Magnetic sensor device

Abstract

The invention relates to the following magnetic sensor device, which can prevent the magnetic powder adsorbed by a magnet for applying a magnetic field from being adsorbed to a magnetic flux detecting part and can reduce the influence caused by the magnetic field of the magnet for applying a magnetic field to the magnetic flux detecting part. In a magnetic pattern detecting device, the magnetic sensor device comprises a magnetic field applying magnet for applying a magnetic field to a medium, and a magnetic sensor element, wherein the magnetic sensor device forms a magnetic flux detecting part for detecting the magnetic flux at a state of applying a bias magnetic field to the medium which is applied with a magnetic field. The magnets for applying the magnetic field are arranged on the two sides of the movement direction of the medium relative to the magnetic sensor element so as to act as a first magnet and a second magnet for applying magnetic fields, and the first magnet and the second magnet for applying magnetic fields, which are opposite to each other in the movement direction of the medium, are opposite to each other by different poles in a manner of clamping the magnetic sensor element.

Description

technical field [0001] The present invention relates to a magnetic sensor device for detecting magnetic properties and the like of an object mounted with a magnetic body and a medium such as a banknote printed with magnetic ink. Background technique [0002] When detecting the magnetic properties of objects mounted with magnetic bodies, banknotes printed with magnetic ink, etc., a magnetic sensor device is provided at a position in the middle of the conveying path of the medium, and the magnetic sensor device includes a configuration magnetic flux detection device. A magnetic sensor element and a magnetic field applying magnet (see Patent Documents 1, 2, and 3). [0003] Among the magnetic sensor devices, in the magnetic sensor devices described in Patent Documents 1 and 2, the magnetic field applying magnet and the magnetic sensor element are arranged so that the magnetic field applying magnet and the magnetic sensor element face each other in the direction orthogonal to th...

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Problems solved by technology

[0008] However, as described in Patent Documents 1 and 2, if the magnetic field applying magnet is arranged so that the magnetic sensor element faces, magnetic powder or the like will be attracted to the magnetic field applying magnet. The magnetic powder is attached to the magnetic sensor element, and the sensitivity is reduced

[0009] On the other hand, as in Patent Document 3, when the magnetic field applying magnet is arranged at a position deviated from the magnetic sensor element in the moving direction of the medium, the magnetic sensor element will detect the magnetic permeability of the medium when detecting the magnetic permeability of the medium. The magnetic field of the magnetic field applying magnet makes it impossible to distinguish the magnetic permeability from the residual magnetic flux

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