Abstract: A rain sensor equipped to a transparent substrate includes a light emitter emitting irradiation lights toward the transparent substrate, light receivers receiving reflected lights of the irradiation lights being reflected on the transparent substrate, a defining section defining an incident angle of each reflected light with respect to each light receiver, and a detection section detecting rainfall amount based on signals output from the light receivers. The light emitter emits the irradiation lights toward an irradiation region defined on the transparent substrate. The irradiation region is divided into multiple detection regions. The detection regions correspond to respective light receivers. The defining section defines the incident angle of each reflected light reflected on the detection region such that each reflected light enters corresponding light receiver. The detection section detects the rainfall amount based on the signals output from the light receivers corresponding to the irradiation regions.

Abstract: A rain sensor equipped to a transparent substrate includes a light emitter emitting irradiation lights toward the transparent substrate, light receivers receiving reflected lights of the irradiation lights being reflected on the transparent substrate, a defining section defining an incident angle of each reflected light with respect to each light receiver, and a detection section detecting rainfall amount based on signals output from the light receivers. The light emitter emits the irradiation lights toward an irradiation region defined on the transparent substrate. The irradiation region is divided into multiple detection regions. The detection regions correspond to respective light receivers. The defining section defines the incident angle of each reflected light reflected on the detection region such that each reflected light enters corresponding light receiver. The detection section detects the rainfall amount based on the signals output from the light receivers corresponding to the irradiation regions.

Abstract: An optical sensor includes: first and second light receiving elements on a semiconductor substrate; a light blocking film over the semiconductor substrate via a light transmitting film; and first and second openings corresponding to the light receiving elements and disposed in the light blocking film. First and second virtual lines are defined to extend from the centers of the first and second light receiving elements and pass through the centers of the first and second openings, respectively. At least one of elevation angles and left-right angles of the first and second virtual lines are different. The photosensitive area of the first light receiving element is larger than the aperture area of the first opening. The photosensitive area of the second light receiving element is larger than the aperture area of the second opening.

Abstract: In a PWM communication system, a sensor unit transmits as reference pulses transmission signals, which exhibit duty cycles of 100% and 0%, respectively, prior to transmission of a transmission signal, which has data items compressed thereinto by a signal processing circuit. An input capture circuit of an ECU measures the duty time and the PWM cycle of the transmission signal according to a timer clock of a timer circuit. A signal processing circuit of the ECU produces a duty cycle correction factor k based on the measured duty times and PWM cycles of the reference pulses, produces receiving data based on the duty time and the PWM cycle of the transmission signal, and the duty cycle correction factor, and separates the receiving data into sensor output values of a pressure sensor and a temperature sensor.

Abstract: An optical sensor includes: first and second light receiving elements on a semiconductor substrate; a light blocking film over the semiconductor substrate via a light transmitting film; and first and second openings corresponding to the light receiving elements and disposed in the light blocking film. First and second virtual lines are defined to extend from the centers of the first and second light receiving elements and pass through the centers of the first and second openings, respectively. At least one of elevation angles and left-right angles of the first and second virtual lines are different. The photosensitive area of the first light receiving element is larger than the aperture area of the first opening. The photosensitive area of the second light receiving element is larger than the aperture area of the second opening.

Abstract: In a PWM communication system, a sensor unit transmits as reference pulses transmission signals, which exhibit duty cycles of 100% and 0%, respectively, prior to transmission of a transmission signal, which has data items compressed thereinto by a signal processing circuit. An input capture circuit of an ECU measures the duty time and the PWM cycle of the transmission signal according to a timer clock of a timer circuit. A signal processing circuit of the ECU produces a duty cycle correction factor k based on the measured duty times and PWM cycles of the reference pulses, produces receiving data based on the duty time and the PWM cycle of the transmission signal, and the duty cycle correction factor, and separates the receiving data into sensor output values of a pressure sensor and a temperature sensor.

