MAGNETIC SENSOR DEVICE

Abstract

Magnetic sensor device comprising the following: - a rod-shaped magnet (9); - a support (7) arranged parallel to the magnet (9) along the longitudinal direction of the magnet (9) and comprising a magnetoresistive element (4) formed on a surface of the support that faces another surface that faces the magnet (9), wherein the support (7) is formed with a magnetic body (7a) extending along the longitudinal length of the magnet (9); and - a guide (14, 14e) having a bottom region arranged between the magnet (9) and the support (7), and a side wall region extending upwards from the bottom region and along a side surface of the magnet (9) which is in longitudinal contact with a surface of the magnet (9) opposite the support (7), wherein the bottom region and the side wall region are formed from a non-magnetic body which is in contact with the magnet (9) and extends in the longitudinal direction of the magnet (9); - wherein the magnet (9) is attracted to and held by the support (7) by the magnetic attraction between the magnet (9) and the support (7), wherein the guide (14, 14e) is arranged between them, and - wherein the magnet (9) adheres to the guide (14, 14e) and is able to slide in the longitudinal direction with respect to the guide (14, 14e).

Description

Technical field

[0001] The invention relates to a magnetic sensor device capable of detecting a micromagnetic pattern formed on a planar medium, for example on a banknote. background

[0002] Patent literature 1 describes a magnetic sensor device comprising the following: a transport route for transporting an object to be detected or measured; a magnet with a magnetic pole located on one side of the object being measured, generating a transverse magnetic field that penetrates the object being measured; An element with a magnetoresistance effect, arranged between the magnet and the object being measured, having an output terminal and emitting a change in a magnetic field component in the transport direction in the transverse magnetic field as a change in a resistance value, wherein the change is caused by the magnetic field component of the object being measured, which is transported in the transverse magnetic field.

[0003] Patent literature 1 describes a configuration of a magnetic circuit for generating a transverse magnetic field in which magnets are arranged opposite each other, with the object being measured located between them; furthermore, a configuration is given in which a magnet is arranged on one side of the object being measured, and a magnetic body is arranged on the other surface of it, which is opposite the magnet.

[0004] Patent literature 2 describes a magnetic sensor comprising: a plate, a magnetoresistive element having a pair of magnetoresistive areas arranged parallel to each other with a constant distance between them on the plate; a conductor layer arranged in a position such that each of the pair of magnetoresistive areas is equidistant; and a resistor connected electrically in series with the conductor layer.

[0005] Patent literature 3 specifies a configuration to obtain a long magnetic circuit using a plurality of short magnets arranged in an array, forming a uniform magnetic flux density distribution in the array direction.

[0006] JP 2015-7580A describes a magnetic sensor device comprising: a magnetic unit facing a surface of a detectable object having a magnetic component and forming a magnetic field crossing the detectable object; and a magnetoresistive element positioned between one of the magnetic poles of the magnetic unit and the detectable object to output as a change in resistance value a change in the component in the direction of travel of the cross-magnetic field caused by a magnetic component of the detectable object being transported in the cross-magnetic field. The magnetic unit is movably arranged in the direction of travel relative to the magnetoresistive effect element such that the component in the direction of travel of the cross-magnetic field exerted on the magnetoresistive effect element assumes a predetermined magnitude.

[0007] JP H11-101658A describes a magnetic detection element, a retaining element for holding the magnetic detection element, a magnet, a flexible copper laminate plate, and a resin holder, all housed within a casing. A retaining element formed within the holding element is elastic and presses the magnetic detection element toward the retaining element. The retaining element holds the magnetic detection element and regulates its position to maintain a constant position. The magnet is held by the retaining element. The retaining element is connected to the casing at the tip of the connecting part. The flexible copper laminate plate is curved along the surface of the retaining element and protrudes from the casing. State of the art patent literature Patent Literature 1 Unexamined Japanese Patent Application Publication JP 2012 - 255 270A Patent Literature 2 Unexamined Japanese Patent Application Publication JP H08 - 201 493A Patent literature 3 International patent application publication WO 2013 / 114 993 A1. Summary of the invention: Technical problem

[0008] In the magnetic sensor devices described in patent literature 1 and patent literature 2, the sensor output signal is influenced by the magnetic flux density of a magnetic field generator formed by a magnet and a magnetic body. Therefore, a long magnetic field generator with a uniform magnetic flux density distribution along its length is required to enable the use of such a long magnetic sensor device.

[0009] As a configuration for achieving a long magnetic field generator with a uniform magnetic flux density distribution in the longitudinal direction, patent literature 3 describes a structure in which magnets are rigidly arranged in a line and in close contact with continuous iron-based metal yokes. However, if a magnet with a small coefficient of linear expansion is mounted on an iron-based yoke with a large coefficient of linear expansion compared to the magnet, a problem arises in that the magnetic field generator may develop warps or twists and be damaged due to a difference in the coefficients of linear expansion caused by changes in the ambient temperature.

[0010] If twisting or warping occurs in the magnetic field generator, interference arises between the magnetic field generator and the transport plane of the magnetic sensor device on which the object being measured is transported. This interference impairs transport because the object being measured gets stuck on the magnetic sensor device. Furthermore, a problem arises in the reading direction (longitudinal direction) of the magnetic sensor device insofar as the scanning sensitivity in this direction is affected, and a stable scanning output signal cannot be obtained due to the difference in distance between the object being measured and the magnetic field generator.

[0011] If the magnetic field generator is damaged, the magnetic flux density of the magnetic field generator is not uniform along the longitudinal direction of the magnetic sensor device. Therefore, the response behavior of the sensors is not constant along the longitudinal direction of the magnetic sensor device.

[0012] The present invention was designed to solve the problems described above. The invention therefore aims to provide a long magnetic sensor device in which twisting or warping of the magnet does not occur and the magnet is not damaged, even when temperature changes occur in a case where the linear expansion coefficient of the magnet differs from that of a component to which the magnet is attached. Solution to the problem

[0013] The problem underlying the invention is solved by a magnetic sensor device having the features of independent claim 1. Advantageous embodiments of the invention are specified in dependent claims 2 to 6. Advantageous effects of the invention

[0014] According to the present invention, the magnet is fixed, except in the longitudinal direction of the magnetic sensor device, and is arranged to be slidably displaceable in the longitudinal direction, utilizing the guide and the magnetic attraction force. Thus, no warping or distortion of the magnetic field generator occurs, and no associated damage results from a difference between the linear expansion coefficients of the magnet and the yoke.

