Capacitive keyboard device with a keystroke triggering threshold adaptively adjustable capability

摘要

A capacitive keyboard device with a keystroke triggering threshold adaptively adjustable capability is proposed, which is designed for integration to an electronic unit, such as PDA (Personal Digital Assistant) computers, mobile phone unit, and calculator, for use as a data input device for the electronic unit. The proposed capacitive keyboard device is characterized by the operation of a triggering threshold adaptive adjustment function that can adaptively adjust the keystroke triggering threshold of the capacitive keyboard device in response to the user's habitual key-pressing action during each use, which also takes account of all internal factors (such as decay of the capacitor structure) and external factors (such as physical characteristics of the user's fingers). This feature allows the capacitive keyboard device to be reliable in operation for long period of use.