Alps Electric Co., Ltd.

Other

Ichirou Tokunaga

Takashi Hatanai

Yoshito Sasaki

Seiji Kikuchi

Hirofumi Okumura

Toshio Ogawa

Hironori Kato

Yoshio Sanpei

Toshiyuki Hoshi

A magnet is provided on a detection member that moves on a straight line. A Hall element serving as a magneto-electric element is provided on a fixed member that opposes the magnet. A surface of the magnet that opposes the Hall element is formed into a radius or trapezoidal shape. With this arrangement, linear outputs can be obtained at any rotational angles even when a rotator rotates a plurality of times.

Magnetic displacement detecting device having linear changing magnetic field over the length of the service

A rotational angle detecting device includes a rotation detecting section for outputting sinusoidal first and second detection signals as a result of the rotation of a rotor connected to a rotary member, a storage section for updating and storing the first and second detection signals, and a controlling section. The first and second detection signals have constant amplitudes, have the same periods, and have wavelengths which are output of phase. The controlling section compares the amplitude values of most recent first and second detection signals output from the rotation detecting section, and determines whether or not the amplitude values fall within proper ranges. When the controlling section determines that they fall within the proper ranges, a piece of detection information which is created based on the most recent first and second detection signals is supplied to a controller. On the other hand, when the controlling section determines that they do not fall within the proper ranges, the controlling section destroys the most recent first and second detection signals, and does not supply detection information to the controller. The invention provides a rotational angle detecting device for performing required controlling operations using detection signals output from the rotational detecting section which have been determined as being proper detection signals.

Device for detecting the rotational angle of a rotary member

The encoder of the present invention includes at least a pair of giant magnetoresistive effect elements, in which the giant magnetoresistive effect elements to be paired are formed on a substrate in a state that the elements are connected mutually electrically with the orientations of magnetization axes of the pinned magnetic layers each facing the same direction in parallel, a magnetic coding member is rotatably supported to face the giant magnetoresistive effect elements on the substrate, and the magnetic coding member has a plurality of magnetic poles formed along the direction of rotation of itself.

Encoder provided with giant magnetoresistive effect elements

The present invention is characterized in that a first giant magnetoresistive effect element and a second giant magnetoresistive effect element are provided along a first straight line with the magnetization of the pinned magnetic layer c oriented in a fixed direction, and that a third giant magnetoresistive effect element and a fourth giant magnetoresistive effect element are provided along a second straight line, which is parallel to the first straight line, with the magnetization of the pinned magnetic layer oriented 180&deg; opposite to the directions of magnetization of the pinned magnetic layers in the first and second giant magnetoresistive effect elements.

Magnetic field sensor having giant magnetoresistive effect elements, manufacturing method and apparatus therefor

The potentiometer of the present invention includes at least a pair of giant magnetoresistive effect elements, in which the giant magnetoresistive effect elements to be paired are formed on a substrate in a state that the elements are connected mutually electrically with the orientations of magnetization axes of the pinned magnetic layers facing 180&deg; opposite each other, and a magnetic coding member is rotatably provided to face the giant magnetoresistive effect elements on the substrate, the magnetic coding member is disposed in such a manner that the center of rotation of the magnetic coding member passes through an intermediate position of the giant magnetoresistive effect elements to be paired, and the magnetic coding member has at least two magnetic poles formed along the direction of rotation of itself.

Growing community of inventors

Miyagi-ken, Japan

Ichirou Tokunaga