JP2009222517A - Magnetic position detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic position detection device for detecting a position while maintaining high reliability even if the position of a subject to be detected is detected by a magnetic resistance effect sensor. <P>SOLUTION: This magnetic position detection device includes: a magnetic resistance effect sensor 120 consisting of a first magnetic detection part made of magnetic resistant elements M11-M14, M21-M24 consisting of a fine magnetic resistant film having a narrow wire width and a second magnetic detection part made of magnetic resistant elements M31-M34, M41-M44 consisting of a magnetic resistant film having a large wire width; and a magnet for applying a magnetic field to this sensor 120. The magnetic position detection device detects the position in the direction along the central axis m of the magnet based on the ratio value of the respective values of the sensor sensitivity of the first and the second magnetic detection parts, and the position in the rotating direction centered around the central axis m of the magnet is detected based on an output signal from the first magnetic detection part. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a magnetic position detection device that detects a position of a detection object using a magnetoresistive sensor composed of a magnetoresistive element.

  As a device using this type of magnetic position detection device, for example, a by-wire shift device described in Patent Document 1 is known. The shift device detects a shift lever that can be operated in two axial directions, ie, a first axial direction and a second axial direction orthogonal to each other, and an operation position of the shift lever in the first and second axial directions, respectively. And a magnetic position detecting device. Here, the magnetic position detection device includes a first magnet that rotates around a predetermined rotation axis in accordance with an operation of the shift lever in the first axial direction, and an operation of the shift lever in the second axial direction. Accordingly, a yoke that reciprocates along the direction of the rotation axis of the first magnet and a second magnet that abuts on or separates from the yoke as the yoke reciprocates are provided. ing. In addition, the magnetic position detecting device detects a change in the magnetic vector of the magnetic field formed by the first magnet, and changes a voltage signal output according to the detected magnetic vector. (MRE sensor) is provided. Further, the magnetic position detecting device detects a change in the magnetic flux density of the magnetic field formed by the second magnet, and changes the voltage signal output according to the magnitude of the detected magnetic flux density. A sensor is also provided.

  According to such a configuration as the shift device, for example, if the shift lever is operated in the first axial direction, the first magnet rotates about its rotation axis, and the magnetic field formed by the first magnet is reduced. Since the magnetic vector changes, the output signal of the MRE sensor changes with the change of the magnetic vector. Therefore, the operation of the shift lever in the first axial direction can be detected based on the change in the output signal of the MRE sensor. For example, if the shift lever is operated in the second axial direction, the magnetic flux generated by the second magnet when the yoke abuts on the second magnet or moves away from the second magnet. Since the density changes, the output signal of the Hall sensor changes with the change of the magnetic flux density. Therefore, the position of the yoke can be detected based on the change in the output signal of the Hall sensor, and the operation of the shift lever in the second axial direction can also be detected from the position of the yoke. become.

It should be noted that this Patent Document 1 may adopt an MRE sensor instead of the Hall sensor as a sensor for detecting a change in the magnetic flux density of the magnetic field formed by the second magnet. Are listed.
JP 2007-62664 A

  As described above, even if the MRE sensor is adopted as a sensor for detecting the change in the magnetic flux density of the magnetic field formed by the second magnet, the position of the yoke can be surely detected. It becomes. However, since the magnetoresistive element constituting the MRE sensor generally has physical properties such that its resistance value changes due to the influence of its own temperature, the output signal of the MRE sensor also changes as the temperature of the MRE sensor changes. Change. For this reason, when a change occurs in the output signal of the MRE sensor, the magnetic field formed by the second magnet even though the change is actually caused by a change in temperature or the like of the sensor. May be erroneously determined to be caused by a change in the magnetic flux density, and as a result, the position of the yoke may be erroneously detected.

  This problem is not limited to the magnetic position detection device that is mounted on a by-wire type shift device and detects the position of the yoke, and the position corresponding to the yoke is set as the detection target, and the position of the detection target is magnetically detected. This is a problem common to magnetic position detection devices that detect using a resistance effect sensor.

  The present invention has been made in view of such circumstances, and its purpose is to detect the position of the detection object while maintaining high reliability even when the position of the detection object is detected by a magnetoresistive sensor. Another object is to provide a magnetic position detecting device.

  In order to solve the above-mentioned problem, the invention described in claim 1 includes two magnetic detection units each composed of two types of magnetoresistive elements having different resistance change rates with respect to the magnitude of the magnetic flux density of the applied magnetic field. A magnetoresistive sensor having a magnet, and a detected object that is made of a magnet and that can move in the direction of approaching and separating from the magnetoresistive sensor while applying a magnetic field to the magnetoresistive sensor. The distance between the magnetoresistive sensor and the magnetoresistive sensor is determined when the magnitude of the magnetic flux density of the magnetic field applied to the magnetoresistive sensor changes with the movement of the detected object. While maintaining the state where the resistance value of one type of magnetoresistive element constituting one of the magnetic sensing units is saturated, the resistance value of one type of magnetoresistive element constituting the other magnetic sensing unit is changed. The sensor sensitivity, which is a value indicating the magnitude of the output voltage in accordance with the magnitude of the magnetic flux density of the applied magnetic field, is detected for each of the two magnetic detection units, and the detected sensors The gist is to calculate a ratio value of the sensitivity values and detect the position of the detected object in the moving direction based on the calculated ratio value.

  As described above, the magnetoresistive element constituting the magnetoresistive effect sensor generally has physical properties such that its resistance value changes under the influence of its own temperature or the like, and therefore the magnitude of the magnetic flux density of the applied magnetic field. The value of the sensor sensitivity indicating the magnitude of the output voltage according to the value also changes with changes in the temperature of the sensor. However, the magnetic resistance sensor is provided with two magnetic detectors each composed of two types of magnetoresistive elements having different resistance change rates with respect to the magnitude of the magnetic flux density of the applied magnetic field. If the sensor sensitivity value of each part is detected and the ratio value of each detected sensor sensitivity value is calculated, a value in which the influence of the temperature etc. of the magnetoresistive element is offset can be obtained. Will be able to. On the other hand, if the detected object moves in the direction of approaching and separating from the magnetoresistive sensor, the resistance value of one type of magnetoresistive element constituting one of the two magnetic detectors is Almost no change is made, but a change occurs in the resistance value of one type of magnetoresistive element constituting the other magnetic detector. That is, the value of the sensor sensitivity of one magnetic detection unit is maintained in a saturated state, and the value of the sensor sensitivity of the other magnetic detection unit changes. Therefore, the value of the ratio of the sensor sensitivity values of the two magnetic detection units changes according to the position of the detected object in the moving direction. Therefore, the movement of the detected object is based on the ratio value of the sensor sensitivity values. The direction position can be detected. For this reason, according to the configuration, the influence of the temperature or the like of the magnetoresistive element is reduced, and the position of the detection object can be detected while maintaining high reliability.

  According to a second aspect of the present invention, in the magnetic position detecting device according to the first aspect, the detected object is movable in the direction of approaching and separating from the magnetoresistive sensor, and the movement thereof. The shaft is further rotatable with the shaft as a rotating shaft, and the resistance value is maintained saturated when the magnetic flux density of the magnetic field applied to the magnetoresistive effect sensor changes as the detected object moves. The gist is to detect the position of the detected body in the rotational direction based on a voltage signal output from one of the magnetic detection units constituted by one type of magnetoresistive element.