[0015] Therefore, a long magnetic sensor device can be specified that is capable of detecting a measurement object that has a magnetic component, and the magnetic sensor device offers stable operation even when the ambient temperatures change. Brief description of the drawings

[0016] The drawings show in: Fig. 1 a sectional view in a plane orthogonal to the main scanning direction of a magnetic sensor device according to embodiment 1 of the present invention; Fig. 2A a perspective view to illustrate the magnetic sensor device according to embodiment 1, viewed from one side of the transport route; Fig. 2B a perspective view to illustrate the magnetic sensor device according to embodiment 1, viewed from below; Fig. 3A a perspective view to illustrate a carrier of the magnetic sensor device according to embodiment 1; Fig. 3B a sectional view to illustrate the carrier according to embodiment 1; Fig. 4A a perspective view to illustrate a housing of the magnetic sensor device according to embodiment 1, viewed from the transport path side; Fig. 4B a perspective view to illustrate the housing of the magnetic sensor device according to embodiment 1, viewed from below; Fig. 5A a perspective view to illustrate a state in which a sensor plate, the carrier, an element with magnetoresistance effect and a signal amplification IC are installed in the magnetic sensor device according to embodiment 1; Fig. 5B a sectional view to illustrate a detector according to embodiment 1; Fig. 6A a perspective view to illustrate a magnetic field generator of the magnetic sensor device according to embodiment 1; Fig. 6B a sectional view to illustrate the magnetic field generator according to embodiment 1; Fig. 7 a sectional view to illustrate a state in which a sensor and the magnetic field generator of the magnetic sensor device according to embodiment 1 are connected to each other; Fig. 8 a sectional view to illustrate a state in which the sensor and the magnetic field generator are installed in the housing of the magnetic sensor device according to embodiment 1; Fig. 9 a sectional view to illustrate a state in which a heat sink is attached to the arrangement according to Fig. 8 is attached; Fig. 10 a sectional view to illustrate a condition in which a cover is attached to the arrangement according to Fig. 9 is attached; Fig. 11 a sectional view in a plane orthogonal to the main scanning direction of a magnetic sensor device according to embodiment 2 of the present invention; Fig. 12A a perspective view of a guide for a magnetic sensor device according to embodiment 3 of the present invention, viewed from the transport path side; Fig. 12B a perspective view of the guide of the magnetic sensor device according to embodiment 3, viewed from below; Fig. 12C a side view of the guide of the magnetic sensor device according to embodiment 3; Fig. 13A a perspective view to illustrate a state in which a magnet and a yoke are fitted into the guide according to embodiment 3; Fig. 13B a ​​side view to illustrate a state in which the magnet and the yoke are fitted into the guide according to embodiment 3; and in Fig. 14 a sectional view in a plane orthogonal to the main scanning direction of a magnetic sensor device according to embodiment 4 of the present invention. Description of the embodiments

[0017] Embodiments of the invention are explained in more detail below with reference to the accompanying drawings. In the drawings, the parts and components designated by the same reference numerals are identical or corresponding parts or components. Design 1

[0018] Fig. Figure 1 shows a sectional view in a plane orthogonal to the main scanning direction of a magnetic sensor device according to embodiment 1 of the present invention. Fig. Figure 2A shows a perspective view to illustrate the magnetic sensor device according to embodiment 1, viewed from the transport path side. Fig. Figure 2B shows a perspective view illustrating the magnetic sensor device according to embodiment 1, viewed from below. Three axes X, Y, and Z are shown in the diagram. Fig. 1 an orthogonal coordinate system, which has been defined for a better understanding of the drawings.

[0019] The X-axis denotes a horizontal reading direction and thus the primary scanning direction of the magnetic sensor device. The primary scanning direction is the longitudinal direction of the magnetic sensor device. The Y-axis denotes a transport direction and thus a secondary scanning direction of a detectable or measured object relative to the magnetic sensor device. The secondary scanning direction is a transverse direction of the magnetic sensor device. The Z-axis indicates the vertical direction of the magnetic sensor device.

[0020] Furthermore, the following applies: In all embodiments of the present invention, the transport of the object to be detected or measured is a relative movement between the magnetic sensor device and the object to be detected. The movement includes a case in which the object to be detected does not move while the magnetic sensor device itself moves in a direction opposite to the direction of transport, as well as a case in which the magnetic sensor device is fixed and the object to be detected moves or is transported.

[0021] According to Fig. 1 The magnetic sensor device comprises in sequence an element 4 with magnetoresistance effect, a carrier 7, a guide 14, a rod-shaped magnet 9 and a yoke 10, extending from the transport path of the object to be detected or measured 20 into the negative Z-direction, orthogonal to the main scanning direction (X-direction) and orthogonal to the transport direction 21 (Y-direction) of the object to be detected or measured 20, such as a banknote.

[0022] The rod-shaped magnet 9 is a rectangular prism with a rectangular cross-section. The longitudinal direction of magnet 9 is arranged parallel to the main scanning direction.

[0023] The support 7 is arranged parallel to the magnet 9, along the longitudinal direction of the magnet 9, and is formed from a magnetic body that extends along the length of the magnet 9 in the longitudinal direction, i.e., the main scanning direction. The magnetoresistive element 4 is installed in a surface that faces the surface of the support 7, which in turn faces the magnet 9.

[0024] The guide 14 has a base that is positioned between the magnet 9 and the support, and a side wall section that projects vertically from the base along a side surface that is in contact with a surface of the magnet 9, which is oriented parallel to the support 7 along its longitudinal direction. The guide 14 has a base and a side wall section in contact with the magnet 9 and is formed from a non-magnetic body that extends along the longitudinal direction of the magnet 9.

[0025] The yoke 10 is in close contact with a surface of the magnet 9 on the opposite side of the carrier 7. In embodiment 1, the magnetic sensor device has a heat sink 11 which is in close contact with the outermost surface of the guide 14 on the opposite side of the carrier 7. The heat sink 11 is also in contact with the yoke 10. Furthermore, the magnetic sensor device has a cover 1, a housing 2, a sensor plate 3, and a signal processing plate 13.

[0026] The cover 1 is an element that forms a transport plane 1 for an object to be examined in the magnetic sensor device. As shown in Fig. As shown in Figure 2A, the cover 1 extends in the X-direction of the transport path side of the magnetic sensor device and has a shape that covers the installation side of the element 4 with magnetoresistance on a surface of the housing 2 in the Z-direction. The housing 2 has the shape of a frame with an opening for accommodating and holding the respective components of the magnetic sensor device, a positioning hole, and a mounting surface.

[0027] The sensor plate 3 is positioned between the cover 1 and the carrier 7 and has a structure in which a non-conductive element 3a and a conductive element 3b are formed in a wiring pattern, with these elements stacked in the Z-direction. The conductive element 3b is attached to the carrier 7, and the non-conductive element 3a is attached to the cover 1, each with double-sided adhesive tape or an adhesive. The sensor plate 3 is formed, for example, from a resin sheet, such as a glass-epoxy resin, bismaleimide triazine resin (BT resin), or the like.

[0028] The Fig. Figure 3A shows a perspective view to explain the support in the magnetic sensor device according to embodiment 1. Fig. Figure 3B shows a sectional view to illustrate the carrier according to embodiment 1. The carrier 7 is formed from a soft magnet carrier 7a and a non-magnetic carrier 7b and has an integral structure in which the soft magnet carrier 7a and the non-magnetic carrier 7b are connected to each other in the Y direction.

[0029] The carrier 7 is fitted into an opening 2b of the housing 2 and secured there with an adhesive or similar material. The magnet 9 is arranged on a surface on the opposite side of a surface that is in contact with the sensor plate 3 of the carrier 7. The soft magnet carrier 7a is, for example, made of stainless steel, while the non-magnetic carrier 7b is, for example, made of brass.

[0030] As in Fig. As shown in Figure 1, the element 4 with magnetoresistance effect is attached to a surface of the soft magnet carrier 7a in the positive Z-direction, i.e. the transport path side, with an adhesive or the like, and it is electrically connected to the conductive element 3b of the sensor plate 3 via a wire.

