KEY INPUT DEVICE, ESPECIALLY WITH REGARDS TO PREVENTING EXCESSIVE TRANSFORMATION OF A DOME AND FATIGUE STRESS CONCENTRATION

摘要

PURPOSE: A key input device is provided to deliver a key button power pressed by a user to a dome with a determined degree, thereby preventing fatigue stress concentration to enhance durability. CONSTITUTION: A plurality of dome switch members(20) are located on an upper surface of a PCB(10). An operation protrusion(31) is formed in a place corresponding to the dome switch members(20). An actuator pad member(30) is formed on an upper part of the dome switch members(20). A fatigue fracturing preventer is concavely formed in the actuator pad member as a peripheral pillar of the operation protrusion(31). The fatigue fracturing preventer elastically transforms only central parts of the dome switch members(20), and prevents fatigue fractures of the dome switch members(20). A plurality of key buttons(40) are formed on an upper surface of the actuator pad members(30) corresponding to the operating protrusion(31).