Abstract: A magnetic rotary encoder for detecting incremental angular displacement, angular velocity and rotating direction using magneto-resistors is disclosed. A drum, disk or cupshaped rotary member is attachable to a rotatable shaft. A magnetic medium is provided on a surface of the rotary member and is divided at a pitch p into a plurality of magnetic sections each of which has a magnetic signal recorded. The magnetic medium produces an alternating magnetic field as the rotary member revolves. Alternatively, a plurality of permanent magnets are provided on the surface of the rotary member to produce the alternating magnetic field of the rotary member revolves. A magnetic field detector includes at least one magneto-resistor having a stripe-like configuration with width D. The magneto-resistor is located in the vicinity of the rotary member so as to be spaced from the magnetic medium or the permanent magnets by equal to or less than p at its nearest portion and by equal to or less than 20p at its furthest portion.

Abstract: A rotational direction detection device is disclosed which has a single permanent magnet rotatable in response to the rotation of a rotary shaft. A magnetic field sensor is composed of a plurality of magnetic field detecting elements responsive to a rotating magnetic field produced by the rotation of the permanent magnet for generating an output representative of the rotation of the rotary shaft. The magnetic field detecting elements are arranged so that signals developed by at least two such elements differ in phase by a phase angle of other than 0 degree and 180 degrees. A rotary condition detector is responsive to the output of the magnetic field sensor for determining the rotational direction of the rotary shaft.

Abstract: A pressure sensor comprises essentially magnetoresistive elements formed on a diaphragm serving as a stress magnifier. The diaphragm may be made, for example, of glass in a thickness of 0.5 millimeter, and the magnetoresistive elements can be formed thereon in any desired pattern of thin stripes by ordinary thin-film techniques. Such sensor elements can be mass produced, e.g., by vapor deposition and etching on a large sheet of diaphragm material and cutting into chips of desired shape and size.