A graphics drawing tablet used for sketching new images or tracing old ones. Also called a "graphics tablet," the user contacts the surface of the device with a wired or wireless pen or puck. Often mistakenly called a mouse, the puck is officially the "tablet cursor."
For sketching, either the pen or puck is used. For tracing, the puck is preferred because its crosshairs, visible through a clear glass lens, lets you precisely pinpoint ends and corners of detailed drawings.
Most tablets allow parts of the tablet surface to be customized into buttons that can be tapped to select menus and functions in the application.
Digitizer Mode and Mouse Mode
Tablets typically support two modes of operation. "Digitizer mode" creates a one-for-one correspondence between tablet and screen. Wherever the tablet is touched, the screen is drawn in the exact same location. In contrast, "mouse mode" moves the screen pointer relative to any starting position on the tablet surface, just like an ordinary computer mouse.
The Output Is X-Y Coordinates
When drawing or tracing on the tablet, a series of x-y coordinates (vector graphics) are created, either as a continuous stream of coordinates, or as end points. See pen tablet
, tablet PC
Drawings created or traced on tablets are stored as mathematical line segments. Objects are drawn with a pen or puck, but are traced with the puck.
Digitizing Three Dimensions
The 3DRAW PRO 3D digitizer system from Polhemus records x, y and z coordinates of an object by touching its surfaces with a pen. It measures the tip position in 3D space and outputs directly to popular CAD and graphics programs. (Image courtesy of Polhemus, Inc.)