Unit 2.1: Input devices
Input devices means that the device is able to enter information into computer system. This data maybe a simple numeric data typed by keyboard, sound picked up by a microphone. Many different input devices available today, their uses in the real world and the different input signals that they process.
Input devices used in organisation
There are many variety jobs now in these day. Many worked by the help of technology. Such as the animation studio use graphic tablet and light pens to transfer sketches into the computer. In the shop, barcode and magnetic stripe readers are used when selling foods. These are the sort of input devices that would be found in any business or organisation, from a hospital to a local shop.
Analogue and digital data
Computers process digital binary information made up of only '0's and '1's. This allow different devices to communicate with each other using the same information. Modern input and output devices use digital data, but some are still based on analogue system and require a converter. With an analogue to digital converter (ADC) this data is converted into a digital binary value a computer can process.
Here is the list of inputs
Advantages:
• Can control the devices or machines from a short distance.
• Convenience because each button have many different functions.
Disadvantages:
• The devices or machines might be more difficult to control if you lost the remote control.
Pressure sensor is used input pressure readings to a microprocessor or computer e.g. weighing scale, automatic door, etc.
Advantages:
• Data does not need to be read manually.
• More accurate than traditional weighing scale.
Disadvantages:
• Object of suitable weight can incorrectly activate them.
• ADC converter is required.
Light Pen (Old Technology)
Definition : Light pen is a pen-kind computer input device in a form of light-sensitive wand connected to the computer. It is similar to the touch screen.
Advantage :
• Good position accurate.
• Ease of hand movement.
Disadvantage :
• Easily Damage.
• Can only use on some computer screen.
Mouse
Definition:The mouse controls the position of the pointer on the screen in any computer system.
Advantages:
• It is easier to use than a keyboard for people who have limited finger movement.
• design for long term repetitive use.
• Wireless version are now available.
Disadvantages:
• Requires a flat surface to use on.
• The Wireless version needs an internal power supply.
• Ball mechanism in order mice can stop working.
Graphic tablet is an input device that is used to input freehand drawings into the computer.
• Advantages
• It can be used to input much more natural drawings than can be achieved with a mouse.
• Unlike a mouse click, graphic tablet pens are often pressure sensitive, allowing for variations in line thickness and shade.
• Disadvantages :
• It requires space and practice to use.
• It become impossible to use if the stylus or pen is lost or broken.
It is used to read data from the magnetic stripes on identity and banking cards.
Magnetic stripe reader is used to read data from the magnetic stripes on identity and banking cards.
Advantages:
- Data can be input into a system quickly.
- More accurate than typing manually.
- Data is hidden from sight within the stripe, so is more secure than a printout or screen.
Disadvantages:
-They’re not that secure as data stored on a chip
- Very limited storage capacity in the stripes.
Light sensor is used to measure and adjust the light levels. Then it put those information into a microprocessor or a computer. Mostly used in the street light, photography and the space telescopes
Advantages:
· Can detect very small change of the light levels and the data could be read automatically by the computer.
Disadvantages:
· Sometimes it can read the light levels incorrectly because it can mixed up the natural light (sunlight) with the man-made light (light that come from the torch)
· Need to use the ADC (Analogue to Digital) converter, use to change the analogue information (information in the real world e.g. temperature) into the digital information (computer data).
Optical Mark Reader (OMR) is used to read and input information form a form, class register or test paper.
Advantages:
· Whole pages of information can be read very quickly.
· Only small pencil marks are required to complete a form.
Disadvantages:
· Incorrectly completed forms can result in errors.
· Characters or numbers cannot be read.
Chip Reader /OR CHIP and PIN
Definition : Chip and Pin is an input device that read the chip. Normally use with credit card.
Advantage :
· More secure since it’s need pin to access.
· Chip can hold lots of info.
· Data can be encrypted.
Disadvantage :
· Chip on the can can be faulty.
· Some shop are careless to use pin.
Pin Pad are used to enter into ATM machines, EFTPOS system, entry doors and handheld device.
Advantages:
· Pin codes help to prevent unauthorised access.
· Secure doors can only be access if you have a physical key or cards.
Disadvantages:
· People can see the user entering the code.
· Anyone who has the correct code they can control the device.
· Pin numbers can be forgotten.
Numeric keypad is one of the input device that is used where only numerical information needs to be entered.
Advantages :
· It’s very simple to use.
· It is ideal for banking or mathematical systems.
· It saves space than the other bigger input devices.
Disadvantages :
· It is limited to numerical data only, not the others such as letters or pictures.
Temperature sensor
Used to input temperature readings to a microprocessor / computers. Used in microprocessor-controlling washing machines,computer-controlled greenhouse and microprocessor-controlling central heating system.
Advantages:
· Much more accurate than traditional thermometers and able to detect very small temperature changes.
· Data doesn't need to be read manually; the microprocessor does it automatically.
Disadvantages
· An additional analogue to digital (ADC) converter is required to input the signal into a computer to process.
Barcode reader is used to scan and get the information from the barcodes that are on the products, books or membership cards and put those information into the computer.
