Denso Corporation

Nippon Soken, Inc.

Toyota Jidosha Kabushiki Kaisha

Toshikazu Itakura

Toshiki Isogai

Seiki Aoyama

Hisanori Yokura

Michitaka Hayashi

Masato Ishihara

A pressure sensor includes a sensor chip that detects a pressure of a pressure medium; and a case that accommodates the sensor chip and has an inlet port connected with the outside, the case having a pressure inlet portion surrounding the inlet port. The pressure inlet portion is configured from: a front wall placed forward of the case with a clearance; a top wall and a pair of side walls, each which is connected to the front wall; and an opening introducing the pressure medium into the inlet port from a lower position with respect to the inlet port. The top wall is connected to the side walls and angled in entirety toward an upper position with respect to the inlet port. The front wall has an opening end configuring the opening, the opening end being recessed toward the top wall in an arc shape.

Pressure sensor

An angular velocity sensor includes a sensor unit, a detection unit and a connecting part electrically connecting the sensor unit and the detection unit. The detection unit drives the sensor unit and detects an angular velocity acting on the sensor unit. The detection unit supplies a carrier signal to a movable electrode of a capacitor of the sensor unit and supplies a driving signal to a fixed electrode of the capacitor via the connecting part for performing a servo control. A C/V converter circuit of the detection unit receives capacitance generated at the capacitor through a driving signal transmission line of the connecting part in a state where supply of the driving signal is stopped, and converts the capacitance into a voltage. A determination part of the detection unit determines whether the driving signal transmission line has disconnection or not based on the voltage outputted from the C/V converter circuit.

Angular velocity sensor

A capacitive humidity sensor includes: a humidity sensing element with a humidity sensitive film and electrodes; and a processing circuit. The film has a dielectric constant variable in accordance with moisture. The electrodes detect capacitance of the film and outputs a signal corresponding to the capacitance. The processing circuit processes the signal. The film is made of inorganic material having fine pores for adsorbing the moisture. A diameter of the fine pores is set to be a predetermined diameter so that capillary tube aggregation phenomenon occurs at a predetermined relative humidity. The capacitance of the film has a change rate with respect to the relative humidity. The change rate in case of the relative humidity higher than the predetermined relative humidity is larger than that in case of the relative humidity lower than the predetermined relative humidity.

Humidity sensor

An inspection device inspects a humidity sensor having a sensor portion and a circuit portion, which are integrated into one chip. The inspection device includes: an inspection chamber for accommodating a wafer, in which a plurality of humidity sensors are disposed as a sensor chip in a wafer state; a probe for contacting an electrode pad of the circuit portion; a tester electrically connected to the probe for inspecting electric properties of the humidity sensor; and a temperature-humidity control portion for controlling a temperature and a humidity in the inspection chamber.

Inspection device for humidity sensor and method for adjusting sensor characteristics of humidity sensor

A humidity sensor includes: a substrate; a pair of electrodes on the substrate; a humidity sensitive member between the electrodes having a capacitance changeable in accordance with humidity; an output element connecting to the electrodes in order to detect a capacitance of the humidity sensitive member and outputting a signal corresponding to the capacitance; and a setting member for setting a maximum amount of moisture in the humidity sensitive member to be a standard maximum amount of moisture. The humidity sensitive member is capable of absorbing a moisture up to the maximum amount of moisture. The setting member includes at least one of an element for reducing the maximum amount of moisture and an element for increasing the maximum amount of moisture.

Humidity sensor with setting member for setting maximum amount of moisture in humidity sensitive member

A capacitive humidity sensor includes a semiconductor substrate, a protective layer and a humidity sensitive section including a pair of comb electrodes and a humidity sensitive layer having a dielectric constant, which changes in accordance with humidity. The comb electrodes are disposed on one surface of the semiconductor substrate through the protective layer to face each other with a predetermined gap. An interface between the protective layer and the humidity sensitive layer is planarized so that the sensor prevents a hysteresis in a variation of capacitance. For example, a surface of the protective layer can be made flat by polishing.

