Abstract:
The present invention relates to a magnetic sensor which can detect a weak magenetic field and improve the detection precision with an easy and convenient configuration. A magnetic sensor is provided with a magnetic body changing the direction of a magnetic field input to a magnetoresistance effect element in the vicinity of the magnetoresistance effect element in which the resistance value changes according to the direction of the input magnetic field, the magnetic body has at leas one projection portion in the direction almost parallel to direction in which the magnetic induction occurs in the magnetoresistance effect element. The direction in which the projection portion of the magnetic body projects is substantially parallel to the direction in which the magnetization of the magnetoresistance effect element is fixed.

Description:
[0001]    The present invention relates to a magnetic sensor, especially a magnetic sensor utilizing a magnetoresistance effect element. 
       BACKGROUND 
       [0002]    A magnetic sensor capable of detecting the change of the magnetic field is developed as a measuring device and used in various applications such as the galvanometer, the magnetic encoder and the like. One example of such a magnetic sensor is disclosed in the following Patent Document 1 in which a GMR element (Giant Magneto Resistive element) is used as the element for detecting the change of the magnetic field. The GMR element is a kind of element in which the output resistance value changes according to the input magnetic field, and the change of the magnetic field to be detected can be measured based on the output resistance value. 
         [0003]    As one example showing the specific configuration of the magnetic sensor where the GMR element is used, as described in Patent Document 1, four GMR elements are provided in the substrate to form a bridge circuit. As such, the change of the resistance value in the GMR element is detected by detecting the differential voltage in the bridge circuit, wherein the change of the resistance value in the GMR element is with the change of the magnetic field which becomes a detection object. In this respect, a sensor that is highly sensitive to the change of magnetic field has been provided. 
         [0004]    In particular, as an element to detect the change of magnetic field, a GMR chip (the chip for detecting magnetic field) is provided in the magnetic sensor as disclosed in Patent Document 1, wherein the GMR chip utilizes the spin valve typed GMR elements (Giant Magneto Resistive element) in which the output resistance value changes depending on the direction of the input magnetic field. As such, each GMR element is magnetized fixedly in a specific direction in one surface so as to detect the magnetic field in the specified direction. Here, in order to downsize the GMR chip and also to lower the deviation in each resistance value, four GMR elements which have already formed the bridge circuit are provided on one GMR chip. Thus, all four GMR elements are magnetized fixedly in the same direction. 
         [0005]      FIG. 1  and  FIG. 2  illustrate the characteristic of the GMR element. First of all, the characteristic of the GMR element used in the present invention will be described with reference to  FIG. 1  and  FIG. 2 . The GMR element is the GMR element (Giant Magneto Resistive element) made in the spin valve type in which output resistance value changes depending on the direction of the input magnetic field. As such, in  FIG. 1  and  FIG. 2 , the relationship between the approach angle and the resistance value is shown, wherein the approach angle refers to the angle of magnetic field H relative to the GMR element. 
         [0006]    In the example as shown in  FIG. 1 , GMR elements are formed on the upper surface of GMR chip  1 . The GMR elements are arranged in such a manner that they are magnetized fixedly in the direction indicated by arrow A. Thus, the magnetic field in the direction as indicated by arrow A can be detected. 
         [0007]    In  FIG. 1 , the GMR elements are arranged in magnetic field H that enters in the direction perpendicular to the form surface of the GMR elements. In this respect, the resistance value of the GMR element turns to “R 0 ” as shown in  FIG. 2 . In contrast, if the direction of magnetic field inclines, the incidence angle of magnetic field H relative to the GMR element surface deviates from the perpendicular direction with an angle of i.e., −Δθ or +Δθ, as shown in  FIG. 1  with dotted lines, wherein Δ(Delta) refers to the variation. In this way, the GMR element is magnetized fixedly in one direction and the resistance value of the GMR element changes when the direction of the magnetic field changes with respect to said direction, as shown in  FIG. 2 . As such, the GMR element has the following characteristic. If the resistance value is defined as R 0  when the magnetic field enters in a perpendicular direction, the resistance value will have substantial change when the direction of the magnetic field H inclines with a tiny angle. 
         [0008]      FIG. 3  and  FIG. 4  show the configuration of the conventional magnetic sensor. When the magnetic field in one direction is detected by using a GMR chip where the bridge circuit as described above has been formed, magnetic body  21  which changes the direction of the magnetic field input to the GMR element is provided in the vicinity of the element forming part where the GMR elements in pair that are adjacent but not connected to each other in the bridge circuit are provided at almost symmetrical positions, as described in Patent Document 1. 
