Capacitive touch keyboard and double-click sensor for laptop computer has X-Y position sensors connected to computing and identification circuits with output to host system

摘要

The computer keyboard assembly (2) has a capacitive keyboard (21) which may be operated by the touch of a finger (10). Two adjacent sides of the keyboard are connected to X (22) and Y (23) working circuits. These circuits are connected to a computer circuit (24) sending X and Y signals to a change sensing or differentiation circuit (25). The difference circuit output signals (D x, D y) enter an identification circuit (26). This checks if the sum of the first and second touches and the time interval between them is less than a reference time. The output of the identification circuit is transmitted to a host system (3) via an interface (27).