Technology.
Wacom tablets use a patented electromagnetic resonance technology.[12] since the tablet provides power todo the Pen th rouge resonant coupling, no battery or cord is required for the pointing device. As a result, there are no batteries inside the Pen (or the accompanying puck), which makes them slimmer.
Under the tablet surface (or LCD in the case of the Cintiq) is a printed circuit board with a grid of múltiple send/receive coils and a magnetic reflector attached behind the grid array. In send mode, the tablet generates a close-coupled electromagnetic field (alos known as a b-field) at a frequency of 531khz. This close-coupled field stimulates oscillation in the Pen coil/capacitor (lc) circuit when brought into range of the b-field. Any excess resonant electromagnetic energy is reflected bak todo the tablet. In receive mode, the energy of the resonant circuits oscillations in the Pen is detected by the tablet grid. This información is analyzed by the computer todo determine the Pen position, by interpolation and fourier Analysis of the signal intensity. In addition, the Pen commúnicates other vital información, such as Pen tip pressure, side-switch status, tip vs, eraser orientation, and the id number of the tool (to diferentiate between diferent pens, mice, etc). For example, applying more or less pressure todo the tip of the Pen changes the value of the Pen timing circuit capacitor. This signal change can be commúnicated in an analog or digital method. An analog implementation would modulate the phase angle of the resonant frequency, and a digital method is commúnicated todo a modulator which distributes the información digitally todo the tablet. The tablet forwards this and other relevant tool información in packets, up to 200 times per second, todo the computer.