         [0009]    Further, magnetic body  21  can change the external magnetic field in one direction into a different direction between the GMR elements. In this way, four GMR elements inside the bridge circuit are provided in such a manner that the magnetic field comes out in the direction in which the magnetization is fixed relative to one and comes out in the opposite direction relative to another one. As such, a high differential voltage is output from the bridge circuit, and the magnetic field in one direction can be detected in precision. 
         [0010]      FIG. 5  is a schematic view showing the magnetic field H introduced to the GMR element parts  11  and  12  through magnetic body  21  as described in Patent Document 1. The magnetic field bends due to magnetic body  21 , and the component of the magnetic field is generated in the GMR element parts  11  and  12  in the direction of the induced magnetic field (magnetic field component in the X-axis direction) and the resistance value of said GMR element changes. Thus, the sensor is provided which is highly sensitive to the change of the magnetic field. In addition, in the following description, the direction parallel to that where the GMR element is magnetized fixedly is defined as the X-axis direction, and the direction which is perpendicular to that where the GMR element is magnetized fixedly and also is located on the surface where the GMR elements are formed is defined as the Y-axis direction. Further, the direction perpendicular to the surface where the GMR elements are formed is defined as the Z-axis direction. 
         [0011]    Patent Document 2 has disclosed a sensor in which several magnetic bodies are provided for the magnetoresistance effect element to convert the external magnetic field in the vertical direction into magnetic field component in the horizontal direction so that the component of the magnetic field entering in the vertical direction is detected. 
       PATENT DOCUMENTS 
       [0012]    Patent Document 1: JP-P5500785 
         [0013]    Patent Document 2: JP-P5597206 
       SUMMARY 
       [0014]    However, in the techniques disclosed in Patent Document 1 and Patent Document 2, the following problem exists. That is, in the detection of a weak magnetic field, the intensity of the magnetic field coming out of the element part is not sufficiently large. Thus, it is necessary to improve the magnetic detection precision. 
         [0015]    Thus, the objective of the present invention is to solve the technical problem mentioned above. That is, the present invention aims to improve the detection precision of the magnetic sensor with an easy and convenient configuration. 
         [0016]    Here, the magnetic sensor according to one embodiment of the present invention, wherein a magnetic body which changes the direction of a magnetic field input to a magnetoresistance effect element is provided in the vicinity of the magnetoresistance effect element in which the resistance value changes according to the direction of the input magnetic field, wherein the magnetic body has at least one projection portion for introducing the magnetic field to be detected to the magnetic-resistive element effectively so as to improve the detection precision. 
         [0017]    In addition, since the direction in which the projection portion of the magnetic body projects is substantially parallel to the direction in which the magnetization of the magnetoresistance effect element is fixed, the magnetic field to be detected is introduced to the magnetoresistance effect element effectively so that the detection precision is improved. 
         [0018]    Preferably, the end of the magnetic body in the direction in which the projection portion projects is disposed closer to a central side of the magnetic body than the end of the magnetoresistance effect element at a side opposite to the central side of the magnetic body. Further, it is preferable that the magnetic body and the magnetoresistance effect element do not overlap in the direction perpendicular to the placement surface of the magnetoresistance effect element. 
         [0019]    Preferably, at least a part of the projection portion of the magnetic body contacts with the placement surface of the magnetic body. 
         [0020]    Further, the magnetic body is preferably the soft magnetic body. 
         [0021]    According to the invention mentioned above, the detection precision of the magnetic sensor can be improved by introducing the magnetic field to be detected to the magnetoresistance effect element through the projection portion of the magnetic body. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]      FIG. 1  is a view showing the configuration of the GMR chip. 
           [0023]      FIG. 2  is a diagram showing the characteristic of the GMR element. 
           [0024]      FIG. 3  is a view showing the configuration of the conventional magnetic sensor (the surface involving X-Z axis). 
           [0025]      FIG. 4  is a view showing the configuration of the conventional magnetic sensor (the surface involving X-Y axis). 
           [0026]      FIG. 5  is a schematic view showing the magnetic flux introduced to the GMR element part in the example of prior art, 
           [0027]      FIG. 6  is a view showing the configuration of the magnetic sensor in Embodiment 1 (the surface involving X-Z axis). 
           [0028]      FIG. 7  is a view showing the configuration of the magnetic sensor in Embodiment 1 (the surface involving X-Y axis). 
           [0029]      FIG. 8  is a schematic view showing the magnetic flux introduced to the GMR element part in Embodiment 1. 
           [0030]      FIG. 9  is a view showing the enlarged GMR element part in the example of prior art. 
           [0031]      FIG. 10  is a view showing the enlarged GMR element part in Embodiment 1. 
