Alpine Electronics, Inc.

Tdk Corporation

Renesas Technology Corp.

Renesas Electronics Corporation

Alps Alpine Co., Ltd.

Synaptics Display Devices Gk

Renesas Sp Drivers Inc.

Kei Tanabe

Yoshihisa Iwamoto

Goro Sakamaki

Takashi Ohyama

Shigeru Ohta

Yasuhito Kurokawa

Takatoshi Uchida

Tamon Kasajima

Akihiro Ogawa

Takakazu Imai

Akihiro Unno

Naoki Shimamura

Yoshikazu Yokota

Masashi Takahashi

Atsushi Matsuda

Kunihiko Tani

Yusuke Yoshida

Ryo Ito

Arata Tada

Nobuo Kakinuma

Junya Fukuda

Akio Suzuki

Masaru Yamagami

Masami Anzai

Haruki Uesugi

Yuki Asazuma

Yu Yamagami

Takahiro Aoki

Shigeki Takei

An outer structure of a magnetic circuit is held inside a holder recess of a magnetic circuit holder of a frame. A pressing portion is screw-fixed to a mounting surface of the magnetic circuit holder. Elastically deformable pressing arms are formed at the pressing portion, and the pressing arms press a restriction surface of the outer structure of the magnetic circuit.

Speaker

An object of the present invention is to provide a magnetic sensor less subject to an environmental magnetic field. A magnetic sensor includes magnetic detection elements MRto MRpositioned on a first plane Pand a magnetic memberA provided on a second plane P. The magnetic memberA includes first and second leg partsandand a first main body partpositioned between the first and second leg partsandso as to form a first spacebetween itself and the second plane P. The magnetic detection elements MRto MRare covered with the first main body part. According to the present invention, magnetic field to be detected is collected to the first and second leg partsand, and the magnetic detection elements MRto MRare covered with the first main body part, thereby allowing an environmental magnetic field acting as noise to bypass the magnetic detection elements MRto MRthrough the first main body part. Thus, influence of the environmental magnetic field can be reduced.

Magnetic sensor

A gas sensor includes a feedback circuit part and a sensor circuit part. The feedback circuit part includes a reference resistor and a first temperature sensing element which are connected in series, a first heater resistor that heats the first temperature sensing element, and a first amplifier circuit that controls the amount of current to flow in the first heater resistor based on an internal potential. The sensor circuit part includes a second temperature sensing element and a second heater resistor that heats the second temperature sensing element. A current according to the output of the first amplifier circuit flows in the second heater resistor. With this configuration, it is possible to automatically change the amount of current to flow in the second heater resistor according to ambient temperature without digital processing to thereby heat the second temperature sensing element to a constant temperature.

Gas sensor

Disclosed herein is a sensor module that includes a substrate having a top surface and a back surface, a sensor element mounted on the top surface of the substrate, an external terminal formed on the back surface of the substrate, and a case fixed to the substrate so as to cover the sensor element. The case has a top plate part having a plurality of through holes. The top plate part has a center area having no through holes and a through hole formation area having the plurality of through holes, the through hole formation area being positioned so as to surround the center area.

Sensor module

The present invention relates to a magnetic sensor which can improve the detection precision of a weak magnetic field and can be downsized. A magnetic sensor is provided with a magnetic body changing the direction of a magnetic field input to a magnetoresistance effect element in the vicinity of the magnetoresistance effect element in which the resistance value changes according to the direction of the input magnetic field, the magnetic body has a mean for changing the direction of a magnetic field on the surface at a side where the magnetoresistance effect element is formed. The chamfer part of the magnetic body may be chamfered with a shape having at least one flat surface.

To provide a magnetic sensor capable of supporting a magnetic block stably and allowing a further size reduction of the sensor chip. A magnetic sensor includes a sensor chip and a magnetic block which are mounted on a circuit board. The sensor chip is mounted on the circuit board such that a mounted surface thereof faces a mounting surface, and the magnetic block is mounted on the circuit board such that first and second surfaces and face an element formation surface and the mounting surface, respectively. The magnetic block has a cutout portion, and some of terminal electrodes Eto Eare disposed within a space formed by the cutout portion. According to the present invention, the magnetic block can be supported stably. In addition, the presence of the cutout portion in the magnetic block allows a further size reduction of the sensor chip.

