Active vs. Passive Digitizer?
You may have used touch screen devices such as a Pocket PC (or a cell phone). A touch screen is a passive digitizer. Passive refers to the fact that a touch screen only knows the position of the stylus (or finger) when the touch screen is pressed by the stylus (or finger). This pressure causes the pointer on the screen to jump to the location of the press and instantly “click”. By contrast, with most mainstream Tablet PCs, touching the screen does nothing (except perhaps smudge the screen). The reason is that these Tablet PCs don’t use touch screens. Rather, the screen includes an active digitizer. This active digitizer emits signals which are reflected by a special pen when that pen is close to the digitizer. This feature enables the user to “hover” over items on the screen and, for example, navigate through menus without accidentally activating an item. What’s so great about an active digitizer? You need a special (and more expensive) pen. You’re also out of luck (temporarily) if you
