Computer Input Devices Overview

Input Devices

• Input is any data and instructions entered into the memory of a computer

An input device serves a crucial role in computing by facilitating the interaction between the user and the computer system. These devices translate physical actions, such as typing or clicking, into a format that the computer can understand, enabling effective communication and operation of software applications.

Keyboard

• A keyboard is an input device that contains keys users press to enter data and instructions into a computer
• Most desktop computer keyboards have wired and wireless variations
  • Wired keyboards have a USB port
  • Wireless keyboards have bluetooth and IrDA connections
• An ergonomic keyboard is designed to reduce the chance of wrist and hand injuries
• Keyboards on mobile devices are smaller and/or have fewer keys
  • Some phones use predictive text input to save time entering text

Pointing Devices

• A mouse is a pointing device that fits under the palm of your hand, the most widely used pointing device on desktop computers
  • Mice can be wired or wireless
• Mouse operations include:
  • Point
  • Click
  • Right-click
  • Double-click
  • Triple-click
  • Drag
  • Right-drag
  • Rotate wheel
  • Free-spin wheel
  • Press wheel
  • Tilt wheel
  • Press thumb button
• Other pointing devices include:
  • Trackball - stationary pointing device
  • Touchpad - flat, small, rectangular pointing device sensitive to pressure
  • Pointing Stick - pressure-sensitive pointing device shaped like a pencil eraser on a keyboard

Touch Screens and Touch-Sensitive Pads

• A touch screen is a touch-sensitive display device
• Touch-sensitive pads are found in devices like the Microsoft Surface

Pen Input

• Pen input uses a stylus or digital pen to write, draw, or make selections on a flat surface

Game Controllers

• Game controllers are input devices used in video and computer games to control on-screen objects
• Game controllers include variations like:
  • Gamepads
  • Joysticks
  • Light guns
  • Wheels
  • Dance pads
  • Motion-sensing controllers

Digital Cameras

• Digital cameras allow users to take pictures and store them digitally
• Digital camera types include:
  • Studio cameras
  • Field cameras
  • Point-and-shoot cameras
• Resolution and the number of bits stored in each pixel affect digital camera photo quality
  • Resolution is the number of horizontal and vertical pixels in a display device
  • Each pixel consists of one or more bits of data
  • More bits per pixel results in higher quality

Scanners and Reading Devices

• Scanners read images and documents converting them into digital form
• Scanner variations include:
  • Flatbed
  • Pen or Handheld
  • Sheet-fed
  • Drum
• Optical character recognition (OCR) reads text from documents
• Turnaround documents are returned to the company that created and sent them
• Optical mark recognition (OMR) reads hand-drawn marks like circles or rectangles
• Bar code readers use laser beams to read bar codes
• RFID (radio frequency identification) uses radio signals to communicate with a tag placed on an object
  • RFID is used for:
    • Tracking runners
    • Tracking location of soldiers
    • Tracking airline baggage
    • Managing inventory
    • Gauging pressure and temperature of tires

Other Input Devices

• POS (point-of-sale) terminals record purchases, process payments, and update inventory
• ATMs (automated teller machines) allow users to access their bank accounts
• DVD kiosks are self-service DVD rental machines

Input Devices for Physically Challenged Users

• Input devices exist to assist physically challenged users:
  • Keyboards with larger keys
  • On-screen keyboards
  • Various on-screen pointing devices
  • Head-mounted pointers
  • Gesture recognition
  • Computerized implant devices

This quiz covers the fundamentals of computer input devices, including keyboards and mice. Learn about their functions, variations, and ergonomic designs. Test your knowledge on how these devices enable user interaction with computers.