Abstract: An ultrasonic sensor includes a transmitting device, a receiving device, and a circuit device. The circuit device determines that the receiving device receives an ultrasonic wave reflected from an object, when an output voltage of the receiving device is equal to or greater than a first threshold. The circuit device includes a humidity detection section configured to detect an ambient humidity of the transmitting and receiving devices and a threshold adjustment section configured to calculate, based on the detected ambient humidity, a sound pressure of the ultrasonic wave that is received by the receiving device after propagating over a round-trip distance between the ultrasonic sensor and the object. The threshold adjustment section reduces the first threshold, when the output voltage corresponding to the calculated sound pressure is less than a second threshold that is greater the first threshold.

Abstract: An ultrasonic sensor includes a transmitting device, receiving devices arranged in an array, and a circuit device. One receiving device is configured as a reference receiving device. The circuit device includes a reference signal generator and first and second synchronous detectors. The reference signal generator generates a reference signal by using a received signal of the reference receiving device. The first synchronous detector performs synchronous detection of a received signal of one of the receiving devices based on the reference signal to detect a distance to an object. The second synchronous detector performs synchronous detection of received signals of the receiving devices except the reference receiving device based on the reference signal to detect a direction of the object.

Abstract: An ultrasonic sensor for detecting an object includes: a piezoelectric element having a piezoelectric body and first and second electrodes for sandwiching the piezoelectric body; an acoustic matching element having a reception surface, which receives an ultrasonic wave reflected by the object; and a circuit electrically coupled with the piezoelectric element via a wire. The piezoelectric element is embedded in the acoustic matching element so that the acoustic matching element covers at least the first electrode, a part of a sidewall of the piezoelectric element and a part of the wire between the circuit and the piezoelectric element, and the sidewall of the piezoelectric element is adjacent to the first electrode.

Abstract: An ultrasonic sensor is disclosed. The ultrasonic sensor includes a piezoelectric element and an acoustic matching member. The piezoelectric element is configured to detect ultrasonic wave transmitted from a transmitter and reflected by a detection target object located in a detection target space. The acoustic matching member is configured to conduct the received ultrasonic wave to the piezoelectric element. The piezo electric element is covered with the acoustic matching member including a principal oscillation portion and a supplement oscillation portion. Thickness of a part of the supplement oscillation portion, the part covering the piezoelectric element, is smaller than a predetermined thickness threshold.

Abstract: An ultrasonic sensor includes a transmitting device, receiving devices arranged in an array, and a circuit device. One receiving device is configured as a reference receiving device. The circuit device includes a reference signal generator and first and second synchronous detectors. The reference signal generator generates a reference signal by using a received signal of the reference receiving device. The first synchronous detector performs synchronous detection of a received signal of one of the receiving devices based on the reference signal to detect a distance to an object. The second synchronous detector performs synchronous detection of received signals of the receiving devices except the reference receiving device based on the reference signal to detect a direction of the object.

Abstract: In an ultrasonic sensor, a first receiving device is configured to be sendable and receivable an ultrasonic wave. The ultrasonic wave sent from the first receiving device is transmitted through a vibration-reducing member disposed between the first receiving device and a second receiving device, and the second receiving device detects the ultrasonic wave. The ultrasonic sensor self diagnoses whether the second receiving device is operated without malfunction based on a detection signal of the second receiving device.

Abstract: An ultrasonic flow meter includes a first ultrasonic sensor, a second ultrasonic sensor, a volume-flow operation portion, a temperature operation portion, a pressure operation portion, and a correction operation portion. The ultrasonic sensors transmit and receive a plurality of ultrasonic waves of different frequencies and are disposed on opposite sides of a flow channel in which fluid flows. The volume-flow operation portion calculates a volume flow of the fluid based on a propagation time difference of the ultrasonic wave. The temperature operation portion analyzes signals from one of the ultrasonic sensors and calculates a temperature of the fluid. The pressure operation portion analyzes signals from one of the ultrasonic sensors and calculates a pressure of the fluid. The correction operation portion corrects the volume flow with the temperature and the pressure.

Abstract: An ultrasonic sensor includes a piezoelectric element and an acoustic matching member that are joined together to form an ultrasonic detector base. The ultrasonic detector base is sectioned by a clearance extending in an ultrasonic propagation direction to form multiple ultrasonic detectors arranged in an array. The clearance does not entirely section the ultrasonic detector base so that the ultrasonic detectors are joined together by a portion of the ultrasonic detector base.

Abstract: An ultrasonic sensor includes an ultrasonic detecting element, an acoustic matching member, and an oscillation damping member. The ultrasonic detecting element detects an ultrasonic wave. The acoustic matching member has a receiving surface that is adapted on a side of the certain object to be exposed to a space, in which the detected body exists. The receiving surface receives the ultrasonic wave reflected by the detected body. The acoustic matching member is made of a material having an acoustic impedance larger than that of air and smaller than that of the ultrasonic detecting element. The oscillation damping member is disposed between an attachment portion and the acoustic matching member. The attachment portion is adapted for attaching the ultrasonic sensor to the certain object. The oscillation damping member damps transmission of oscillation from the certain object to the acoustic matching member.

Abstract: An operator-specifying apparatus is combined with an on-board device such as a navigation device mounted on an automotive vehicle. An ultrasonic sensor device is mounted on a frame of a display panel of the navigation device. A hand of a person who is manipulating the navigation device, a driver or an assistant, is detected by the ultrasonic sensor device. If it is determined that the driver is manipulating (or about to manipulate) the navigation device when the vehicle is being driven, manipulation of the navigation device is prohibited to secure safety in driving. On the other hand, if it is found out the assistant is operating the navigation device, such prohibition is canceled to effectively use the navigation device.

