Construction and working of digitizer

Digitizer is the input devices used to select coordinate(position) values for an object interactivaly in 2D or 3D plane.

It is also used for drawing and painting the (graphical) objects. curves and surface shapes can be drawnby joining the coordinate positions with the straightline segment.

Graphics tablet (a type of digitizer) is a locator device consisting of a flat surface and a pen-like stylus which specifies a particular location on the flat surface. these are constructed by building a grid of wires in a rectangular fashion, on the tablet surface . The electromagnetic pulse generation causes an electric signal to be induced in a coil of wire attached to the stylus. the signal strength, and the coded pulses determines the tablet's position. sometimes, sound waves are used to determine the position of a stylus. this type of tablet in which sparks are emitted from a stylus tip with a sound is called an acoustic tablet. in acoustic tablets, microphones (strip or point) are used for determining the sound. these microphones can be placed any where on the surface.

3D digitizers uses sonic or electromagnetic transmission for recording the position of a tablet. in this, the transmitter and the receiver are coupled in a similar manner as they are coupled in a data glove.