Unit 2 input-output

Notes

1. INPUT DEVICES

2. INPUT DEVICES An input device is any hardware device that sends data to the computer, without any input devices, a computer would only be a display device and not allow users to interact with it, much like a TV.

3. KEYBOARD A keyboard typically has characters engraved or printed on the keys and each press of a key typically corresponds to a single written symbol. However, to produce some symbols requires pressing and holding several keys simultaneously or in sequence. We can say that a keyboard  is a typewriter-style keyboard, which uses an arrangement of buttons or keys, to act as mechanical levers or electronic switches.

4. CLASSIFICATION ON THE BASIS OF SIZE Standard keyboard Desktop computer keyboards, such as the 101-key US traditional keyboards or the 104-key Windows keyboards, include alphabetic characters, punctuation symbols, numbers and a variety of function keys. 

5. Laptop-size keyboard Keyboards on laptops and notebook computers usually have a shorter travel distance for the keystroke and a reduced set of keys. They may not have a numerical keypad, and the function keys may be placed in locations that differ from their placement on a standard, full-sized keyboard.

6. Thumb-sized keyboard Smaller keyboards have been introduced for laptops (mainly net tops), PDAs, smartphones, or users who have a limited workspace

7. Non-standard layout and special-use types Chorded keyboards While other keyboards generally associate one action with each key, chorded keyboards associate actions with combinations of key presses. Since there are many combinations available,  the user to enter characters or commands formed by pressing several keys together, like playing a "chord" on a piano .

8. Foldable keyboards    A foldable keyboard is also called flexible keyboards, these are made of soft plastic or silicone which can be rolled or folded on itself for travel. These keyboards can conform to uneven surfaces, and are more resistant to liquids than standard keyboards. These can also be connected to portable devices and smartphones. Some models can be fully immersed in water, making them popular in hospitals and laboratories, as they can be disinfected .

9. Projection/laser Projection keyboards project an image of keys, usually with a laser, onto a flat surface. The device then uses a camera or infrared sensor to "watch" where the user's fingers move, and will count a key as being pressed when it "sees" the user's finger touch the projected image. Projection keyboards can simulate a full size keyboard from a very small projector. Because the "keys' are simply projected images, they cannot be felt when pressed.

10. ON SCREEN KEYBOARD START MENU > ALL PROGRAMS > ACCESSORIES>EASE OF ACCESS>ON SCREEN KEYBOARD

11. MULTIMEDIA KEYBOARD,WIRELESS KEYBOARD EGRONOMIC KEYBOARD

12. Keyboard Layout

13. AZERTY KEYBOARD

14. POINT-AND-DRAW DEVICES A pointing device is an input interface that allows a user to input data to a computer. Graphical user interfaces(GUI) allows a user to control and provide data to a computer using physical gestures-point click and drag. For example-by moving a hand-held mouse across the surface of the physical desktop and activating switches on the mouse. Movements of the pointing device are echoed on the screen by movements of the pointer (or cursor ) and other visual changes.

15. Various types of point and draw devices Mouse Electronic pen Touch screen

16. MOUSE

17. MOUSE A simple two button mouse with one scroll wheel

18. The first known publication of the term " mouse " as a pointing device is in Bill English's 1965 publication "Computer-Aided Display Control ". The first computer mouse, held by inventor Douglas Engelbart , showing the wheels that make contact with the working surface

19. Different types of mouse Mechanical mouse: Houses a hard rubber ball that rolls as the mouse is moved. Sensors inside the mouse body detect the movement and translate it into information that the computer interprets.

20. The PS/2 connector is a 6-pin Mini-DIN connector used for connecting some mice to a PC compatible computer system .

21. Opto -mechanical:   This is the same as the mechanical mouse except that it uses optical sensors to the motion of the ball. You should use a mouse pad under the mouse to run on

22. Optical mouse: Uses an LED sensor to detect tabletop movement and then sends off that information to the computer for merry munching

23. A mouse with many buttons: The extra buttons can be programmed to do specific things, such as navigate the Web or turn pages when you’re reading a document. The typical button modified mouse has about five buttons .

24. A  Mini-mouse  is a small egg-sized mouse for use with laptop computers; usually small enough for use on a free area of the laptop body itself, it is typically optical, includes a retractable cord and uses a USB port to save battery life.

25. Trackball mouse: Like an upside-down mouse. Rather than roll the mouse around, you use your thumb or index finger to roll a ball on top of the mouse. The whole contraption stays stationary, so it doesn’t need a lot of room, and its cord never gets tangled.

26. A trackball is a pointing device consisting of a ball held by a socket containing sensors to detect a rotation of the ball about two axes—like an upside-down mouse with an exposed protruding ball. TRACKBALL

27. JOYSTICK A joystick is an input device consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling. Joysticks, also known as 'control columns', are the principal control in the cockpit of many civilian and military aircraft, either as a center stick or side-stick. They often have supplementary switches on them to control other aspects of the aircraft's flight.