[0031] A signal amplification IC 5 is attached to a surface of the non-magnetic carrier 7b in the positive Z-direction (transport path side) using an adhesive or similar material. The signal amplification IC 5 is electrically connected to the conductive element 3b of the sensor plate 3 via a wire 6 and is further electrically connected to the magnetoresistive element 4. The wire 6 is, for example, a metal wire, such as a gold wire, an aluminum wire, or the like.

[0032] As in Fig. As shown in Figure 1, the cover 1 is a component forming the transport plane 1b to be detected in the magnetic sensor device. It consists of a curved, non-magnetic metal sheet, such as aluminum or the like, to avoid influencing the magnetic field. The cover 1 has a slope 1a to guide the transport, allowing the object 20 to be detected, hereinafter referred to as the measurement object 20, to be transported along the slope. The slope 1a prevents the measurement object 20 from being transported in any direction except the transport direction, i.e., the Y-direction.

[0033] The cover 1 serves to protect the magnetic sensor device from shocks and abrasion caused by impact and rubbing when the object 20 is transported on the magnetic sensor device. Furthermore, an interaction occurs between the signal amplification IC 5 and light, which generates noise.

[0034] The cover also serves to block external light, preventing it from entering the signal amplification IC 5. The cover 1 is positioned between the object being measured 20 and the magnetoresistive element 4. Therefore, the material used for the cover 1 is preferably non-magnetic to avoid impairing the magnetic sensing capability.

[0035] In embodiment 1, the cover 1 is made, for example, from a bent sheet of metal. There are no restrictions regarding the materials and manufacturing processes, provided the material possesses the aforementioned properties and functions. For example, the cover 1 can be molded from a synthetic resin that has a light-blocking effect.

[0036] As in Fig. As shown in Figure 1, the housing 2 is a component used to accommodate other elements inside. Fig. Figure 4A shows a perspective view to illustrate a housing of the magnetic sensor device according to embodiment 1, viewed from the transport path side. Fig. Figure 4B shows a perspective view to illustrate the housing of the magnetic sensor device according to embodiment 1, viewed from below.

[0037] The housing 2 is formed from a black resin and includes a step 2a, an opening 2b, an opening 2c, a cover carrier 2d, an opening 2e, a plate mounting surface 2f, and a plate mounting hole 2g. The carrier 7, which integrates the sensor plate 3, the magnetoresistive element 4, the signal amplification IC 5, and the wire 6, is positioned between the cover 1 and the step 2a and supported in the Z-direction.

[0038] Opening 2b positions the carrier 7 in the X and Y directions, in which the sensor plate 3, the magnetoresistive element 4, the signal amplification IC 5, and the wire 6 are integrated. Opening 2c positions the integrated magnet 9 and the yoke 10 in the X and Y directions. The cover carrier 2d forms an outer surface that is chamfered towards the transport direction 21 of the measured object 20. The chamfered surface of the cover 1 is in contact along the cover carrier 2d and is attached to the housing 2.

[0039] When the heat sink 11 is attached to the yoke 10, the opening 2e forms surfaces that position the heat sink 11 in the X and Y directions. The signal processing plate 13 is positioned at the plate mounting hole 2g using a fastening element 8, for example, a screw, which engages in the plate mounting hole 13a formed in the signal processing plate 13; in this way, the signal processing plate 13 is attached to the plate mounting surface 2f.

[0040] Since the signal amplification IC 5 reacts to light and can generate noise, the housing 2 also functions as a light barrier, preventing external light from reaching the signal amplification IC 5. In embodiment 1, it is specified that molded black resin is used to form the housing 2. Provided the above-mentioned functions are sufficiently fulfilled, there are no restrictions regarding the materials and manufacturing processes for the housing.

[0041] As in Fig. As shown in Figure 1, the sensor plate 3 is formed from a non-conductive element 3a, a conductive element 3b, and a conductive element 3c. A space is formed in the non-conductive element 3a so that the cover 1 does not come into contact with the magnetoresistive element 4, the signal amplification IC 5, and the wire 6. Wiring is formed in the conductive element 3b to transmit electrical signals from the magnetoresistive element 4 and the signal amplification IC 5. The conductive element 3c is electrically connected to a cable 15 and transmits electrical signals to the signal processing plate 13.

[0042] Fig. Figure 5A shows a perspective view illustrating a state in which the sensor plate, the carrier, the magnetoresistive element, and the signal amplification IC are assembled in the magnetic sensor device according to embodiment 1. The sensor plate 3, the carrier 7, the magnetoresistive element 4, and the signal amplification IC 5 together form a detector. Fig. Figure 5 shows a sectional view to illustrate such a detector according to embodiment 1. The sensor plate 3 is attached to a surface of the carrier 7 in the positive Z-direction. The sensor plate 3 is positioned in the Z-direction and is in contact with the carrier 7.

[0043] A positioning hole 3d is formed in the sensor plate 3, and a positioning hole 7c is formed in the carrier 7. Positions in the X-direction and in the Y-direction are determined, for example, by inserting a pin through the positioning hole 3d and the positioning hole 7c and fixing it in these positions. The at least two positioning holes 3d and the at least two positioning holes 7c are each configured accordingly.

[0044] The magnetoresistive element 4 is attached with an adhesive or similar substance to the same surface as the surface on which the sensor plate 3 of the soft magnet carrier 7a is mounted. The position of the magnetoresistive element 4 in the Z-direction is determined by the element 4 with magnetoresistive effect that is in contact with the soft magnet carrier 7a.

[0045] The element 4 with magnetoresistance effect is arranged inside an opening 3e for this element with magnetoresistance effect of the circuit board 3.

[0046] Two centers at both ends of the positioning holes 3d of the sensor plate 3 are connected by an imaginary line segment, and the element 4 with magnetoresistance effect is arranged and fixed parallel to the imaginary line segment, so that the position of the element 4 with magnetoresistance effect in the Y direction is determined.

[0047] Furthermore, the center of the aforementioned imaginary line segment and the center of element 4 with magnetoresistance in the X-direction are the same, and thus the position of element 4 with magnetoresistance in the X-direction is determined. If there is a need to position the detector area of ​​the magnetic sensor device, then its positions in the X- and Y-directions can be offset parallel to the X- and Y-directions.

[0048] The magnetoresistive element 4 detects a change in the transport direction component of the magnetic field generated by the object 20, including its magnetic components, such as a banknote transported in the transport direction 21. This change in the transport direction component of the magnetic field alters the resistance value of the magnetoresistive element 4, thereby changing the signal it emits.

[0049] The signal amplification IC 5 amplifies the signal emitted by the magnetoresistive element 4. The wire 6 electrically connects the magnetoresistive element 4 and the signal amplification IC 5 to the conductive element 3b of the sensor plate 3.

[0050] As in Fig. 1 and Fig. As shown in Figure 5B, the signal amplification IC 5 is attached with an adhesive or the like to the same surface as the surface on which the sensor plate 3 of the non-magnetic carrier 7b is mounted, and its position in the Z direction is determined by the signal amplification IC 5 being in contact with the non-magnetic carrier 7b. The positions in the X and Y directions of the signal amplification IC 5 are determined such that the centers in the X and Y directions of the signal amplification IC 5 and the centers of an opening 3f for the signal amplification IC 5 are located at the same positions in the X and Y directions.

