Abstract: When registering the ID code of a transmitter in a receiver, a commander is brought close to the transmitter and then a manipulation switch of the commander is pressed. Then, the commander transmits an instruction signal to the transmitter. In response to the instruction signal, the transmitter transmits a response signal including eight consecutive data frames. When receiving the signal from the transmitter, the receiver counts the number of the data fames in the received signal. f the number of the data frames is eight, the receiver determines that the received signal is a response signal generated based on manipulation of the commander and registered the ID code in the response signal. That is, the receiver determines whether to register the ID code in the received signal based on the number of the data frames included in the received signal. As a result, the ID code of the transmitter is easily registered in the receiver.

Abstract: A tire condition monitoring apparatus has a pressure sensor that measures air pressure in a tire of a vehicle. The apparatus also has a transmitter that transmits pressure data measured by the pressure sensor, and a receiver that receives and processes data transmitted by the transmitter. The pressure sensor has a diaphragm exposed to air of the tire, and metallic material covering the diaphragm. The transmitter has a power supply circuit and a connecting member. The power supply circuit supplies electricity for activating the transmitter. The connecting member connects the power supply circuit with the metallic material such that the potential of the metallic material is the same as the potential of the power supply circuit.

Abstract: A transmission controller for a transmitter compares the value of data of the temperature in a tire measured by a temperature sensor with a predetermined threshold temperature, and determines the number of times a transmitting circuit performs the transmitting operation in a cycle of a predetermined length of time. For example, when the temperature in the tire rises, the number of times the transmitting circuit performs the transmitting operation in the predetermined cycle is increased. Therefore, the reduction in the reception probability of a receiver is limited even when the transmission output of the transmitter is reduced due to temperature affect.

Abstract: Optical fiber cables interconnect a master node and a plurality of slave nodes to configure a network. A master controller transmits instruction signals each corresponding to one of the slave nodes to the network. When receiving the corresponding one of the instruction signals from the network, each slave controller adds detection result information based on the state detected by a state detecting section and transmits the instruction signal to the network as a return signal for the master node. Based on the detection result information in each return signal from the network, the master controller acquires the state of the load device that corresponds to the return signal. Therefore, the states of load devices are reliably monitored.

Abstract: A transmitter for a tire condition monitoring apparatus is located in a tire of a vehicle and transmits data indicating the tire condition using a carrier wave. The transmitter includes an oscillating circuit and a controller. The oscillating circuit generates a carrier wave frequency and has a predetermined characteristic carrier wave frequency. The controller corrects the generated carrier wave frequency in accordance with the difference between the characteristic carrier wave frequency and a predetermined reference carrier wave frequency.

Abstract: A transmitter of a tire condition monitoring apparatus has an acceleration sensor, a transmission circuit, an antenna and a transmission controller. The transmitter is provided in a tire of a vehicle. The acceleration sensor detects a running state of the vehicle. The transmission circuit generates a transmission signal containing data representing a condition of the tire and outputs the transmission signal. The antenna wirelessly transmits the transmission signal. The transmission controller changes a transmission power of the transmission circuit according to a detection result of the running state detection device. This is capable of transmitting signals with an appropriate transmission power.

Abstract: In an internal memory of a reception controller such as, for example, a ROM, a correction table is stored for correcting air pressure data. The reception controller receives a signal representing vehicle speed from a speedometer of the vehicle. The reception controller obtains a correction value from the correction table on the basis of the vehicle speed signal to add and deduct the correction value obtained and the air pressure data received. For this reason, the reception controller can obtain corrected air pressure data.

Abstract: A specific ID code of a transmitter 3 is registered in a receiver 4 in the following procedure. A commander 5, which is connected to the receiver 4 with a cable 6, is located close to the corresponding transmitter 3. An operation switch 7 of the commander 5 is then depressed. The commander 5 transmits an instruction signal to the transmitter 3 and the turned-on state of the operation switch 7 is conveyed to the receiver 4 via the cable 6. The transmitter 3 wirelessly transmits a response signal including the ID code in response to the instruction signal. On the other hand, upon receiving the response signal from the transmitter while the commander 5 is conveying the turned-on state of the operation switch 7, the receiver 4 stores the ID code in the received response signal. Therefore, the ID code of each transmitter is easily registered in the receiver 4.

Abstract: A transmission controller for a transmitter compares the value of data of the temperature in a tire measured by a temperature sensor with a predetermined threshold temperature, and determines the number of times a transmitting circuit performs the transmitting operation in a cycle of a predetermined length of time. For example, when the temperature in the tire rises, the number of times the transmitting circuit performs the transmitting operation in the predetermined cycle is increased. Therefore, the reduction in the reception probability of a receiver is limited even when the transmission output of the transmitter is reduced due to temperature affect.

Abstract: A pressure sensor has a diaphragm that is exposed to air in a tire of a vehicle. A transmitter wirelessly transmits data representing the air pressure of the tire. A casing accommodates the transmitter and the pressure sensor. A lid closes an opening of the casing. A metal body is provided on the lid. When the opening of the casing is closed with the lid, the diaphragm is covered with the metal body.

