Input
By Hollee Smalley
What is Input?
• Input is any data or instructions entered into
the memory of a computer.
What are input devices?
• An input device is any hardware component
that allows users to enter data or
instructions.
• Popular input devices include: the
keyboard, mouse, stylus, digital pen,
microphone, digital camera, and scanner.
The keyboard
• A keyboard is an input device that contains
keys users press to enter data into a
computer.
• Computer keyboards have a typing area that
includes letters of the alphabet, numbers,
punctuation marks, and other basic keys.
• Function keys are programmed to issue
commands.
Keyboard connections
• Desktop computer keyboards are usually
attached via a cable to a small serial port.
• A cordless keyboard is a battery powered
device that transmits data using wireless
technology, such as radio waves or infrared
light waves.
Keyboard Ergonomics
• An ergonomic keyboard has a design that
reduces the chance of wrist and hand
injuries.
• The goal of ergonomics is to incorporate
comfort, efficiency, and safety into the
design of the items in the workplace.
Pointing devices
• A pointing device is an input device that
allows a user to control a pointer on the
screen.
• A pointer is a small symbol on the screen
whose location and shape change as the user
moves a pointing device.
Pointing devices cont.
• A mouse is a pointing device that allows users to
control the movement of the pointer. It is the most
widely used pointing device on the desktop
computer.
– A mechanical mouse translates the movement of a ball
in its underside into signals the computer can process,
– An optical mouse uses devices that emit and sense light
to detect the mouse’s movement.
– A cordless mouse transmits data using wireless
technology.
Other pointing devices
• A trackball is a stationary device with a ball
that one rotates to move the pointer.
• A touch pad is a flat, pressure-sensitive
device that you slide your finger across to
move the pointer.
• A pointing stick is a device positioned on
the keyboard that you push to move the
pointer.
Other pointing devices cont.
• A joystick is a steering wheel type device that you
turn to stimulate driving a vehicle.
• A light pen is a light-sensitive device that you
press at the screen to select an object.
• A touch screen is a touch-sensitive display device
that you interact with by touching areas if the
screen.
• A stylus or digital pen uses pressure to write text
and draw lines.
Voice input
• Voice input is the process of entering data by
speaking into a microphone.
• Voice recognition is the computer’s capability of
distinguishing spoken words.
• Most voice recording programs are a combination
of speaker-dependent software, which makes a
profile of your voice, and speaker-independent
software, which has a built-in set of word patterns.
Audio input
• Audio input is the process of entering any
sound into the computer such as speech,
music, and sound effects.
Input devices for mobile users
• The primary input device for a PDA is a
basic stylus.
• The primary for a tablet PC is a digital pen,
with which you can write on the device’s
screen.
Digital cameras
• A digital camera allows users to take
pictures and store the photographed images
digitally.
• Resolution describes the sharpness and
clearness of an image.
• The image is downloaded to a computer’s
hard disk via cable or copied from the
camera’s storage media.
Video input
• Video input is the process of capturing fullmotion images into a computer and storing
them onto a storage medium, like a hard
drive.
– A PC video camera enables users to capture
video and still images and then send or
broadcast the images over the internet.
– A web cam displays its output on a web page.
Scanners and reading devices
• A scanner is a light-sensitive input device
that reads printed text and graphics and
translates the results into a form the
computer can process.
– A flat-bed scanner works like a copy machine
except it creates a file of the document.
– An optical reader uses a light to read marks and
codes and converts them into digital data.
Data collection devices
• Data collection devices obtain data directly
at the location where the transaction or
event takes place.
• Data collection devices are used in factories
or warehouses, anywhere cleanliness is not
easily controlled.
Terminals
• A terminal consists of a keyboard, monitor, video
card, and a memory.
• Terminals have three basic categories:
– Dumb terminal-has no processing power, therefore,
cannot function as an independent device.
– Smart terminal- has a processor, giving it the capability
of performing some functions independent of the host
computer.
– Special-purpose terminal- perform specific tasks and
contain features uniquely designed for use in a specific
industry.
Biometric input
• A biometric device translates a personal
characteristic into digital code that is compared
with a digital code stored in the computer to
identify an individual.
– Fingerprint scanner- captures curves and indentations of
a fingerprint.
– Face recognition system- capture a live face image.
– Voice verification- compares live speech with a stored
voice pattern,
– Iris recognition system- reads patterns in the iris of the
eye.
Input devices for the physically
challenged users
• The Americans with Disabilities Act requires any
company with 15 or more employees to make
reasonable attempts to accommodate the needs of
physically challenged workers.
• Some example to help those who are physically
challenged:
– Voice recognition
– On-screen keyboards
– Keyguards- allows one to rest hands on the keyboard
without accidentally pressing any keys.