Abstract: A double-electrode capacitive sensor for detecting a detection object includes: an electrode assembly having first and second electrodes and an insulation substrate; and a detection circuit. The first and second electrodes are disposed on first and second surfaces of the substrate, respectively. The detection circuit applies an alternating voltage between a ground and the first electrode, and detects an electric potential of the second electrode, or controls the electric potential of the second electrode to follow the alternating voltage. The detection circuit detects a capacitance change between the first electrode and the ground when the detection object approaches the first electrode for determining whether the detection object approaches the first electrode. A periphery of the second electrode is substantially opposite to a periphery of the first electrode.

Abstract: A passenger seat device includes a detector electrode for detecting occupancy of the seat, a seat heater powered by an on-board electric power source, and a waterproof sheet for preventing water permeated into the seat from reaching the seat heater. Whether the seat is occupied or not is detected based on changes in an impedance coupled to the detector electrode. The impedance is affected by the water if it reaches the seat heater, and a sensitivity of the occupancy detection is adversely affected. A shielding electrode insulated from the detector electrode and disposed between the detector electrode and the seat heater may be provided to reduce an amount of parasitic capacitance formed between the detector electrode and the seat heater. An alternating voltage may be supplied to the detector electrode and the shielding electrode.

Abstract: The present invention facilitates the construction of a waterproof sensor assembly having, for example, a sensor main body arranged in a vehicle seat, a sensor terminal, a sensor terminal protection portion, a first packing having a hollow ring shape, a second packing having a hollow ring shape, a connector casing having a hollow ring shaped opening, and a connector cover for covering the opening connector casing opening. The sensor terminal protection portion has a hollow ring shape and is integrated with a periphery of the sensor main body. The sensor terminal is integrated with the sensor terminal protection portion such that the sensor terminal protrudes from an inner periphery of the sensor terminal protection portion toward an inside of the sensor terminal protection portion. The arrangement of the first and second packing and the connector case and cover provide a high performance waterproof sealing of the sensor and parts thereof.

Abstract: An occupant sensing electrode is embedded in a seat. An empty seat capacitance reducing electrode is placed between the occupant sensing electrode and a seat frame of the seat in an opposed relationship to the occupant sensing electrode. A dielectric base film may be interposed between the occupant sensing electrode and the empty seat capacitance reducing electrode. The occupant sensing electrode may include a plurality of electrode portions. The electrode portions may include high potential electrode portions and low potential electrode portions.

Abstract: An electrostatic seat occupant detecting system of a vehicle has a vehicle body and a seat. The electrostatic seat occupant detecting system includes an antenna unit that includes a main electrode and a sub-electrode disposed near the main electrode, an AC power source, a switch unit for switching supply of AC voltage to the antenna unit to form one of a first electric field between the vehicle body and the main electrode thereby providing a seat-occupant detecting mode and a second electric field between the main electrode and the sub-electrode thereby providing a wet condition detecting mode, and a seat-occupant detecting ECU.

Abstract: A capacitance type sensor installed in a vehicle includes the first electrode, the second electrode, and the third electrode. The first electrode is arranged inside a seating portion of a seat or a backrest portion of the seat, or both. The second electrode is arranged adjacent to the first electrode inside at least one of the seating portion and the backrest portion of the seat, whatever the first electrode is arranged. The second electrode forms an electric field together with the first electrode between them in a wetness determination mode in which a wet condition of the seat is determined. The third electrode forms an electric field together with the first and the second electrode between them in an occupant determination mode in which an occupant in the seat is determined.

Abstract: A capacitance-type sensor for detecting a condition of an occupant on a vehicle seat includes an electrode. The electrode is disposed within a detection area in the vehicle seat. The electrode generates an electric field. The detection area is based on a surface pressure distribution obtained when an adult sits on the seat.

Abstract: A passenger detection system for detecting a sitting of a passenger on a seat of a vehicle has a capacitive passenger detection electrode which is embedded in the seat to detect the sitting, a surface unit attached to an upper surface of the seat, a driving unit which applies a voltage between the passenger detection electrode and a vehicle GND, and a detection unit for detecting a capacitance between the passenger detection electrode and the vehicle GND. At least a covering portion of the surface unit is rendered electrically conductive. The passenger detection electrode is covered with the covering portion. Thus, a sitting of the seat can be substantially detected by the passenger detection system.

Abstract: A capacitance-based occupant detection system accurately determines seat occupancy and a failure of an electrode and between electrodes and includes an impedance calculation section, a Re/Im part calculation section, and a determination section. A first impedance Z1 is calculated including a main-body impedance Za between a main electrode and a vehicle body. The Re/Im part calculation section calculates real and imaginary parts of the first impedance Z1 based on the first impedance Z1 calculated by the impedance calculation section. The determination section determines the presence or absence of destruction of the main electrode and a guard electrode based on an imaginary part of the first impedance Z1 calculated by the Re/Im part calculation section.

Abstract: A double-electrode capacitive sensor for detecting a detection object includes: an electrode assembly having first and second electrodes and an insulation substrate; and a detection circuit. The first and second electrodes are disposed on first and second surfaces of the substrate, respectively. The detection circuit applies an alternating voltage between a ground and the first electrode, and detects an electric potential of the second electrode, or controls the electric potential of the second electrode to follow the alternating voltage. The detection circuit detects a capacitance change between the first electrode and the ground when the detection object approaches the first electrode for determining whether the detection object approaches the first electrode. A periphery of the second electrode is substantially opposite to a periphery of the first electrode.