[0051] As in Fig. 1, Fig. 3A and Fig. As shown in Figure 3B, the carrier 7 has a soft magnet carrier 7a and a non-magnetic carrier 7b. The position in the Z-direction of the carrier 7 is determined by bringing a surface of the carrier 7 in the Z-direction into contact with the step 2a of the housing, and each position in the X-direction and Y-direction of the carrier 7 is determined by bringing the surfaces in the X-direction and Y-direction of the carrier 7, respectively, into contact with the opening 2b. The carrier 7 serves to support the sensor plate 3 in the Z-direction, and the soft magnet carrier 7a serves to direct the direction of the magnetic field generated by the magnet 9 in the Z-direction.

[0052] Fig. Figure 6A shows a perspective view to illustrate a magnetic field generator in the magnetic sensor device according to embodiment 1. Fig. Figure 6B shows a sectional view to illustrate the magnetic field generator according to embodiment 1. The magnetic field generator comprises the magnet 9, the yoke 10, and the guide 14. The square U-shaped cross-section of the guide 14, parallel to the YZ plane, extends in the X direction, and one surface of the guide 14 is in contact with a surface of the support 7 in the negative Z direction.

[0053] The surface of the guide 14, parallel to the XZ plane, is positioned in the Z direction from both ends of the surface that are in contact with the carrier 7 in the secondary scanning direction. The guide 14 has a structure in which the magnet 9 fits into the interior of the square U-shaped cross-section. The guide 14 is attached to the carrier 7 with an adhesive or the like. The guide 14 is formed from a non-magnetic metal, such as aluminum, or synthetic resin, but for the reasons described below regarding radiation improvement, a non-magnetic metal is desirable. For example, the guide 14 can be formed by a metal extrusion process.

[0054] The magnet 9 is held in a state in which it is in contact with the guide 14, which is placed between the magnet 9 and the carrier 7, due to the attractive force that magnetizes the soft magnet carrier 7a. For example, a neodymium sintered magnet is used for the magnet 9.

[0055] The yoke 10 is a metal plate with soft magnetism, which is attracted by the magnetic force of the magnet 9 against the surface of the magnet 9 on the opposite side of the support 7 in the negative Z-direction. A side wall region of the guide 14 is present in the Y-direction of the yoke 10, and this side wall region limits the movement of the yoke 10 in the Y-direction. The yoke 10 consists of a soft magnetic body, such as stainless steel, iron, or the like.

[0056] The in Fig. The heat sink 11 shown in Figure 1 is an element for radiating heat from the interior of the magnetic sensor device to the outside ambient air and is in close contact with the outermost surface of the guide 14 on the opposite side of the carrier 7; the heat sink 11 is in contact with a surface on the opposite side of a surface of the yoke 10, which is in contact with the magnet 9.

[0057] The heat sink 11 is expediently formed from a non-magnetic metal, such as aluminum or the like. The heat sink 11 is fitted into the opening 2c in the housing 2 and secured with an adhesive or the like. The signal processing board 13 is electrically connected to the sensor board 3 by the cable 15 and is mounted on the outside of the heat sink 11 on the side of the surface opposite the cover 1 of the housing 2.

[0058] As in Fig. 1 and Fig. As shown in Figure 6B, the cross-section of the guide 14, which lies parallel to the YZ plane, has a square U-shaped form. The magnet 9 and the yoke 10 are fitted into the interior of the square U-shaped cross-section of the guide 14, and this cross-section limits the movement of the magnet 9 and the yoke 10 in the Y direction. The magnet 9 is positioned closer to the support 7 than that of the yoke 10.

[0059] The dimensions of magnet 9 and yoke 10 in the X and Y directions are equal to the dimensions inside guide 14 in the X and Y directions. Yoke 10 is held in a position where it is attracted to and in contact with magnet 9 due to the magnetic force of magnet 9. An adhesive or similar material can also be used to further secure yoke 10 through magnetic force.

[0060] The integrated guide 14, the magnet 9, and the yoke 10 together form a magnetic field generator. The magnetic field generator is arranged parallel to a series of magnetoresistive elements 4 in the longitudinal direction. The magnet 9 serves to generate a magnetic field and exert a magnetic force on the object 20, while the yoke 10 amplifies the magnetic field generated by the magnet 9. The guide 14 is expediently made of a non-magnetic material so as not to interfere with the magnetic field.

[0061] The position of the magnetic field generator in the Z-direction is determined by contact between a carrier-adherent surface 14a of the guide 14 and a surface opposite a surface to which the magnetoresistive element 4 of the carrier 7 is attached. The position of the magnetic field generator in the X-direction is determined by aligning the center of the guide 14 in the X-direction and the center of the magnetoresistive element 4 in the X-direction. Similarly, the position in the Y-direction is determined by aligning the center of the guide 14 in the Y-direction and the center of the magnetoresistive element 4 in the Y-direction. The guide 14 is attached to the carrier 7 using an adhesive or similar material.

[0062] If the position of the guide 14 changes in the Y-direction, then the position of the magnet 9, which is fitted into the interior of the guide 14, also changes in the Y-direction, and thus the magnetic forces acting on the magnetoresistive element 4 and the object 20 being measured change. Therefore, the position of the guide 14 in the Y-direction should be precisely adjusted while monitoring the performance of the magnetic sensor device.

[0063] The guide 14 is attached to the support 7. The magnet 9 is held by the attractive force, which causes the magnet 9 to move close to the soft magnet support 7a via the guide 14, where the attractive force is a magnetic force. Thus, the magnet 9 is slidably displaceable in the X-direction, while the magnet is attracted to and held by the guide 14.

[0064] An elastic fastening material, such as a silicone-based adhesive or the like, can be used in combination to fix the magnet 9 and the guide 14, as support to maintain the position of the magnet 9 by the magnetic force.

[0065] In embodiment 1 according to the invention, for example, a metal is extruded and formed into the guide 14. However, there are no restrictions regarding the materials and manufacturing methods, as long as the respective element performs the function described above to a sufficient degree.

[0066] As in Fig. As shown in Figure 1, the heat sink 11 is connected to the outermost surface of the guide 14 on the opposite side of the support 7 and to the surface of the yoke 10 on the opposite side of the magnet 9 by means of an adhesive or the like, such that the position of the heat sink 11 in the Z-direction is determined. The position in the X-direction and the position in the Y-direction of the heat sink 11 are determined by bringing each of its surface in the X-direction and surface in the Y-direction of the heat sink 11 into contact with the opening 2e of the housing.

[0067] The heat sink 11 has the function of dissipating the heat to the outside, which is mainly generated by the element 4 with magnetoresistance effect and the signal amplification IC 5, and preventing the magnetic sensor device itself from heating up to a high temperature.

[0068] As in Fig. As shown in Figure 1, the position of the signal processing plate 13 in the Z-direction is determined by bringing one of the surfaces of the signal processing plate 13 into contact with the plate mounting surface 2f of the housing 2 in the Z-direction. Furthermore, the position in the X-direction and the position in the Y-direction of the signal processing plate 13 are determined by fastening the signal processing plate 13 using a fastening element 8 in a state in which the axis of the plate mounting hole 2g of the housing 2 and the axis of the plate mounting hole 13a of the signal processing plate 13 are aligned.