28. TOUCHPAD A touchpad (or track pad) is a pointing device featuring a tactile sensor, a specialized surface that can translate the motion and position of a user's fingers to a relative position on screen. They are a common feature of laptop computers and also used as a substitute for a computer mouse where desk space is scarce.

29. LIGHTPEN A light pen is a computer input device in the form of a light-sensitive wand used in conjunction with a computer's CRT TV set or monitor. It allows the user to point to displayed objects, or draw on the screen, in a similar way to a touch screen but with greater positional accuracy .

30. LASER PEN MOUSE A laser pointer or laser pen is a small portable and visible laser designed to highlight something of interest by projecting a small bright spot of colored light onto it . This invisible laser light component causes a degree of extra potential hazard in these devices when pointed at nearby objects and persons .

31. TOUCH SCREEN Touch screen is the most simple, intuitive and easiest to use of all input devices. A touch screen enables a user to choose from available options by simply touching the desired icon or menu item displayed on a computer’s screen with his/her finger.

32. MICROPHONES

33. Stand alone microphones rest on a base that sits on the user's desk. These microphones tend to have a long and narrow appearance. This style of microphone tends to produce more white noise than headset microphones and the light designs can easily lose balance if someone or something bumps the device. Stand Alone

34. Many companies that make Web cams for computers also manufacture models that include microphone capability. Consumers can purchase this style of accessory instead of purchasing both products separately. These combination devices save room in the user's workspace and are especially useful for video chats and calls. Many of them attach to the top or side of the computer monitor with a clip so that the Webcam faces the user, capturing audio and video. These are also digital devices that rely on the USB port to connect with the user's computer. Web cam Microphones

35. Some computers and laptops, including all Macs, have built-in microphones that require no additional purchase or installation. Users can consult their computer manual to determine if it includes a built-in microphone. Computers that do have an integrated microphone may have one or more small holes located near the top or bottom of the monitor and, possibly, a microphone image to indicate the presence of the device. Users who desire higher quality audio input may still wish to purchase an external microphone for use with their computers Int egrated Microphones

36. GAME PAD AND CONTROLLERS

37. Game Pad And Controller A gamepad (also called  joypad  or  control pad ), is a type of game controller held in the hand, where the digits (especially thumbs) are used to provide input. Gamepads generally feature a set of action buttons handled with the right thumb and a direction controller handled with the left.

38.   TYPES OF GAME CONTROLLERS 1. Gamepad 2 .Paddle 3 .Trackball 4 .Joystick 5 .Arcade style Joystick

39. 6. Steering wheel 7 .Yoke 8.Pedals 9. Keyboard and mouse 10 .Touch screen 12.Motion sensing 11 .Light gun

40. STEERING WHEEL AND PADDLE

41. The steering wheel, essentially a larger version of a paddle, is used in most racing arcade games as well as more recent racing simulators such as  Live for Speed ,  Grand Prix Legends ,  GTR2 , and Richard Burns Rally . While most arcade racing games have been using steering wheels since  Speed Race in 1974, [ the first steering wheels for home systems appeared on fifth-generation consoles such as the PlayStation and Nintendo. STEERING WHEEL

42. PADDLE A paddle is a controller that features a round wheel and one or more fire buttons. The wheel is typically used to control movement of the player or of an object along one axis of the video screen. Paddle controllers were the first analog controllers and they lost popularity when "paddle and ball" type games fell out of favor. 

43. WEB CAM AND IMAGE SCANNER

44. Vision - Input Systems As a technological discipline, computer vision seeks to apply its theories and models to the construction of computer vision systems. Examples of applications of computer vision include systems for: Controlling processes Detecting events Organizing information Modeling objects or environments Interaction

45. Vision - Input Systems Allow computer to accept input just by seeing an object. Input data is normally an object’s shape and features in the form of an image. As a scientific discipline, computer vision is concerned with the theory behind artificial systems that extract information from images. The image data can take many forms, such as video sequences, views from multiple cameras, or multi-dimensional data from a medical scanner.

46. Vision - Input Systems Camera is the most common input device which is used in the Vision –Input Devices as it can capture the Depth of the images in 2D and 3D . This also include the Processor and combination of filters to convert the physical image to digital data.

47. A  webcam  is a video camera which feeds its images in real time to a computer or computer network, often via USB, internet or Wi-Fi. WEB CAM Their most popular use is the establishment of video links, permitting computers to act as videophones or videoconference stations. This common use as a video camera for the World Wide Web gave the webcam its name

48. Image Scanner is a device that optically scans images, printed text, handwriting, or an object, and converts it to a digital image. IMAGE SCANNER Types of Image Scanners Flat - bed Scanner Hand - held Scanner

49. Flat - Bed Scanner Looks Like a photocopy machine Has a box with a glass plate on the top & a lid. Document to be scanned is placed on the glass plate. A light source below the glass plate moves from 1 line to the another & scans all the lines. Takes few seconds to scan a document.