           [0032]      FIG. 11  shows the stimulation results in the example of prior art and Embodiment 1 about the intensity of the magnetic field in the magnetoresistance effect element part in the X-axis direction. 
           [0033]      FIG. 12  is a view showing the configuration of the magnetic sensor in Embodiment 2 (the surface involving X-Z axis). 
           [0034]      FIG. 13  is a view showing the configuration of the magnetic sensor in Embodiment 2 (the surface involving X-Y axis). 
           [0035]      FIG. 14  is a schematic view showing the magnetic flux introduced to the GMR element part in Embodiment 2. 
           [0036]      FIG. 15  shows the stimulation results in the example of prior art and Embodiment 2 about the intensity of the magnetic field in the magnetoresistance effect element part in the X-axis direction. 
           [0037]      FIG. 16  is a view showing the configuration of the magnetic sensor in Embodiment 3 (the surface involving X-Z axis). 
           [0038]      FIG. 17  is a view showing the configuration of the magnetic sensor in Embodiment 3 (the surface involving X-Y axis). 
           [0039]      FIG. 18  is a schematic view showing the magnetic flux introduced to the GMR element part in Embodiment 3. 
           [0040]      FIG. 19  shows the stimulation results in the example of prior art and Embodiment 3 about the intensity of the magnetic field in the magnetoresistance effect element part in the X-axis direction. 
           [0041]      FIG. 20  is a view showing the configuration of the magnetic sensor in Embodiment 4 (the surface involving X-Z axis). 
           [0042]      FIG. 21  is a view showing the configuration of the magnetic sensor in Embodiment 4 (the surface involving X-Y axis). 
           [0043]      FIG. 22  is a schematic view showing the magnetic flux introduced to the GMR element part in Embodiment 4. 
           [0044]      FIG. 23  shows the stimulation results in the example of prior art and Embodiment 4 about the intensity of the magnetic field in the magnetoresistance effect element part in the X-axis direction. 
           [0045]      FIG. 24  is a view showing the configuration of the magnetic sensor in Embodiment 5 (the surface involving X-Z axis). 
           [0046]      FIG. 25  is a view showing the configuration of the magnetic sensor in Embodiment 5 (the surface involving X-Y axis). 
           [0047]      FIG. 26  is a schematic view showing the magnetic flux introduced to the GMR element part in Embodiment 5. 
           [0048]      FIG. 27  shows the stimulation results in the example of prior art and Embodiment 5 about the intensity of the magnetic field in the magnetoresistance effect element part in the X-axis direction. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0049]    The specific configuration in the present invention will be described in the following embodiments. Hereinafter, the basic configuration of the magnetic sensor in the present invention will be described in Embodiment 1, and the configuration of the magnetic sensor to be specifically used in to the present invention will be described in Embodiments 2 to 5. 
         [0050]    The GMR is described as an example of the magnetoresistance element, but the element having the magnetoresistance effect can also be used, including the TMR element, AMR element and the like. 
       Embodiment 1 
       [0051]    The first embodiment of the present invention will be described with reference to  FIG. 6  to  FIG. 11 .  FIG. 6  is a view showing the configuration of the magnetic sensor according to the present embodiment in the surface involving X-Z axis.  FIG. 7  is a view showing the configuration of the magnetic sensor according to the present embodiment in the surface involving X-Y axis.  FIG. 8  is a schematic view showing the magnetic field entering the GMR element part through the magnetic body in the present embodiment.  FIG. 9  is a schematic view showing the magnetic field entering the GMR element part through the magnetic body in the example of prior art where the GMR element part is enlarged.  FIG. 10  is a schematic view showing the magnetic field entering the GMR element part through the magnetic body in present embodiment where the GMR element part is enlarged.  FIG. 11  shows the stimulation results according to the example of prior art and the present embodiment about the intensity of the magnetic field in the magnetoresistance effect element part in the X-axis direction. 
       [Configuration] 
       [0052]    The shape of the soft magnetic body according to the present embodiment will be described with reference to  FIG. 6  and  FIG. 7 . GMR elements  111  and  112  are formed in GMR chip  110 . These GMR elements form a bridge circuit. In the vicinity of the bridge circuit, magnetic body  121  is provided which changes the direction of the magnetic field input to the magnetoresistance effect element. In addition, projection portions  122   a  and  122   b  are provided in the magnetic body  121  in the direction almost parallel to direction A in which the magnetic induction occurs in the magnetoresistance effect element. Further, the end of magnetic body  121  in the X-axis direction of projection portion  122  is preferably provided closer to the center of magnetic body  121  (that is, interior side) than the end of GMR elements  111  and  112  at an opposite side to the center side of magnetic body in the X-axis direction. Further, the magnetic body and the magnetoresistance effect element preferably do not overlap in the direction perpendicular to the placement surface of the magnetoresistance effect elements. Magnetic body  121  is the soft magnetic body made of the material such as the ferrite material, the permalloy (Ni—Fe alloy), Sendust (Fe—Si—Al alloy) or the like. The material is not restricted as long as magnetic body  121  can change the direction of magnetic field H mentioned above. 
