Alps Alpine Co., Ltd.

Alps Electric Co., Ltd.

Kiyoshi Sasai

Tatsumi Fujiyoshi

Shinichi Sagawai

Akira Asao

Satoshi Waga

Akihisa Iikura

Kazunari Takida

Yoshinobu Kakihara

Kazufumi Naganuma

Yoshihiro Sudoh

Masahiro Kimura

Kenji Shimizu

Mitsuo Bitoh

A calculation unit calculates a detection value of a capacitance of a capacitor based on a detection signal. A correction unit repeatedly performs a shift to a correction mode. When the correction mode is entered, the correction unit controls an AC voltage output unit so that a difference between amplitudes of first and second AC voltages changes, and obtains a correction value corresponding to a change in the detection value of the calculation unit caused by the change in the difference between the amplitudes. The correction unit corrects the detection value calculated by the calculation unit in accordance with the change in the correction values obtained in the correction mode.

Capacitance detection device, capacitance detection method, and input device

A sensor device includes a sensor unit that generates a detection signal having the same detection frequency as an entered sinusoidal analog signal and matching a physical quantity to be detected; a reference signal generating unit that generates a reference signal having the detection frequency, according to the entered analog signal; converting units that convert the detection signal and reference signal to digital signals in synchronization with a clock signal; a demodulating unit that multiplies the digital detection signal by each of two sinusoidal synchronization signals having the detection frequency, the phases of the two synchronization signals being shifted from each other by one-fourth of a cycle, and generates two demodulated signals free from a harmonic component; and a correcting unit that corrects the demodulated signals according to the digital reference signal so as to suppress variations, in the demodulated signals, caused by variations in the clock signal phase.

Sensor device

An electrostatic capacitance sensor includes: at least one detection electrode; drive electrodes, capacitors being respectively formed between the drive electrodes and the at least one detection electrode; a driver capable of causing voltages of the drive electrodes to change independently from each other; a reference voltage generator that generates a reference voltage; a detection signal generator that transfers charge so that a voltage of the at least one detection electrode approaches the reference voltage and that generates a detection signal according to the transfer of the charge; and a controller that controls the driver. The driver is capable of applying the reference voltage to each of the drive electrodes. When the driver causes a voltage of one or more of the drive electrodes to change, the controller controls the driver so as to apply the reference voltage to the remaining drive electrodes.

Electrostatic capacitance sensor

A capacitance detection device includes a first voltage output circuit configured to output a first alternating current voltage supplied to a shield electrode provided proximate to a detection electrode, a second voltage output circuit configured to output a second alternating current voltage whose frequency and phase are the same as that of the first alternating current voltage and whose amplitude is less than that of the first alternating current voltage, and a current output circuit configured to output a driving current Is to the detection electrode so that the difference between the voltage of the detection electrode and the second alternating current voltage becomes smaller, and output a detection signal corresponding to the driving current. The second voltage output circuit outputs a second alternating current voltage whose amplitude is adjusted so that the driving current in the absence of the object proximate to the detection electrode.

Capacitance detection device for detecting capacitance between object proximate to detection electrode and the detection electrode and input device used for inputting information according to proximity of object

In a sine-wave multiplier, signal components included in an output signal Quand corresponding to the product of a third-order harmonic component of a first square wave Wand an input signal Vi and the product of a fifth-order harmonic component of the first square wave Wand the input signal Vi are offset by a signal component included in an output signal Quand corresponding to the product of a fundamental component of a second square wave Wand the input signal Vi and a signal component included in an output signal Quand corresponding to the product of a fundamental component of a second square wave Wand the input signal Vi.

Sine-wave multiplier and input device including the same

Provided is a sine wave multiplication device of simple configuration, broad input signal level range, and minimal fluctuation in characteristics due to temperature. A signal component that corresponds to a product of an input signal Si and the third harmonic wave of a first square wave Wincluded in an output signal Su; and a signal component that corresponds to a product of the input signal Si and the fifth harmonic wave of the first square wave Wis canceled by: a signal component that corresponds to a product of the input signal Si and the fundamental wave of a second square wave Wincluded in an output signal Su; and a signal component that corresponds to a product of the input signal Si and the fundamental wave of a second square wave Wincluded in an output signal Su

Sine wave multiplication device and input device having the same

A differential signal is input to a pair of gates of a differential pair, a differential signal generated by a load circuit connected to drains of the differential pair is amplified by a differential amplifier stage, and the amplified differential signal is fed back to a pair of sources of the differential pair via a feedback circuit. It is possible to maintain a high input impedance in the pair of gates of the differential pair while not being influenced by a gain of negative feedback of an amplifier circuit, and it is possible to perform amplification in an input stage by using a pair of a first transistor and a second transistor of the differential pair. Therefore, compared with the related art, it is possible to decrease the number of transistors in the input stage and to reduce a flicker noise.

Amplifier circuit

In an integration mode, since a switch becomes OFF, a positive feedback path from an output terminal of an operational amplifier to a positive input terminal is blocked. Therefore, oscillation can be prevented even when a voltage of a signal line connected to a reference voltage supply point varies due to an impedance of the reference voltage supply point not being 0. In the integration mode, a resistor and a capacitor function as a noise filter. Further, in a reset mode, a switch becomes ON, and charge is accumulated in the capacitor depending on a reference voltage of the reference voltage supply point.

Signal processing circuit

A thin film device comprising a substrate which is magnetic and has insulation property at least on the surface, coils formed spirally in a planar configuration on the substrate, a first interlayer insulation film formed to a portion excepting for the terminal portion of the coils and a magnetic material connection portion of the substrate, a magnetic film and a second interlayer insulation film formed successively on the first interlayer insulation film excepting for the terminal portions, and bump electrodes formed in connection with the terminal portions in which a crystallite material having a composition: Fe.sub.78 Ta.sub.10 C.sub.12 is used as the magnetic film. The thin film device can be formed an a reduced size and having a large inductance value. When the device is used as a noise filter, a cut-off frequency range can be lowered.

Growing community of inventors

Miyagi-ken, Japan

Kiyoshi Sasai