Murata Manufacturing Co., Ltd.

Masaaki Takata

Kenji Nishiyama

Yuuki Ishii

Takaaki Mori

Yuzo Mizushima

Katsumi Fujimoto

Chikahiro Horiguchi

Yasuhiro Kuratani

Shinichiro Ichiguchi

Noritaka Kishi

Noriyuki Ueki

Yasuhiro Shimizu

Shoji Nagumo

Nobumasa Kitamori

Hitoshi Sakaguchi

Hiromasa Koyama

Takahide Nakadoi

Masaru Amano

A vibration device includes a light-transmissive body, and a vibrator to vibrate the light-transmissive body at a vibration acceleration of equal to or more than about 1.5×10m/sand equal to or less than about 8.0×10m/s.

Vibration device and vibration control method

A cleaning device includes a protection cover in a viewing field of a camera, a piezoelectric material to vibrate the protection cover, a driver to drive the piezoelectric material, a vibrator to detect a signal related to a vibration level of the protection cover vibrated with the piezoelectric material, and a controller to control the driver based on a signal detected by the vibration sensor so that the signal detected by the vibrator matches a predetermined target value of the vibration level of the protection cover.

Cleaning device, imaging unit including cleaning device, and control method

In a cleaning device, a signal processing circuit determines that a foreign substance has adhered to a surface of a protection cover based on at least two pieces of information among a change amount of a resonant frequency when a vibration portion is driven at a first voltage, a change amount of a current value relating to an impedance detected by an impedance detector, and a temporal change of an image captured by an imaging portion, and cleans the surface of the protection cover by controlling the vibration portion in accordance with the determination.

Cleaning device, imaging unit including the same, and cleaning method

A cleaning device includes a casing holding an image capturing device, a protective cover disposed in a visual field of the image capturing device, a vibrator to vibrate the protective cover, a controller to control the vibrator, a monitor to detect an electrical characteristic value associated with a vibration of the vibrator, and a storage to store determination criteria based on which the controller evaluates the electrical characteristic value detected by the monitor. The controller is configured to evaluate the electrical characteristic value based on the plurality of determination criteria stored in the storage and clean a surface of the translucent body by controlling the vibrator according to the determination.

Cleaning device, and image capturing apparatus including cleaning device

A current sensor includes a magnetic sensor, a magnetic sensor, a first calculator, a second calculator, and an output. The first magnetic sensor senses a magnetic field to generate a first sensor signal and a second sensor signal. The second magnetic sensor senses a magnetic field having a phase opposite to that of the magnetic field sensed by the first magnetic sensor in accordance with the current to generate a third sensor signal and a fourth sensor signal. The first calculator receives the first sensor signal and the third sensor signal to generate a first arithmetic signal. The second calculator receives the second sensor signal and the fourth sensor signal to generate a second arithmetic signal. The output receives the first arithmetic signal and the second arithmetic signal and generates an output signal based on the respective signals that are input.

Current sensor

An amplifier circuit converts a charge signal into a voltage signal. The charge signal indicates a detection result outputted from a piezoelectric device that detects a detection object as a change in an amount of a charge. The charge signal includes a displacement signal in a predetermined frequency band. The amplifier circuit includes an operational amplifier including an inverting input terminal receiving the charge signal and an output terminal for outputting the voltage signal, a resistor electrically connected between the inverting input terminal and the output terminal, and a capacitor connected in parallel with the resistor. A resistance value of the resistor and a capacitance value of the capacitor are set such that, in the frequency band of the displacement signal, an absolute value of an impedance of the resistor is lower than an absolute value of an impedance of the capacitor.

Amplifier circuit and detection apparatus including the same

This disclosure provides an antenna apparatus in which stable antenna characteristics are maintained by detecting surrounding conditions that affect the antenna characteristics and appropriately compensating the antenna characteristics. More specifically, when surrounding condition such as a human body (e.g., a palm or fingers) approaches and enters an electric field of a pseudo dipole formed by an antenna element electrode, a stray capacitance is sensed and stable antenna characteristics are maintained by appropriately controlling an antenna matching circuit to compensate for a change in the antenna characteristics due to the approach of the surrounding condition.

Growing community of inventors

Nagaokakyo, Japan

Masaaki Takata