IT_Chapter_3B

Devices for the Hand

• Pen based input

– Tablet PCs, PDA

– Pen used to
write data

– Pen used as
a pointer

– Handwriting recognition

– On screen keyboard

• Touch screens

– Sensors determine where finger points

– Sensors create an X,Y coordinate

– Usually presents a menu to users

– Found in cramped or dirty environments

• Game controllers

– Enhances gaming experience

– Provide custom input to the game

– Modern controllers offer feedback

– Joystick

– Game pad

Optical Input Devices

• Allows the computer to see input

• Bar code readers

– Converts bar codes to numbers

• UPC code

– Computer find number in a database

– Works by reflecting light

• Amount of reflected light indicates number

• Image scanners

– Converts printed media into electronic

– Reflects light off of the image

– Sensors read the intensity

– Filters determine color depths

• Optical character recognition (OCR)

– Converts scanned text into editable text

– Each letter is scanned

– Letters are compared to known letters

– Best match is entered into document

– Rarely 100% accurate

Audiovisual Input Devices

• Microphones

– Used to record speech

– Speech recognition

• “Understands” human speech

• Allows dictation or control of computer

• Matches spoken sound to known phonemes

• Enters best match into document

• Musical Instrument Digital Interface

– MIDI

– Connects musical instruments to computer

– Digital recording or playback of music

– Musicians can produce professional results

• Digital cameras

– Captures images electronically

– No film is needed

– Image is stored as a JPG file

– Memory cards store the images

– Used in a variety of professions