Patent ID: 7515037

Claim:
A remote operation system comprising: responders that are provided to correspond to tires of a vehicle and detect a pressure of the tires; an interrogator that is provided in a main body of the vehicle and communicates with the responders so as to process pressure data, wherein the interrogator further comprises a synchronous detector and a first carrier oscillator; a plurality of antennas that are provided in a main body of the vehicle in a vicinities of the tires, respectively, and are connected to the interrogator; a portable transmitter for a remote operation that communicates with the interrogator and unlocks doors of the vehicle, wherein the transmitter further comprises a second carrier oscillator, a modulated signal oscillator, a modulator, and a battery that drives the second carrier oscillator and the modulated signal oscillator; wherein the transmitter and the interrogator communicate with each other in an ID confirmation mode and in an unlock mode subsequent to the ID confirmation mode, and the interrogator unlocks the door after confirming an ID of the transmitter; wherein the first carrier oscillator and the second carrier oscillator output carriers having the same frequency, in the ID confirmation mode, the second carrier oscillator and the modulated signal oscillator are driven by the battery, and a modulated wave on which an ID recognition signal is superimposed is generated by the modulator and transmitted to the interrogator, and in the unlock mode, only the modulated signal oscillator is driven by the battery, and the carrier from the interrogator is modulated by the modulated signal from the modulated signal oscillator, a signal for modulation is transmitted from the transmitter and inputted to the synchronous detector, and the interrogator inputs the carrier from the first carrier oscillator to the synchronous detector; and wherein the interrogator has a reception intensity detector that detects an intensity of a received signal from the transmitter received by each antenna, and when each antenna receives an unlock signal to be transmitted from the transmitter, a door closest to one of the antennas which receives a signal having the highest reception intensity is unlocked.