         [0053]    Magnetic body  121  is preferably composed of one component. However, as long as magnetic body  121  is capable of changing the direction of magnetic field H, the number of the components to constitute magnetic body  121  is not particularly restricted. 
       [Function] 
       [0054]    Hereinafter, magnetic field H introduced to GMR element parts  111  and  112  through the configuration mentioned above will be described with reference to  FIG. 8  to  FIG. 10 . Similar to that in the example of prior art, the magnetic field entering magnetic body  121  from the upper part of the figure in Z-axis direction is bended by magnetic body  121  and is introduced into the interior of magnetic body  121 . 
         [0055]    Magnetic field H introduced into the interior of magnetic body  121  moves towards the outside of the magnetic body  121  in the X-axis direction through the projecting shape in the vicinity of projection portion  122  of magnetic body  121 . In this way, the magnetically concentrated magnetic field H enters the vicinity of GMR elements  111  and  112 , so the intensity of magnetic field to be detected is increased. Further, it can be seen from  FIG. 9  and  FIG. 10  where the GMR element parts from the example of prior art and the present example are enlarged that magnetic field H bends towards the X-axis direction to a larger extent in the present embodiment when the incidence angles of magnetic field H that enters to the GMR element part are compared. As such, with respect to magnetic field H entering GMR element  111 , not only the intensity of the magnetic field is increased, but also the component of magnetic field H in X-axis increases due to the bending of magnetic field H with the effects from magnetic body  121  and projection portion  122   a , wherein the magnetic induction occurs in the GMR element in the X-axis direction. Thus, the detection precision of the magnetic sensor can be improved. Although not shown, at the opposite side along X-axis, the same happens to magnetic field H entering GMR element  122  with the effects from magnetic body  121  and projection portion  122   b . As a result, the component of magnetic field H in the X-axis direction increases so that the detection precision of the magnetic sensor can be improved, wherein the magnetic induction occurs in the GMR element in the X-axis direction. 
         [0056]    With respect to  FIG. 11 , a simulation is performed to predict the intensity of magnetic field H introduced to GMR element parts  111  and  112  through the configuration mentioned above, and the result is described and compared against that from the example of prior art. It can be confirmed in Embodiment 1 that the intensity of magnetic field H introduced to GMR element parts  111  and  112  is denser compared to that in the example of prior art. 
         [0057]    With the functions mentioned above, the detection precision of the magnetic sensor can be improved by increasing the intensity of the magnetic field introduced to the GMR element part. 
       Embodiment 2 
       [0058]    The second embodiment of the present invention will be described with reference to  FIG. 12  to  FIG. 15 .  FIG. 12  is a view showing the configuration of the magnetic sensor according to the present embodiment in the surface involving X-Z axis.  FIG. 13  is a view showing the configuration of the magnetic sensor according to the present embodiment in the surface involving X-Y axis.  FIG. 14  is a schematic view showing the magnetic field entering the GMR element part through the magnetic body in the present embodiment.  FIG. 15  shows the stimulation results according to the example of prior art and the present embodiment about the intensity of the magnetic field in the magnetoresistance effect element part in the X-axis direction. 
       [Configuration] 
       [0059]    The shape of the soft magnetic body according to the present embodiment will be described with reference to  FIG. 12  and  FIG. 13 . GMR elements  211  and  212  are formed in GMR chip  210 . These GMR elements form a bridge circuit. In the vicinity of the bridge circuit, magnetic body  221  is provided to change the direction of the magnetic field input to the magnetoresistance effect element. In addition, projection portions  222   a  and  222   b  are provided in magnetic body  121  in the direction almost parallel to direction A in which the magnetic induction occurs in the magnetoresistance effect element. 
         [0060]    Further, chamfer parts  223   a  and  223   b  towards the placement surface of the GMR element are provided on the fore-ends of projection portion  222  in magnetic body  221 . 
         [0061]    Further, the end of magnetic body  221  in the X-axis direction of projection portion  222 is preferably provided closer to the center of magnetic body  221  (that is, interior side) than the end of GMR elements  211  and  212  at the opposite side to the center side of magnetic body in X-axis direction. Further, the magnetic body and the magnetoresistance effect element preferably do not overlap in the direction perpendicular to the placement surface of the magnetoresistance effect elements. 
