Input devices - Lecture notes 1-3 PDF

Preview

Summary

inpute ...

Description

What is an Output Device? An output device is a piece of computer hardware that receives data or instructions from a computer. Essentially, the computer interacts with the output device in some way. The most common output devices are the monitor and printer, but there are many others. The key distinction between an input device and an output device is that the former sends data to the computer, whereas the latter receives data from the computer. Input and output devices that provide computers with additional functionality are also called peripheral, or auxiliary devices. An output device is any peripheral that receives data from a computer, usually for display, projection, or physical reproduction. For example, the image shows an inkjet printer, an output device that can make a hard copy of anything shown on the monitor. Monitors and printers are two of the most commonly used output devices used with a computer. OUTPUT DEVICES:  Monitor (LED, LCD, CRT etc)  Printers (all types)  Plotters  Projector  LCD Projection Panels  Computer Output Microfilm (COM)  Speaker(s)  Head Phone  Visual Display Unit  Film Recorder  Microfiche 1. Monitor The most common output device used with computers is the monitor, which displays video images and text. A monitor essentially consists of a screen, circuitry, a power supply, buttons to adjust screen settings, and a casing that contains all of these components. The first monitors used the same technology as early televisions, relying on a cathode ray tube and fluorescent screen, but nowadays they incorporate flat panel display technology. VDT(video display terminal) and VDU(video display unit) are alternative names for monitors. 2. Printer Printers are another common output device found in homes in offices. In computing terms, they take electronic data stored on a computer and generates a hard copy of it. Usually that means printing images and text onto paper. There are numerous different types of printer, with Inkjet and laser printers being two of the most common. Modern printers usually connect to a computer with a USB cable or via Wi-Fi. 3. Computer Speakers Computer speakers are hardware devices that transform the signal from the computer's sound card into audio. Speakers are essential if you want a louder sound, surround sound, fuller bass, or

1

just a better quality of audio. External computer speakers began to appear in stores in the early 1990's when computer gaming, digital music, and other forms of media became popular. Some computer speakers are wireless nowadays, connecting to the computer via Bluetooth. 4. Headphones Also known as earphones, headphones allow you to listen to audio without disrupting other people in the vicinity. They connect via the computer line out, or to the speakers. The first headphones were invented in 1910 for U.S. Navy use. Nowadays, headphones come in all sorts of shapes and sizes, from basic earbuds to the more traditional style with padding around the earpieces and a connecting band that fits over the user's head. 5. Projector As its name suggests, this output device "projects" computer images onto a wall or screen. Projectors are typically used for presentations, watching movies, or as a teaching aid, as they enable an entire roomful of people to see images generated by a single computer. Modern projectors usually connect to the computer via an HDMI cable or VGA. 6. GPS GPS (Global Positioning System) uses a network of satellites to provide information, which can then be used to calculate the location of a specific device. It is often used with other digital technology, such as mapping apps. GPS can produce very accurate results, it was originally developed for the U.S. military, but following the downing of a civilian airlines flight by Soviet jets in 1983, the system was made available for commercial use. 7. Sound Card The sound card controls the output of sound signals, enabling devices like speakers and headphones to work. The sound card is known as an expansion card, which means it can be added to the motherboard. Although a sound card is not essential to a computer's basic functionality, you need one if you wish to play games, watch movies, listen to music, and use audio and video conferencing. 8. Video Card As with the sound card, the video card is an expansion card that slots into the motherboard. The video card processes images and video, enabling visuals to be seen on a display. Most computers have basic video and graphics capabilities built into the computer's motherboard, but for faster, more detailed graphics, a video card is required. 9. Braille Reader A braille reader is a peripheral device that enables a blind person to read text displayed on a computer monitor. The text is sent by the computer to the device, where it translated into a braille format and made readable by pushing rounded pins up through a flat surface. Braille readers are also called braille displays and come in various sizes. 10. Plotter

2

A plotter is a similar type of hardware device to a printer. Unlike a printer, however, plotters use writing tools, such as pen, pencil, marker, to draw lines. Designed to use vector graphics, plotters were once commonly employed for computer-aided design, but have now been largely replaced by wide-format printers. What is an Input Device? An input device is essentially a piece of hardware that sends data to a computer. Input devices either interact with or control the computer in some way. The most common input devices are the mouse and the keyboard, but there are many others. The key distinction between an input device and an output device is that the former sends data to the computer, whereas the latter receives data from the computer. Input and output devices that provide computers with additional functionality are also called peripheral, or auxiliary devices. 10 Examples of Input Devices 1. Keyboard Keyboards are the most common type of input device. Before keyboards, interaction with computers was generally carried out using punch cards and paper tape. Most English language keyboards use the QWERTY layout for the alphabetic keys, surrounded by number, symbol, function, and other key types. By pressing the relevant keys, the user feeds data and instructions to the computer. 2. Mouse The mouse interacts with a computer through process known as "point and click". Essentially, when the user moves the mouse on the mouse pad, the pointer moves in a corresponding direction on the monitor screen. The concept of a computer mouse has its roots in the trackball, a related pointing device that was invented in 1946, which used a "roller ball" to control the pointer. Most modern computer mice have two buttons for clicking, and a wheel in the middle for scrolling up and down web pages. 3. Touchpad Also known as a trackpad, a touchpad is a common substitute for a computer mouse. Essentially a specialized surface that can detect the movement of the user's finger and use that information to direct a pointer and control a computer. Touchpads were first introduced for laptops in the 1990's, and it's now rare to find a laptop without one. 4. Scanner The word "scanner" can be used in a number of different ways in the computer world, but here I am using it to mean a desktop image scanner. Essentially, it's an input device that uses optical technology to transfer images (or sometimes text) into a computer, where the signal is converted into a digital image. The digital image can then be edited, emailed, or printed. 5. Digital Camera Digital cameras can be used to capture photographs and videos independently. Later, the files can be transferred to the computer, either by connecting the camera directly with a cable, removing