  In the magnetoresistive effect sensor, for example, it is possible to detect the position in the rotation direction of the detected object that is formed of a magnet and rotates around a predetermined rotation axis. In this case, in this case, the magnetoresistive element It is necessary to adjust in advance the distance between the object to be detected and the magnetoresistive effect sensor so that the magnetic flux density of a magnitude that saturates the resistance value is applied to the magnetoresistive effect sensor. In this respect, as in the same configuration, the resistance is detected when the magnetic flux density of the magnetic field applied to the magnetoresistive sensor changes as the object to be detected moves in the direction toward and away from the magnetoresistive sensor. If the position in the rotational direction of the detected object is detected using a voltage signal output from one magnetic detection unit composed of one type of magnetoresistive element that is maintained in a saturated state, One magnetoresistive sensor can detect both the position of the detected object in the moving direction and the position in the rotating direction thereof.

  According to a third aspect of the present invention, in the magnetic position detection device according to the first or second aspect, two types of magnetoresistive elements having different resistance change rates with respect to the magnetic flux density of the applied magnetic field have different line widths. Each of the two magnetic detectors is formed of a magnetoresistive element formed by a magnetoresistive film having a large line width, and the other magnetic detector is formed of two types of magnetoresistive films. Is composed of a magnetoresistive element formed by a magnetoresistive film having a narrow line width.

  In general, in a magnetoresistive element, as the line width of the magnetoresistive film forming the element increases, the resistance value is more likely to be saturated even if the magnetic flux density of the applied magnetic field is small. The smaller the thickness is, the more the physical property that the resistance value is not saturated unless the magnetic flux density of the applied magnetic field is large. For this reason, specifically, as in the same configuration, two types of magnetoresistive elements having different resistance change rates with respect to the magnetic flux density of the applied magnetic field are respectively formed by two types of magnetoresistive films having different line widths. In addition, one of the two magnetic detectors is composed of a magnetoresistive element formed by a magnetoresistive film having a large line width, and the other magnetic sensor is formed by a magnetoresistive film having a thin line width. The structure which consists of a magnetoresistive element made can be employ | adopted. If two types of magnetoresistive elements having different resistance change rates with respect to the magnetic flux density of the applied magnetic field are formed by two types of magnetoresistive films having different line widths, these two types of magnetoresistive elements are used. The film thickness can be the same. For this reason, when the magnetoresistive effect sensor is manufactured, the process of forming the magnetoresistive film can be basically performed as one process, so that two types of resistance change rates with respect to the magnetic flux density of the applied magnetic field are different. The magnetoresistive element can be easily manufactured.

  According to a fourth aspect of the present invention, in the magnetic position detection device according to the first or second aspect, the two types of magnetoresistive elements having different resistance change rates with respect to the magnetic flux density of the applied magnetic field are different in film thickness. Each of the two magnetic detectors is formed of a magnetoresistive element formed of a thick magnetoresistive film, and the other magnetic detector is formed of two types of magnetoresistive films. However, the gist of the invention is that it is composed of a magnetoresistive element formed by a thin magnetoresistive film.

  In general, in a magnetoresistive element, the thinner the magnetoresistive film forming the element, the easier it is to saturate even if the magnetic flux density of the applied magnetic field is small. As the thickness increases, the resistance value does not saturate unless the magnetic flux density of the applied magnetic field is large, and the amount of change in the resistance value increases. Therefore, specifically, as in the same configuration, two types of magnetoresistive elements having different resistance change rates with respect to the magnetic flux density of the applied magnetic field are respectively formed by two types of magnetoresistive films having different thicknesses, One of the two magnetic detectors is composed of a magnetoresistive element formed by a thick magnetoresistive film, and the other magnetic detector is formed by a thin magnetoresistive film. A configuration including a magnetoresistive element can be employed. Further, if two types of magnetoresistive elements having different resistance change rates with respect to the magnetic flux density of the applied magnetic field are formed by two types of magnetoresistive films having different film thicknesses, the magnetoresistive effect sensor is applied When a change occurs in the magnetic flux density of the magnetic field generated, the value of the ratio of the sensor sensitivity values of the two magnetic detectors greatly changes. The position of the detection object can be detected with higher accuracy.

  In this case, specifically, according to the invention described in claim 5, one of the two types of magnetoresistive elements having different resistance change rates with respect to the magnetic flux density of the applied magnetic field is: Eight annular elements are arranged on the semiconductor substrate of the magnetoresistive sensor in an inclined manner by 45 °, and the other magnetoresistive element is located outside the one magnetoresistive element and is also inclined by 45 °. It is possible to adopt a configuration in which eight circularly arranged concentric circles are provided, and each of the two magnetic detection units has two full bridge circuits each composed of four magnetoresistive elements.

  According to the magnetic position detection device of the present invention, a magnetic position detection device capable of detecting the position while maintaining high reliability even when the position of the detection object is detected by a magnetoresistive sensor. Will be able to provide.

(First embodiment)
A magnetic position detection device according to a first embodiment of the present invention will be described below with reference to FIGS. Here, FIG. 1 shows a perspective structure inside a vehicle provided with a lever switch device to which the magnetic position detection device according to the present embodiment is applied.

  As shown in FIG. 1, the lever switch device 10 is fixedly disposed at a position near the steering device 1 in the driver's seat of the vehicle and is operated by the driver himself. FIG. 2 shows a perspective structure of the lever switch device 10. As shown in FIG. 2, the lever switch device 10 has a lever unit main body 11 fixed to the vehicle as its main body, and is cantilevered by the lever unit main body 11 to be used for a switching operation of in-vehicle equipment. The operation lever 12 is basically provided. Here, for example, when an external force is applied by the driver, the operation lever 12 tilts in the direction indicated by the arrows x1 and x2 with the portion supported by the lever unit body 11 as the base end. It also tilts in the direction indicated by the arrows y1 and y2 inside. A rotary switch 13 is provided at the distal end of the operating lever 12 so as to rotate about a central axis m extending in the longitudinal direction of the lever 12, that is, to rotate in the directions indicated by arrows a1 and a2 in the drawing. ing. Further, a push button 14 that moves in the direction along the central axis m, that is, the direction indicated by the arrows z1 and z2 in the drawing, is provided at the tip of the rotary switch 13. And in this lever switch apparatus 10, switching of the headlight mounted in a vehicle, a small light, and a fog lamp is each operated through operation of the rotary switch 13 and the push button 14. FIG. On the other hand, a magnetic position detection device including a magnetoresistive effect sensor (MRE sensor) is provided inside the operation lever 12 as a device for detecting each operation position of the rotary switch 13 and the push button 14. Next, with reference to FIG. 3, the structure of the magnetic position detection device will be described. FIG. 3 shows an exploded perspective structure of the operation lever 12.

  As shown in FIG. 3, the magnetic position detecting device 100 includes a movable shaft 101 projecting from the bottom surface of the rotary switch 13 formed in a substantially cylindrical shape along the central axis m, and the movable shaft. And a rectangular parallelepiped magnet 102 attached to the tip of 101. Here, the movable shaft 101 is attached to the rotary switch 13 so as to be integrally rotatable, and moves relative to the rotary switch 13 in the direction of the central axis m in conjunction with the operation of the push button 14. The magnet 102 is attached to the movable shaft 101 so that the center thereof is located on the central axis m, and is magnetized so that the N pole and the S pole are aligned in a direction perpendicular to the central axis m. Has been. On the other hand, in the operation lever 12, the printed circuit board 110 is fixed inside a cylindrical cover 15 that is a part to be gripped when the driver operates the lever 12. When the rotary switch 13 is attached to the cover 15 while the movable shaft 101 and the magnet 102 are inserted into the cover 15, the printed circuit board 110 and the magnet 102 are separated by a predetermined distance in the direction along the central axis m. Thus, they will be arranged in the form of facing each other. The printed circuit board 110 is provided with an MRE sensor 120 on the surface facing the magnet 102, and a magnetic field is applied from the magnet 102 to the MRE sensor 120.