         [0062]    Magnetic body  221  is the soft magnetic body made of the material such as the ferrite material, the permalloy (Ni—Fe alloy), Sendust (Fe—Si—Al alloy) or the like. The material is not restricted as long as magnetic body  221  can change the direction of magnetic field H. 
         [0063]    Magnetic body  221  is preferably composed of one component. However, as long as magnetic body  221  is capable of changing the direction of magnetic field H, the number of the components to constitute magnetic body  221  is not particularly restricted. 
       [Function] 
       [0064]    Hereinafter, magnetic field H introduced to GMR element parts  211  and  212  through the configuration mentioned above will be described with reference to  FIG. 14 . Similar to that in the example of prior art, the magnetic field entering magnetic body  221  from the upper part of the figure in the Z-axis direction is bended by magnetic body  221  and is introduced into the interior of magnetic body  221 . 
         [0065]    Magnetic field H introduced into the interior of magnetic body  221  moves towards the outside of the magnetic body  221  in the X-axis direction through the projecting shape in the vicinity of projection portion  222  of magnetic body  221 . Further, with the effect from chamfer parts  223   a  and  223   b  in the fore-end of the projection portion, magnetic field H is magnetically concentrated on the end of projection portion  222  in the Y-axis direction. In this way, the magnetically concentrated magnetic field H enters the vicinity of GMR elements  211  and  212 , so the intensity of magnetic field to be detected is increased. Further, similar to Embodiment 1, magnetic field H entering the GMR element part bends towards X-axis direction to a large extent in the present embodiment, wherein the magnetic induction occurs in the GMR element in the X-axis direction. As such, with respect to magnetic field H entering GMR element  211 , not only the intensity of the magnetic field is increased, but also the component of magnetic field H in the X-axis increases due to the bending of magnetic field H with the effects from magnetic body  221  and projection portion  222 , wherein the magnetic induction occurs in the GMR element in the X-axis direction. Thus, the detection precision of the magnetic sensor can be improved, 
         [0066]    With respect to  FIG. 15 , a simulation is performed to predict the intensity of magnetic field H introduced to GMR element parts  211  and  212  through the configuration mentioned above, and the result is described and compared against that from the example of prior art. It can be confirmed in Embodiment 2 that the intensity of magnetic field H introduced to GMR element parts  211  and  212  is denser compared to that in the example of prior art. 
         [0067]    With the functions mentioned above, the detection precision of the magnetic sensor can be improved by increasing the intensity of the magnetic field introduced to the GMR element part. 
       Embodiment 3 
       [0068]    The third embodiment of the present invention will be described with reference to  FIG. 16  to  FIG. 19 .  FIG. 16  is a view showing the configuration of the magnetic sensor according to the present embodiment in the surface involving X-Z axis.  FIG. 17  is a view showing the configuration of the magnetic sensor according to the present embodiment in the surface involving X-Y axis.  FIG. 18  is a schematic view showing the magnetic field entering the GMR element part through the magnetic body in the present embodiment.  FIG. 19  shows the stimulation results according to the example of prior art and the present embodiment about the intensity of the magnetic field in the magnetoresistance effect element part in the X-axis direction, 
       [Configuration] 
       [0069]    The shape of the soft magnetic body according to the present embodiment will be described with reference to  FIG. 16  and  FIG. 17 . GMR elements  311  and  312  are formed in GMR chip  310 . These GMR elements form a bridge circuit. In the vicinity of the bridge circuit, magnetic body  321  is provided to change the direction of the magnetic field input to the magnetoresistance effect element. In addition, projection portions  322   a  and  322   b  are provided in magnetic body  321  in the direction almost parallel to direction A in which the magnetic induction occurs in the magnetoresistance effect element. 
         [0070]    Further, magnetic body  321  and projection portion  322  are connected by slopping connection parts  324   a  and  324   b  in the projection portion. 
         [0071]    Further, the end of magnetic body  321  in the X-axis direction of projection portion  322  is preferably provided closer to the center of magnetic body  321  (that is, interior side) than the end of GMR elements  311  and  312  at the opposite side to the center side of magnetic body in X-axis direction. Further, the magnetic body and the magnetoresistance effect element preferably do not overlap in the direction perpendicular to the placement surface of the magnetoresistance effect element. 
         [0072]    Magnetic body  321  is the soft magnetic body made of the material such as the ferrite material, the permalloy (Ni—Fe alloy), Sendust (Fe—Si—Al alloy) or the like. The material is not restricted as long as magnetic body  321  can change the direction of magnetic field H. 
