Have you heard of drawing tablets? They are digital drawing pads on which you can use a special pen to make your hand-drawn design elements. So, they are a form of input device for a computer. Using a graphic pad is as simple as using a pen on paper, literally! The tablet comes with a special stylus used to ‘draw’ on the flat surface. Whatever you ‘draw’ appears on the computer monitor rather than the tablet itself, so this can take a little getting used to if you are completely new to digital drawing pads. Some of the higher end models on the other hand have the true functionality of a monitor apart from serving as drawing pads. This brings the tablet closer to the experience of actually drawing using a paper and pencil, and such tablets are a pleasure to use and a lot of fun as well.
The purpose of any drawing tablet is to transfer the motion of your stylus on pad, into a digital reproduction of that action. Do be able to do this, the tablet needs good interaction between the ‘pen’ and surface and effective transfer of information to the computer unit. Different companies use different tactics to make this transfer of information as effective as possible.
Let us take a look at some of the different kinds of drawing pads.
1. Passive Drawing Tablets
The most commonly made passive pads are made by the Wacom company. Here, the horizontal and vertical wires act as transmitters and receives. The wires create an electromagnetic signal which is recognized by the stylus. The stylus in turn transmits its own signal, and hence the communication between ‘pen’ and ‘paper’. A constant communication between the stylus and the tablet results in an accurate reproduction of the whatever the artist draws on the tablet. The better the communication, the better is the quality of reproduction. The Wacom tablets are pretty easy to use, and do not require batteries.
2. Active Drawing Tablets
Active tablets on the other hand DO require batteries. These batteries power the stylus to send out a constant signal to the tablet. The main disadvantage of this category of tablets is the fact that the stylus is heavier. Battery replacement is a minor issue, but prevails never the less so we need to mention it. But then, the communication between the pen and paper is very effective in this case, and you rarely ever find jitter when using an active tablet. Maybe it comes down to this question – Are you comfortable using a bulky pen?
3. Acoustic Drawing Tablets
These were earlier referred to as the spark tablets. They use a miniature sound generator within the stylus, and this acoustic signal is transmitted to the tablet for communication, which in turn has microphones to understand the sound signal.
4. Capacitative Drawing Tablets
These tablets use either electrostatic or capacitative signals for communication.
Whatever the category of tablet, the end result needs to be the effective reading of the placement of the stylus, its tilt angle and other such information used to reproduce the design on monitor.
For all these technologies, the tablet can use the received signal to also determine the distance of the stylus from the surface of the tablet, the tilt (angle from vertical) of the stylus, and other information in addition to the horizontal and vertical positions.