Abstract: An ultrasonic sensor is provided with a substrate unit where a thin-walled portion is arranged and a piezoelectric oscillator which is formed at the substrate unit. The piezoelectric oscillator includes two electrodes and a piezoelectric film positioned between the two electrodes. The thin-walled portion and the piezoelectric oscillator construct a membrane structure which will resonate at a predetermined frequency.

Abstract: An ultrasonic sensor for detecting an object includes: a substrate; a transmission device for transmitting an ultrasonic wave; a plurality of reception devices for receiving the ultrasonic wave; and a circuit for processing received ultrasonic waves, which are received by the reception devices after the ultrasonic wave transmitted from the transmission device is reflected by the object. The transmission device and the reception devices are integrated into the substrate. The dimensions of the sensor are minimized, and detection accuracy of the sensor is improved.

Abstract: An ultrasonic sensor is disclosed. The ultrasonic sensor includes a plurality of sensor elements arranged in an array. Each sensor element includes an ultrasonic sensing element and an acoustic matching member. The ultrasonic sensor further includes a bonding member having a thickness approximately equal to a space interval between adjacent ultrasonic sensing elements. The bonding member adhesively fixes the plurality of sensor elements, and includes a portion contacting each ultrasonic sensing element. An elastic modulus of the portion is smaller than that of each ultrasonic sensing element.

Abstract: A vibration sensor for detecting a vibration of a vibrating object includes a plurality of detecting members. Each of the detecting members includes a vibrating portion disposed to be separated from the vibrating object, a transmitting portion for transmitting the vibration from the vibrating object to the vibrating portion, and a detecting portion disposed on a vibrating face of the vibration portion. The detecting portion outputs an electrical signal corresponding to a resonance of the vibrating portion. At least two of the vibrating portions of the detecting members have resonance frequencies, which are different from each other.

Abstract: An ultrasonic sensor according to the present invention is used, for example, for detecting an obstacle positioned in front of an automotive vehicle. The ultrasonic sensor includes an piezoelectric element connected to an acoustic matching member and a processing circuit, all contained in a casing. Ultrasonic waves reflected on an object are received by the acoustic matching member and converted into electrical signals in the piezoelectric element. The electrical signals are processed in the processing circuit to thereby detect a distance to the object and/or positions of the object. A surface of the acoustic matching member connected to the piezoelectric element is made larger than the piezoelectric element to form an overhang area on a conductive layer formed on the acoustic matching member. In this manner, electrical connection in the ultrasonic sensor is easily made, and detection sensitivity of the ultrasonic sensor is enhanced.

Abstract: An ultrasonic sensor includes a sending device and a receiving device. The sending device has a sending surface for sending an ultrasonic wave into a sending area. The receiving device has a receiving surface for receiving the ultrasonic wave reflected by an external object from a receiving area. The sending area has an overlapping area with the receiving area. The overlapping area is offset to one of the sending area and the receiving area.

Abstract: In a direction detecting device, a transmitting wave generator encodes a transmitting signal with a code having a high autocorrelation so as to generate a transmitting wave. A transmitter transmits the transmitting wave and a plurality of receiver elements receives a reflected wave reflected by an object. A direction calculating unit calculates a direction of the object based on a phase difference between a correlation value calculated based on the reflected wave received by one of the receiver elements and a correlation value calculated based on the reflected wave received by another one of the receiver elements, a distance between the one of the receiver elements and the another one of the receiver elements, and a wavelength of the transmitting wave.

Abstract: A detector made of lanthanum-doped lead zirconate titanate detects intensity of ultraviolet light radiated inside of a vehicle. The detector sends ultrasonic wave to an incidence direction of ultraviolet light, and detects ultrasonic wave reflected by an object. An electrical unit determines the object to be an occupant of the vehicle or not based on the reflected ultrasonic wave. The electrical unit outputs a signal representing that a predetermined or more amount of ultraviolet light is radiated to the occupant, when the detector detects the predetermined or more amount of ultraviolet light and when the electrical unit determines the object to be the occupant.

Abstract: An ultrasonic sensor composed of a substrate and a piezoelectric vibrator mounted on the substrate is advantageously used as a sensor for detecting a distance to an object located in front of an automotive vehicle. Ultrasonic waves transmitted from the sensor are reflected by the object, and the reflected waves are received by the sensor. Based on the reflected waves, the distance from the vehicle to the object is calculated. To reduce rigidity and thereby to lower a resonant frequency of the substrate to a desirable level, grooves are formed in the substrate. A thickness of the substrate is not reduced to maintain its mechanical strength against an impact force. A resonant frequency which is desirable to realize a sufficiently high directivity and sensitivity is obtained in this manner without enlarging a size of the ultrasonic sensor.

Abstract: An ultrasonic sensor includes an ultrasonic detector for detecting an ultrasonic wave, an acoustic matching member joined to the ultrasonic detector, a housing in which the ultrasonic detector and the acoustic matching member are accommodated, a vibration isolator located between the acoustic matching member and an inner side wall of the housing to damp an unwanted vibration from outside, and a cushion member located between the ultrasonic detector and an inner bottom wall of the housing to absorb external force applied to the ultrasonic sensor The cushion member is not in contact with the acoustic matching member.