Mitsubishi Electric Corporation

Mitsubishi Electric Research Laboratories, Inc.

Takuya Noguchi

Takeshi Musha

Hajime Nakajima

Yoshinao Tatei

Masanori Nimura

Hisanori Torii

Toru Sasaki

Amit Kumar Agrawal

Jay E Thornton

Osamu Nasu

Yoshinori Miyamoto

Shinichiro Yoshida

Yuji Kubo

Yoshitomo Nakamura

Fumiaki Tsuchiya

Hitoshi Hasegawa

Daisuke Kanamori

Shigenori Takeda

Toshio Mekata

Haruhiko Takeyama

Shizuka Ueda

Takashi Iwamoto

Takashi Hirai

Toshiro Nakashima

Tatsuya Nagatani

Makito Seki

Toshikazu Satone

Haruyuki Hasegawa

Akira Yokoyama

Yasuhiro Kitayama

Youichi Omura

Masashi Okuma

A rotation speed detector includes: a base material to be attached to a rotating body; a first magnetic pole having an arcuate strip shape and provided on the base material; a second magnetic pole having an arcuate strip shape and provided on the base material; and a power generation element including a magnetic wire configured to cause a large Barkhausen effect, and a pickup coil. The power generation element is arranged to face the first magnetic pole and the second magnetic pole so that a longitudinal direction of the magnetic wire is provided along a radial direction of the first magnetic pole and the second magnetic pole. A non-magnetic gap is provided between the first magnetic pole and the second magnetic pole.

Rotation speed detector

The present disclosure includes: a magnetic member configured to cause a large Barkhausen effect; a power generation coil disposed so as to be wound around the magnetic member; and soft magnetic members formed at both end portions of the magnetic member so as to be in contact with the magnetic member and so as to press the magnetic member. Consequently, evenness of a magnetic flux density inside the magnetic member is increased, and the large Barkhausen effect is stably caused, whereby a highly stable power generation element is obtained.

Power generation element, and magnetic sensor, encoder, and motor using the same

A power generation element includes a magnetic member that produces a large Barkhausen effect and magnetism collection members including an insertion part having the magnetic member inserted therethrough. The magnetism collection member includes a first component on an opposite side of a boundary plane to a magnetic field generation unit and a second component on the same side of the boundary plane as the magnetic field generation unit, the boundary plane passing through a center of an imaginary circle inscribed in the insertion part and having a diameter equal to a length of the insertion part in a third direction perpendicular to first and second directions, the first direction is a direction of the insertion of the magnetic member, and the second direction is a direction in which the magnetic field generation unit is disposed. A volume of the second component is larger than a volume of the first component.

Power generation element, magnetic sensor, encoder, and motor

An encoder includes: a magnet rotatably supported; a control board including a magnetic field sensor that detects a magnetic field produced by the magnet and outputs a signal, and an arithmetic unit that detects rotation of the magnet on the basis of the output of the magnetic field sensor; a magnetic shielding cover made of a soft magnetic material; an encoder bracket used to fix the magnetic shielding cover; a protective cover fixed with being sandwiched between the magnetic shielding cover and the encoder bracket to cover the magnet and the control board to prevent entry of foreign substances; and a sealing member sandwiched between the protective cover and the encoder bracket. The magnetic shielding cover covers the magnet, the control board, and the protective cover, and the sealing member is compressed between the encoder bracket and the protective cover.

Encoder and motor

An encoder includes a magnetic sensor having higher detection sensitivity to a magnetic field applied in a reading direction, while having lower detection sensitivity to a magnetic field applied in a direction forming a greater angle with respect to the reading direction, an encoder substrate having the magnetic sensor mounted thereon, a magnetic shield to shield against a magnetic field including a side portion covering sides of the magnetic sensor and a top-side portion covering a top of the magnetic sensor, a permanent magnet located to face the encoder substrate, a shaft having the permanent magnet attached to a tip end of the shaft, and a bracket to support the shaft in a rotatable manner, wherein on the side portion of the magnetic shield, a notch as a connector insertion portion is located not to overlap an extended area of the magnetic sensor in the reading direction.

Encoder

To obtain a position detection device capable of detecting highly accurate and robust position by suppressing affect of error detection of an edge, provided is a configuration for performing a validity determination of edges detected by binarizing an image signal () converted by a light-receiving element () for receiving light irradiated from a light source () toward a scale () having a code pattern, and performing position detection after removing the edges determined to be invalid as edges that have been affected by foreign matter and the like among the edges on which the validity determination has been performed.

Position detection device

Provided is an absolute encoder capable of detecting the absolute angle at high resolution and with high precision. An image sensor receives light in an absolute value code pattern of a scale, an edge detecting unit detects from the received light signal an edge pixel position and an edge direction, and an edge position correcting unit corrects the edge pixel position based on the edge direction. A phase detecting unit detects from the corrected edge pixel position the phase shift amount of a shift from a reference pixel position of the image sensor, and a high precision detection unit uses a rough absolute position detected by a rough detection unit and the phase shift amount detected by the phase detecting unit to detect the absolute position with high precision.

Absolute encoder

An optical encoder includes: an optical scale having periodical optical patterns and can be relatively and angularly displaced; a projector for irradiating the optical scale with light; a light receiver for receiving light from the optical scale; and a calculator for calculating an absolute rotation angle &#x3b8; of the optical scale in accordance with a signal from the light receiver. The optical patterns include a plurality of light shielding portions and a plurality of light transmitting portions, each of the portions being located alternately. When a pitch of an n-th light shielding portion in a predetermined circumferential direction is denoted by Pn and a width of the n-th light shielding portion is denoted by Wn, a transmissivity T(&#x3b8;n) corresponding to an angle &#x3b8;n of the n-th light shielding portion and the pitch Pn of the light shielding portion satisfy predetermined equations, and the width Wn of the light shielding portion in the optical pattern varies in accordance with a function of the pitch Pn of the light shielding portion.

Optical encoder

Present invention provides an optical encoder capable of improving the precision of an interpolation angle in a single signal track, in an encoder of sine-wave angle interpolation type. The optical encoder includes a waveform, in which a phase-modulated wave is superimposed in a predetermined period over a sine-wave of a fundamental period, as a signal track (), and an optical detector () for extracting the sine signal and the cosine signal of the phase-modulated wave. An operation unit () operates electric angles individually from the output signals of a first optical detector pair and a second optical detector pair belonging to the optical detector, and determines the sum and difference of the electric angles, thereby acquiring the electric angle and the phase-modulated wave of the fundamental period.

Optical encoder having a single signal track and an optical detecting part with sine and cosine signals

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Tokyo, Japan

Takuya Noguchi