JP2010107320A - Magnetic detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic detection device capable of increasing detection distance by using a Hall element that is similar to conventional types. <P>SOLUTION: The magnetic detection device 1 includes: the Hall element 20; and a magnetism collecting body 30, disposed at the detection side of magnetism in the Hall element 20. The area of a first surface 31, located opposite to the Hall element 20 in the magnetism collecting body 30, is made smaller than that of a second area 32 positioned at a side opposite to the first surface 31 in the magnetism collecting body 30. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a magnetic detection device.

  Conventionally, a magnetic detection device for detecting opening and closing of a window or a door has been widely used. As such a magnetic detection device, for example, a magnetic detection device using a reed switch is known, and in such a magnetic detection device, when a magnet provided in a drive part of a window or a door is close to the reed switch, In addition, the reed switch closes the contact point to detect the opening and closing of the drive part (see Patent Document 1).

  In addition, as a response to the recent demand for miniaturization of magnetic detection devices, magnetic detection devices using Hall elements are known. According to such a magnetic detection device, it is possible to detect that the magnet has approached a detection distance of 10 mm or less based on the output of the Hall element.

Japanese Patent Laid-Open No. 2001-14990

  However, the conventional magnetic detection device can detect a magnet only at a relatively close detection distance of 10 mm or less, and can stably detect the presence or absence of a magnet arranged with a detection distance longer than that. It was difficult. This is because the magnetic flux of the magnet decreases in inverse proportion to the square of the distance, so that the magnetic flux from the magnet 10 mm or more away is significantly reduced before entering the Hall element. It is difficult to detect accurately.

  On the other hand, in order to increase the detection distance, it is conceivable to increase the detection area of the Hall element. However, since the Hall element is mass-produced with a fixed dimension to some extent, it is practically difficult to increase the size of the Hall element. In addition, since the Hall element is an electronic component, it is often packaged for waterproofing and dustproofing, and in order to increase the Hall element, it is necessary to review the design of the entire magnetic detection device. Is not preferred.

  The present invention has been made in view of the above, and an object of the present invention is to provide a magnetic detection device capable of increasing a detection distance while using a Hall element similar to the conventional one.

  In order to solve the above-described problems and achieve the object, a magnetic detection device according to claim 1 includes a magnetic sensing element and a magnetic current collector disposed on a magnetic detection side of the magnetic sensing element, and In the magnetic body, the area of the first surface facing the magnetic sensing element is smaller than the area of the second surface located on the opposite side to the first surface in the magnetic current collector.

  According to a second aspect of the present invention, in the magnetic detection device according to the first aspect, the area of the first surface of the magnetic collector is set to the area of the surface on the magnetic detection side of the magnetic sensing element. It is characterized by being made smaller.

  According to a third aspect of the present invention, there is provided the magnetic detection device according to the first or second aspect, wherein a second magnetic current collector is disposed on a side opposite to the magnetic detection side of the magnetic sensing element. To do.

  According to a fourth aspect of the present invention, there is provided the magnetic detection device according to the third aspect, wherein the second magnetic current collector is a circle along the direction from the magnetic sensing element to the second magnetic current collector. It is characterized by being columnar or prismatic.

  According to the magnetic detection device of the first aspect, the magnetic flux of the magnet can be efficiently incident on the magnetic sensing element via the magnetic current collector, and the detection distance of the magnetic detection device can be improved. In particular, since the area of the first surface is smaller than the area of the second surface, the magnetic flux incident on a wide range of the second surface can be converged on the narrow first surface and introduced into the magnetic sensing element. The magnetic sensing element can be made to be incident well, and the detection distance of the magnetic detection device can be increased to a distance (for example, 30 mm or more) that was impossible in the past.

  According to the magnetic detection device of the second aspect, since the area of the first surface of the magnetic current collector is made smaller than the area of the magnetic sensing side surface of the magnetic sensing element, the magnetic flux converged by the magnetic current collector Can be introduced into the effective detection surface of the magnetic sensing element without waste, so that the magnetic flux can be incident on the magnetic sensing element more efficiently and the detection distance of the magnetic detection device can be further increased.

