Patent ID: 7750798

Claim:
A detecting apparatus that detects positions of a plurality of wheels provided on a vehicle, the apparatus comprising a plurality of transceivers, one of the plurality of transceivers being mounted on each of the plurality of wheels of the vehicle, and a receiver being mounted on a body of the vehicle, each of the plurality of transceivers comprising: a wheel-mounted receiving unit that receives a trigger signal sent from the vehicle-mounted receiver; a first controlling unit that detects a reception strength of the trigger signal and produces reception strength data representing the reception strength; and a transmitting unit that transmits the reception strength data to the vehicle-mounted receiver; and the vehicle-mounted receiver comprising: a triggering unit that sends out the trigger signal to at least two of the plurality of transceivers; a second receiving unit that receives the reception strength data from the transceiver transmitting units; a second controlling unit that determines whether or not to adopt the reception strength data for detecting the positions of the wheels depending on whether or not the reception strength of the trigger signal is within a predetermined range assigned to the trigger signal; and a detection unit that detects the respective positions of the wheels using the reception strength data only if the reception strength of the trigger signal is within the predetermined range, where reception strength data are also used for detecting the positions of the wheels.