A touchpad is a device designed to translate user input in the form of motions aimed at moving a cursor to a computer. It works much like a mouse, allowing users to move a cursor to select items and perform other functions, but is designed in a different way. Instead of using sensors and a roller ball or laser like a mouse, a touchpad is a soft pad with sensors that respond to finger movements on the pad. Since a touchpad does not require desk space, it can commonly be found embedded into lap tops, personal digital assistants, and portable media players. For users who prefer the touchpad interface, touchpads are available for desktop computers as well.
Under the soft skin of the touchpad, there is an array of sensors which create an electrical field. The finger changes the character of the electrical field, allowing the user to drag a cursor across the screen. Most touchpads come equipped with mouse buttons allowing the user to click on objects, while others interpret taps on the touchpad as taps of a mouse button. A tap and drag can be used to select an item, for example. The commands that the touchpad recognizes are all configurable, depending on user needs.
In addition to the basic mouse-like function that a touchpad provides, it can also be programmed to have “hot spots.” When the user taps on one of these spots, it can be used to scroll a document, open a frequently used program, or perform some other commonly used function. Preferences for these zones can be changed in the preferences for the touchpad, which also include sensitivity preferences. Most manufacturers also include safeguards with their touchpads, so that they will not respond to being brushed with a palm or an object other than a finger.
Computer manufacturers began developing touchpads in the late 1980s, and by the mid 1990s, several laptops had been released with a touchpad design. The touchpad was a vast improvement over the trackballs or nubbin pointers included in laptops previously, and quickly began to dominate the laptop market. Sensing the potential for other markets, companies also developed products like drawing tablets, which translate “drawing” with a specialized pen on the tablet into art on the screen, and this technology is also used for tablet computers, which are capable of recognizing handwriting on the motion sensitive pad.