Light Pen : This is a pen shaped device allowing natural
movement on the screen. The pen contains the light receptor and is activated by
pressing the pen against the display screen. Receptor is the scanning beam
which helps in locating the pens position. Suitable system software is provided
to initiate necessary action when we locate an area on the display surface with
the help of the light pen.
There are a few other pointing devices known as track balls
and joy sticks which are used more on entertainment usage like games. We will
not discuss them in this section.
Voice/Speech Input : One of the most exciting area of
research is in recognizing human voices/speech so that this could form input to
computer directly. This approach will eliminate the need for keying in data and
will facilitate casual users to use the computer very easily. There are several
problem areas for research since speech recognition system should be able to
identify who is speaking and what the message is. Voice recognition techniques
along with several other techniques to convert the voice signals to appropriate
words and derive the correct meaning of words are required for a commercially
viable comprehensive speech recognition system. We have found limited success
in this area and today devices are available commercially to recognize and
interpret human voices within limited scope of operation.
