Abstract: Disclosed herein is a magnetic field generator that includes a solenoid coil, a soft magnetic body disposed in an inner diameter area of the solenoid coil, and a signal generating part configured to supply an AC signal to the solenoid coil. Since the soft magnetic body is disposed in the inner diameter area of the solenoid coil, the reach of a magnetic field can be significantly expanded as compared with when an air-core coil is used.

Abstract: An object of the present invention is to provide a magnetic sensor capable of, while suppressing an increase in manufacturing cost, controlling the gap size so as to make the gap between the element formation surface of the sensor chip and the magnetism collecting member as small as possible and to make variations among products fall within a certain range and a manufacturing method for such a magnetic sensor. A magnetic sensor includes a sensor chip 20a mounted on a substrate 2 such that the element formation surface 20a is perpendicular to the substrate 2 and a magnetism collecting member 30 mounted on the substrate 2 such that the surface 31 faces the substrate 2 and the surface 32 faces the element formation surface 20a. The surfaces 31 and 32 of the magnetism collecting member 30 have flatness higher than that of the other surfaces thereof.

Abstract: A magnetic sensor includes a sensor chip mounted on a substrate such that an element formation surface thereof is perpendicular to the substrate and a magnetism collecting member mounted on the substrate such that a surface thereof faces the substrate and a surface thereof faces the element formation surface. The arithmetic mean waviness Wa of the surface of the magnetism collecting member is 0.1 ?m or less. When the arithmetic mean waviness Wa of the surface of the magnetism collecting member that faces the element formation surface is set to 0.1 ?m or less, it is possible to significantly suppress a deterioration in detection sensitivity due to the presence of a gap between the element formation surface and the magnetism collecting member and to significantly reduce variations in detection sensitivity among products.

Abstract: A magnetic sensor includes a sensor chip mounted on a substrate such that an element formation surface thereof is perpendicular to the surface of the substrate and a magnetism collecting member mounted on the substrate such that a surface thereof faces the element formation surface. The magnetism collecting member has a surface positioned on the side opposite to the surface, and both the surfaces are flattened. This reduces a gap between the element formation surface and the magnetism collecting member and reduces variations among products. In addition, since the surface is also flattened, the magnetism collecting member has no directionality with respect to the sensor chip when it is mounted on the substrate, so that working efficiency during assembly can be improved.

Abstract: To reduce the number of components and simplify the circuit configuration in a magnetic field detection device capable of detecting a weak magnetic field without using a shield room. A magnetic field detection device includes a cancel coil wound around a winding core part of a bobbin, magnetic sensors fixed to mutually different positions of the bobbin, and a feedback circuit that makes a cancel current flow in the cancel coil according to an output signal from the magnetic sensor to cancel the environmental magnetic field in a cancel space. Since the cancel coil is used in common for the magnetic sensors, it is possible to reduce the number of components to be used and to simplify the circuit configuration.

Abstract: To facilitate a change in the number and layout of magnetic field detection devices to be arranged in an array. A magnetic field detection device includes a cancel coil wound around a bobbin, a cover member fixed to the bobbin and covering the cancel coil in a direction perpendicular to the axial direction of the cancel coil, and magnetic sensors fixed to the bobbin or cover member. The cover member has side surfaces and extending in the z-direction and positioned on mutually opposite sides. The side surfaces have first and second engagement portions, respectively, and the first engagement portion has a shape engageable with the shape of the second engagement portion. This makes it possible to arrange a desired number of the magnetic field detection devices.