  Next, with reference to FIGS. 4 and 5, changes in the relative positional relationship between the magnet 102 and the MRE sensor 120 due to the operation of the rotary switch 13 and changes in the magnetic field will be described. Here, FIG. 4 shows a side structure of the rotary switch 13, and FIGS. 5A to 5C show a cross-sectional structure taken along line AA of FIG. 4 and 5, a state (position) rotated by a predetermined angle from the axis m10 in the direction indicated by the arrow a1 with respect to the axis m10 passing through the central axis m is indicated by the axis m11 and from the axis m11. A state (position) of further rotation by a predetermined angle in the direction indicated by the arrow a1 is indicated by an axis m12.

  As shown in FIG. 4, in the rotary switch 13, a position where the reference line mr passing through the central axis m coincides with the axis m10 is set as a reference position Pa0, and is normally held at this position. In addition, when an external force is applied in the direction indicated by the arrow a1 from the state where the rotary switch 13 is held at the reference position Pa0 in this way, the reference line mr is a position where the reference line mr coincides with the axis m11. It rotates to the operation position Pa1, and that position is maintained. Further, when an external force is applied in the direction indicated by the arrow a1 from the state where the rotary switch 13 is held at the first operation position Pa1, the reference line mr is a position where the reference line mr coincides with the axis m12. Further rotation to the second operation position Pa2 is maintained. By the way, the rotary switch 13 returns to the first operation position Pa1 or the reference position Pa0 when an external force is applied in the direction indicated by the arrow a2 from the state held at the second operation position Pa2. Then, assuming that the rotary switch 13 is operated from the state where the rotary switch 13 is located at the reference position Pa0 to the second operation position Pa2 via the first operation position Pa1, the position of the magnet 102 is as shown in FIGS. It changes in the mode shown in.

  That is, the magnet 102 rotates integrally with the movable shaft 101 in the direction indicated by the arrow a1 around the central axis m, and from the reference position Pα0 where the reference line mj passing through the central axis m coincides with the axis m10. The reference line mj rotates through a first rotation position Pα1 that coincides with the axis m11, and then turns to a second rotation position Pα2 that coincides with the axis m12. At this time, the relative position in the rotation direction about the central axis m of the magnet 102 with respect to the MRE sensor 120 changes, and the magnetic vector of the magnetic field applied to the MRE sensor 120 changes.

  Next, a change in the relative positional relationship between the magnet 102 and the MRE sensor 120 and a change in the magnetic field due to the operation of the push button 14 will be described with reference to FIGS. Here, FIG. 6 shows the front structure of the push button 14, and FIG. 7 shows the front structure of the magnetic position detection device 100. In FIG. 6, a state (position) displaced by a predetermined distance from the coaxial line m20 in the direction indicated by the arrow z1 with respect to the axis m20 intersecting the central axis m is indicated by an axis m21.

  As shown in FIG. 6, the push button 14 has a position where the position mp of the end face coincides with the axis m20 as a reference position Pz0, and is normally held at this position. In addition, when an external force is applied to the push button 14 in the direction indicated by the arrow z1 from the state where the push button 14 is held at the reference position Pz0, the first operation position where the position mp of the end face coincides with the axis m21. It moves to Pz1 and its position is maintained. When an external force is further applied in the direction indicated by the arrow z1 from the state where the push button 14 is held at the first operation position Pz1, the push button 14 is moved once in the direction indicated by the arrow z1, The position returns to the reference position Pz0. If the push button 14 is operated from the state where the push button 14 is located at the reference position Pz0 to the first operation position Pz1, the position of the magnet 102 changes in the manner shown in FIG.

  That is, the magnet 102 moves together with the movable shaft 101 in the direction indicated by the arrow z1, and moves from the first operation position d0 indicated by the solid line in the figure, which is a position away from the MRE sensor 120, to the MRE sensor 120. It moves to the second operation position d1 indicated by a broken line in the drawing, which is a close position. At this time, the relative position of the MRE sensor 120 in the direction along the central axis m of the magnet 102 changes, and the magnetic flux density is larger when the magnet 102 is located at the second operation position d1. Applied to the MRE sensor 120.

  Next, the structure of the MRE sensor 120 that detects such changes in magnetic vector and magnetic flux density will be described with reference to FIG. FIG. 8 shows a planar structure of the MRE sensor 120.

  As shown in FIG. 8, the MRE sensor 120 includes a magnetic sensing surface that senses a change in the magnetic field formed by the magnet 102, and the central axis on the same semiconductor substrate in such a manner that the magnetic sensing surface is inclined by 45 °. Eight magnetoresistive elements M11 to M14, M21 to M24 are arranged in a ring shape with m as the center. In addition, eight magnetoresistive elements M31 to M34 and M41 to M44 are provided outside the magnetoresistive elements M11 to M14 and M21 to M24, and are arranged in an annular shape around the central axis m in a manner that is inclined by 45 °. It has been. Here, these magnetoresistive elements M11 to M14, M21 to M24, M31 to M34, and M41 to M44 are made of a magnetoresistive film mainly composed of a ferromagnetic metal, and the resistance value thereof changes according to the applied magnetic field. In addition, when the magnetic flux density exceeding a predetermined size is applied, the resistance value is saturated. The magnetoresistive elements M11 to M14, M21 to M24, M31 to M34, and M41 to M44 are alternately connected at the ends of a plurality of linear films formed longer toward the outside. It is formed in a pattern. In the MRE sensor 120, the thicknesses of the magnetoresistive films forming the magnetoresistive elements M11 to M14, M21 to M24, M31 to M34, and M41 to M44 are set to constant thicknesses and arranged on the outside. The line width of the magnetoresistive film forming the eight magnetoresistive elements M31 to M34, M41 to M44 is set to the line of the magnetoresistive film forming the eight magnetoresistive elements M11 to M14 and M21 to M24 disposed inside. It is set to be thicker than the width. Thereby, in this MRE sensor 120, it applies with eight magnetoresistive elements M11-M14, M21-M24 arrange | positioned inside, and eight magnetoresistive elements M31-M34, M41-M44 arrange | positioned outside. The resistance change rates with respect to the magnetic flux density of the magnetic field are different from each other. In the MRE sensor 120, a magnetic detection unit that detects a change in the magnetic vector and magnetic flux density of the magnetic field is a first magnetic detection unit including eight magnetoresistive elements M11 to M14 and M21 to M24 arranged inside. And two magnetic detection units including a second magnetic detection unit including eight magnetoresistive elements M31 to M34 and M41 to M44 arranged on the outside.

  FIG. 9A shows an electrical configuration including the first magnetic detection unit of the MRE sensor 120, and FIG. 9B illustrates an electrical configuration including the second magnetic detection unit. An equivalent circuit is shown.

  As shown in FIG. 9A, in the circuit composed of the first magnetic detection unit 121 of the MRE sensor 120, the four magnetoresistive elements M11 to M14 constitute one full bridge circuit, and Another full bridge circuit is configured by the four magnetoresistive elements M21 to M24. In this circuit, a constant voltage Vcc is applied between the magnetoresistive elements M11 and M13 and between the magnetoresistive elements M21 and M23, and between the magnetoresistive elements M12 and M14, and the magnetoresistive element M22. , M24 are grounded. The circuit is provided with a differential amplifier 140 that takes in the midpoint potential between the magnetoresistive elements M11 and M12 and the midpoint potential between the magnetoresistive elements M13 and M14 and performs differential amplification. ing. Also provided is a differential amplifier 141 that takes in the midpoint potential between the magnetoresistive elements M21 and M22 and the midpoint potential between the magnetoresistive elements M23 and M24 and performs differential amplification. In this circuit, as each differential amplification output by the differential amplifiers 140 and 141, a first sine signal that continuously changes in accordance with changes in the magnetic field applied to the magnetoresistive elements M11 to M14 and M21 to M24. V11 and the first cosine signal V12 are output, respectively. In the following, the first sine signal V11 and the first cosine signal V12 are abbreviated as first output signals V11 and V12.

