Patent ID: 9530589
Filing Date: 2016-12-27
CPC Classification: H01H,H04M

Claim Text:
1. A key board of mobile phone applied in key circuit of the mobile phone, comprising: a printed circuit board (PCB); a first electrode having a pair of circular edges with two oppositely and parallelly disposed straight edges connecting the pair of circular edges; a second electrode having a hollow circular shape with an inner side having a shape corresponding to an outer periphery of the first electrode and an outer periphery with a plurality of tooth profile structures extending away from the first electrode and in a direction substantially parallel to the straight edges of the first electrode; and a third electrode substantially enclosing the second electrode with one of the tooth profile structures thereof exposed; wherein the first electrode, the second electrode and the third electrode are concentrically disposed on the PCB, the second electrode is disposed between the first electrode and the third electrode without exposing the first electrode to the third electrode.