Abstract: A pressure sensor includes: a housing having a pressure introduction port; and a connector case integrated with the housing. The connector case includes: a protruding portion that protrudes in the pressure introduction port along with the introduction direction from one end of the connector case, and has a concavity hollowed in a direction perpendicular to the introduction direction; a sensor chip having a pressure gauge on one surface of the chip in the concavity; a terminal having one end inserted and molded in the connector case; and a bonding wire that electrically connects the sensor chip and the one end of the terminal. The connector case seals a connection portion between the bonding wire and the terminal, a connection portion between the boding wire and the sensor chip, and the bonding wire.

Abstract: A peak voltage detector circuit detects a peak voltage of an input voltage. The input voltage is input into a first input terminal of a comparator. A counter circuit counts up a counter value in synchronization with a first clock signal, when a signal output from the comparator is in a first state. The counter circuit counts down the counter value in synchronization with a second clock signal. A digital-analog conversion circuit outputs an output voltage corresponding to the counter value, and the output voltage is input into a second input terminal of the comparator. The first clock signal has a wave period shorter than that of the second clock signal.

Abstract: 1st to nth pairs of transistors (n=an odd number) are connected in parallel, and each pair of transistors has an upper transistor and a lower transistor connected in series. A point between the upper transistor and the lower transistor of a preceding pair of transistors is connected to a gate of the lower transistor of a subsequent transistor, and the point between the upper transistor and the lower transistor of nth pair of transistors is connected to the gate of the first lower transistor. A capacitor is inserted between the lower transistor and a direct power source. A current regulating circuit connected to gates of the upper transistors, wherein the current regulating circuit supplies a gate voltage to each gate of the each upper transistor.

Abstract: A pressure sensor for use in an engine by installation of the pressure sensor into an installation hole of an engine head is provided. The pressure sensor includes: a body having a first end; a pressure receiving diaphragm disposed in the first end; a sealing surface disposed on the side surface of the body; and an expansion member, which is disposed on the side surface of the body so that, with respect to the first end of the body, the expansion member is located closer than the sealing surface. When heat is generated by an engine operation after the installation of the first end of the body into the installation hole, the expansion member expands due to the heat to fill in a space between an inner surface of the installation hole and a side surface of the body.

Abstract: A pressure sensor includes: a housing having a pressure introduction port; and a connector case integrated with the housing. The connector case includes: a protruding portion that protrudes in the pressure introduction port along with the introduction direction from one end of the connector case, and has a concavity hollowed in a direction perpendicular to the introduction direction; a sensor chip having a pressure gauge on one surface of the chip in the concavity; a terminal having one end inserted and molded in the connector case; and a bonding wire that electrically connects the sensor chip and the one end of the terminal. The connector case seals a connection portion between the bonding wire and the terminal, a connection portion between the boding wire and the sensor chip, and the bonding wire.

Abstract: A fluid sensor detects property of fluid by dipping the sensor in the fluid. The sensor includes: a semiconductor substrate; and a comb-teeth electrode made of a first diffusion layer and disposed on a first surface of the substrate. Although the comb-teeth electrode is capable of directly contacting the fluid without a protection film, corrosion resistance of the sensor against the fluid is improved. Further, since the sensor has no protection film, the sensor can detect the property accurately.

Abstract: A peak voltage detector circuit detects a peak voltage of an input voltage. The input voltage is input into a first input terminal of a comparator. A counter circuit counts up a counter value in synchronization with a first clock signal, when a signal output from the comparator is in a first state. The counter circuit counts down the counter value in synchronization with a second clock signal. A digital-analog conversion circuit outputs an output voltage corresponding to the counter value, and the output voltage is input into a second input terminal of the comparator. The first clock signal has a wave period shorter than that of the second clock signal.