Advantages:
· Faster and more accurate than re-typing the information into the computer.
· Barcodes can be use around the world.
Disadvantages:
· The barcode only contain the numerical code but not all of the information.
· The barcodes can be easily damaged and unreadable.
Trackerball is an alternative for a mouse, useful for people who have limited movement in their hands.
Advantages:
· Requires very little space to operate.
· Useful for people with limited hand movement.
· Disadvantages:
· Often removable and can be lost.
· Not widely use.
Keyboard is what we can find normally in our life. it use to enter text into computer
Advantage :
· Long-term repetitive use and widely available.
· Got wireless version.
· Function key can be set.
Disadvantage :
· Data can be put as fast as we can types.
· People with physical problem can be struggle.
· Strain injury after long period of continue work.
· Wireless version require a battery.
Touch Pad
Definition: An alternative to a mouse, built in laptops.
Advantages:
· Do not need a separate a mouse.
· Take up less space.
Disadvantages:
· Requires fine finger control.
· This can become uncomfortable after prolonged use.
Scanner is a input device that allow hard copies of images (such as drawings or photographs) or text to be transferred to a computer.
Advantages :
· Images can be scanned at very high resolution.
· It often built into printers to create multi-functional devices.
Disadvantages :
· High-resolution scanning produces large file sizes.
· It is time-consuming.
OCR (Optical Character Reader ) are used to transfer handwritten or printed text into editable text on a computer.The letter ‘R’ can
stand for either ‘Reader’ or ‘Recognition’.
Advantage:
· Much quicker than manually retyping information.
Disadvantages:
· Handwriting must be neat and legible.
· Errors can often be made and text will still need.
· Information displayed in tables can be read inaccurately.
QR Code is a matrix barcode (or two-dimensional code), readable by QR scanners, mobile phones with a camera, and smartphones.
Advantages:
· Faster and more accurate way.
· QR codes are internationally to identify products
Disadvantages:
· QR codes can be damaged and couldn't be scan.
Joystick is used to control objects on a screen in computer games, flight simulators, etc.
Advantages :
· Machinery can be controlled remotely.
· Easy to use as there are few buttons.
· Can be controlled with one hand.
Disadvantages:
· Limited to directional control.
· Limited to thumb and first finger button; additional function may require additional devices.
MICR [Magnetic Ink Character Reader] is normally use in a bank, to do the cheque. It is a character recognition technology
Advantages:
· Info can be read quickly
· Data don’t have to be input manually
· Magnetic ink are difficult to forge
Disadvantages:
· Equipment are expensive
· Paper can be damage, as a result the info can be incorrect
Microphone is an input device which is used to input sounds and voices.
Advantages :
· These can be used with computers with voice recognition software to control system.
· Used to enable chat facilities on computers and other devices.
· It’s extremely common and inexpensive.
· Used to input voiceovers for multimedia presentation.
Disadvantages :
· Voice command software often must be taught to recognise a user’s voice.
· Digital audio files can take up a lot of space.
· It needs to be quite near the sound source in order to work correctly.
Webcam is a camera that can be used to take a photo, recording video and video conferencing. The webcam can be attached to the PCs, laptops and mobile phones.
Advantages:
• · Allows people to chat face to face across the world at their own homes.
• · Cheaper than the video cameras and not complicated to used.
Disadvantages:
• · Usually designed for video online and don’t normally have internal storage.
• · Often use a lower resolution than a standard digital camera.
•
A touch screen is a computer display screen that is also an input device. The screens are sensitive to pressure; a user interacts with the computer by touching pictures or words on the screen.
Advantage:
-Touchscreen devices have limited buttons that will possibly break after 3 – 4 years
-Touchscreen devices usually have more simple user interfaces Ex. Ipod Apps
-Having less or not buttons means that you can put more effort into having a big screen
-For the people worried about hygiene, most devices are easy to clean, some are even dirt, dust and grease resistant
-For people new or uncomfortable with normal desktops, touchscreens are easy to use helping more people get used to using computers
Disadvantage:
-The screen has to be big enough to be able to touch the buttons without missing
-Having a big bright screen and needing massive computing power to run this means a very low battery life
-In direct sunlight it is much less effictian and most of the time very difficult to read the screen
-If a touchscreen devise were to crash the whole screen would be unresponsive, and because of the lack of buttons revoering it would be very difficult
-The screens will get very dirty
-You have to be within arms reach of the device
-Touchscreen devices usually have more simple user interfaces Ex. Ipod Apps
-Having less or not buttons means that you can put more effort into having a big screen
-For the people worried about hygiene, most devices are easy to clean, some are even dirt, dust and grease resistant
-For people new or uncomfortable with normal desktops, touchscreens are easy to use helping more people get used to using computers
Disadvantage:
-The screen has to be big enough to be able to touch the buttons without missing
-Having a big bright screen and needing massive computing power to run this means a very low battery life
-In direct sunlight it is much less effictian and most of the time very difficult to read the screen
-If a touchscreen devise were to crash the whole screen would be unresponsive, and because of the lack of buttons revoering it would be very difficult
-The screens will get very dirty
-You have to be within arms reach of the device
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