reduced in comparison with the case of the fig6 a an amount of totally reflected and transmitted light is increased an electric signal corresponding to the first pressure is applied to the electric elastic layer 224 such that physical properties in the electric elastic layer 224 vary that is the electric elastic layer 224 is significantly contracted upward and downward in fig6 c if the user applies second pressure higher than the first pressure to a predetermined light transmitting region an external path of the light transmitting region is blocked such that the light passing through the core layer is not emitted to the outside an electric signal corresponding to the second pressure is applied to the electric elastic layer such that the physical properties in the electric elastic layer vary that is the electric elastic layer is contracted upward and downward larger than that of fig6 a fig7 is an exemplary diagram illustrating a process of processing a physical stimulation according to the exemplary embodiment of the present invention fig7 shows in detail a process of applying how to feedback if pressure corresponding to a desired operation is applied using an input device first when there is no pressure the input device sets a variable pressdownstate to zero pressdownstate 0 s 710 if the pressure is applied the input device determines whether.