Patent attributes
A keyboard includes a base plate, a pressure sensing layer, plural key structures, a circuit board, a flexible layer and a controlling unit. The pressure sensing layer is disposed on the base plate and located under the circuit board. The flexible layer is disposed on the pressure sensing layer and located under the circuit board. While a key structure is depressed, a part of the key structure is penetrated through the circuit board to press the flexible layer, and a force is transmitted from the flexible layer to the pressure sensing layer. The controlling unit compares the force with a predetermined force value. According to the comparing result, the controlling unit generates a corresponding pressure sensing signal. Consequently, the use of a single key structure can achieve the functions of multiple keys.