Patent ID: 8427454

Claim:
An electromagnetic pen with a multi-function tail part, comprising: a body having a front part and tail part wherein there are a first oscillator circuit disposed in said front part of said body and a second oscillator circuit disposed in said tail part of said body and said first oscillator circuit comprises a first coil wound around a permeability material and distributed in a direction parallel to center line of said body; a pen-tip part disposed on said front part of said body for writing or selecting on a tablet; and a multi-function electromagnetic ring disposed on said tail part of said body for emitting different electromagnetic signals to make said tail part of said electromagnetic pen to perform different functions in different situations wherein said second oscillator circuit comprises a second coil disposed in said multi-function electromagnetic ring and said second coil is wound around inside said multi-function electromagnetic ring and distributed in a direction perpendicular to center line of said body and the direction in which said second coil is distributed is perpendicular to the direction in which said first coil is distributed, wherein there is a film disposed on central area of said multi-function electromagnetic ring, and wherein there is a crisscross pattern or a circular pattern formed on a surface of said film by printing or etching for assisting a user to recognize the center point of said multi-function electromagnetic ring for sensing.