. Quicker than doing it yourself
  4. Mechanical - manual operation only. Electro-mechanical - moving parts can wear. Linear motor - low force
8. LED Monitors
  1. Displays images and text using light
  2. Phones,tvs, computer monitors, digital clocks
  3. Energy efficient, long lifetime, no warm-up period, controllable
  4. Expensive to buy
  5. Light emitting diode
9. LCD Monitors
  1. Displays images and text using liquid
  2. Tv monitors
  3. Sharpness, geometric distortion, brightness, physical screen shape
  4. Cost, resolution, interference, motion artifacts
  5. Liquid crystal display
10. CRT monitors
  1. Cathode ray tube
  2. A vacuum tube contains electron guns and a flourescent screen to view images
  3. Old tvs
  4. Highest resolutions, motion artifacts, cost
  5. Brightness, sharpness, emissions
11. Projectors
  1. Light passes through each frame of film to display images
  2. Whiteboards (at school), old films
  3. Enables lots of people to see something from a distance
  4. Image quality may not be good when projected

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Input Devices

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	Created by jowetts11 over 10 years ago