  On the other hand, as shown in FIG. 9B, the circuit composed of the second magnetic detection unit 122 of the MRE sensor 120 basically has the same circuit configuration as the first magnetic detection unit 121. . That is, also in the circuit including the second magnetic detection unit 122, one full bridge circuit is configured by the four magnetoresistive elements M31 to M34, and another full circuit is configured by the four magnetoresistive elements M41 to M44. A bridge circuit is configured. Also in this circuit, a constant voltage Vcc is applied between the magnetoresistive elements M31 and M33 and between the magnetoresistive elements M41 and M43, and between the magnetoresistive elements M32 and M34, and between the magnetoresistive elements M42 and M42, Between M44, each is grounded. This circuit is also provided with a differential amplifier 142 that takes in the midpoint potential between the magnetoresistive elements M31 and M32 and the midpoint potential between the magnetoresistive elements M33 and M34 and performs differential amplification. ing. Also provided is a differential amplifier 143 that takes in the midpoint potential between the magnetoresistive elements M41 and M42 and the midpoint potential between the magnetoresistive elements M43 and M44 and performs differential amplification. In this circuit, the second sine signal that continuously changes in accordance with the change in the magnetic field applied to the magnetoresistive elements M31 to M34 and M41 to M44 as the differential amplification outputs by the differential amplifiers 142 and 143. V21 and the second cosine signal V22 are output, respectively. Hereinafter, the second sine signal V21 and the second cosine signal V22 are abbreviated as second output signals V21 and V22.

  As shown in FIG. 10, in the magnetic position detection apparatus 100 according to the present embodiment, the first output signals V11 and V12 and the second output signals V21 and V22 output from the MRE sensor 120 are It is taken into the vehicle-side control device 200 that controls various controls. The control device 200 detects the operation positions of the rotary switch 13 and the push button 14 based on the first output signals V11 and V12 and the second output signals V21 and V22, and detects the detected rotary. Based on the operation positions of the switch 13 and the push button 14, the switching of the vehicle headlight 201, small light 202, and fog lamp 203 is controlled.

Next, a method for detecting the operation position of the push button 14 based on the first output signals V11 and V12 and the second output signals V21 and V22 will be described.
First, the first sine signal V11 and the first cosine signal V12 output from the first magnetic detection unit 121 can be expressed by the following (1) and (2), respectively. In these (1) and (2), V1 is the sensor sensitivity (the magnitude of the output voltage) of the first magnetic detector 121, and θ is the rotation of the magnet 102 in the directions indicated by the arrows a1 and a2. Each angle is shown.

V11 = V1sin θ (1)
V12 = V1 cos θ (2)
On the other hand, the second sine signal V21 and the second cosine signal V22 output from the second magnetic detection unit 122 can be expressed by the following (3) and (4), respectively. In these (3) and (4), V2 indicates the sensor sensitivity (the magnitude of the output voltage) of the second magnetic detection unit 122.

V21 = V2sin θ (3)
V22 = V2 cos θ (4)
Incidentally, the sensor sensitivity values V1 and V2 of the first and second magnetic detectors 121 and 122 are respectively the magnitudes of the resistance values of the magnetoresistive elements constituting the first and second magnetic detectors 121 and 122, respectively. It is a value that changes based on the length. Here, as described above, the resistance values of the magnetoresistive elements constituting the first and second magnetic detectors 121 and 122 change in accordance with the applied magnetic field and exceed a predetermined size. When the magnetic flux density is applied, the value is saturated. That is, the sensor sensitivity values V1 and V2 change according to the magnitude of the magnetic flux density of the magnetic field applied to the first and second magnetic detectors 121 and 122, and the magnetic flux density exceeds a predetermined magnitude. Is a value that saturates when applied to the first and second magnetic detectors 121 and 122.

  As described above, the first and second magnetic detectors 121 and 122 are each composed of two types of magnetoresistive elements having different resistance change rates with respect to the magnetic flux density of the applied magnetic field. However, the sensor sensitivity values V1 and V2 change slightly with the change in magnetic flux density of the magnetic field applied to the MRE sensor 120.

  Therefore, in the magnetic position detection apparatus 100 according to the present embodiment, first, the sensor sensitivity value V1 of the first magnetic detection unit 121 is calculated from the first output signals V11 and V12 based on the following equation (5). In addition, the sensor sensitivity value V2 of the second magnetic detection unit 122 is calculated from the second output signals V21 and V22 based on the following equation (6).

V1 = √ (V11 ² + V12 ² ) (5)
V2 = √ (V21 ² + V22 ² ) (6)
Then, the position of the magnet 102 in the direction indicated by the arrows z1 and z2 is detected by using the difference in change mode of the sensor sensitivity values V1 and V2 of the first and second magnetic detectors 121 and 122, Thereby, the operation position of the push button 14 is detected.

  Subsequently, referring to FIG. 11, changes in sensor sensitivity values V1 and V2 of the first and second magnetic detectors 121 and 122 accompanying changes in the magnetic flux density of the magnetic field applied to the MRE sensor 120 are described. The situation will be described.

  Here, FIG. 11 shows the position of the magnet 102 in the direction indicated by the arrows z1 and z2 and the values V1 and V2 of the sensor sensitivities of the first and second magnetic detectors 121 and 122, respectively. It is the graph which showed the relationship between both with respect to the vertical axis | shaft. In the graph of FIG. 11, the solid line indicates the change tendency of the sensor sensitivity value V1 of the first magnetic detection unit 121, and the alternate long and short dash line indicates the change tendency of the sensor sensitivity value V2 of the second magnetic detection unit 122. Show.

  For example, as shown in FIG. 7 above, the direction in which the magnet 102 is indicated by the arrow z1 from the position d2 separated from the reference position Pz0 in the direction indicated by the arrow z2, that is, from the position sufficiently separated from the MRE sensor 120. , And gradually approach the MRE sensor 120. At this time, the magnetic flux density of the magnetic field applied to the MRE sensor 120 changes in such a manner that it gradually increases. As shown in FIG. 11, the sensor sensitivities of the first and second magnetic detectors 121 and 122 are changed. Both values V1 and V2 gradually increase and gradually saturate to reach a constant value. Here, when the change modes of the values V1 and V2 of the sensor sensitivities are compared, first, the sensor sensitivity value V1 of the first magnetic detection unit 121 is saturated, and then the second magnetic detection unit is followed. The sensor sensitivity value V2 of 122 is saturated.

  In the magnetic position detection apparatus 100 according to the present embodiment, the distance between the magnet 102 and the MRE sensor 120 is adjusted as follows. That is, when the magnet 102 moves from the first operation position d0 to the second operation position d1 and the magnetic flux density of the magnetic field applied to the MRE sensor 120 changes, the sensor of the first magnetic detection unit 121 While maintaining the state in which the sensitivity value V1 is saturated, the distance is set such that the sensor sensitivity value V2 of the second magnetic detection unit 122 changes. In other words, the resistance values of the magnetoresistive elements M <b> 11 to M <b> 14 and M <b> 21 to M <b> 24 that constitute the first magnetic detection unit 121 are maintained in a saturated state, and the magnetoresistive element that constitutes the second magnetic detection unit 122. The distances at which the resistance values of M31 to M34 and M41 to M44 change are set. As a result, as shown in FIG. 12, when the position of the magnet 102 in the direction indicated by the arrows z1 and z2 changes from the first operation position d0 to the second operation position d1, the first magnetic detection unit 121. The sensor sensitivity value V1 indicates a constant value V1max, and the sensor sensitivity value V2 of the second magnetic detection unit 122 increases from V2 (d0) to V2 (d1).