         [0073]    Magnetic body  321  is preferably composed of one component. However, as long as magnetic body  321  is capable of changing the direction of magnetic field H, the number of the components to constitute magnetic body  321  is not particularly restricted. 
         [0000]    [Function]Hereinafter, magnetic field H introduced to GMR element parts  311  and  312  through the configuration mentioned above will be described with reference to  FIG. 18 . Similar to that in the example of prior art, the magnetic field entering magnetic body  321  from the upper part of the figure in the Z-axis direction is bended by magnetic body  321  and is introduced into the interior of magnetic body  321 . 
         [0074]    Magnetic field H introduced into the interior of magnetic body  321  moves towards the outside of the magnetic body  321  in the X-axis direction through the projecting shape in the vicinity of projection portion  322  of magnetic body  321 . Further, with the effects from slopping connection parts  324   a  and  324   b  in the projection portion, magnetic field H is magnetically concentrated on the ends of projection portion  322  in the Y-axis direction. In this way, the magnetically concentrated magnetic field H enters the vicinity of GMR elements  311  and  312 , so the intensity of magnetic field to be detected is increased. Further, similar to Embodiment 1, magnetic field H entering the GMR element part bends towards X-axis direction to a large extent in the present embodiment, wherein the magnetic induction occurs in the GMR element in the X-axis direction. As such, with respect to magnetic field H entering GMR element  311 , not only the intensity of the magnetic field is increased, but also the component of magnetic field H in the X-axis increases due to the bending of magnetic field H with the effects from magnetic body  321  and projection portion  322 , wherein the magnetic induction occurs in the GMR element in the X-axis direction. Thus, the detection precision of the magnetic sensor can be improved. 
         [0075]    With respect to  FIG. 19 , a simulation is performed to predict the intensity of magnetic field H introduced to GMR element parts  311  and  312  through the configuration mentioned above, and the result is described and compared against that from the example of prior art. It can be confirmed in Embodiment 3 that the intensity of magnetic field H introduced to GMR element parts  311  and  312  is denser compared to that in the example of prior art. 
         [0076]    With the functions mentioned above, the detection precision of the magnetic sensor can be improved by increasing the intensity of the magnetic field introduced to the GMR element part. 
       Embodiment 4 
       [0077]    The fourth embodiment of the present invention will be described with reference to  FIG. 20  to  FIG. 23 .  FIG. 20  is a view showing the configuration of the magnetic sensor according to the present embodiment in the surface involving X-Z axis.  FIG. 21  is a view showing the configuration of the magnetic sensor according to the present embodiment in the surface involving X-Y axis.  FIG. 22  is a schematic view showing the magnetic field entering the GMR element part through the magnetic body in the present embodiment.  FIG. 23  shows the stimulation results according to the example of prior art and the present embodiment about the intensity of the magnetic field in the magnetoresistance effect element part in the X-axis direction. 
       [Configuration] 
       [0078]    The shape of the soft magnetic body according to the present embodiment will be described with reference to  FIG. 20  and  FIG. 21 . GMR elements  411  and  412  are formed in GMR chip  410 . These GMR elements form a bridge circuit. In the vicinity of the bridge circuit, magnetic body  421  is provided to change the direction of the magnetic field input to the magnetoresistance effect element. In addition, projection portions  422   a  and  422   b  are provided in magnetic body  421  in the direction almost parallel to direction A in which the magnetic induction occurs in the magnetoresistance effect element. 
         [0079]    Further, restriction parts  425   a ,  425   b ,  425   c  and  425   d  towards the projecting direction of projection portion  422  in magnetic body  421  are provided at the fore-ends of projection portion  422  of magnetic body  421 . 
         [0080]    Further, the end of magnetic body  421  in the X-axis direction of projection portion  422  is preferably provided closer to the center of magnetic body  421  (that is, interior side) than the end of GMR elements  411  and  412  at the opposite side to the center side of magnetic body in X-axis direction. Further, the magnetic body and the magnetoresistance effect element preferably do not overlap in the direction perpendicular to the placement surface of the magnetoresistance effect element. 
         [0081]    Magnetic body  421  is the soft magnetic body made of the material such as the ferrite material, the permalloy (Ni—Fe alloy), Sendust (Fe—Si—Al alloy) or the like. The material is not restricted as long as magnetic body  421  can change the direction of magnetic field H. 
         [0082]    Magnetic body  421  is preferably composed of one component. However, as long as magnetic body  421  is capable of changing the direction of magnetic field H, the number of the components to constitute magnetic body  321  is not particularly restricted. 