Abstract: To increase, in a magnetic sensor having a magnetoresistive strip and a ferromagnetic film, a magnetic bias to be applied to a magnetoresistive element by magnetically coupling the magnetoresistive strip and ferromagnetic film. A magnetic sensor 1 includes a magnetoresistive strip S, an insulating film 13 that covers the magnetoresistive strip S, and ferromagnetic films M1 and M2 formed on the insulating film 13 and arranged in the x-direction through a magnetic gap G extending in the y-direction. The ferromagnetic films M1 and M2 overlap a plurality of hard magnetic members H through the insulating film 13. This allows two adjacent hard magnetic members H to be magnetically coupled through the ferromagnetic films M1 and M2. This makes it possible to increase the magnetic bias to be applied to a magnetoresistive element R without involving an increase in the size of the hard magnetic member H.

Abstract: To provide a small-sized magnetic sensor capable of achieving closed-loop control. A magnetic sensor includes: a sensor chip mounted on a surface of a substrate such that an element formation surface is perpendicular to the surface of the substrate or inclined by a predetermined angle with respect thereto; an external magnetic member mounted on the surface of the substrate and collecting a magnetic field to be detected in a magnetosensitive element; and a compensating coil wound around the external magnetic member. The compensating coil is thus wound around the external magnetic member, so that it is possible to cancel a magnetic field to be applied to the magnetosensitive element and to prevent the external magnetic member from being magnetically saturated.

Abstract: Disclosed herein is a magnetic sensor that includes a sensor chip having a first magnetic layer, a second magnetic layer, and a magnetosensitive element; a first magnetism collecting member covering the first magnetic layer; and a second magnetism collecting member having a body part covering a back surface of the sensor chip, a first protruding part connected to the body part and covering a side surface of the sensor chip, and a second protruding part connected to the first protruding part and covering the second magnetic layer. The second protruding part has a first surface facing the second magnetic layer. The first surface is higher in flatness than at least one of the other surfaces of the second magnetism collecting member.

Abstract: An object of the present invention is to provide a magnetic sensor capable of, while suppressing an increase in manufacturing cost, controlling the gap size so as to make the gap between the element formation surface of the sensor chip and the magnetism collecting member as small as possible and to make variations among products fall within a certain range and a manufacturing method for such a magnetic sensor. A magnetic sensor includes a sensor chip 20a mounted on a substrate 2 such that the element formation surface 20a is perpendicular to the substrate 2 and a magnetism collecting member 30 mounted on the substrate 2 such that the surface 31 faces the substrate 2 and the surface 32 faces the element formation surface 20a. The surfaces 31 and 32 of the magnetism collecting member 30 have flatness higher than that of the other surfaces thereof.

Abstract: An object of the present invention is to enhance detection accuracy of a magnetic sensor having four bridge-connected magnetic sensing elements. A magnetic sensor includes magnetic layers 41-43 provided on a surface of the sensor substrate 20 and bridge-connected magnetic sensing elements R1-R4. The magnetic layer 41 includes a main area M1 and a converging area S1 having a width gradually reduced with increasing distance from the main area M1, the magnetic layer 42 includes a main area M2 and converging areas S5, S7 each having a width gradually reduced with increasing distance from the main area M2, and the magnetic layer 43 includes a main area M3 and converging areas S6, S8 each having a width gradually reduced with increasing distance from the main area M3. The end portions of the converging areas S1-S4 and the end portions of the converging areas S5-S8 face each other, respectively, through gaps G1-G4, respectively.

Abstract: An object of the present invention is to enhance detection accuracy of a magnetic sensor having four bridge-connected magnetic sensing elements. A magnetic sensor includes magnetic layers 41-43 provided on a surface of the sensor substrate 20 and bridge-connected magnetic sensing elements R1-R4. The magnetic layer 41 includes a main area M1 and a converging area S1 having a width gradually reduced with increasing distance from the main area M1, the magnetic layer 42 includes a main area M2 and converging areas S5, S7 each having a width gradually reduced with increasing distance from the main area M2, and the magnetic layer 43 includes a main area M3 and converging areas S6, S8 each having a width gradually reduced with increasing distance from the main area M3. The end portions of the converging areas S1-S4 and the end portions of the converging areas S5-S8 face each other, respectively, through gaps G1-G4, respectively.