  According to the magnetic detection device of the third aspect, since the second magnetic current collector is disposed on the opposite side to the magnetic detection side of the magnetic sensing element, the magnetic flux converged by the magnetic current collector can be smoothly transferred to the magnetic sensing element. And the detection distance of the magnetic detection device can be further improved.

  According to the magnetic detection device of the fourth aspect, the leakage of magnetic flux after passing through the magnetic sensing element does not adversely affect the detection distance of the magnetic detection device. It is not necessary to make it conical like a magnetic body. Therefore, by forming the second current collector in a columnar shape or a prismatic shape, the second current collector is formed in a shape that can make maximum use of the arrangement space of the second current collector. Since the effect of converging the magnetic flux by the magnetic body can be enhanced, the magnetic flux converged by the magnetic current collector can be passed through the magnetic sensing element more smoothly.

  Embodiments of a magnetic detection device according to the present invention will be described below in detail with reference to the accompanying drawings. [I] First, the specific contents of the present embodiment will be described. [II] Next, a modified example of the present embodiment will be described. However, the present invention is not limited by the present embodiment.

[I] Specific contents of the present embodiment The magnetic detection device according to the present embodiment is for the purpose of detecting magnetism, and as a specific application example, for detecting the opening and closing of windows and doors. It is configured as a magnetic detection device. In the case of this application example, a magnetic detection device is provided at a position where the drive portion of the window or door is not in contact, and the presence or absence of a magnet provided in the drive portion is detected by the magnetic detection device, so that the window or door is detected. Detects the opening and closing of. However, the magnetic detection device according to the present embodiment can be used for any other purpose.

(Constitution)
FIG. 1 is a perspective view of a main part of the magnetic detection device according to the present embodiment, and FIG. 2 is a cross-sectional view of FIG. The magnetic detection device 1 is configured by housing a substrate 10, a Hall element 20, and two magnetic collectors 30 and 40 in a first casing 50 or a second casing 60.

  The substrate 10 is a circuit board for mounting the Hall element 20, and applies current or voltage to the Hall element 20 and determines the presence / absence of the magnet 70 based on the output from the Hall element 20. Since a known structure can be applied as the detailed structure, description of the detailed structure is omitted.

  The Hall element 20 is a magnetic sensing element formed with a known structure of a semiconductor thin film. The Hall element 20 is driven with a constant current or a constant voltage through the substrate 10, detects the magnetic flux of the magnet 70 (indicated by a chain line in FIGS. 1 and 2), and outputs a current or a voltage corresponding to the magnetic flux. (Hereinafter, an example in which a constant current drive is performed and a voltage corresponding to the magnetic flux is output will be described).

  The current collector 30 is disposed on the magnetic detection side of the Hall element 20 (between the Hall element 20 and the magnet 70 in FIG. 1). The magnetism collecting body 30 converges the magnetic flux of the magnet 70 so as to enter the Hall element 20 and is formed of a magnetic material having a high magnetic permeability (for example, a magnetic material such as ferrite). By forming the magnetic current collector 30 in an appropriate shape and arranging it at an appropriate position, the magnetic flux of the magnet 70 can be efficiently incident on the Hall element 20 and the detection distance of the magnetic detection device 1 can be improved.

  Specifically, the magnetic current collector 30 is formed so that the area of the first surface 31 facing the Hall element 20 is smaller than the area of the second surface 32 located on the opposite side of the first surface 31. Yes. This is because the magnetic flux incident on the wide second surface 32 converges on the narrow first surface 31 and is introduced into the Hall element 20 so that the magnetic flux is incident on the Hall element 20 more efficiently.

  Further, the area of the first surface 31 of the magnetic current collector 30 is made smaller than the area of the surface 21 on the magnetic detection side of the Hall element 20. In the surface 21 on the magnetic detection side of the Hall element 20, a surface that is actually effective for magnetic detection (hereinafter referred to as an effective detection surface) is a surface excluding a mold portion and a shield portion, and is on the magnetic detection side. This is because the area of the first surface 31 of the magnetic current collector 30 is equal to the area of the effective detection surface so that the magnetic flux is efficiently incident on the effective detection surface because it is smaller than the surface 21.