       [Function] 
       [0083]    Hereinafter, magnetic field H introduced to GMR element part  411  through the configuration mentioned above will be described with reference to  FIG. 22 . Similar to the example of prior art, the magnetic field entering magnetic body  421  from the upper part of the figure in the Z-axis direction is bended by magnetic body  421  and is introduced into the interior of magnetic body  421 . 
         [0084]    Magnetic field H introduced into the interior of magnetic body  421  moves towards the outside of the magnetic body  421  in the X-axis direction through the projecting shape in the vicinity of projection portion  422  of magnetic body  421 . Further, with the effects from restriction parts  425   a ,  425   b ,  425   c  and  425   d  in fore-end of the projection portion, magnetic field H is magnetically concentrated on the ends of projection portion  422  in the Y-axis direction. In this way, the magnetically concentrated magnetic field H enters the vicinity of GMR elements  411  and  412 , so the intensity of magnetic field to be detected is increased. Further, similar to Embodiment 1, magnetic field H entering the GMR element part bends towards X-axis direction to a large extent in the present embodiment, wherein the magnetic induction occurs in the GMR element in the X-axis direction. As such, with respect to magnetic field H entering GMR element  411 , not only the intensity of the magnetic field is increased, but also the component of magnetic field H in the X-axis increases due to the bending of magnetic field H with the effects from magnetic body  421  and projection portion  422 , wherein the magnetic induction occurs in the GMR element in the X-axis direction. Thus, the detection precision of the magnetic sensor can be improved. 
         [0085]    With respect to  FIG. 23 , a simulation is performed to predict the intensity of magnetic field H introduced to GMR element parts  411  and  412  through the configuration mentioned above, and the result is described and compared against that from the example of prior art. It can be confirmed in Embodiment 4 that the intensity of magnetic field H introduced to GMR element parts  411  and  412  is denser compared to that in the example of prior art. 
         [0086]    With the functions mentioned above, the detection precision of the magnetic sensor can be improved by increasing the intensity of the magnetic field introduced to the GMR element part. 
       Embodiment 5 
       [0087]    The fifth embodiment of the present invention will be described with reference to  FIG. 24  to  FIG. 27 .  FIG. 24  is a view showing the configuration of the magnetic sensor according to the present embodiment in the surface involving X-Z axis.  FIG. 25  is a view showing the configuration of the magnetic sensor according to the present embodiment in the surface involving X-Y axis.  FIG. 26  is a schematic view showing the magnetic field entering the GMR element part through the magnetic body in the present embodiment.  FIG. 27  shows the stimulation results according to the example of prior art and the present embodiment about the intensity of the magnetic field in the magnetoresistance effect element part in the X-axis direction. 
       [Configuration] 
       [0088]    The shape of the soft magnetic body according to the present embodiment will be described with reference to  FIG. 24  and  FIG. 25 . GMR elements  511  and  512  are formed in GMR chip  510 . These GMR elements form a bridge circuit. In the vicinity of the bridge circuit, magnetic body  521  is provided to change the direction of the magnetic field input to the magnetoresistance effect element. In addition, projection portions  522   a  and  522   b  are provided in magnetic body  521  in the direction almost parallel to direction A in which the magnetic induction occurs in the magnetoresistance effect element. 
         [0089]    Further, magnetic body  521  contains slopping parts  526 A and  526 b. Based on the cross-sectional area in the surface involving X-Y axis, it can be sent that the slopping part is wider in the X-axis direction at the surface of magnetic body  521  opposite to that with projection portion  522  than the part where projection portion  522  begins to project. In addition, although not shown, slopping part  26  in magnetic body is not limited to the shape as shown in  FIG. 24 , wherein the length in the X-axis direction becomes longer gradually along the Z-axis direction. Also, other shapes can be used such as the one with the length in the Y-axis direction being longer gradually along the Z-axis direction, the one with the lengths in both the X-axis direction and the Y-axis direction being longer along the Z-axis direction, or the one with the length in the direction deviating from the X-axis direction or the Y-axis direction with a specific angle being longer along the Z-axis direction. 
         [0090]    Further, the end of magnetic body  521  in the X-axis direction of projection portion  522  is preferably provided closer to the center of magnetic body  521  (that is, interior side) than the end of GMR elements  511  and  512  at the opposite side to the center side of magnetic body in X-axis direction. Further, the magnetic body and the magnetoresistance effect element preferably do not overlap in the direction perpendicular to the placement surface of the magnetoresistance effect element. 
         [0091]    Magnetic body  521  is the soft magnetic body made of the material such as the ferrite material, the permalloy (Ni—Fe alloy), Sendust (Fe—Si—Al alloy) or the like. The material is not restricted as long as magnetic body  521  can change the direction of magnetic field H. 