  By the way, when the position of the magnet 102 changes between the first operation position d0 and the second operation position d1, the sensor sensitivity value V2 of the second magnetic detection unit 122 depends on the position of the magnet 102. For example, it is considered that the position of the magnet 102 in the direction indicated by the arrows z1 and z2 can be detected based on the sensor sensitivity value V2.

  However, as described above, the magnetoresistive elements M31 to M34 and M41 to M44 constituting the second magnetic detector 122, including the magnetoresistive elements M11 to M14 and M21 to M24 constituting the first magnetic detector 121, are included. In general, since its resistance value changes under the influence of its own temperature or the like, its sensor sensitivity value V2 also changes as the temperature of the second magnetic detection unit 122 changes. Specifically, for example, as indicated by a two-dot chain line in FIG. 13, when the temperature of the second magnetic detection unit 122 decreases as the temperature of the MRE sensor 120 decreases, the sensor sensitivity value V <b> 2. Shift in the direction of increasing overall. Therefore, when a change occurs in the sensor sensitivity value V2, the change is caused by a temperature change of the magnetoresistive element or the position of the magnet 102 in the direction indicated by the arrows z1 and z2. It is difficult to distinguish whether it is caused or not, and it is difficult to detect the position of the magnet 102 based on the sensor sensitivity value V2.

  Therefore, in the magnetic position detection apparatus 100 according to the present embodiment, the influence of such a temperature change of the magnetoresistive element is reflected in the sensor sensitivity values V1 and V2 of the first and second magnetic detection units 121 and 122, respectively. Focusing on this, by calculating the value of these ratios, a value in which the influence of the temperature change of the magnetoresistive element is offset is obtained. Specifically, a value Vr12 (= V1 / V2) obtained by dividing the sensor sensitivity value V1 of the first magnetic detection unit 121 by the sensor sensitivity value V2 of the second magnetic detection unit 122 is calculated. Based on the calculated sensor sensitivity ratio value Vr12, the position of the magnet 102 in the direction indicated by the arrows z1 and z2, in other words, the operation position of the push button 14 is detected.

FIG. 14 shows the relationship between the position of the magnet 102 in the direction indicated by the arrows z1 and z2 and the sensor sensitivity ratio value Vr12 with respect to the horizontal axis and the vertical axis, respectively.
As shown in FIG. 14, the sensor sensitivity ratio value Vr12 is gradually increased if the position of the magnet 102 in the direction indicated by the arrows z1 and z2 changes from the first operation position d0 to the second operation position d1. Change in a decreasing manner. Here, in the magnetic position detection device 100, the sensor sensitivity ratio value Vr12 (d0) and the second value when the magnet 102 is positioned at the first operation position d0 with respect to the sensor sensitivity ratio value Vr12. An intermediate value Vrd (= (Vr12 (d0) + Vr12 (d1)) / 2) of the sensor sensitivity ratio value Vr12 (d1) at the operation position d1 is set as a threshold value. In the apparatus 100, the sensor sensitivity ratio value Vr12 is calculated from the first output signals V11 and V12 and the second output signals V21 and V22, and the following is based on the sensor sensitivity ratio value Vr12. Thus, the operation position of the push button 14 is detected.

  a1. When it is determined that the sensor sensitivity ratio value Vr12 is greater than or equal to the threshold value Vrd. In this case, it is detected that the position of the magnet 102 in the direction indicated by the arrows z1 and z2 is the first operation position d0, and the operation position of the push button 14 is the reference position Pz0.

  a2. When it is determined that the sensor sensitivity ratio value Vr12 is smaller than the threshold value Vrd. In this case, it is detected that the position of the magnet 102 in the direction indicated by the arrows z1 and z2 is the second operation position d1, and the operation position of the push button 14 is the first operation position Pz1.

Next, a method for detecting the operation position of the rotary switch 13 will be described.
In the magnetic position detection apparatus 100 according to the present embodiment, as described above, the position of the magnet 102 in the direction indicated by the arrows z1 and z2 has changed between the first operation position d0 and the second operation position d1. At this time, the sensor sensitivity value V1 of the first magnetic detection unit 121 is kept saturated. In other words, the first sine signal V11 and the first cosine signal V12 output from the first magnetic detection unit 121 indicate changes in the magnetic flux density of the magnetic field applied from the magnet 102 to the MRE sensor 120. The influence, in other words, the operation position of the push button 14 is not affected. Therefore, in the magnetic position detection device 100 according to the present embodiment, the rotational position of the magnet 102 in the direction indicated by the arrows a1 and a2 is detected based on the first sine signal V11 and the first cosine signal V12, Thereby, the operation position of the rotary switch 13 is detected.

  FIG. 15 is a graph showing the relationship between the rotation angle θ of the magnet 102 in the direction indicated by the arrows a1 and a2 and the first output signals V11 and V12 with respect to the horizontal axis and the vertical axis, respectively.

  As shown in FIG. 15, the first sine signal V11 and the first cosine signal V12 are a sine wave shape and a cosine wave shape according to the rotation angle θ of the magnet 102 in the directions indicated by the arrows a1 and a2, respectively. To change. FIG. 16 is a graph showing a change tendency of the arctangent value Vat (= arctan (V12 / V11)) calculated based on the first sine signal V11 and the first cosine signal V12.

  As shown in FIG. 16, the arctangent value Vat gradually decreases linearly from a positive value to a negative value according to the rotation angle θ, and becomes a positive value at a predetermined period. Repeated changes such as decreasing again, the value changes in a zigzag shape. In the magnetic position detection apparatus 100 according to the present embodiment, the relative position between the magnet 102 and the MRE sensor 120 in the direction indicated by the arrows a1 and a2 is adjusted as follows. That is, when the magnet 102 is rotated from the state at the reference position Pα0 shown in FIGS. 5A to 5C to the second rotational position Pα2 through the first rotational position Pα1. The relative position between them is adjusted so that the arc tangent value Vat linearly changes from the positive value Vat1 to the negative value Vat2 through the value “0”. Here, in this magnetic position detection device 100, the half value (Vat1 / 2) of the positive value Vat1 and the half value (Vat2 / 2) of the negative value Vat2 are threshold values for the arctangent value Vat. As each. The apparatus 100 calculates the arctangent value Vat from the first sine signal V11 and the first cosine signal V12, and then operates the rotary switch 13 based on the arctangent value Vat as follows. To detect.

  b1. When it is determined that the arctangent value Vat is equal to or greater than the threshold value (Vat1 / 2). In this case, it is detected that the rotational position of the magnet 102 in the direction indicated by the arrows a1 and a2 is the reference position Pα0, and the operation position of the rotary switch 13 is the reference position Pa0.

  b2. When it is determined that the arctangent value Vat is a value smaller than the threshold value (Vat1 / 2) and a value equal to or larger than the threshold value (Vat2 / 2). In this case, it is detected that the rotation position of the magnet 102 in the direction indicated by the arrows a1 and a2 is the first rotation position Pα1, and the operation position of the rotary switch 13 is the first operation position Pa1.

  b3. When it is determined that the arctangent value Vat is smaller than the threshold value (Vat2 / 2). In this case, it is detected that the rotation position of the magnet 102 in the direction indicated by the arrows a1 and a2 is the second rotation position Pα2, and the operation position of the rotary switch 13 is the second operation position Pa2.

  According to such a configuration as the magnetic position detecting device, when the resistance values of the magnetoresistive elements M11 to M14, M21 to M24, M31 to M34, and M41 to M44 are changed by the influence of the temperature of the MRE sensor 120 or the like. Even in this case, the position of the magnet 102 in the direction indicated by the arrows z1 and z2 can be detected. At the same time, the rotational position of the magnet 102 in the direction indicated by the arrows a1 and a2 can be detected.

