Patent ID: 7619509

Claim:
A tire monitoring system comprising: a vehicle body side controller able to transmit a wireless signal to each tire through a vehicle body side antenna arranged near each tire in a vehicle in which tires are mounted on both transversal sides orthogonal to a running direction so as to form a pair; and a sensor unit arranged in each tire and measuring a state of each tire and able to transmit information based on its measuring result as a wireless signal, wherein said vehicle body side controller respectively transmits a request signal to each sensor unit through each vehicle body side antenna, and the tire monitoring system has each sensor unit able to receive this request signal through a tire side antenna arranged in each tire; said vehicle body side antenna and the tire side antenna are constructed by a coil antenna; said tire side antenna is arranged in each tire such that a coil axis of said tire side antenna approximately becomes parallel to a rotating axis of each tire; and said vehicle body side antenna is arranged near each tire such that no coil axis of said vehicle body side antenna becomes parallel to the rotating axis of each tire.