Tire condition monitoring apparatus

An apparatus for monitoring the conditions of a plurality of tires of a vehicle, the apparatus comprising:

• a commander having an operation switch, wherein the commander transmits an instruction signal when the operation switch is turned on;
• a plurality of transmitters each provided in one of the tires, wherein a unique identification data is assigned to each transmitter in advance, and wherein each transmitter includes a tire condition sensor for detecting the condition of the corresponding tire, a receiving portion for receiving the instruction signal, and a transmitting portion for transmitting a signal that includes at least data representing the tire condition detected by the tire condition sensor and the identification data;
• and
• a receiver located in the body of the vehicle, wherein the receiver includes a receiving portion for receiving signals transmitted from the transmitters and a rewritable ID memory for storing the identification data of the transmitters,
• wherein each transmitter has a first transmission mode, in which the transmitter transmits a signal regardless whether the commander transmits the instruction signal, and a second transmission mode, in which the transmitter transmits a signal in response to the instruction signal from the commander, wherein the signal transmitted according to the first transmission mode is a first signal, the first signal including a plurality of data frames, and wherein the signal transmitted according to the second transmission mode is a second signal, the second signal including a plurality of data fames the number of which is different from the number of the data frames included in the first signal, and
• wherein the receiver determines whether the received signal is the first signal or the second signal based on the number of the data frames included in the received signal, wherein, when the received signal is the first signal, the receiver continues processing the first signal if the identification data in the first signal matches with one of the identification data in the ID memory, and wherein, when received signal is the second signal, the receiver stores the identification data in the second signal in the ID memory.