Abstract: A tire condition monitoring apparatus has a pressure sensor that measures air pressure in a tire of a vehicle. The apparatus also has a transmitter that transmits pressure data measured by the pressure sensor, and a receiver that receives and processes data transmitted by the transmitter. The pressure sensor has a diaphragm exposed to air of the tire, and metallic material covering the diaphragm. The transmitter has a power supply circuit and a connecting member. The power supply circuit supplies electricity for activating the transmitter. The connecting member connects the power supply circuit with the metallic material such that the potential of the metallic material is the same as the potential of the power supply circuit.

Abstract: A transmitting method of a transmitter useful in a vehicle having at least one wireless apparatus control system and a wireless tire condition monitoring system. The data format used to control the at least one wireless apparatus of a vehicle and a data format showing a tire condition are identical. The data format includes data showing the type of a transmitter. Data used to control the apparatuses of the vehicle or data showing a tire condition is wirelessly transmitted using that data format.

Abstract: A commander transmits a command signal that includes a channel code set by a channel code setting switch. When receiving the transmission command signal from the commander, a transmitter transmits a response signal that contains the channel code contained in the command signal and a unique ID code of the transmitter. When receiving the response signal from the transmitter, a receiver stores the ID code contained in the response signal in the memory if the channel code contained in the response signal is related to a channel code set by a channel code setting switch. As a result, the ID codes of the transmitter is correctly registered in the receiver.

Abstract: A compact and light semiconductor sensor for detecting pressure and acceleration. A pressure sensor is formed on a first surface of an intermediate plate. An acceleration sensor is formed on a second surface of the intermediate plate. A first plate having a diaphragm is bonded to the intermediate plate to define a hermetic chamber of the pressure sensor. A second plate is bonded to the second surface of the intermediate plate. A spring support supports the mass in a manner relatively movable with respect to the second plate.

Abstract: A transmitter of a tire condition monitoring apparatus that has a superior moisture resistant characteristic, enables reduction in size, and facilitates manufacturing. The transmitter includes a casing formed from resin. An electric circuit unit is arranged in the casing to detect the condition of the tire and generate a signal corresponding to the condition of the tire. A battery is arranged in the casing to supply the electric circuit unit with power. The casing is insert molded to embed the electric circuit unit and the battery in the resin forming the casing.

Abstract: A transmitter for a tire condition monitoring apparatus is located in a tire of a vehicle and transmits data indicating the tire condition using a carrier wave. The transmitter includes an oscillating circuit and a controller. The oscillating circuit generates a carrier wave frequency and has a predetermined characteristic carrier wave frequency. The controller corrects the generated carrier wave frequency in accordance with the difference between the characteristic carrier wave frequency and a predetermined reference carrier wave frequency.

Abstract: When registering the ID code of a transmitter in a receiver, a commander is brought close to the transmitter and then a manipulation switch of the commander is pressed. Then, the commander transmits an instruction signal to the transmitter. In response to the instruction signal, the transmitter transmits a response signal including eight consecutive data frames. When receiving the signal from the transmitter, the receiver counts the number of the data fames in the received signal. f the number of the data frames is eight, the receiver determines that the received signal is a response signal generated based on manipulation of the commander and registered the ID code in the response signal. That is, the receiver determines whether to register the ID code in the received signal based on the number of the data frames included in the received signal. As a result, the ID code of the transmitter is easily registered in the receiver.

Abstract: A specific ID code of a transmitter 3 is registered in a receiver 4 in the following procedure. A commander 5, which is connected to the receiver 4 with a cable 6, is located close to the corresponding transmitter 3. An operation switch 7 of the commander 5 is then depressed. The commander 5 transmits an instruction signal to the transmitter 3 and the turned-on state of the operation switch 7 is conveyed to the receiver 4 via the cable 6. The transmitter 3 wirelessly transmits a response signal including the ID code in response to the instruction signal. On the other hand, upon receiving the response signal from the transmitter while the commander 5 is conveying the turned-on state of the operation switch 7, the receiver 4 stores the ID code in the received response signal. Therefore, the ID code of each transmitter is easily registered in the receiver 4.

Abstract: A commander transmits a command signal that includes a channel code set by a channel code setting switch. When receiving the transmission command signal from the commander, a transmitter transmits a response signal that contains the channel code contained in the command signal and a unique ID code of the transmitter. When receiving the response signal from the transmitter, a receiver stores the ID code contained in the response signal in the memory if the channel code contained in the response signal is related to a channel code set by a channel code setting switch. As a result, the ID codes of the transmitter is correctly registered in the receiver.

Abstract: A transmitter of a tire condition monitoring apparatus that has a superior moisture resistant characteristic, enables reduction in size, and facilitates manufacturing. The transmitter includes a casing formed from resin. An electric circuit unit is arranged in the casing to detect the condition of the tire and generate a signal corresponding to the condition of the tire. A battery is arranged in the casing to supply the electric circuit unit with power. The casing is insert molded to embed the electric circuit unit and the battery in the resin forming the casing.