Patent ID: 8712465

Claim:
A mobile terminal device, comprising: a body; operation portions provided to the body; a conductive portion provided to the body, an electrical state of the conductive portion changing in response to an operation on the operation portions; an operation detecting unit that is connected to the conductive portion, and detects an operation on the operation portions based on change in the electrical state of the conductive portion; an antenna element connected to the conductive portion; a power supply unit connected to the conductive portion via the antenna element; a signal processing unit that is connected to the power supply unit and processes a signal resonated by the conductive portion; and a circuit board, wherein the conductive portion comprises a signal line that electrically connects the operation portions and the operation detecting unit, wherein the signal line transfers a signal indicating an operation is performed to the operation portions, wherein the signal line is connected to the power supply unit and operates as an antenna element, wherein the signal processing unit processes a signal resonated by the antenna element and the conductive portion, wherein an insulating layer is formed on a surface layer of the circuit board, and the conductive portion is formed as a conductive pattern on a layer that is inner than the insulating layer, wherein the conductive portion and the antenna element are capacitively connected with each other, by capacitively coupling the conductive pattern and the antenna element with the insulating layer interposed therebetween, wherein the antenna element includes an elastic deformation portion being elastically deformable, and wherein the elastic deformation portion abuts the insulating layer.