As described above, according to the magnetic position detection apparatus according to the present embodiment, the following effects can be obtained.
(1) The MRE sensor 120 is provided with the first and second magnetic detection units 121 and 122 made of magnetoresistive elements having different resistance change rates with respect to the magnetic flux density of the applied magnetic field. A magnetic field was applied. Then, when the distance between the MRE sensor 120 and the magnet 102 changes in the direction indicated by the arrows z1 and z2, the sensor sensitivity value V1 of the first magnetic detection unit 121 is saturated. And the distance at which the change in the sensor sensitivity value V2 of the second magnetic detection unit 122 changes is set. In other words, the resistance values of the magnetoresistive elements M <b> 11 to M <b> 14 and M <b> 21 to M <b> 24 that constitute the first magnetic detection unit 121 are maintained in a saturated state, and the magnetoresistive element that constitutes the second magnetic detection unit 122. The distances at which the resistance values of M31 to M34 and M41 to M44 change are set. Further, a sensor sensitivity ratio value Vr12 that is a ratio of the sensor sensitivity values V1 and V2 of the first and second magnetic detectors 121 and 122 is calculated, and the calculated sensor sensitivity ratio value Vr12 is obtained. Based on this, the position of the magnet 102 in the direction indicated by the arrows z1 and z2 is detected. As a result, the influence of the temperature or the like of the MRE sensor 120 is reduced, and as a result, the position of the magnet 102 in the direction indicated by the arrows z1 and z2 can be detected while maintaining high reliability. At the same time, the rotational position of the magnet 102 in the direction indicated by the arrows a1 and a2 can be detected.

(2) Two types of magnetoresistive elements having different resistance change rates with respect to the magnetic flux density of the applied magnetic field are magnetoresistive elements M11 to M14, M21 to M24 made of a magnetoresistive film having a thin line width, and a magnet having a wide line width. The magnetoresistive elements M31 to M34 and M41 to M44 made of a resistance film are used. As a result, the magnetoresistive elements M11 to M14, M21 to M24, M31 to M34, and M41 to M44 can be set to the same thickness, so that the MRE sensor 120 can be manufactured. The process of forming the magnetoresistive film can be basically made one process. Therefore, two types of magnetoresistive elements having different resistance change rates with respect to the magnetic flux density of the applied magnetic field can be easily formed.
(Second Embodiment)
Next, a second embodiment of the magnetic position detection device according to the present invention will be described with reference to FIGS. The basic structure of the magnetic position detection device according to the second embodiment and the lever switch device to which the device is applied conforms to the structure shown in FIGS. Here, FIG. 17 shows a planar structure of the MRE sensor 120 as a diagram corresponding to FIG. In the following description, the same elements as those shown in FIGS. 2 to 10 are denoted by the same reference numerals, and redundant description is omitted. Hereinafter, differences between the elements will be mainly described.

  As shown in FIG. 17, the MRE sensor 120 provided in the magnetic position detection apparatus 100 according to the present embodiment is provided with the magnetoresistive elements M11 to M14 and M21 to M24 as they are, and the magnetoresistive element. In place of M31 to M34 and M41 to M44, magnetoresistive elements M51 to M54, M61 to M64 are provided. Here, in the MRE sensor 120, the line widths of the magnetoresistive films forming the magnetoresistive elements M51 to M54 and M61 to M64 are the line widths of the magnetoresistive films forming the magnetoresistive elements M11 to M14 and M21 to M24. Is set to the same length. However, as shown in FIG. 18 with a cross-sectional structure taken along line BB in FIG. 18, the film thicknesses of the magnetoresistive films forming the magnetoresistive elements M51 to M54 and M61 to M64 are the magnetoresistive elements M11 to M14, It is set to be thicker than the thickness of the magnetoresistive film forming M21 to M24. Thereby, also in this MRE sensor 120, it applies with eight magnetoresistive elements M11-M14, M21-M24 arrange | positioned inside, and eight magnetoresistive elements M51-M54, M61-M64 arrange | positioned outside. The resistance change rates with respect to the magnetic flux density of the magnetic field are different from each other. Also in the MRE sensor 120, the first magnetic detection unit 121 is configured by eight magnetoresistive elements M11 to M14 and M21 to M24 arranged on the inner side. The eight magnetic resistance elements M51 to M54 and M61 to M64 arranged on the outside constitute a third magnetic detection unit 123 instead of the second magnetic detection unit 122.

  FIG. 19 is a diagram corresponding to FIG. 11 described above, and the sensor sensitivity values V1, V3 of the first and third magnetic detectors 121, 123 and the positions of the magnets 102 in the directions indicated by the arrows z1, z2. Is a graph showing the relationship between the vertical axis and the horizontal axis. In the graph shown in FIG. 19, the solid line indicates the change tendency of the sensor sensitivity value V1 of the first magnetic detection unit 121, and the alternate long and short dash line indicates the change tendency of the sensor sensitivity value V3 of the third magnetic detection unit 123. Is shown.

  For example, as shown in FIG. 7 above, the direction in which the magnet 102 is indicated by the arrow z1 from the position d2 separated from the reference position Pz0 in the direction indicated by the arrow z2, that is, from the position sufficiently separated from the MRE sensor 120. , And gradually approach the MRE sensor 120. At this time, the magnetic flux density of the magnetic field applied to the MRE sensor 120 changes in such a manner that it gradually increases, and as shown in FIG. 19, the sensor sensitivities of the first and third magnetic detectors 121 and 123, respectively. Both values V1 and V3 gradually increase and gradually saturate to reach a certain value. Here, when the change modes of the values V1 and V3 of the sensor sensitivities are compared, first, the sensor sensitivity value V1 of the first magnetic detection unit 121 is saturated, and then the third magnetic detection unit is followed. The sensor sensitivity value V3 of 123 is saturated, and the sensor sensitivity value V3 is larger than the sensor sensitivity value V1 when the value is saturated. Therefore, referring to the previous FIG. 11, when the change mode of the sensor sensitivity value V2 and the change mode of the sensor sensitivity value V3 are compared, the value at the time of saturation is higher than the sensor sensitivity value V2. The sensitivity value V3 is larger.

  In the magnetic position detection apparatus 100 according to this embodiment, the distance between the magnet 102 and the MRE sensor 120 is adjusted as follows. That is, when the magnet 102 moves from the first operation position d0 to the second operation position d1 and the magnetic flux density of the magnetic field applied to the MRE sensor 120 changes, the sensor of the first magnetic detection unit 121 While maintaining the state where the sensitivity value V1 is saturated, the distance is set such that the sensor sensitivity value V3 of the third magnetic detection unit 123 changes. Specifically, as shown in FIG. 20, when the position of the magnet 102 in the direction indicated by the arrows z1 and z2 changes from the first operation position d0 to the second operation position d1, the first magnetic detection is performed. The sensor sensitivity value V1 of the unit 121 indicates a constant value V1max, and the sensor sensitivity value V3 of the third magnetic detection unit 123 increases from V3 (d0) to V3 (d1).

  In the magnetic position detection apparatus 100 according to the present embodiment, the value Vr13 (= V1) obtained by dividing the sensor sensitivity value V1 of the first magnetic detection unit 121 by the sensor sensitivity value V3 of the third magnetic detection unit 123. / V3) is calculated, and the position of the magnet 102 in the direction indicated by the arrows z1 and z2, that is, the operation position of the push button 14 is detected based on the calculated sensor sensitivity ratio value Vr13. Yes.

  FIG. 21 shows the relationship between the position of the magnet 102 in the direction indicated by the arrows z1 and z2 and the value Vr13 of the sensor sensitivity ratio with respect to the horizontal axis and the vertical axis, respectively, corresponding to FIG. Is.

