WHAT IS INPUT DEVICES?

FUNCTIONS OF INPUT DEVICES :

•  Accept the data from the outside worlds.
•  Convert that data into computer coded information.
•  Supply this data to Central Processing Unit for further processing.

CLASIFICATION OF INPUT DEVICES:

STANDARD INPUT DEVICE: KEYBOARD

• Keyboard is most commonly used input device.
•  It is similar like a type writer which is used to enter data in the computer.
•  It contains sets of keys such as alphabets, number & special signs.

• Usually have from 101 to 105 keys, including the letters of the alphabet,
  numbers, punctuation marks, and other basic keys.
• Many have a numeric keypad on the right side of the keyboard.
• An enhanced keyboard has twelve or more function keys along the top, two
  CTRL keys, two ALT, keys, and a set of arrow and additional keys.

• Function keys, labeled with the letter F followed by a number, are special keys
  programmed to issue commands to a computer.
• To issue commands, users often can press a function key in combination with other
  special keys (SHIFT, CTRL, ALT, and others).
• Keyboards also often have a WINDOWS key(s) and an APPLICATION key.
  ◦ The WINDOWS key displays the Windows Start menu.
  ◦ The APPLICATION key displays an item’s shortcut menu.

KEYBOARD ERGONOMICS

• Many keyboards have a rectangular shape with the keys aligned in straight,
  horizontal rows.
• Users who spend a lot of time typing on these keyboards sometimes experience
  repetitive strain injuries (RSI).

• The goal of ergonomics is to incorporate comfort, efficiency, and safety in the
  design of the workplace.

Keyboards for Mobile Computers and Mobile Devices

• On notebook computers and some handheld computers the keyboard is built in
  the top of the system unit.
  
• To fit in these mobile computers and devices, the keyboards usually are smaller and have
  fewer keys.

POINTING DEVICES

• A pointing devices is an input devices that allows a user to control a pointer on the
  screen.
• They are used to move the insertion point, select objects, and click buttons.
• In a graphical user interface, a pointer is a small symbol on the screen, whose
  location and shape change as a user moves a pointing device.
  

MOUSE

• A mouse is a pointing device that fits under the palm of your hand comfortably.
• It is the most widely used pointing device on desktop computers.
  
• With a mouse, users control the movement of the mouse pointer.

• The top and sides of a mouse have one to four buttons; some also have a wheel.
• An optical mouse uses devices that emit and sense light to detect the mouse’s
  movement.                                                                                                                                                                                                      

OTHER POINTING DEVICES

• Trackball, Touchpad, Pointing Stick, Touch Screen, Touch-sensitive Pads, Stylus, Pen,
  Signature Capture Pad, and Graphics Tablet.

TRACKBALL

• A trackball is a stationary pointing devicewith a ball on its top or side.
  
• To move the pointer, rotate the ball.

TOUCHPAD

• A touchpad is a small, flat, rectangularpointing device that is sensitive to pressure and motion.

POINTING STICK

• A pointing stick is a pressure-sensitive pointing device shaped like a pencil eraser
  that is positioned between keys on a keyboard.

TOUCH SCREENS 

• A touch screen is a touchsensitive display device.
• Multi-touch can recognize multiple points of contact at the same time.
• Some models of desktop computers and many mobile devices have touch screens.
  
• A kiosk, a free standing computer, usually includes touch screens.

TOUCH SENSITIVE PADS

• A touch-sensitive pad is an input device that enables users to scroll through and play music,
  view pictures, watch videos, etc., found in portable media players.
  
• They typically contain buttons and/or wheels that are operated with a thumb or finger.

PEN INPUT

• With pen input, you touch a stylus or digital pen on a flat surface to write, draw,
  or make selections
  
• A stylus is a small metal or plastic devices that looks like a tiny ink pen but uses
  pressure instead of ink.
• A stylus is a small metal or plastic devices that looks like a tiny ink pen but uses
  pressure instead of ink.

OTHER INPUT FOR SMART PHONES

GAME CONTROLLERS

• Video games and computer games use a game controller as the input device that
  directs movements and actions of onscreen objects.
  