[0069] The fastening element 8 can be a screw, or a crimp or similar device can be used to attach the signal processing plate 13 to the housing 2. The fastening method itself is irrelevant, provided that a reliable fastening is achieved.

[0070] A method for manufacturing a magnetic sensor device according to embodiment 1 is described below. The basic process of this manufacturing method comprises a carrier assembly process, a sensor plate assembly process, a magnetic field generator assembly process, and a final assembly process. Among these manufacturing steps, the carrier assembly process must be carried out before the sensor plate assembly process, while the final assembly process can only take place after these processes.

[0071] As in Fig. 3A and Fig. As shown in Figure 3B, the carrier mounting process is a process for attaching the soft magnet carrier 7a in an opening 7d of the non-magnetic carrier 7b. The fastening methods include an adhesive bond using a synthetic resin adhesive or a connection by riveting. If there is a difference in thickness between the soft magnet carrier 7a and the non-magnetic carrier 7b, one surface is fixed in the Z-direction as a reference so that no step occurs on the reference surface.

[0072] The magnetic sensor device according to embodiment 1 has a soft magnet carrier 7a, which serves to align the direction of the magnetic field generated by the magnet 9 in the Z-direction. However, there is a case in which aligning the magnetic field in the Z-direction is not necessary, depending on the required sensitivity of the magnetic sensor device. In this case, the soft magnet carrier 7a is not required, and the non-magnetic carrier 7b without the opening 7d is used as the carrier 7. In this case, a carrier assembly process is not required.

[0073] The sensor plate assembly process is a process in which the carrier 7 is attached to the sensor plate 3, and the magnetoresistive element 4 and the signal amplification IC 5 are attached to the carrier 7 and connected to the sensor plate 3. An adhesive is applied to a bonding surface between the carrier 7 and the sensor plate 3; furthermore, in the manner described above, the positioning hole 3d and the positioning hole 7c are aligned and positioned by inserting a pin or the like, and the sensor plate 3 is attached to the carrier 7.

[0074] As in Fig. As shown in Figure 5A, the respective elements 4 with magnetoresistance effect and signal amplification ICs 5 are arranged in an array and mounted parallel to the line segment that connects the positioning holes 7c at both ends, with at least two such positioning holes 7c being formed in the carrier 7. The signal amplification ICs 5 and the elements 4 with magnetoresistance effect are each electrically connected via the conductive element 3b of the sensor plate 3 and the respective wires 6.

[0075] When the sensor plate 3, the magnetoresistive element 4 and the signal amplification IC 5 are attached to the carrier 7, the mounting surface should be the same surface as the surface to which the soft magnet carrier 7a and the non-magnetic carrier 7b are attached, without any step.

[0076] When the magnetoresistive element 4 is attached to the soft magnet carrier 7a, care must be taken to ensure that the magnetoresistive element 4 does not protrude outwards from the opening 3e for this element in the sensor plate 3, for example towards the plate side. Similarly, when the signal amplification IC 5 is mounted on the non-magnetic carrier 7, care must be taken to ensure that the signal amplification IC 5 does not protrude outwards from the opening 3f for this signal amplification IC in the sensor plate 3, for example towards the plate side.

[0077] As in Fig. 6A and Fig. As shown in Figure 6B, the magnetic field generator assembly process is a process for integrating the guide 14, the magnet 9, and the yoke 10. The number of magnets 9 is not limited to one, and a multiple of magnets 9 can be arranged and integrated in the main scanning direction.

[0078] The magnet 9 and the yoke 10 are fitted into a recess in the guide 14, which has a square U-shaped cross-section. The guide 14 and the yoke 10 are arranged such that they surround four surfaces of the magnet 9 in the Y-direction and the Z-direction. The yoke 10 is held in place by the magnetic force of the magnet 9. However, the holding force of the magnet can be enhanced by using an adhesive or similar material to prevent the position of the yoke 10 from changing.

[0079] Since the force required to hold the magnet 9 and the yoke 10 is not applied to the recess of the guide 14, the magnet 9 and the guide 14 can be temporarily fixed with an adhesive or similar material to prevent them from coming loose during the assembly process. In this case, elastic fastening materials, such as a silicone-based adhesive, are suitable as temporary fixings.

[0080] The Z-direction and Y-direction positions of magnet 9 are determined by inserting magnet 9 into the recess of guide 14 and bringing it into contact with the bottom surface of the recess and a pair of side walls that project from the bottom surface at both ends in the transport direction. The longitudinal positions of magnet 9 and guide 14 are determined by aligning one surface of one end of magnet 9, along the longitudinal direction of guide 14, with the other surface of magnet 9, along the longitudinal direction of guide 14.

[0081] The Z-direction position of the yoke 10 is determined by attaching the yoke 10 to the surface of the magnet 9 in the Z-direction, ensuring that the surface is not in contact with the guide 14. The X-direction position of the yoke 10 is determined by aligning one surface at one end in the X-direction of the yoke 10 with the corresponding surface at one end in the X-direction of the magnet 9. The Y-direction position of the yoke 10 is determined by aligning one surface at one end in the Y-direction of the yoke 10 with the corresponding surface at one end in the Y-direction of the magnet 9.

[0082] The final assembly process involves connecting the magnetic field generator to the carrier 7, to which the sensor plate 3 is attached. It is then placed and secured in the housing 2. Next, the heat sink 11 is attached to the magnetic field generator, and the cover 1 and the signal processing plate 13 are attached to the housing 2.

[0083] Fig. Figure 7 shows a sectional view to illustrate a state in which a sensor and the magnetic field generator of the magnetic sensor device according to embodiment 1 are connected. The carrier mounting surface 14a of the guide 14 for the magnetic field generator is in contact with a surface on the opposite side of the surface on which the sensor plate 3 of the carrier 7 is attached.

[0084] The guide 14 is formed along the soft magnet carrier 7a, and the center of the guide 14 in the X-direction and the center of the soft magnet carrier 7a in the X-direction are aligned. Since the performance of the magnetic sensor device changes depending on the position of the magnet 9 fitted into the guide 14, a clamping device can be used that is capable of adjusting the fixing position of the magnet 9.

[0085] The attractive force, caused by the magnetic force, which draws the magnet 9 inserted into the guide 14 close to the soft magnet carrier 7a, functions due to the contact between the guide 14 and the carrier 7. This secures the position of the magnet 9 in the Z-direction in the state in which it is fitted into the guide 14. There are also cases in which the guide 14 and the magnet 9 are temporarily fixed using adhesive or similar materials. In such cases, the temporary fixing materials should preferably be elastic, such as silicone-based adhesives or the like.

[0086] Fig. Figure 8 shows a sectional view to illustrate a state in which the sensor and the magnetic field generator are assembled in the housing of the magnetic sensor device according to embodiment 1. In the connected state of the sensor and the magnetic field generator, the surface on the opposite side of the surface to which the sensor plate 3 of the carrier 7 adheres is brought into contact with the step 2a of the housing 2; the surface of the carrier 7 in the X-direction and the surface of the opening 2b of the housing 2 in the X-direction are brought into contact with each other; the surface of the carrier 7 in the Y-direction and the opening 2b of the housing 2 in the Y-direction are brought into contact with each other, and the carrier 7 is fitted into the opening 2b. Then the magnet 9 is fitted into the opening 2c in the housing 2.

