A digitizer tablet is a device used to enter two-dimensional or three-dimensional graphical data into a computer. A picture, diagram or text can be easily drawn or traced on the flat surface of the digitizer. A special stylus and software take the place of pen and paper. The digitizer driver software can generally detect the height of the stylus above the graphics pad, its angle with the pad and any pressure put upon it. The two-dimensional absolute position of the stylus is always known, unlike that of a mouse—a digitizer tablet can be used as a pointing device in addition to, or in place of, a mouse.
The stylus used with a digitizer tablet often resembles a thick pen or pencil. It contains a small amount of circuitry and may also include a battery. It usually has a few buttons on it as well. The buttons might not correspond to those on a mouse—a stylus may have to be tapped on the pad to "double-click." Like a pencil, the opposite end of the stylus can often be used to "erase" a line.
Some people who have repetitive-strain injuries, or want to avoid them, use a digitizer in place of a mouse. They prefer the longer, sweeping arm motions of a stylus. Without it, prolonged wrist-heavy mouse movements often aggravate their condition.
A digitizer tablet often comes with a mouse-like "puck" in addition to the stylus. It may have an optical loupe attached to assist with Computer-Aided Design (CAD) work. It is also likely to include quite a few buttons. These can often be programmed as shortcuts for common graphics software operations.
The first computer-based digitizer tablets were created in the late 1950s and early 1960s. They were used with handwriting movement analysis and CAD systems. By the mid 1970s, they evolved enough to make high-end CAD commercially successful. During the 1980s, tablets were bundled with some personal computers. Handwriting recognition and painting programs were often included as well.
A digitizer tablet may also be known as a graphics tablet or drawing tablet. Many technologies have been used in this type of computer input device. Electromagnetic properties can be used on both the stylus and the tablet to determine position. A passive induction design may eliminate the need for a stylus battery.
In an acoustic design, the stylus can generate clicks which are triangulated by the tablet. An optical pad may use a very small camera in the stylus in conjunction with pattern-matching software. A capacitive tablet is somewhat similar to a touchscreen, but carries much higher precision. Like most other designs, it can detect the position of the stylus above the tablet surface.
Variations on modern digitizers are used in interactive whiteboards and some hand-held games. A tablet computer integrates a graphics pad and a fully-functional computer system. Many artists, engineers, architects and other designers often use a digitizer tablet in their daily work. Some people also find it to be a natural way to enter Asian and other non-Latin language characters.