         [0092]    Magnetic body  521  is preferably composed of one component. However, as long as magnetic body  521  is capable of changing the direction of magnetic field H, the number of the components to constitute magnetic body  521  is not particularly restricted. 
       [Function] 
       [0093]    Hereinafter, magnetic field H introduced to GMR element parts  511  and  512  through the configuration mentioned above will be described with reference to  FIG. 26 . Similar to that in the example of prior art, the magnetic field entering magnetic body  521  in the Z-axis direction from the upper part of the figure is bended by magnetic body  521  and is introduced into the interior of magnetic body  521 . 
         [0094]    Magnetic field H introduced into the interior of magnetic body  521  moves towards the outside of the magnetic body  521  in the X-axis direction through the projecting shape in the vicinity of projection portion  522  of magnetic body  521 . Further, with the effect from slopping part  526  in the magnetic body, magnetic field H entering magnetic body  521  focuses in the center of magnetic body  521  in the X-axis direction as it goes towards projection portion  522 . In this way, magnetic field H is strengthened. As such, magnetic field H focusing in the center of magnetic body  521  in the X-axis direction is magnetically concentrated on the ends of projection portion  522  in the Y-axis direction. Thus, the magnetically concentrated magnetic field H enters the vicinity of GMR elements  511  and  512 , so the intensity of magnetic field to be detected is increased. Further, similar to Embodiment 1, magnetic field H entering the GMR element part bends towards X-axis direction to a large extent in the present embodiment, wherein the magnetic induction occurs in the GMR element in the X-axis direction. As such, with respect to magnetic field H entering GMR element  311 , not only the intensity of the magnetic field is increased, but also the component of magnetic field H in the X-axis increases due to the bending of magnetic field H with the effects from magnetic body  521  and projection portion  522 , wherein the magnetic induction occurs in the GMR element in the X-axis direction. Thus, the detection precision of the magnetic sensor can be improved. 
         [0095]    With respect to  FIG. 27 , a simulation is performed to predict the intensity of magnetic field H introduced to GMR element parts  511  and  512  through the configuration mentioned above, and the result is described and compared against that from the example of prior art. It can be confirmed in Embodiment 5 that the intensity of magnetic, field H introduced to GMR element parts  511  and  512  is denser compared to that in the example of prior art. 
         [0096]    With the functions mentioned above, the detection precision of the magnetic sensor can be improved by increasing the intensity of the magnetic field introduced to the GMR element part. 
       INDUSTRIAL APPLICATION 
       [0097]    The present invention can be applied to various measuring devices such as the magnetic sensor, the galvanometer and the encoder. Thus, the present invention can be utilized in the industry. 
       DESCRIPTION OF REFERENCE NUMERALS 
       [0098]      1  GMR chip 
         [0099]      10  GMR chip in example of prior art 
         [0100]      11 ,  12  element disposing part in example of prior art 
         [0101]      21  magnetic body in example of prior art 
         [0102]      110  GMR chip in Embodiment 1 
         [0103]      111 ,  112  element disposing part in Embodiment 1 
         [0104]      121  magnetic body in Embodiment 1 
         [0105]      122  projection portion in Embodiment 1 
         [0106]      210  GMR chip in Embodiment 2 
         [0107]      211 ,  212  element disposing part in Embodiment 2 
         [0108]      221  magnetic body in Embodiment 2 
         [0109]      222  projection portion in Embodiment 2 
         [0110]      223  chamfer part in fore-end of projection portion in Embodiment 2 
         [0111]      310  GMR chip in Embodiment 3 
         [0112]      311 ,  312  element disposing part in Embodiment 3 
         [0113]      321  magnetic body in Embodiment 3 
         [0114]      322  projection portion in Embodiment 3 
         [0115]      324  sloping connection part in projection portion of Embodiment 3 
         [0116]      410  GMR chip in Embodiment 4 
         [0117]      411 ,  412  element disposing part in Embodiment 4 
         [0118]      421  magnetic body in Embodiment 4 
         [0119]      422  projection portion in Embodiment 4 
         [0120]      425  restriction part in fore-end of projection portion in Embodiment 4 
         [0121]      510  GMR chip in Embodiment 5 
         [0122]      511 ,  512  element disposing part in Embodiment 5 
         [0123]      521  magnetic body in Embodiment 5 
         [0124]      522  projection portion in Embodiment 5 
         [0125]      526  slopping part in magnetic body of Embodiment 5 
         [0126]    A fixed direction of magnetization 
         [0127]    H mangetic field