[0087] Fig. Figure 9 shows a sectional view to illustrate a state in which a heat sink is attached to the arrangement shown in Fig. Figure 8 shows that the heat sink 11 is connected to the outermost surface of the guide 14, which is opposite the support 7, and to a surface of the yoke 10, which is opposite the surface to which the magnet 9 adheres. The position in the X direction and the position in the Y direction of the heat sink 11 are determined by fitting the heat sink 11 into the opening 2e of the housing 2.

[0088] Fig. Figure 10 shows a sectional view to illustrate a state in which a cover is attached to the arrangement, which is in Fig. Figure 9 shows that a surface on the opposite side of the transport plane 1b of the cover 1 is connected to a surface on the opposite side of the support 7 of the sensor plate 3. The cover 1 is positioned such that it covers one side of the housing 2 in the Z-direction. The position of the cover 1 in the X-direction is determined by aligning the center of the cover 1 in the X-direction with the center of the housing 2 in the X-direction.

[0089] As in Fig. 1 and Fig. As shown in Figure 4B, one surface of the signal processing plate 13 is in contact with the plate mounting surface 2f of the housing 2 in the Z direction; the center axes of at least two plate mounting holes 13a formed in the signal processing plate 13 and the center axes of at least two plate mounting holes 2g formed in the housing 2 are aligned with each other; and the positions of the signal processing plate 13 and the housing 2 in the X direction and the positions of the signal processing plate 13 and the housing 2 in the Y direction are determined by fastening them using fasteners 18. Furthermore, the cable 15 provides an electrical connection between the signal processing plate 13 and the sensor plate 3.

[0090] The steps described above lead to the completion of the final assembly process, and the magnetic sensor device according to Fig. 1 to 2B is completed. Furthermore, the guide 14 according to embodiment 1 has two side wall regions along the respective two side surfaces at both ends of the magnet 9 in the Y-direction. If a movement of the magnet in the positive or negative Y-direction can be regulated at the side surface of the opening 2c in the housing 2, then only the opposite side wall region needs to be formed.

[0091] In embodiment 1, if the guide 14 has two side wall regions extending along the respective two side walls at both ends of the magnet 9 in the Y-direction, then an additional working space can be formed in the opening 2c in the Y-direction. This makes it easy to adjust the position of the magnet 9 in the Y-direction for the element 4 with magnetoresistance effect.

[0092] Furthermore, the magnet 9 is columnar. However, its cross-section is not limited to being rectangular or square. For example, its cross-section can also be trapezoidal or parallelogram-shaped. If, for instance, the cross-section of the magnet 9 is asymmetric with respect to the ZX plane, as in the case of a parallelogram, then the magnetic field in the ZX plane will be asymmetric. Subsequently, the behavior of the magnet 9 when the temperature of the magnetic sensor device changes is described.

[0093] If the temperature of magnet 9 changes in response to a temperature change in the magnetic sensor device, and this change is proportional to the magnitude of the temperature change and the dimensions of magnet 9, then the respective dimensions of magnet 9 expand or contract in the X, Y, and Z directions. The dimensions in the Y and Z directions of magnet 9 are relatively small compared to its length in the X direction and are not significantly altered by a temperature change.

[0094] However, a temperature change increases the length of magnet 9 in the X-direction relative to the reading width of the magnetic sensor device. To obtain a longer magnetic sensor device, it is necessary to increase the length of the magnet in the X-direction. The rate of change in the length of magnet 9 in the X-direction increases relative to its length in the X-direction as the temperature of the magnetic sensor device changes.

[0095] If the magnet 9 expands or contracts in the X-direction due to a temperature change, its position in the X-direction and its position in the Z-direction do not change due to the magnetic attraction that draws the magnet 9 close to the soft magnet carrier 7a. This is because the magnetic force is exerted by the magnet and because the magnet is in contact with the guide 14. Therefore, expansion or contraction of the magnet 9 occurs only in the X-direction along the guide 14.

[0096] The magnet 9 can be connected to the guide 14 and the yoke 10 using an adhesive or similar material. However, it is necessary to use a soft adhesive, such as a silicone-type adhesive, to avoid restricting expansion or contraction of the magnet 9 relative to the guide 14 in the X-direction.

[0097] To prevent the position of magnet 9 from shifting, it can be rigidly attached to the yoke 10, which is made of stainless steel, and the support 7, which is made of brass, in which a hard synthetic resin, such as an epoxy resin, is used. The support 7 is assumed to consist of the soft magnet support 7a made of stainless steel and the non-magnetic support 7b made of brass. In general, the coefficient of linear thermal expansion of stainless steel lies between 9 and 18 (10 -6 / K) during the linear expansion coefficient of brass between 18 and 23 (10 -6 / K) is located.

[0098] When a neodymium sintered magnet is used for magnet 9 in embodiment 1, it is assumed that magnet 9 is magnetized in the Z-direction and in general the linear expansion coefficient of a neodymium sintered magnet is -2.3 (10 -6 / K) in the directions orthogonal to the magnetization (X-direction and Y-direction) and at 6.8 (10 -6 / K) in a direction parallel to the magnetization (Z-direction).

[0099] The linear expansion coefficients of stainless steel and brass and the linear expansion coefficient of a neodymium sintered magnet have opposite directions to each other. Therefore, if a temperature change occurs in a state where the magnet 9 is tightly fixed, a force parallel to the contact surface between the yoke 10 or the support 7 and the magnet 9 is applied, and these forces have different linear expansion coefficients. The force parallel to the surface leads to a twisting or damage of the magnet 9.

[0100] In the magnetic sensor device according to embodiment 1, the guide 14, which holds the magnet 9, is attached to the carrier 7. The magnet 9 is held by the attractive force, which ensures that the magnet 9 comes close to the soft magnet carrier 7a, by means of the magnetic force across the guide 14. Since the magnet 9 is attracted by the magnetic force and held on the guide 14, the magnet 9 is displaceable in the X-direction with respect to the guide 14.

[0101] If the ambient temperature changes, even if the expansion / contraction values ​​of the support 7 and the magnet 9 differ, the magnet 9 will expand / contract relative to the guide 14 without being regulated by the guide 14. In this way, no stress is exerted on the magnet 9. Consequently, the magnet 9 does not twist or warp and is not damaged.

[0102] Furthermore, in embodiment 1, the aluminum guide 14 is attached to the support 7 with an adhesive or the like. Since the linear coefficient of expansion of aluminum is generally 23 (10 -6 / K), depending on the combination with materials of the carrier 7, the magnet 9 may experience twisting or distortion as well as damage similar to that of the fixed magnet 9.

[0103] However, aluminum does not interfere with the magnetic circuit, and the cross-sectional shape of the aluminum can be changed independently of the performance of the magnetic sensor device. Therefore, the strength can be increased by changing the cross-sectional shape of the guide 14, and this can counteract the force caused by the difference in the linear expansion coefficients.

[0104] Next, the way in which the heat generated in the magnetic sensor device is dissipated to the external environment is described.

[0105] The main heat sources in the magnetic sensor device are the magnetoresistive element 4 and the signal amplification IC 5. In embodiment 1, the use of aluminum as the material for the guide 14 efficiently dissipates the heat generated by the magnetoresistive element 4 and the signal amplification IC 5 to the heat sink 11.

