Abstract: An encoder unit comprising an object to be detected having a track having a first region with a magnetization pattern at a predetermined pitch and a second region having no periodic magnetization pattern, and a detector having a magnetoresistance effect element arranged in the direction which intersects the direction of the magnetic flux of the magnetization pattern and in opposed relationship with the object to be detected. The encoder unit is simple in construction yet capable of detecting the position of the object to be detected with a higher degree of accuracy than conventional encoders.

Abstract: Magnetic thin films are formed on two base plates in relation to tracks of a recording medium. After a non-magnetic thin film is disposed on the magnetic thin films, the two base plates are joined via the non-magnetic thin film to form a magnetic gap, so that a magnetic head is fabricated. The magnetic head can be mass-produced in a simple process with uniform quality, and offers a small area of the surface opposite to each other in adjacent recording and/or reproducing portions, so that crosstalk is reduced.

Abstract: A magnetoresistive effect thin film magnetic sensor has a temperature compensating magnetoresistive effect (MR) element arranged non-parallel to a signal detecting MR element to prevent the temperature compensating MR element from being influenced by an external magnetic signal field. Alternatively, it has an L-shaped temperature compensating MR element arranged closely to the signal detecting MR element to prevent the temperature compensating MR element from being influenced by the external magnetic signal field. It further has a magnet member arranged closely to or in contact with the temperature compensating MR element to enhance a positional precision of the temperature compensation and reduce a time lag.

Abstract: The present invention is directed to improvements in a perpendicular magnetic recording-reproducing head. One of the improvements comprises the use of a magneto-resistive effect element to form the main pole of the magnetic head. This feature of the invention enables a stable and faithful reproduction of information recorded in a magnetic recording medium up to the shortest wavelength and to obtain a sufficiently large reproducing output signal. Another improvement comprises the use of such magneto-resistive effect elements in layers. The multilayer structure permits production of a large reproducing output and also an optimum S/N ratio even if the width of track is small.

Abstract: A process for making magnetic reluctance effect type magnetic heads comprises forming the magnetic sensor, first lead and second lead sections in series by use of the same material. The noise in the magnetic head is reduced, yet the output is increased by making the first lead section of a width larger than that of the magnetic sensor and second lead sections. The reproducing sensitivity of the magnetic head is increased by forming a plurality of magnetic sensor sections in series within a rectangular area. The control of the magnetic characteristics of the head are controlled for providing less dispersion by providing a substrate on which a magnetic reluctance effect type material varying in electric resistance in response to any magnetic field is formed into a film, the substrate being optionally etched by the use of photolithography to form the magnetic sensor sections, the first lead section and the second lead section on the substrate in given configurations.