CAPACITIVE SENSING KEYBOARD AND POINTING DEVICE

A combination keyboard and pointing device is incorporated in a portable computer and includes a dielectric base member on a top side of which a spaced series of electrically conductive pad member portions of a capacitance-based proximity sensing system are formed. Manually depressible key members are positioned above the pads. With the sensing system switched to a typing mode, the pads capacitively sense the proximity, velocity and acceleration of a user's fingers depressing their associated keys and output signals useable by the computer to display the character associated with the depressed key. A sensed increased stroke velocity of each manually depressed key may be used to alter the key character image displayed on the screen, for example capitalizing, bolding or underlining the character. The sensing system may be manually or automatically switched from its typing mode to a pointing mode in which it capacitively senses various hand and finger motions and orientations to carry out various pointing functions, such as cursor movements, pick functions, and scrolling functions, in response to the sensed hand and finger motions and orientations.