Patent ID: 7251993

Claim:
A tire information communication system provided in a vehicle on which a tire wheel with a tire having an annular conductor provided over a whole periphery thereof is mounted and which the tire wheel is electrically conductive via an axle to a vehicle ground serving as an electrical ground of a vehicle body, the system transmitting and receiving information about inner pressure of the tire, the system comprising: a tire-pressure detector mounted on the tire wheel for detecting a pressure of the tire, thereby transmitting a result of detection; a tire monitor mounted on the vehicle body for obtaining information about tire pressure from the tire-pressure detector; a tire-side transmission circuit provided in the tire-pressure detector for applying AC voltage containing information about tire pressure between the tire wheel and the annular conductor so that a radio wave is radiated from the annular conductor; a vehicle ground isolation provided in the tire monitor so as to receive the radio wave from the annular conductor thereby to be capable of generating AC voltage between the vehicle ground and the vehicle ground isolation; and a body-side receiving circuit provided in the tire monitor for obtaining the information about the tire pressure from the AC voltage generated between the vehicle ground and the vehicle ground isolation.