3

the memory card and slotting it into the computer, or through other transfer methods such as Bluetooth. Once the photos are on the computer, they can be edited, emailed, or printed. 6. Microphone A microphone captures audio and send it to the computer, where the audio is converted to a digital format. Once the audio has been digitized, it can be played back, copied, edited, uploaded, or emailed. Microphones can be used to record audio, or to relay sounds live as part of a video chat, or audio stream. 7. Joystick Joysticks are commonly used as a way of controlling computer video games (as well as having a host of other uses, such as controlling jet planes and construction machinery). Essentially, the joystick is a stick that pivots on a base and sends its angle or direction to the computer. There is also often a trigger, as well as one or more buttons that can be pressed too. 8. Graphic Tablet Also known as digitizers, graphic tablets are input devices used for converting hand-drawn artwork into digital images. The user draws with a stylus on a special flat surface, as if they were drawing on a piece of paper. The drawing appears on the computer screen and can be saved, edited, or printed. Instead of just scanning finished drawings into the computer using a scanner, the graphic tablet offers greater control and versatility for artists. 9. Touch Screen Many devices nowadays use a touch screen rather than a mouse as a way for users to point, drag, or select options on a screen. As the name suggests, a touch screen is a touch sensitive screen which reacts to fingers moving across it. Touch screens are particularly common with portable devices, such as tablets, palmtops, laptops, and smartphones. 10. Webcam Webcams are different from digital cameras in that firstly, they cannot operate independently from a computer, and secondly, they have no inbuilt memory. Although webcams can capture photographs and videos, more often they are used to live stream videos. An input device is a piece of hardware used to provide data to a computer used for interaction and control. It allows input of raw data to the computer for processing. Here’s a list of some input devices used in computers and other computing devices:  Keyboard – one of the primary input devices used to input data and commands. It has function keys, control keys, arrow keys, keypad and the keyboard itself with the letters, numbers and commands. Keyboards are connected to the computer through USB or Bluetooth. A laptop keyboard is more compact than a desktop keyboard to make the laptop smaller and lighter. Smartphones and tablets use on-screen keyboard to input messages and select commands.  Mouse – an input device used to control the cursor and coordinates. It can be wired or wireless. It allows the user to do the following:  Move the mouse cursor

4

Select Scroll Open or execute a program Drag-and-drop Hover Perform other functions with the use of additional buttons A laptop uses a touchpad as the mouse. A smartphone and tablet use a touchscreen as primary input device and the user’s finger is used as the mouse. Microphone – an input device that allows users to input audio into their computers. Here are some uses of the microphone:  Audio for video  Computer gaming  Online chatting  Recording musical instruments  Recording voice for dictation, singing and podcasts  Voice recorder  Voice recognition  VoIP – Voice over Internet Protocol Digital Camera – is an input device that takes pictures digitally. Images are stored as data on memory cards. It has an LCD screen that allows users to preview and review images. Digital cameras have become popular over film cameras because of the following features:  LCD screen – allows users to view the photos and videos immediately  Storage – can store thousands of pictures  Picture development – allows users to choose and pick which pictures to develop  Size – takes up less space and can be easily carried Scanner – is an input device that reads an image and converts it into a digital file. A scanner is connected to a computer through USB. There are different types of scanners:  Flatbed scanner – uses a flat surface to scan documents  Sheetfed scanner – like a laser printer where paper is fed into the scanner  Handheld scanner – the scanner is dragged over the page to be scanned  Card scanner – for scanning business card Touchscreen – is an input device that allows users to interact with a computer using their fingers. It is used widely in laptop monitors, smartphones, tablets, cash registers and information kiosks. Most common functions of touchscreens are as follows:  Tap  Double-tap  Touch and hold  Drag  Swipe  Pinch Barcode Reader – also known as barcode scanner or point of sale (POS) scanner, is an input device capable of reading barcodes. Webcam – is an input device connected to the computer and the internet that captures still picture or motion video.       









 

5

Biometric devices – is an input device used to input biometric data into a computer. Here are the types of biometric devices:  Face scanner  Hand scanner  Finger scanner  Voice scanner  Stylus – is a pen-shaped input device used to write or draw on the screen of a graphic tablet or device. Initially it was just used for graphic tablets and PDAs, but now, it has become popular on mobile devices as a replacement for the user’s fingers. It’s used for more accurate navigation and to keep oils from user’s fingers off the device screen. Digital Data Storage Devices: 10 Examples 

1.