• They include gamepads, joysticks and wheels, light guns, dance pads, and a
  variety of motion sensing controllers.
• Gamepad: held with both hands; controls actions of players or objects in games.
• Joystick: handheld vertical lever mounted on a base.
• Wheel: a steering-wheel 0 type input device.
  Light Gun: used to shoot targets and moving
  objects when the trigger is pulled.
• Dance Pad: flat electronic device divided into panels that users press with their feet.
• Motion-Sensing Game Controllers: allow the user o guide on-screen elements
  by moving hand held input device in predetermined directions through the air.

DIGITAL CAMERAS

• A digital camera is a mobile device that allows users to take pictures and store
  the photographed images digitally, instead of on traditional film.
• Some look like traditional cameras, others are built into mobile devices.
• Contents can be downloaded and stored into computers.
• Resolution is the number of horizontal and vertical pixels in a display device.

VOICE INPUT

• Voice input is the process of entering input by speaking into a microphone.
• Voice recognition, or speech recognition, is the compute’s capability of
  distinguishing spoken words.
  
• Voice recognition programs recognize a vocabulary of preprogrammed words,
  ranging from two to millions of words.

AUDIO INPUT

• Voice input is part of a larger category called audio input.
• Audio input is the process of entering any sound into the computer such as speech,
  music, and sound effects.
• Music production software allows users to record, compose, mix, and edit music
  and sounds.

VIDEO INPUT

• Video input is the process of capturing full-motion images and storing them on a
  computer’s storage medium.
  
• Computers record digital signals from digital devices, such as digital video (DV)
  cameras, or convert analog signals to digital signals.

WEB CAMS

• A Web cam is a type of digital video camera that enables a home or small
  business user to capture video and still images and broadcast them over the
  Internet.
• They attach to the computer’s USB port or FireWire port.
  
• Some can display their output on a Web page by streaming.

VIDEO CONFERENCING

• A video conference is a meeting between two or more geographically separated
  people who use a network or the Internet to transmit audio and video data.

SCANNERS AND READING DEVICES

• An optical scanner, usually called a scanner, is a light-sensing input device that
  reads printed text and graphics and then translates the results into a form the
  computer can process.
  ◦ Flatbed
  ◦ Pen or Handheld
  ◦ Sheet-Fed
  ◦ Drum
• Once you scan a document or picture, you can display the scanned object on the
  screen, modify its appearance, and store it.
  
• Many scanners include OCR (optical character recognition) software, which
  can read and convert text documents into electronic files, which is useful if you need
  to modify a document.

OPTICAL CHARACTER RECOGNITION

• Optical character recognition is a technology that involves reading
  typewritten, computer printed, or handprinted characters form ordinary
  documents and translating the images into a form that the computer can process.
  
• A turnaround document is a document that you return to the company that
  creates and sends it.

OPTICAL MARK RECOGNITION

• Optical Mark Recognition (OMR) is a technology that reads hand-drawn marks
  such as small circles or rectangles.
  
• A person places these marks on a form, such as a test or survey.

BARCODE READERS

• An optical reader that uses laser beams to read bar codes by using light patterns
  that pass through the bar code lines.

RFID READERS

• RFID (radio frequency identification) is a technology that uses radio signals to
  communicate with a tag placed in or attached to an object, animal, or person.
• An RFID reader reads information on the tag via radio waves.

BIOMETRIC INPUT

• Biometrics is the technology of authenticating a person’s identity by verifying
  a personal characteristic.
• A biometric identifier is a physiological or behavioral characteristic.
• A biometric device translates a personal characteristic into a digital code.
• A fingerprint reader captures curves and indentations of a fingerprint.
  
• Others: face recognition, hand geometry, voice verification, signature verification, iris
  recognition.

TERMINALS

• A terminal is a computer, usually with limited processing power, that enables users to send
  data to and/or receive information from a host computer.
• Most retail stores use a POS Terminal (point of sale) to record purchases, process credit
  or debit cards, and update inventory.
• An automated teller machine (ATM) is a selfservice banking machine that connects to a
  host computer through a network.