[0106] The heat generated in the magnetoresistive element 4 and the signal amplification IC 5 is conducted to the carrier 7, with which the magnetoresistive element 4 and the signal amplification IC 5 are in contact. The components in contact with the carrier 7 are the sensor plate 3, the housing 2, and the guide 14. Of these components, the non-conductive element 3a of the sensor plate 3 is made of epoxy glass, and its thermal conductivity is low, as the thermal conductivity of epoxy glass is generally 0.4 [(W / m K)]; therefore, the heat is hardly dissipated because the non-conductive element 3a does not contain any metal for heat dissipation.

[0107] Furthermore, the housing 2 consists of a synthetic resin with low thermal conductivity, the thermal conductivity of the commonly used polycarbonate resin being approximately 0.24 [(W / m K)]; thus, heat is hardly dissipated. Most of the heat supplied to the support 7 is dissipated to the guide 14, the thermal conductivity of which is generally 236 [(W / m K)].

[0108] The guide 14 is in contact with the support 7, the magnet 9, the yoke 10, and the heat sink 11. The heat supplied to the guide 14 by the support 7 is conducted to the magnet 9, the yoke 10, and the heat sink 11. The magnet 9 is only in contact with the guide 14 and the yoke 10. Therefore, the heat supplied to the magnet 9 by the guide 14 is conducted to the yoke 10.

[0109] Since the yoke 10 is only in contact with the guide 14, the magnet 9, and the heat sink 11, the heat supplied to the yoke 10 by the guide 14 and the magnet 9 is transferred to the heat sink 11. Since the guide 14 is in direct contact with the heat sink 11, the heat is transferred directly from the guide 14 to the heat sink 11.

[0110] The heat from the heat sink 11 is conducted and radiated into the opening 2e and forwarded to the signal processing board 13 and to the ambient air via the wiring pattern of the signal processing board, in particular ground, and the wiring pattern of the power supply, as well as a through-hole.

[0111] When the magnet is in direct contact with the carrier 7, without the guide 14, the heat is conducted from the carrier 7 to the magnet 9, from the magnet 9 to the yoke 10, and from the yoke 10 to the heat sink 11, and then released into the outside ambient air.

[0112] If aluminum is used as the material for the guide 14, such aluminum has a higher thermal conductivity than the magnet 9; in embodiment 1, a neodymium sintered magnet is used, and such a neodymium sintered magnet generally has a thermal conductivity of 6.5 [(W / m K)]. This results in more heat being transferred to the heat sink 11, and the heat dissipation to the ambient air can be increased in the configuration according to embodiment 1 with the guide 14, compared to a configuration without the guide 14.

[0113] If heat dissipation to the external ambient air increases, a temperature rise in the magnetic sensor device can be suppressed; this prevents demagnetization of the magnet 9 and ensures a stable output signal without impairment of sensitivity. Design 2

[0114] Fig. Figure 11 shows a sectional view in a plane orthogonal to the main scanning direction of the magnetic sensor device according to embodiment 2 of the present invention. In embodiment 2, instead of a synthetic resin with low thermal conductivity, a metal, for example magnesium, which has high thermal conductivity, is used as the material for the housing 2. The thermal conductivity of magnesium is generally 156 [(W / m K)].

[0115] The heat generated by the magnetoresistive element 4, the signal amplification IC 5, and other components can be dissipated to the entire magnetic sensor device by replacing the housing 2, which has the largest volume among the components forming the magnetic sensor device, with a material having high thermal conductivity.

[0116] The heat dissipation throughout the magnetic sensor device increases the areas contributing to heat dissipation, thus improving the heat dissipation efficiency. The heat generated inside the magnetic sensor device is primarily transferred to the housing 2 and radiated from the outer surface of the housing to the surrounding air. Therefore, a heat sink inside the housing is not strictly necessary.

[0117] As in Fig. As shown in Figure 11, the magnetic sensor device according to embodiment 2 does not have a heat sink 11, and the opening 2c is not connected to the opening 2e. Otherwise, the configuration is the same as in embodiment 1. A surface of the guide 14 on the opposite side of the support 7 and a surface on the opposite side of the magnet of the yoke 10 are in contact with the bottom surface of the opening 2c formed in the housing 2. The heat conducted to the guide 14 is transferred to the housing 2 at the bottom surface of the opening 2c and is released and radiated from the outer surface of the housing 2 to the ambient air.

[0118] The heat generated in element 4 with magnetoresistance effect and signal amplification IC 5 is supplied to the carrier 7, conducted from the carrier 7 to the housing 2, and then dissipated from the housing 2 to the external ambient air, with the housing 2 being made of a material with high thermal conductivity. The thermal resistance between the heat source and the external environment decreases, and the heat dissipation efficiency is improved by dissipating the heat to the external environment without using thermal conduction through the guide 14, the magnet 9, and the yoke 10.

[0119] Furthermore, in embodiment 2, the side wall area of ​​the guide 14 can only be formed on the opposite side if the side wall of the opening 2c in the housing 2 is able to regulate a movement of the magnet in the positive or negative Y direction. embodiment 3

[0120] Fig. Figure 12 shows a perspective view of a guide for the magnetic sensor device according to embodiment 3 of the present invention, viewed from the transport path side. Fig. Figure 12B shows a perspective view of the guide of the magnetic sensor device according to embodiment 3, viewed from below. Fig. Figure 12C shows a side view of the guide for the magnetic sensor device according to embodiment 3. The magnetic sensor device according to embodiment 3 differs from embodiment 2 in the design of the guide. Otherwise, the configuration of the arrangement is the same as in embodiment 2.

[0121] The Fig. Figure 13A shows a perspective view to illustrate an arrangement in which a magnet and a yoke are fitted into the guide according to embodiment 3. Fig. Figure 13B shows a side view to illustrate an arrangement in which the magnet and the yoke are fitted into the guide according to embodiment 3. The guide 14 according to embodiment 3 has a projection 14b which is in contact with the magnet 9 on the inner surface of the square U-shaped cross-section of the guide 14.

[0122] Reducing the contact area between the magnet 9 and the guide 14 reduces the frictional resistance between the magnet 9 and the guide 14 in the magnetic field generator assembly process and facilitates the assembly of the magnetic field generator.

[0123] In embodiment 3, the projection 14b of the guide 14 is formed by an embossing process in which material is pushed out from the back of the surface that is in contact with the magnet 9 up to the middle of the plate thickness in a forming tool; and therefore the back of the projection 14b has a recess.

[0124] An opening is formed at the base of the projection 14b in the guide 14. This is because the guide 14 is formed by a sheet metal bending process, and a sheet metal bending tool could not otherwise be positioned because it would be blocked by the projection 14b; this is because the area of ​​the projection 14b cannot be bent at a right angle in the positive Z-direction.

[0125] If the bending is not at a right angle and the magnet 9 is fitted into the guide 14, then a corner area of ​​the magnet 9 collides with the guide 14. This causes the magnet 9 to be fixed in an inclined state. When the magnet 9 is inclined, the magnetic field exerted on the magnetoresistive element 4 changes; this impairs the performance of the magnetic sensor device.

