Abstract: A ring-type magnetic head is of a structure in which a metallic magnetic film is sandwiched between two substrates, and the metallic magnetic film has a saturation magnetic field not less than 50 A/m in all directions parallel to a film plane thereof; the direction of lamination of the sandwich is generally perpendicular to a gap-forming surface of the head; where the metallic magnetic film is a Co-containing magnetically soft film having a crystallization temperature Tx greater than the Curie temperature Tc, the metallic magnetic film is subjected to a first heat treatment at a temperature not less than Tc and a second heat treatment at a temperature Ta of Tc-180.degree. C..ltoreq.Ta.ltoreq.Tc-30.degree. C.

Abstract: A method and an apparatus for guidance of a road condition for providing prospective information concerning a configuration of a forthcoming curve or intersection on a traveling route for ensuring safe driving, particularly in the dark or roads such as winding roads, mountainous roads and so forth. The apparatus includes a detecting circuit for detecting a traveling link among a plurality of links in road information on which a vehicle is traveling; a circuit for detecting an instantaneous position of the vehicle and a traveling direction of the vehicle; and a circuit for calculating a distance from the instantaneous vehicle position to a forthcoming end of the traveling link on the basis of the instantaneous vehicle position and the traveling direction.

Abstract: The present invention provides a process for producing a polyester ether copolymer which comprises conducting polycondensation after or while melting and mixing a polyester, of 0.3 (dl/g) or more in intrinsic viscosity, and a polyether having hydroxy groups or their derivatives at its terminals and having a molecular weight of 200 or more. The present invention can dispense with the steps of esterification, transesterification, etc., because of the use of the preformed polyester. Moreover, it shortens the reaction time so that only a small quantity of polyester is produced as a by-product. In addition, since the thermal history of the polyesterh is so small, deterioration of the polymer during production is suppressed. Furthermore, this process enables continuous production of products with good quality, which serves to markedly improve productivity.

Abstract: The present invention involves a direction sensor and a navigation system containing the direction sensor. The direction sensor has an earth magnetism sensor and a rate gyro sensor that calculates a compensated direction by weighted means process of the outputs from the earth magnetism sensor and the rate gyro sensor. The compensated direction has a high detection accuracy similar to the rate gyro sensor over a short time period, but does not have an error accumulation of the rate gyro sensor during a long time interval because the rate gyro sensor is substantially calibrated with the accurate direction obtained by the averaging outputs of the earth magnetism sensor. The navigation system has distribution information of the magnetic disturbances to the earth magnetism on a map and it reduces the weighted mean ration to the earth magnetism sensor when the magnetic disturbance at the locating position is large.

Abstract: An output signal processing unit of a fluxgate sensor including a fluxgate for detecting the magnetic north of a vehicle and a low pass filter for removing a high frequency component from an output of the fluxgate sensor, characterized in that it comprises, a rate sensor detecting an angular velocity of rotation based on the turning of the vehicle, the low pass filter making the cutoff frequency thereof high or low depending on the increase or decrease of the angular velocity of rotation of the rate sensor.