  Furthermore, the shape of the magnetic current collector 30 is a conical shape in which the first surface 31 and the second surface 32 are circular, and the cross-sectional area increases from the first surface 31 to the second surface 32.

  On the other hand, the magnetic collector 40 is a second magnetic collector disposed on the opposite side of the Hall element 20 from the magnetic detection side (on the opposite side of the Hall element 20 in FIG. 1 from the magnet 70). The magnetic current collector 40 allows the magnetic flux converged by the magnetic current collector 30 to pass through the Hall element 20 smoothly. Like the magnetic current collector 30, the magnetic current collector 40 is made of a magnetic material having a high magnetic permeability (for example, a magnetic material such as ferrite). Is formed. By forming the magnetic current collector 40 in an appropriate shape and arranging it in an appropriate position, the magnetic flux converged by the magnetic current collector 30 can be smoothly passed through the Hall element 20 via the magnetic current collector 40, and the magnetic The detection distance of the detection device 1 can be further improved.

  Here, since the leakage of the magnetic flux after passing through the Hall element 20 does not adversely affect the detection distance of the magnetic detection device 1, the magnetic collector 40 does not need to be conical like the magnetic collector 30. On the other hand, it is more important to increase the magnetic flux inducing effect by forming the magnetic current collector 40 in a shape that can maximize the arrangement space. Therefore, in the present embodiment, the magnetic current collector 40 is formed in a columnar shape or a prismatic shape, so that the magnetic flux induction effect by the magnetic current collector 40 is enhanced, and the magnetic flux converged by the current collector 30 is passed through the current collector 40. Passing through the Hall element 20 more smoothly.

  Next, a housing structure for the magnetic current collectors 30 and 40 will be described. The substrate 10, the Hall element 20, and the magnetic current collector 40 are accommodated in the first casing 50, and are fixed to the first casing 50 by an arbitrary structure in this interior. On the other hand, the magnetic current collector 30 is accommodated in the second housing 60, and is fixed to the second housing 60 by an arbitrary structure in the inside. The second casing 60 is fixed so as to surround the first casing 50. In addition, since the detection distance of the magnetic detection apparatus 1 can be further improved as the distance between the Hall element 20 and the magnetic collector 30 is smaller, the thickness of the first casing 50 can be made as thin as possible. preferable.

  Thus, the structure using the first casing 50 and the second casing 60 has various advantages. For example, by housing electronic components such as the substrate 10 and the Hall element 20 in the first housing 50, the first housing 50 can be easily formed into a waterproof structure or a dust-proof structure. Further, the magnetic current collector 40 can be omitted. When the magnetic current collector 40 is omitted in this way, the substrate 10 and the Hall element 20 are disposed inside the first housing 50 as in the conventional case. become. Therefore, the magnetic detection device 1 according to the present embodiment can be configured only by providing the current collector 30 and the second housing 60 with respect to the components of the existing magnetic detection device. Such a magnetic detection device 1 can be manufactured at low cost, and the existing magnetic detection device can be improved to provide the magnetic detection device 1 according to the present embodiment. However, if these advantages can be ignored, all the parts including the magnetic current collector 30 may be accommodated integrally using only one housing. In this case, the entire magnetic detection device 1 is waterproof. In addition, it is easy to adopt a dust-proof structure, and the entire magnetic detection device 1 is integrated into a single unit, which makes it easier to handle. Alternatively, an opening may be provided in the vicinity of the Hall element 20 in the first housing 50, and the magnetic current collector 30 may be brought into contact with the Hall element 20 or may be further brought closer through the opening.

(Shape and position of magnetic collector and experimental results)
Next, the shape and position of the magnetic current collectors 30 and 40 will be described with reference to experimental results by the inventors of the present application.

  FIG. 3 is a diagram for defining symbols used to describe the shapes and positions of the magnetic collectors 30 and 40. Hereinafter, the outer dimension of the Hall element 20 is d1, the diameter of the first surface 31 facing the Hall element 20 in the magnetic current collector 30 is d2, and the second surface 32 of the magnetic current collector 30 located on the opposite side of the first surface 31 is. The diameter is d3, the diameter of the first surface 41 facing the Hall element 20 in the current collector 40 is d4, the diameter of the second surface 42 located on the opposite side of the first surface 41 in the current collector 40 is d5, The mutual distance from the magnetic collector 30 is L1, the length of the magnetic collector 30 is L2, the mutual distance between the magnetic collector 30 and the magnet 70 is L3, and the mutual distance between the Hall element 20 and the magnetic collector 40 is L4. The length of the magnetic body 40 is L5. A direction from the magnet 70 through the magnetic current collector 30 to the Hall element 20 is referred to as a vertical direction, and a direction orthogonal to the vertical direction is referred to as a horizontal direction.