50. Hand – Held Scanner Contains LEDs & can be held in hand. To scan, dragged slowly over the document from 1 end to another. Has to be dragged very slowly & steadily. Used only when high accuracy is not needed. Cheaper than a flatbed scanner. Used when volume of documents to be scanned is low.

51. OMR – Optical Mark Reader Scanner capable of recognizing a pre-specified type of mark by pencil or pen Very useful for grading tests with objective type questions, or for any input data that is of a choice or selection nature

52. OMR Sheet

53. BAR CODE READER SUPPLIER IDENTIFICATION NUMBER SPECFIC PRODUC-T CODE NUMBER

54. Digitizer Input device used for converting (digitizing) pictures, maps and drawings into digital form for storage in computers Commonly used in the area of Computer Aided Design (CAD) by architects and engineers to design cars, buildings medical devices, robots, mechanical parts, etc. Used in the area of Geographical Information System(GIS) for digitizing maps available in paper form

55. Electronic Card Reader Electronic cards are small plastic cards having encoded data appropriate for the application for which they are used Electronic-card reader is used to read data encoded on an electronic card and transfer it to the computer for further processing Used together as a means of direct data entry into a computer system Used by banks for use in automatic teller machines(ATMs) and by organizations for controlling access of employees to physically secured areas

56. Electronic Card Reader is the magnetic stripe. is the signature strip is the CVC2 code

57. Speech Recognition Devices Input device that allows a person to input data to a computer system by speaking to it Today’s speech recognition systems are limited to accepting few words within a relatively small domain and can be used to enter only limited kinds and quantities of data

58. Uses of Speech Recognition For inputting data to a computer system by a person in situations where his/her hands are busy For data input by dictation For authentication of a user by a computer system based on voice input For limited use of computers by individuals with physical disabilities

59. Plotters A device that draws pictures on paper based on commands from a computer. Plotters differ from printers in that they draw lines using a pen. As a result, they can produce continuous lines, whereas printers can only simulate lines by printing a closely spaced series of  dots . In general, plotters are considerably more expensive than printers.

60. Uses of Plotters Draftsmen, Architects, Technicians, or anyone else who wants to produce a color line drawing of something they have drafted. Producing what used to be called "blueprints" is what plotters are used for.

61. OUTPUT DEVICES

62. OUTPUT DEVICES Output means result or the processed form of any thing. output is the processed form of input. Computer also provides us output of the data which we enter in it after processing. Output is the result of input. 

63. Output Devices The devices, which are used for output processed data are called output devices. A computer uses output devices to communicate with the world, which is outside the computer. Although there are many kinds of input devices, there are currently three common types of output devices: · Monitor · Printers · Sound systems

64. Computer Monitor A monitor or display  (also called screen or visual display unit) is an electronic visual display for computers. A monitor looks like a television and it displays alphanumeric and graphic output.  

65. Types of Monitors · CRT (Cathode ray tube): Monitors of this type screen are used commonly in homes, colleges and offices. These monitors are big and require big area to place, power and have weight more than 10 pounds. We cannot move these monitors easily. · Flat - panel tube: These monitors are also available nowadays in markets. These monitors are normally used in Laptop computers and we can also use these monitors in desktop computers. There are several types of flat-panel monitors, but the most common is the liquid crystal display (LCD) monitor.

66. Printers Translates information that has been processed by the system unit Output referred to as hard copy Features Resolution Color capability Speed Memory 68

67. Printers Features Resolution Measured in dots per inch (dpi), typically 300, 600 or 1200. More the dots, better the image but the more ink is used. Color capability Black and white or color Speed Measured in pages per minute (ppm) Memory Stores printing instructions and documents in queue. 69

68. Types of printers Ink-jet printer Laser printer Personal laser printers Shared laser printers Thermal printer Other printers Dot-matrix Plotters Photo printers 70

69. Sound Cards A  sound card  (also known as an  audio card ) is an internal  computer   expansion card  that facilitates the input and output of  audio signals  to and from a computer under control of computer programs.

70. Speakers Speakers  are output devices that allow you to hear sound from your computer. Computer speakers are just like stereo speakers. There are usually two of them and they come in various sizes.

71. Computer headsets include headphones through which the user can hear audio output from the computer as well as a microphone that the user can use to create audio input. Typical analog headsets contain two 3.5 mm plugs, Consumers also may purchase USB headsets that connect via the computer's USB port and transmit the audio data digitally. HEADSETS

72. End of Unit 2!!