Hard Drive Disk

2.

Floppy Disk

3.

Tape

4.

Compact Disc (CD)

5.

DVD and Blu-ray Discs

6.

USB Flash Drive

7.

Secure Digital Card (SD Card)

8.

Solid State Drive (SSD)

9.

Cloud Storage

10.

Punch Card

I will go into more details regarding each device below. 1. Hard Disk Drive A hard disk drive (also known as a hard drive, HD, or HDD) can be found installed in almost every desktop computer and laptop. It stores files for the operating system and software programs, as well as user documents, such as photographs, text files, and audio. The hard drive uses magnetic storage to record and retrieve digital information to and from one or more fastspinning disks. 2. Floppy Disk Also know as a diskette, floppy, or FD, the floppy disk is another type of storage medium that uses magnetic storage technology to store information. Floppy disks were once a common storage device for computers and lasted from the mid-1970's through to the start of the 21st century. The earliest floppies were 8-inch (203 mm) in size, but these were replaced by 5 1⁄4-inch (133 mm) disk drives, and finally a 3 1⁄2 inch (90 mm) version. 3. Tape In the past, magnetic tape was often used for digital data storage, because of its low cost and ability to store large amounts of data. The technology essentially consisted of a magnetically thin

6

coated piece of plastic wrapped around wheels. Its relative slowness and unreliability compared to other data storage solutions has resulted in it now being largely abandoned as a media. 4. Compact Disc (CD) The compact disc, known for short as a CD, is a form of optical storage, a technology which employs lasers and lights to read and write data. Initially compact discs were used purely for music audio, but in the late 1980's they began to be also used for computer data storage. Initially, the compact discs that were introduced were CD-ROM's (read only), but this was followed by CD-R's (writable compact discs) and CD-RW's (re-writable compact discs). 5. DVD and Blu-ray Discs The DVD (digital versatile disc) and Blu-ray disc (BD) are formats of digital optical disc data storage which have superseded compact discs, mainly because of their much greater storage capacity. A Blu-ray disc, for example, can store 25 GB (gigabytes) of data on a single-layer disc and 50 GB on a dual-layer disc. In comparison, a standard CD is the same physical size, but only holds 700 MB (megabytes) of digital data. 6. USB Flash Drive Also known as a thumb drive, pen drive, flash-drive, memory stick, jump drive, and USB stick, the USB flash drive is a flash memory data storage device that incorporates an integrated USB interface. Flash memory is generally more efficient and reliable than optical media, being smaller, faster, and possessing much greater storage capacity, as well as being more durable due to a lack of moving parts. 7. Secure Digital Card (SD Card) A common type of memory card, SD cards are used in multiple electronic devices, including digital cameras and mobile phones. Although there are different sizes, classes, and capacities available, they all use a rectangular design with one side "chipped off" to prevent the card from being inserted into the camera or other device the wrong way. 8. Solid State Drive (SSD) A solid state drive uses flash memory to store data and is sometimes used in devices such as netbooks, laptop, and desktop computers instead of a traditional hard disk drive. The advantages of an SSD over a HDD include a faster read/write speed, noiseless operation, greater reliability, and lower power consumption. The biggest downside is cost, with an SSD offering lower capacity than an equivalently priced HDD. 9. Cloud Storage With users increasingly operating multiple devices in multiple places, many are turning to online and cloud computing solutions. Cloud computing basically involves accessing services over a network via a collection of remote servers. Although the idea of a "cloud of computers" may sound abstract to those unfamiliar with this metaphorical concept, in practice it can provide tremendous storage solutions for devices that are connected to the internet. 10. Punch Card

7

Punch cards (or punched cards) were a common method of data storage used in the early computers. Basically, they consisted of a paper card with punched or perforated holes that have been created by hand or machine. The cards were entered into the computer to enable the storage and accessing of information. This form of data storage media pretty much disappeared as new and better technologies were developed. Input Devices:  Graphics Tablets  Cameras  Video Capture Hardware  Trackballs  Barcode reader  Digital camera  Gamepad  Joystick  Keyboard  Microphone  MIDI keyboard  Mouse (pointing device)  Scanner  Webcam  Touchpads  Pen Input  Microphone  Electronic Whiteboard  OMR  OCR  Punch card reader  v)MICR (Magnetic Ink character reader)  Magnetic Tape Drive OUTPUT DEVICES:  Monitor (LED, LCD, CRT etc)  Printers (all types)  Plotters  Projector  LCD Projection Panels  Computer Output Microfilm (COM)  Speaker(s)  Head Phone  Visual Display Unit  Film Recorder  Microfiche Both Input–OutPut Devices:  Modems  Network cards 8

     

9

Touch Screen 4. Headsets (Headset consists of Speakers and Microphone. Speaker act Output Device and Microphone act as Input device) 5. Facsimile (FAX) (It has scanner to scan the document and also have printer to Print the document) 6.Audio Cards / Sound Card...