  4 to 7, each position when the magnet 70 is moved in the lateral direction with respect to the Hall element 20 is defined as the horizontal axis (the position of 0 on the horizontal axis indicates that the magnet 70 is in front of the Hall element 20. 4 is a graph with the output of the Hall element 20 as the vertical axis, FIG. 4 is a distance L1 = 1.0 mm between the Hall element 20 and the magnetic collector 30, and FIG. 5 is a distance L1 = FIG. 6 shows the case where the distance L1 = 2.0 mm, and FIG. 7 shows the case where the distance L1 = 3.0 mm. The plots shown in FIGS. 4 to 7 are plots in the case where the distance L3 between the magnetic collector 30 and the magnet 70 is 20 mm, 25 mm, 30 mm, 35 mm, and 40 mm. FIG. 8 is a graph in which the horizontal axis represents each position when the distance L3 between the current collector 30 and the magnet 70 is changed, and the vertical axis represents the output of the Hall element 20. The plots shown in FIG. 8 are plots when the distance L1 between the Hall element 20 and the magnetic collector 30 is 1.0 mm, 1.5 mm, 2.0 mm, and 3.0 mm. 4 to 8 show experimental results when only the magnetic collector 30 is arranged and the magnetic collector 40 is omitted. The magnetism collecting body 30 was formed of ferrite, and a conical member having a diameter d2 = 2.0 mm, a diameter d3 = 10.0 mm, and a length L2 = 10.0 mm was used. The Hall element 20 has an outer dimension d1 of 2 × 3 mm rectangular parallelepiped shape.

  As shown in FIGS. 4 to 8, since the output of the Hall element 20 increases as the mutual distance L1 between the Hall element 20 and the magnetic collector 30 becomes smaller, the Hall element 20 and the magnetic collector 30 mutually It is preferable to make them close to each other as much as possible, and it is more preferable to make them contact each other. Further, since the output of the Hall element 20 increases as the mutual distance L3 between the magnetic current collector 30 and the magnet 70 becomes smaller, it is preferable to bring the magnetic current collector 30 closer to the magnet 70 as much as possible. Even if the magnet 70 is separated from the magnet 70 by a distance L3 = 40 mm, the output of the Hall element 20 changes greatly when the position of the magnet 70 is changed with respect to the Hall element 20 (see FIG. 4). In the case of the distance L1 = 1.0 mm, the plot of the distance L3 = 40 mm shows that the output of the Hall element 20 is about 17 mV when the position = −4 × 5 = −20 mm, and the Hall element when the position = 0 mm. 20 output = about 24 mV), the magnet 70 can be detected. Therefore, it has been found that the detection distance of the magnetic detection device 1 can be increased to about 40 mm by arranging only the magnetic collector 30.

  FIG. 9 is a table showing changes in the detection output improvement rate depending on the shape of the magnetic collector 40. Here, a comparison was made with respect to the case where the magnetic current collector 40 is not provided, the magnetic current collector 40 having a cylindrical shape, and the magnetic current collector 40 having a conical shape. The magnetic current collector 40 is formed of ferrite. As the cylindrical magnetic current collector 40, L5 = 10 mm when d4 = d5 = 10 mm, L5 = 10 mm when d4 = d5 = 3 mm, L5 = 1 mm when d4 = d5 = 10 mm, When each of d4 = d5 = 3 mm and L5 = 3 mm is compared, a conical magnetic collector 40 having a diameter d4 = 2.0 mm, a diameter d5 = 10.0 mm, and a length L2 = 10.0 mm is used. did. Here, when the conical current collector 40 is used, the arrangement direction of the current collector 40 is a direction in which the surface having the smaller diameter faces the Hall element 20 (hereinafter, the positive direction), and the direction having the larger diameter. Comparison was made in the direction in which the surface faces the Hall element 20 (hereinafter referred to as the reverse direction). Here, the mutual distance L1 between the Hall element 20 and the magnetic collector 30 is set to 3.0 mm, the mutual distance L3 between the magnetic collector 30 and the magnet 70 is set to 40 mm, and the mutual relationship between the Hall element 20 and the magnetic collector 40 is set. The measurement was performed with the distance L4 = 0 mm. The detection output improvement rate is ((V1-V0) / V0), where V0 is the detection output of the Hall element 20 when the magnetic collector 40 is provided, and V1 is the detection output of the Hall element 20 when there is no magnetic collector 40. × 100 (%) was calculated.

