Input devices and their uses CH - 2.1 Tr. Zin Wah Oo 1. Keyboards Topics 2. Numeric keypads 3. Pointing devices 4. Remote control 5. Joysticks and driving wheels 6. Touch screens (as an input device) 7. Scanners 8. Digital cameras 9. Microphones 10. Sensors 11. Light pens Keyboards most common method used for data entry used as the input device on many electronic items is connected to te computer through a USB and wireless connection virtual or type of touchscreen technology. When the character on the keyboard is pressed, it is converted into a digital signal, which the computer interprets. Keyboards Ergonomic keyboards have the keys arranged differently designed to give more support to the wrists and hands how the computer can recognise a letter pressed on the keyboard: there is a membrane or circuiut board at the base of the keys. CPU can determine which key has been pressed. CPU refers to an index file to identify which character the key press represents. Tr. Zin Wah Oo uses input of data into applications software typing in commands to the computer Numeric keypads is used to enter numbers only Uses Automatic teller machines (ATMs) Mobile phones to allow phone numbers Point of sale terminals (POS) in case the barcode reader fails to read the barcode Chip and PIN devices when paying by credit/debit cards Fast entry of numeric data into a spreadsheet Tr. Zin Wah Oo Mouse a pointing device user controls the position of a pointer on the screen by moving the mouse around. two buttons; the left button - used to select items by double clicking the right button - brings up drop-down menus. a scroll button - speeds up the process of moving through a document. The optical mouse and the cordless or wireless mouse are in use on modern computers. Uses opening, closing and minimising software grouping, moving and deleting files image editing controlling the position of a pointer on the screen to allow selection from a menu or selecting an icon, and for scrolling up and down/left and right Tr. Zin Wah Oo Touchpad are used as a pointing device in many laptop computers. The pointer is controlled by the user moving their finger on the touchpad and gently tapping it to simulate the left-hand button of a mouse have buttons under the touchpad which serve the same function as the left and right buttons on a mouse. uses are same with mouse' s uses. Trackerball similar to a mouse except that a ball is on the top or the side of the device the user controls the pointer on the screen by rotating the ball with their hand Some trackerballs have two buttons, which have the same function as the leftand right-hand mouse buttons. If they have a third button, it is equivalent to a double click Tr. Zin Wah Oo usesgood alternative to a mouse for people with conditions such as RSI Used in an industrial control room environment Used in some luxury cars to select functions Remote control for the operation of other devices using infrared signals. The buttons on the keypad are used to select options usesTelevisions, satellite systems, DVD/Blu-ray players and Hi-Fi systems all use remote controls to alter functions Used to control multimedia systems. Used in industrial applications to remotely control processes, stop and start machinery, etc Tr. Zin Wah Oo Joystick have similar functions to a mouse and a trackerball By gripping the stick, a pointer on the screen can be controlled Buttons are used to make selections. Often they have another button on the top of the stick that is used for gaming purposes usesUsed in video/computer games Used in simulators (for example, flight simulators) to mimic actual controls. Driving wheel connects to a computer usually through a USB port. wheel allows you to simulate the turning of a steering wheel there are associated devices which allow you to accelerate and brake. Sensors are used to pick up left/right movement usesUsed in video/computer games Used in simulators Tr. Zin Wah Oo Touch screens (as an input device) user can choose an option by simply touching a button/icon on the screen The selection is automatically made without the need for any pointing device. Uses Self-service tills Automatic teller machines (ATMs) Point of sale terminals Mobile phones, tablets and satellite navigation systems. etc. Scanners used to enter information from hard copy The most common type is the flatbed scanner (is made up of a glass panel and lid.) hard copy document or photo is scanned by a light source and produces a computer-readable image Images of text can be used with optical character recognition (OCR) software to produce editable text documents usesScan in documents and convert into a format for use in various software packages. Scan in old/valuable documents/books, thus protecting the originals, as well as producing records in case the paper copies are lost/destroyed (this is also known as archiving). Scan in photographs Scan in barcodes at POS terminals. Tr. Zin Wah Oo Digital cameras have largely replaced traditional film-based cameras. images are stored on a memory card (solid-state memory) can be transferred to a computer (directly reading the memory card, USB port,using wireless data transfer) Uses Taking photographs Used as a data-capture device Dentists use digital cameras to take photos of a patient’s teeth to help them diagnose any problems The creation of virtual reality tours around houses, historical buildings, industrial plants, and so on Tr. Zin Wah Oo Microphones are either built into the computer or are external devices connected through the USB port or using Bluetooth connectivity a microphone can convert sound waves into an electric current. current produced is converted to a digital format so that a computer can process it or store it Diagram of how a microphone works When sound is created, it causes the air to vibrate. When a diaphragm picks up the air vibrations, the diaphragm also vibrates copper coil is surrounded by a permanent coil is connected to the diaphragm using a cone. when the diaphragm vibrates, the cone moves in and out causing the copper coil to move forwards and backforwards . that cuts through the magnetic field around the permanent magnet, inducing an electric current. electic current is amplified and sent to a recording device. Tr. Zin Wah Oo usesTo input speech/sounds to be used in various applications Input in voice-recognition software Microphones can also be used as a sensor to pick up sound Used in video-conferencing or Voice over Internet Protocol (VoIP) applications. Sensors a device that inputs data to a computer data is a measurement of some physical quantity that is continuously changing physical quantities are analogue in nature computers only understand digital data (1s and 0s), the information from the sensors needs to be converted; this is done using an analogue to digital converter (ADC) Light pens used with computers as an input device contain sensors that send signals to a computer whenever light changes are detected. only work with CRT monitors Uses Selecting objects on CRT screens. Drawing on screen (for example, with CAD packages). h n • h ■