Abstract: A pressure sensor device (1) includes a sensing element (2) for sending an analog signal according to pressure. The pressure sensor device (1) outputs the analog voltage to a microcomputer (20) through an input-output terminal (8). An input-output control circuit (4) monitors the voltage value in the input-output terminal (8). When the voltage of the input-output terminal (8) is set to high by the microcomputer (20) and is dislocated from a predetermined range, the input-output control circuit (4) functionally changes the input-output terminal (8) outputting a detecting signal to a terminal for inputting an external signal from the microcomputer. After the input-output terminal (8) is changed to the terminal for inputting the external signal, a range control circuit (7) fetches an external command signal through the input-output terminal (8) and switches the output characteristics.

Abstract: Detecting the rotational direction of a rotor is feasible by allowing a constant current source to supply a constant current flowing from an electric potential supply line to the earth in response to a turning-on action of a switch. Accordingly, detecting both the rotational speed and the rotational direction of the rotor is feasible by using three wiring cables of a power source line, an earth line, and a signal line outputting a pulse signal in accordance with the rotation of the gear. Using such a one-stage voltage adjustment enables the detection signal processing circuit to reduce electric power consumption compared with a system requiring a two-stage voltage adjustment.

Abstract: An A/D converter has inverting elements and delay elements alternately disposed in series. Each inverting element receives an analog voltage signal as a power source and converts a pulse signal in an inversion operation time depending on the analog voltage signal. Each delay element delays transmission of the pulse signal. The transmission of the pulse signal is started from a starting inverting element at a start time, and a transit position of the pulse signal is detected at a detection time later than the start time by a predetermined time. A digital value indicating a level of the analog voltage signal is determined from the detected transit position of the pulse signal. Because transmission of the pulse signal is delayed by the delay elements, the transit position depending on the analog voltage signal can be correctly detected.

Abstract: A peak voltage detector circuit detects a peak voltage of an input voltage. The input voltage is input into a first input terminal of a comparator. A counter circuit counts up a counter value in synchronization with a first clock signal, when a signal output from the comparator is in a first state. The counter circuit counts down the counter value in synchronization with a second clock signal. A digital-analog conversion circuit outputs an output voltage corresponding to the counter value, and the output voltage is input into a second input terminal of the comparator. The first clock signal has a wave period shorter than that of the second clock signal.

Abstract: A binarization circuit for binarizing a pulsative analog signal includes: a first comparator circuit for reversing an output signal when the analog signal becomes smaller than a threshold voltage and when the analog signal becomes larger than a high side threshold voltage; a second comparator circuit for reversing an output signal when the analog signal becomes larger than the threshold voltage and when the analog signal becomes smaller than a low side threshold voltage; and a selector circuit for inputting the output signals from the first and second comparator circuits and for reversing an output signal when the analog signal becomes smaller than the threshold voltage and when the analog signal becomes larger than the threshold voltage.

Abstract: 1st to nth pairs of transistors (n=an odd number) are connected in parallel, and each pair of transistors has an upper transistor and a lower transistor connected in series. A point between the upper transistor and the lower transistor of a preceding pair of transistors is connected to a gate of the lower transistor of a subsequent transistor, and the point between the upper transistor and the lower transistor of nth pair of transistors is connected to the gate of the first lower transistor. A capacitor is inserted between the lower transistor and a direct power source. A current regulating circuit connected to gates of the upper transistors, wherein the current regulating circuit supplies a gate voltage to each gate of the each upper transistor.

Abstract: A reference voltage circuit includes an operational amplifier, a first fixed resistance resistor, a second fixed resistance resistor, a third fixed resistance resistor, a first diode and a second diode. The reference voltage circuit further includes a fourth fixed resistance resistor having an end connected to a non-inverting input terminal of the operational amplifier and the other end connected to the first diode. The reference voltage circuit is characterized by a value of the resistance of the fourth resistor being less than the resistance of the first resistor and a temperature coefficient of the fourth resistor being greater than any of the temperature coefficients of the first, second and third resistors.