  As shown in FIG. 9, when the magnetic current collector 40 is arranged, the detection output improvement rate is improved regardless of the shape and arrangement direction of the magnetic current collector 40 (0%) as compared with the case where the magnetic current collector 40 is not provided. (It will be bigger). Further, it was found that when the magnetic current collector 40 is cylindrical, the detection output improvement rate is improved as the diameter d4 = d5 is larger and the length L5 is longer. Further, it was found that when the magnetic collector 40 is conical, the detection output improvement rate is improved in the forward direction rather than in the reverse direction. Further, in the cylindrical magnetic collector 40 of d4 = d5 = 10 mm × L5 = 10 mm and the conical magnetic collector 40 arranged in the positive direction, the cylindrical magnetic collector 40 has a higher detection output improvement rate. I found out.

  Next, FIG. 10 is a diagram showing the magnetic current collector 30 used in the experiments of FIGS. 11 to 21, and FIG. 10A is a large conical current collector 30 (diameter d2 = 2.0 mm, diameter d3 = 10). 0.0 mm, length L2 = 10.0 mm), (b) is a small conical current collector 30 (diameter d2 = 4.0 mm, diameter d3 = 8.0 mm, length L2 = 11.0 mm), (c ) Is a small cylindrical magnetic current collector 30 (diameter d2 = d3 = 9.0 mm, length L2 = 10.5 mm), and (d) is a large cylindrical magnetic current collector 30 (diameter d2 = d3 = 9.5 mm). , Length L2 = 28.0 mm).

  11 to 16, each position when the magnet 70 is moved in the lateral direction with respect to the Hall element 20 or the magnetic collector 30 is set as the horizontal axis (the position 0 is a magnet with respect to the Hall element 20 or the magnetic collector 30. FIG. 11 is a graph in which the output of the Hall element 20 is plotted on the vertical axis, and FIG. 11 shows a case where the concentric large current collector 30 in FIG. 13 is arranged in the opposite direction, FIG. 13 shows the conical large current collector 30 in FIG. 10A arranged in the opposite direction, and FIG. 14 shows the conical small current collector 30 in FIG. When arranged in the direction, FIG. 15 shows the case where the columnar small current collector 30 of FIG. 10C is arranged, and FIG. 16 shows the case where the columnar large current collector 30 of FIG. 10D is arranged. , Respectively. The plots shown in FIGS. 11 to 16 are plots when the distance L1 between the Hall element 20 or the magnetic collector 30 and the magnet 70 is 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, and 60 mm.

  As shown in FIGS. 11 to 16, the output of the Hall element 20 is larger overall when the conical magnetic collector 30 is arranged in the positive direction than when the magnetic collector 30 is not provided. When the conical magnetic current collector 30 is arranged in the positive direction, it is almost the same, and in other cases, it is smaller. Therefore, it can be seen that it is effective to improve the output of the Hall element 20 by disposing the conical magnetic collector 30 in the positive direction. Further, the directivity of the Hall element 20 (indicated by the mutual spread of the curves in FIGS. 11 to 16) is obtained when the conical current collector 30 is arranged in the positive direction as compared to the case where the magnetic current collector 30 is not provided. It has become wide. Therefore, it can be seen that disposing the conical magnetic current collector 30 in the positive direction is effective for widening the directivity of the Hall element 20.