Abstract: A film-type electrostatic capacitance sensor is provided for detecting seat occupancy and for reducing discomfort to a seat occupant and which is easy to produce. The mat of the film-type electrostatic capacitance sensor can be located in a seat portion of a vehicle seat and can include electrodes formed on both sides of a resin film and of a resin coating layer covering the electrodes. The coating layer can be a flexible resin to decrease discomfort for an occupant.

Abstract: The present invention facilitates the construction of a waterproof sensor assembly having, for example, a sensor main body arranged in a vehicle seat, a sensor terminal, a sensor terminal protection portion, a first packing having a hollow ring shape, a second packing having a hollow ring shape, a connector casing having a hollow ring shaped opening, and a connector cover for covering the opening connector casing opening. The sensor terminal protection portion has a hollow ring shape and is integrated with a periphery of the sensor main body. The sensor terminal is integrated with the sensor terminal protection portion such that the sensor terminal protrudes from an inner periphery of the sensor terminal protection portion toward an inside of the sensor terminal protection portion. The arrangement of the first and second packing and the connector case and cover provide a high performance waterproof sealing of the sensor and parts thereof.

Abstract: A passenger seat device includes a detector electrode for detecting occupancy of the seat, a seat heater powered by an on-board electric power source, and a waterproof sheet for preventing water permeated into the seat from reaching the seat heater. Whether the seat is occupied or not is detected based on changes in an impedance coupled to the detector electrode. The impedance is affected by the water if it reaches the seat heater, and a sensitivity of the occupancy detection is adversely affected. A shielding electrode insulated from the detector electrode and disposed between the detector electrode and the seat heater may be provided to reduce an amount of parasitic capacitance formed between the detector electrode and the seat heater. An alternating voltage may be supplied to the detector electrode and the shielding electrode.

Abstract: A passenger seat device includes a seat heater embedded in a seat and a detector electrode embedded underneath the seat heater. Electric power is supplied to the seat heater from an on-board battery through seat heater switches. Alternating voltage or current is supplied to the detector electrode. The detector electrode potential relative to the ground is lowered when the seat is occupied by a passenger. The changes in the potential of the detector electrode is detected by an occupant detector including a microcomputer. The detection is performed when the seat heater is brought to a floating state to suppress an amount of capacitance formed between the seat heater and the detector electrode. Thus, a sensitivity of the occupant detector is improved. The detector electrode may be eliminated, and the occupant conditions may be detected based on a potential of the seat heater to which alternating current or voltage is supplied.

Abstract: An electrode unit for detecting whether a seat is occupied or not (occupancy conditions) is embedded in a seat of an automotive vehicle together with an electrically powered seat heater. Both of the electrode unit and the seat heater are flat, and the electrode unit is laminated on the heat heater. The electrode unit is composed of an upper electrode, a lower electrode and an insulating film disposed between both electrodes. The occupancy conditions are detected based on changes in a capacitance between the upper electrode and a member grounded to a vehicle body. To reduce a capacitance between the upper electrode and seat heater and to thereby improve sensitivity of the detection of the occupancy conditions, an alternating voltage that alternates in accordance with an alternating voltage supplied to the upper electrode is supplied to the lower electrode.

Abstract: An occupant detection system for detecting an occupant on a seat of a vehicle includes an antenna electrode in a seat bottom of the seat, and an electronic unit connected to the antenna electrode and the vehicle. The electronic unit applies a load current to the antenna electrode so as to generate a weak electric field, and detects a potential current passing through the antenna electrode. The electronic unit detects an occupant based on an impedance and a phase difference, which are based on the load current and the potential current.

Abstract: A rotation angle detecting device includes a columnar permanent magnet that has a generally ring-shaped cross-section and a pair of magnetic poles, a pair of semi-cylindrical yokes disposed in a circumferential direction opposite the permanent magnet, a rotary shaft fixed to the permanent magnet at a shifted rotation axis and a magnetic sensor disposed in one of circumferential gaps between the yokes. The rotation axis and the magnetic poles are arranged so that the magnetic flux density becomes maximum at portions of the yoke less than 90 degrees angled from the circumferential gap in which the magnetic sensor is disposed.

Abstract: A passenger detection system has an antenna electrode and a guard electrode mounted to a seat bottom of a seat of a vehicle. The passenger detection system further has a power source means for detecting a presence of a passenger on the seat. The power source means applies electric power to the antenna electrode so that a load current flows in the antenna electrode and a weak electric field is generated from the antenna electrode by the load current. The power source means detects an electric current generated in the antenna electrode in response to the electric field. A capacitance between the antenna electrode and a floor of the vehicle is determined based on the detected electric current in a condition that an electric field generated from the antenna electrode on a side of the guard electrode is cancelled by the guard electrode, to thereby detect a passenger on the seat.

Abstract: A passenger detection system for detecting a sitting of a passenger on a seat of a vehicle has a capacitive passenger detection electrode which is embedded in the seat to detect the sitting, a surface unit attached to an upper surface of the seat, a driving unit which applies a voltage between the passenger detection electrode and a vehicle GND, and a detection unit for detecting a capacitance between the passenger detection electrode and the vehicle GND. At least a covering portion of the surface unit is rendered electrically conductive. The passenger detection electrode is covered with the covering portion. Thus, a sitting of the seat can be substantially detected by the passenger detection system.

Abstract: An occupant sensing electrode is embedded in a seat. An empty seat capacitance reducing electrode is placed between the occupant sensing electrode and a seat frame of the seat in an opposed relationship to the occupant sensing electrode. A dielectric base film may be interposed between the occupant sensing electrode and the empty seat capacitance reducing electrode. The occupant sensing electrode may include a plurality of electrode portions. The electrode portions may include high potential electrode portions and low potential electrode portions.