Capacitive humidity sensor and method of manufacturing the same

A capacitive type humidity sensor includes: a semiconductor substrate; a plurality of humidity devices having a capacitance variable in accordance with a humidity; a standard capacitance device having a standard capacitance, a capacitance change of which in accordance with the humidity is smaller than that of the capacitance of each humidity device; and a CV converter circuit for converting a capacitance difference between the capacitance of each humidity device and the standard capacitance of the standard capacitance device to a signal voltage. The humidity devices, the standard capacitance device and the CV converter circuit are disposed on one side of the substrate.

Capacitive type humidity sensor

A capacitance device includes a dielectric film, the first electrode and the second electrode. One of the two electrodes is divided into a plurality of electrode portions. Each of the divided electrode portions is connected with each other through switching transistors so that appropriate portions contributing to the capacitance can be selected. The device can vary its capacitance with high accuracy.

Variable capacitance device with high accuracy

A capacitance type physical quantity detector includes a sensor unit of which the capacitance varies depending upon a change in the physical quantity and a C-V converter unit which converts a change in the capacitance of said sensor unit into a voltage. The C-V converter unit includes an operational amplifier, a feedback capacitor, switching means connected in parallel with said feedback capacitor, a reference voltage-generating circuit for applying a reference voltage to the operational amplifier, and a drive voltage-generating circuit for applying a drive voltage to said sensor unit. At least any one of the feedback capacitance of said feedback capacitor, the reference voltage formed by said reference voltage-generating circuit or the drive voltage formed by said drive voltage-generating circuit varies depending upon the temperature to correct temperature characteristics of the sensor unit.

Capacitance type physical quantity detector

A capacitive humidity sensor for detecting a humidity change includes a first sensor element having a first capacitance, a second sensor element having a second capacitance and connected in series with the first sensor element, and a humidity sensitive layer having a dielectric constant, which changes in accordance with humidity. The first and the second capacitances change with respect to the humidity change at a different rate. The humidity is detected using the different capacitances of the first and the second sensor elements. The humidity sensitive layer is formed to each sensor element so that each sensor element can be effectively protected.

Capacitive humidity sensor

Method for adjusting sensor characteristics of humidity sensor

A capacitance type humidity sensor includes: a detection substrate including a detection portion on a first side of the detection substrate; and a circuit board including a circuit portion. The detection portion detects humidity on the basis of capacitance change of the detection portion. The circuit portion processes the capacitance change as an electric signal. The detection substrate further includes a sensor pad on a second side of the detection substrate. The sensor pad is electrically connected to the detection portion through a conductor in a through hole of the detection substrate.

Physical quantity sensor and method for manufacturing the same

A moisture sensor device includes a sensor portion having a capacitance that is varied in accordance with surrounding humidity, a signal processor for processing a detection signal of the sensor portion and outputting the signal corresponding to the humidity, a heating portion for heating the sensor portion, and a controller for controlling heating of the heating portion so that the capacitance of the sensor portion is substantially equal to a value under predetermined humidity at least during a self-diagnosis period.

Moisture sensor device and self-diagnosing method therefor

An oscillator includes first, second and third inverters () connected in series. A feedback path is connected from the output terminal of the third inverter () to the input terminal of the first inverterthrough a resistor () while a second feedback path is connected from the output terminal of the second inverter () to the input terminal of the first inverter () through a capacitor (). The second feedback path further includes a resistor () having a temperature coefficient larger than that of resistor () is inserted to adjust the charge/discharge trigger voltage and charge/discharge time of the capacitor ().

Oscillator circuit having stable frequency

A capacitance of a capacitor member, which varies according to a dynamic force such as an acceleration force imposed on the capacitor member, is detected by a detecting circuit. The detecting circuit is composed of an operational amplifier and a switched capacitor circuit connected in parallel to each other. A reset time (t), during which a feedback capacitor in the switched capacitor circuit is discharged, is set to satisfy the following formula: t&#x3e;(&#x394;C+m)/n, where &#x394;C is an initial capacitance of the capacitor member, and n and m are constant factors having values in certain ranges. By setting the reset time (t) according to the above formula, an amount of acceleration imposed on the capacitor member is accurately detected even when the capacitor member has a certain level of the initial capacitance.

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Toyota, Japan

Toshikazu Itakura