  As shown in FIG. 21, the sensor sensitivity ratio value Vr13 also gradually changes when the position of the magnet 102 in the direction indicated by the arrows z1 and z2 changes from the first operation position d0 to the second operation position d1. Change in a decreasing manner. In the magnetic position detection apparatus 100 according to the present embodiment, the sensor sensitivity ratio value Vr13 (d0) when the magnet 102 is located at the first operation position d0 with respect to the sensor sensitivity ratio value Vr13. Also, an intermediate value Vrd (= (Vr13 (d0) + Vr13 (d1)) / 2) of the sensor sensitivity ratio value Vr13 (d1) at the second operation position d1 is set as a threshold value. In the apparatus 100, the operation position of the push button 14 is detected as follows based on the sensor sensitivity ratio value Vr13.

  c1. When it is determined that the sensor sensitivity ratio value Vr13 is greater than or equal to the threshold value Vrd. In this case, it is detected that the position of the magnet 102 in the direction indicated by the arrows z1 and z2 is the first operation position d0, and the operation position of the push button 14 is the reference position Pz0.

  c2. When it is determined that the sensor sensitivity ratio value Vr13 is smaller than the threshold value Vrd. In this case, it is detected that the position of the magnet 102 in the direction indicated by the arrows z1 and z2 is the second operation position d1, and the operation position of the push button 14 is the first operation position Pz1.

  According to such a configuration as the magnetic position detection device, when the push button 14 is operated by the driver and the position of the magnet 102 in the direction indicated by the arrows z1 and z2 changes, the sensor sensitivity ratio value Vr13 is obtained. It will change greatly. Therefore, since the position of the magnet 102 can be easily detected, the operation position of the magnet 102 in the direction indicated by the arrows z1 and z2, in other words, the operation position of the push button 14 can be detected with higher accuracy. become.

As described above, according to the present embodiment, the following effects can be obtained as an effect in place of the effect (2) according to the first embodiment.
(3) Two types of magnetoresistive elements having different resistance change rates with respect to the magnetic flux density of the applied magnetic field are magnetoresistive elements M11 to M14 and M21 to M24 made of thin magnetoresistive films, and thick magnetic films. The magnetoresistive elements M51 to M54 and M61 to M64 each made of a resistance film are formed. As a result, the value Vr13 of the ratios V1 and V3 of the sensor sensitivities of the first and third magnetic detectors 121 and 123 changes greatly, so that the magnet is based on the sensor sensitivity ratio value Vr13. If the position of the direction indicated by the arrows z1 and z2 of 102 is detected, the position can be easily detected, and the position of the magnet 102 indicated by the arrows z1 and z2 can be detected with higher accuracy. become able to.

(Other embodiments)
In addition, each said embodiment can also be changed and implemented as follows.
In the first embodiment, eight magnetoresistive elements M31 to M34 made of a magnetoresistive film having a large line width outside the eight magnetoresistive elements M11 to M14 and M21 to M24 made of a magnetoresistive film having a thin line width. , M41 to M44 are arranged. Instead of this, for example, eight magnetoresistive elements composed of a magnetoresistive film having a narrow line width may be arranged outside the eight magnetoresistive elements composed of a magnetoresistive film having a large line width.

  In the second embodiment, eight magnetoresistive elements M31 to M34 made of a thick magnetoresistive film outside the eight magnetoresistive elements M11 to M14 and M21 to M24 made of a thin magnetoresistive film. , M41 to M44 are arranged. Instead of this, for example, eight magnetoresistive elements composed of thin magnetoresistive films may be arranged outside the eight magnetoresistive elements composed of thick magnetoresistive films.

  The two types of magnetoresistive elements having different resistance change rates with respect to the magnetic flux density of the applied magnetic field are replaced with two types of magnetoresistive films having different line widths in the first embodiment, and in the second embodiment. It was formed by two types of magnetoresistive films having different film thicknesses. Instead of this, for example, two types of magnetoresistive films having different line widths and film thicknesses may be used. In short, it is only necessary that the two magnetic detection units are composed of two types of magnetoresistive elements having different resistance change rates with respect to the magnetic flux density of the applied magnetic field.

  For example, in the first embodiment, the sensor sensitivity value V1 of the first magnetic detection unit 121 is used as the ratio value of the sensor sensitivity values V1 and V2 of the first and second magnetic detection units 121 and 122, respectively. The value Vr12 (= V1 / V2) obtained by dividing the value by the sensor sensitivity value V2 of the second magnetic detection unit 122 is adopted. Instead of this, for example, a value (V2 / V1) obtained by dividing the sensor sensitivity value V2 of the second magnetic detection unit 122 by the sensor sensitivity value V1 of the first magnetic detection unit 121 may be employed. .

  The first magnetic detection unit 121 functions as a portion that detects the rotational position of the magnet 102 in the directions indicated by the arrows a1 and a2, and therefore the magnetoresistive elements M11 to M14 and M21 to M24 constituting the first magnetic detection unit 121 are center axes. It is desirable to arrange in an annular shape centering on m. On the other hand, the second magnetic detection unit 122 does not function as a part for detecting the position of the magnet 102 in the direction indicated by the arrows a1 and a2. Therefore, the magnetoresistive elements M31 to M34 and M41 to M44 constituting the second magnetic detection unit 122 are mainly used. There is no need to arrange the ring around the axis m. For this reason, for example, as shown in FIG. 22, the magnetoresistive elements M11 to M14 and M21 to M24 are arranged in a ring shape around the central axis m, and the magnetoresistive elements M11 to M14 and M21 to M24 are arranged as the central axis m. May be arranged annularly around another central axis n.

  In each of the above embodiments, the magnetic position detection device according to the present invention is applied to the lever switch device 10 to determine the position of the magnet 102 that moves in conjunction with the operation of the rotary switch 13 and the push button 14 of the operation lever. By detecting, the operation positions of the rotary switch 13 and the push button 14 are detected. Instead of this, for example, it is applied to a car navigation system, and a magnet that moves in conjunction with a rotation operation and a push operation of an operation lever for operating the system is provided, and then the position of this magnet is detected. You may make it detect the rotation operation and push operation of an operation lever. In short, it is possible to move in the direction of approaching and moving away from the magnetoresistive effect sensor, and to include a detected body that can rotate about its moving axis as a rotation axis. What is necessary is just to detect a position.

In each of the above embodiments, the position of the magnet 102 in the direction indicated by the arrows z1 and z2 and the position in the direction indicated by the arrows a1 and a2 are detected. However, for example, a lever switch not provided with the rotary switch 13 In the apparatus, only the position in the direction indicated by the arrows z1 and z2 may be detected. In short, any object may be used as long as it includes a detected object that can move in the direction of approaching and separating from the magnetoresistive sensor and detects the position of the detected object in the moving direction.
(Appendix)
Next, a technical idea that can be grasped from the above embodiment and its modifications will be additionally described.