A magnetic sensor suppressing bias magnetic field effects includes a magnetic detecting unit including first to fourth magneto-resistive elements to which a first magnetic field to be detected is applied, a differential amplifier into which the output voltage of the magnetic detecting unit is input, a first magnetic field generating conductor which, by a first feedback current output by the differential amplifier, applies to the magnetic detecting unit a second magnetic field to cancel the first magnetic field detected by the magnetic detecting unit, a bias magnetic field detector which detects a bias magnetic field applied to the magnetic detecting unit and outputs a second feedback current corresponding to the bias magnetic field, and a second magnetic field generating conductor which, by the second negative feedback current, applies to the magnetic detecting unit a correcting magnetic field to cancel the bias magnetic field detected by the magnetic detecting unit.

An object of the present invention is to selectively detect a detection magnetic field without separately providing a sensor for detecting an environmental magnetic field. A magnetic field detection device includes a magnetic field detection unitthat generates an output signal Saccording to a magnetic field, a first signal generation unitthat extracts a predetermined frequency component from the output signal Sand generates a cancel signal Sbased on the predetermined frequency component, a first magnetic field generation unitthat applies a first cancel magnetic field to the magnetic field detection unitbased on the cancel signal S, and a second signal generation unitthat generates a detection signal Sbased on the output signal Sof the magnetic field detection unitto which the first cancel magnetic field is applied. According to the present invention, a cancel signal is generated based on a frequency component of an output signal, and a first cancel magnetic field is applied to a magnetic field detection unit using the cancel signal. Therefore, it is not necessary to separately provide a sensor for detecting an environmental magnetic field. Because this configuration reduces the number of parts, downsizing and cost reduction can be realized.

Magnetic field detection device and magnetic field detection method

An object of the present invention is to provide a magnetic sensor that can reduce influences of a disturbance magnetic field while ensuring high detection sensitivity. The magnetic sensor includes a sensor chiphaving an element formation surfaceS on which magnetic detection elements MR, MRare formed, a first magnetic memberplaced on the element formation surfaceS and having a first height Has a height from the element formation surfaceS, and a second magnetic memberlocated on an opposite side of the magnetic detection elements MR, MRto the first magnetic memberand having a second height Hlower than the first height H. According to the present invention, because the height Hof the second magnetic memberis lower than that of the first magnetic member, a detection magnetic field attracted to the second magnetic membercan be reduced while a disturbance magnetic field is shielded by the second magnetic member. Accordingly, influences of the disturbance magnetic field can be reduced while high detection sensitivity is ensured.

Magnetic sensor and magnetic-field detection device including the same

The size and cost of a magnetic sensor suitable for closed loop control is reduced. A magnetic sensor includes a magnetoresistive effect element that is electrically connected between terminals and extends in the x-direction and a magnetic member that is electrically connected between the terminals and extends in the x-direction along the magnetoresistive effect element. The magnetoresistive effect element is disposed offset with respect to the center position of the magnetic member in the y-direction. Magnetic flux to be detected is collected by a magnetic member and current is made to flow in the magnetic member in accordance with the resistance value of the magnetoresistive effect element, achieving closed loop control. The magnetic member functions both as a magnetism collection function and as a cancel coil, which reduces the number of elements required, and which also achieves a reduction in size and cost.

Magnetic sensor including a magnetic member offset from a magnetoresistive effect element

An object of the present invention is to provide a magnetic sensor having enhanced magnetic detection sensitivity by bending magnetic flux more largely. A magnetic sensor includes magnetic detection elements MRand MRpositioned on a plane P separating a first space Sand a second space S, a first magnetic memberdisposed in the first space Sso as to be between the magnetic detection elements MRand MRwhen viewed in the z-direction, and a second magnetic memberdisposed in the second space S. The magnetic detection element MRis positioned between the first magnetic memberand a first partof the second magnetic memberwhen viewed in the z-direction. The magnetic detection element MRis positioned between the first magnetic memberand a second partof the second magnetic memberwhen viewed in the z-direction. According to the present invention, magnetic flux collected by the first magnetic member is attracted to the first and second parts of the second magnetic member, allowing the magnetic flux to be bent more largely. Thus, the magnetic detection sensitivity of the magnetic sensor can be enhanced.

A speaker includes spacers that are disposed between a front end portion of a top yoke, which serves as a first member, and a back end portion of a back portion of a frame, which serves as a second member, to form a gap that defines an air passage. When a bobbin and a vibrating plate vibrate in a front-back direction, an airflow through the air passage, which faces a voice coil, is formed between the space around a magnetic gap and the outside. Accordingly, the voice coil is cooled over the entire circumference thereof.

Growing community of inventors

Tokyo, Japan

Kei Tanabe