A keyboard detects press or release of keys using one or more ranging
techniques. Targets are attached to keys of the keyboard. As keys are
pressed or released, attached targets move into paths of distance
measuring sensors. A range finder determines sensor-target distances and
reports those distances to a microprocessor. Based on that distance data,
the microprocessor identifies the moved keys. The keys and microprocessor
are configured to determine the direction of key motion and to detect
simultaneous press or release of keys in a single row or column. A slider
control, and/or an integral pointing device tracking motion of a user's
finger or other object, may also be included.