  (A) A lever switch device that operates switching of in-vehicle devices through operation of an operation lever provided on the vehicle, wherein the operation lever is provided with a push button that is pressed and a rotary switch that is rotated. The object to be detected moves in a direction approaching and separating from the magnetoresistive sensor as the push button is pressed, and rotates around the moving axis as the rotary switch is rotated. And detecting a push operation of the push button based on a ratio value of sensor sensitivities of the two magnetic detection units, and moving the detected object toward and away from the sensor. When the magnetic flux density of the applied magnetic field changes as the magnetic field moves, the resistance value is maintained in a saturated state. Magnetic position detector according to claim 2, characterized in that for detecting the rotational operation of the rotary switch on the basis of the voltage signal output from one of the magnetic detection unit is made. In recent years, for example, an operation lever provided in a vehicle for operating switching of an in-vehicle device has not only increased switching functions of the in-vehicle device by tilting operation of the lever, but also a new In addition, a rotary switch and a push button are provided, and switching of the in-vehicle device is operated through a rotary operation of the rotary switch and a push operation of the push button. For this reason, it is significant that the magnetic position detection device described above is adopted as a device for detecting such rotary switch rotation operation and push button press operation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view illustrating a perspective structure inside a vehicle provided with a lever switch device to which the first embodiment of a magnetic position detection device according to the present invention is applied. The perspective view which shows the perspective structure about the lever switch apparatus used as the application object of the magnetic position detection apparatus of the said 1st Embodiment. The perspective view which shows the disassembled perspective structure about the operation lever of the lever switch apparatus used as the application object of the magnetic position detection apparatus of the said 1st Embodiment. The side view which shows the side structure of the rotary switch provided in the operation lever about the lever switch apparatus used as the application object of the magnetic position detection apparatus of the said 1st Embodiment. (A)-(c) shows the cross-sectional structure along the AA line of FIG. 3 when the operation position of the rotary switch is the reference position Pa0, the first operation position Pa1, and the second operation position Pa2. FIG. The front view which shows the front structure of the push button provided in the operating lever about the lever switch apparatus used as the application object of the magnetic position detection apparatus of the said 1st Embodiment. The front view which shows the front structure about the magnetic position detection apparatus of the said 1st Embodiment. The top view which shows the planar structure of the magnetoresistive effect sensor about the magnetic position detection apparatus of the said 1st Embodiment. (A), (b) is a circuit diagram which respectively shows the equivalent circuit of the 1st and 2nd magnetic detection part about the magnetoresistive effect sensor of the magnetic-type position detection apparatus of the 1st Embodiment. The block diagram which shows the system structure about the switching operation system of the lever switch apparatus used as the application object of the magnetic position detection apparatus of the said 1st Embodiment. The graph which shows the relationship between the position of the axial direction of the magnet, and each value of the sensor sensitivity of the 1st and 2nd magnetic detection part of a magnetoresistive effect sensor about the magnetic-type position detection apparatus of the said 1st Embodiment. The graph which shows the relationship between the position of the axial direction of the magnet, and each value of the sensor sensitivity of the 1st and 2nd magnetic detection part of a magnetoresistive effect sensor about the magnetic-type position detection apparatus of the said 1st Embodiment. The graph which shows the influence of the temperature change of a magnetoresistive effect sensor about the change of the value of the sensor sensitivity of the 2nd magnetic detection part of a magnetoresistive effect sensor according to the position of the axial direction of a magnet. The graph which shows the relationship between the position of the axial direction of the magnet and the value of the sensor sensitivity ratio of the 1st and 2nd magnetic detection part of a magnetoresistive effect sensor about the magnetic position detection apparatus of the said 1st Embodiment. The graph which shows the relationship between the position of the rotation direction of the magnet and the sine signal and cosine signal which are the output signals from the 1st magnetic detection part of a magnetoresistive effect sensor about the magnetic position detection apparatus of the said 1st Embodiment. The arc tangent calculated based on the position of the magnet in the rotational direction of the first embodiment and the sine signal and cosine signal that are output signals from the first magnetic detector of the magnetoresistive sensor. A graph showing the relationship between values. The top view which shows the planar structure of the magnetoresistive effect sensor about 2nd Embodiment of the magnetic position detection apparatus concerning this invention. FIG. 17 is a cross-sectional view showing a cross-sectional structure along the line BB in FIG. 16. The graph which shows the relationship between the position of the axial direction of the magnet, and each value of the sensor sensitivity of the 1st and 3rd magnetic detection part of a magnetoresistive effect sensor about the magnetic position detection apparatus of the said 2nd Embodiment. The graph which shows the relationship between the position of the axial direction of the magnet, and each value of the sensor sensitivity of the 1st and 3rd magnetic detection part of a magnetoresistive effect sensor about the magnetic position detection apparatus of the said 2nd Embodiment. The graph which shows the relationship between the position of the axial direction of the magnet and the value of the sensor sensitivity ratio of the 1st and 3rd magnetic detection part of a magnetoresistive effect sensor about the magnetic position detection apparatus of the said 2nd Embodiment. The top view which shows the modification of the magnetoresistive effect sensor in the magnetic position detection apparatus of the embodiment.

Explanation of symbols

  M11 to M14, M21 to M24, M31 to M34, M41 to M44, M51 to M54, M61 to M64 ... magnetoresistive elements, 1 ... steering device, 10 ... lever switch device, 11 ... lever unit body, 12 ... operation lever, DESCRIPTION OF SYMBOLS 13 ... Rotary switch, 14 ... Push button, 15 ... Cover, 100 ... Magnetic position detection apparatus, 101 ... Movable shaft, 102 ... Magnet, 110 ... Printed circuit board, 120 ... Magnetoresistive effect sensor (MRE sensor), 121 ... First DESCRIPTION OF SYMBOLS 1 magnetic detection part, 122 ... 2nd magnetic detection part, 123 ... 3rd magnetic detection part, 140-143 ... Differential amplifier, 200 ... Vehicle side control apparatus, 200 ... Control apparatus, 201 ... Headlight, 202 ... Small light, 203 ... Fog light.

Claims (5)

A magnetoresistive sensor having two magnetic detectors each composed of two types of magnetoresistive elements having different resistance change rates with respect to the magnitude of the magnetic flux density of the applied magnetic field, and a magnetoresistive sensor composed of magnets. And an object to be detected that is movable in the direction of approaching and separating from the magnetoresistive sensor,
The distance between the detected object and the magnetoresistive effect sensor is determined when the magnitude of the magnetic flux density of the magnetic field applied to the magnetoresistive effect sensor changes as the detected object moves. The resistance value of one type of magnetoresistive element constituting the other magnetic detector is maintained while the resistance value of one type of magnetoresistive element constituting one of the two magnetic detectors is maintained saturated. Set to the distance where the value changes,
The sensor sensitivity, which is a value indicating the magnitude of the output voltage corresponding to the magnitude of the magnetic flux density of the applied magnetic field, is detected for each of the two magnetic detectors, and the ratio of the detected sensor sensitivity values is calculated. A magnetic position detection device that calculates a value and detects the position of the detected object in the moving direction based on the calculated ratio value. The object to be detected is movable in the direction of approaching and separating from the magnetoresistive effect sensor, and further rotatable with the movement axis as a rotation axis, and with the movement of the object to be detected A voltage output from one magnetic detection unit composed of one type of magnetoresistive element that maintains a saturated resistance value when a change occurs in the magnetic flux density of the magnetic field applied to the magnetoresistive sensor. The magnetic position detection device according to claim 1, wherein the position of the detection target in the rotation direction is detected based on a signal. Two types of magnetoresistive elements having different resistance change rates with respect to the magnetic flux density of the applied magnetic field are respectively formed by two types of magnetoresistive films having different line widths, and one of the two magnetic detection units is magnetically detected. The part is made of a magnetoresistive element formed by a magnetoresistive film having a large line width, and the other magnetic detecting part is made of a magnetoresistive element formed by a magnetoresistive film having a thin line width. The magnetic position detection device described. Two types of magnetoresistive elements having different resistance change rates with respect to the magnetic flux density of the applied magnetic field are respectively formed by two types of magnetoresistive films having different film thicknesses, and one of the two magnetic detectors detects the magnetic field. The part comprises a magnetoresistive element formed by a thick magnetoresistive film, and the other magnetic sensing part comprises a magnetoresistive element formed by a thin magnetoresistive film. The magnetic position detection device described. One of the two types of magnetoresistive elements having different resistance change rates with respect to the magnetic flux density of the applied magnetic field is annularly tilted by 45 ° on the semiconductor substrate of the magnetoresistive effect sensor. The other magnetoresistive elements are arranged on the outer side of the one magnetoresistive element, and are arranged in an annular manner on a concentric circle in a manner inclined by 45 °. The magnetic position detecting device according to any one of claims 1 to 4, comprising two full bridge circuits each including four magnetoresistive elements.

Images