Patent ID: 8270902

Claim:
A communication system for enabling communication between a transmitter which is portable and a receiver which is fixed, using a capacitive coupling through a living body, wherein the receiver comprises: an environment-side electrode and a living body-side electrode sandwiching an insulating layer and electrically insulated from each other; a grounding electrode electrically connected to the environment-side electrode; a reception amplifier which amplifies at least a voltage of the living body-side electrode; a transmission environment-side electrode and a transmission living body-side electrode sandwiching an insulating layer and electrically insulated from each other; and a transmission amplifier which amplifies a signal and outputs at least to the transmission living body-side electrode; the transmitter comprises: a transmission environment-side electrode and a transmission living body-side electrode sandwiching an insulating layer and electrically insulated from each other; a transmission amplifier which amplifies a signal and outputs to at least the transmission living body-side electrode; a reception environment-side electrode and a reception living body-side electrode sandwiching an insulating layer and electrically insulated from each other; and a reception amplifier which amplifies at least a voltage of the living body-side electrode; and the grounding electrode has a side surface section which extends along a vertical direction; and polling is executed for the receiver by transmitting a calling signal from the transmitter.