[0126] During the metal sheet bending process, a small bending radius is created at the inner corner of the bent area. As a countermeasure, a relief groove is formed in the metal sheet beforehand. A relief groove 14d can be formed in the bending area to create a right angle for the guide 14 in the metal sheet in order to apply this method. The presence of the relief groove 14d eliminates any unnecessary contact between the corner area of ​​the magnet 9 and the guide 14 in this area, and the performance of the magnetic sensor device can be stabilized.

[0127] Furthermore, in embodiment 3, the side wall area of ​​the guide 14 can also be formed only on the opposite side if the side wall of the opening 2c in the housing 2 is able to regulate a movement of the magnet 9 in the positive or negative Y direction. Design 4

[0128] Fig. Figure 14 shows a sectional view in a plane orthogonal to the main scanning direction of the magnetic sensor device according to embodiment 4 of the present invention. In embodiment 4, a guide 14e is formed from synthetic resin, and the height of the side wall region extends to the midpoint of the height of the magnet 9. A yoke holder 14f for covering the side of the magnet 9 and the yoke 10 is arranged there to regulate the movement of the yoke 10 in the Y-direction. Otherwise, the configuration is the same as in embodiment 3.

[0129] In the magnetic sensor device according to the present invention, the carrier 7 and the guide 14 are fixed. Therefore, if a temperature change occurs, the carrier 7 and the guide 14 twist or warp due to the difference in their linear expansions.

[0130] In embodiment 4, the strength of the guide 14 is reduced by making the guide 14e from synthetic resin. This reduces twisting or warping, even if a difference in linear expansion occurs between the support 7 and the guide 14 due to a temperature change, since the guide 14 follows the support 7.

[0131] Since the rigidity of the guide 14 is reduced, there is a concern that the movement of the yoke 10 in the Y-direction cannot be sufficiently suppressed. Therefore, an opening is omitted in the Y-direction of the side wall of the guide 14 by adjusting the height of the side wall of the guide 14 so that it extends to the midpoint of the height of the magnet 9 and by reducing the height in the Z-direction. The yoke holder 14f, which covers the side of the magnet 9 and the yoke 10, is designed to regulate the movement of the yoke 10 in the Y-direction.

[0132] Since the yoke holder 14f can regulate the movement of the yoke 10 in the Y-direction relative to the magnet 9, the yoke holder 14f does not need to adhere to or be attached to the magnet 9 and the yoke 10. Therefore, the occurrence of twisting or warping due to a difference in the linear expansion coefficients of the magnet 9 and the yoke 10, as well as the yoke holder 14f, need not be considered. There are no special restrictions regarding the materials used for the yoke holder 14f.

[0133] Since in embodiment 4 the material of the guide 14e is synthetic resin and has low thermal conductivity, heat dissipation from a heat sink 11 cannot be expected, even if a heat sink 11 is attached, as in embodiment 1 or embodiment 2. Therefore, in embodiment 4, similar to embodiment 3, a metal material with high thermal conductivity is used as the material for the housing 2.

[0134] Furthermore, in embodiment 4, the following applies: If the movement of the magnet 9 can be regulated either in the positive Y-direction or the negative Y-direction at the side wall of the opening 2c in the housing 2, then the side wall area of ​​the guide 14e only needs to be formed on the opposite side. In this case, the yoke holder 14f covers the side surface on the side of the side wall area of ​​the magnet 9 and the yoke 10.

[0135] Furthermore, in the configuration according to embodiment 4, the cross-section of the magnet is not limited to a rectangular shape; the cross-section can also be a polygonal line having five or more sides, or the magnet can be a column with a curved cross-section, the outer shape being, for example, a circle, an ellipse, or the like in section.

[0136] The foregoing description includes some embodiments for illustrative purposes. Although specific embodiments have been discussed, the person skilled in the art will recognize that numerous modifications regarding the form and details can be made without departing from the broad scope of protection of the concept according to the invention.

[0137] Therefore, the foregoing description and the drawings are to be understood merely as an explanation, but not in a limiting sense. The present description is therefore not to be interpreted in a limiting manner; rather, the scope of the invention is determined by the claims and their equivalents.

[0138] The present application claims priority from Japanese patent application No. 2015 - 018 152 dated February 2, 2015, the disclosure of which is hereby introduced by reference. Reference symbol list 1 cover 1a Slope 1b Transport level 2 cases 2a level 2b Opening 2c opening 2D cover carrier 2nd opening 2f plate mounting surface 2g plate mounting hole 3 Sensor plate 3a Non-conductive element 3b Conductive element 3c Conductive element 3D positioning hole 3e Opening for element with magnetoresistance effect 3f Opening for signal amplification IC 4 elements with magnetoresistance effect 5 Signal amplification IC 6 wire 7 carriers 7a Soft magnet carrier 7b non-magnetic carrier 7c Positioning hole 7d opening 8 Fastening element 9 Magnet 10 yoke 11 heat sinks 13 Signal processing board 13a Plate mounting hole 14 Leadership 14a Carrier adhesion surface 14b lead 14d Relief groove 14th Guided Tour 14f Yoke holder 15 cables 20 measuring objects 21. Transport direction

Claims

[1] Magnetic sensor device comprising: - a rod-shaped magnet (9); - a support (7) arranged parallel to the magnet (9) along the longitudinal direction of the magnet (9) and comprising a magnetoresistive element (4) formed on a surface of the support that faces another surface that faces the magnet (9), wherein the support (7) is formed with a magnetic body (7a) extending along the longitudinal length of the magnet (9); and - a guide (14, 14e) having a bottom region arranged between the magnet (9) and the support (7), and a side wall region extending upwards from the bottom region and along a side surface of the magnet (9) which is in longitudinal contact with a surface of the magnet (9) opposite the support (7), wherein the bottom region and the side wall region are formed from a non-magnetic body which is in contact with the magnet (9) and extends in the longitudinal direction of the magnet (9); - wherein the magnet (9) is attracted to and held by the support (7) by the magnetic attraction between the magnet (9) and the support (7), wherein the guide (14, 14e) is arranged between them, and - wherein the magnet (9) adheres to the guide (14, 14e) and is able to slide in the longitudinal direction with respect to the guide (14, 14e). [2] Magnetic sensor device according to claim 1, characterized by , that the side wall area has a first side wall which projects upwards from one end in the transverse direction orthogonal to the longitudinal direction of the base area, and a second side wall which projects upwards from the other end in the transverse direction of the base area; and that the magnet (9) is in contact with the first side wall and the second side wall and is attracted to and held by the support (7), with the base area arranged between them. [3] Magnetic sensor device according to claim 1 or 2, characterized by , that the guide (14, 14e) is made of metal. [4] Magnetic sensor device according to any one of claims 1 to 3, characterized by , that it further has a yoke (10) which is in close contact with the magnet (9) on the opposite side of the support (7). [5] Magnetic sensor device according to any one of claims 1 to 4, characterized by, furthermore, that it has a heat sink (11) which is in close contact with the outermost surface of the guide (14) on the opposite side of the support (7). [6] Magnetic sensor device according to claim 4, characterized by , that it has a yoke holder (14f) that covers the side surfaces of the magnet (9) and the yoke (10), and that the height of the bottom area of ​​the side wall area of ​​the guide (14e) is a mean height of the side surface which is in contact along the longitudinal direction with a surface of the magnet (9) opposite the support (7).

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