  FIGS. 17 to 21 are graphs showing the output difference when the magnetic current collector 30 is disposed with respect to the output of the Hall element 20 when the magnetic current collector 30 is not provided as shown in FIG. 11, and FIG. 18 is arranged in the positive direction, FIG. 18 shows a case where the large cone-shaped magnetic collector 30 in FIG. 10A is arranged in the reverse direction, and FIG. 19 shows FIG. 20 is arranged in the positive direction, FIG. 20 is a case where the columnar small magnetic collector 30 of FIG. 10C is arranged, and FIG. 21 is a columnar shape of FIG. A case where a large-sized magnetic current collector 30 is arranged is shown. The vertical axis, the horizontal axis, and the meaning of each plot in FIGS. 17 to 21 are the same as those in FIGS. 11 to 16. As shown in FIGS. 17 to 21, the directivity of the Hall element 20 is such that the magnet 70 is close to the magnetic collector 30 (positioned within 20 mm) when the conical magnetic collector 30 is arranged in the positive direction. ) Wide in case. Further, the output of the Hall element 20 is greater than that in the case where the conical magnetic current collector 30 is disposed in the opposite direction as compared to the case where the magnetic current collector 30 is not provided, or when the cylindrical magnetic current collector 30 is disposed. On the other hand, it is large when the magnet 70 is at a certain distance (a distance of 15 mm or more).

Summarizing the experimental results of FIGS. 11 to 21, the following can be understood.
(1) When the magnetic current collector 30 larger than the size of the Hall element 20 is used, the directivity of the Hall element 20 can be expanded (the apparent size of the Hall element 20 can be increased).
(2) When the conical magnetic current collector 30 is used, the output of the Hall element 20 can be increased when arranged in the positive direction. Further, when arranged in the reverse direction, the output of the Hall element 20 at a close distance can be lowered, so that the effect of suppressing magnetic characteristics can be utilized.
(3) The cylindrical magnetic current collector 30 exhibits intermediate characteristics between the forward direction and the reverse direction of the conical magnetic current collector 30.

(Effect of this embodiment)
As described above, according to the present embodiment, the magnetic flux of the magnet 70 can be efficiently incident on the magnetic sensing element via the magnetic collector 30, and the detection distance of the magnetic detection device 1 can be improved. In particular, since the area of the first surface 31 is made smaller than the area of the second surface 32, the magnetic flux incident on the wide second surface 32 can be converged on the narrow first surface 31 and introduced into the Hall element 20. The magnetic flux can be incident on the Hall element 20 more efficiently, and the detection distance of the magnetic detection device 1 can be increased to a distance (for example, 30 mm or more) that has been impossible in the past.

  Further, since the area of the first surface 31 of the magnetic current collector 30 is made smaller than the area of the magnetic detection side surface 21 of the Hall element 20, the magnetic flux converged by the magnetic current collector 30 is wasted on the effective detection surface of the Hall element 20. Since the magnetic flux can be incident on the Hall element 20 more efficiently, the detection distance of the magnetic detection device 1 can be further increased.

  Further, since the magnetic current collector 40 is arranged on the opposite side of the Hall element 20 to the magnetic detection side, the magnetic flux converged by the magnetic current collector 30 can be smoothly passed through the Hall element 20 via the magnetic current collector 40, and the magnetic field. The detection distance of the detection device 1 can be further improved.

  Further, since the leakage of magnetic flux after passing through the Hall element 20 does not adversely affect the detection distance of the magnetic detection device 1, the magnetic collector 40 does not need to be conical like the magnetic collector. Therefore, by forming the current collector 40 in a columnar or prismatic shape, the current collector 40 is formed in a shape that can make the most of the space for arranging the current collector 40, and the magnetic flux convergence effect by the current collector 40 can be reduced. Therefore, the magnetic flux converged by the magnetic current collector 30 can be passed through the Hall element 20 more smoothly through the magnetic current collector 40.

[II] Modifications of the Embodiments While the present embodiment has been described above, the specific configuration and means of the present invention are within the scope of the technical idea of each invention described in the claims. Modifications and improvements can be made arbitrarily. Hereinafter, such a modification will be described.

(About problems to be solved and effects of the invention)
First, the problems to be solved by the invention and the effects of the invention are not limited to the above-described contents, and the present invention solves the problems not described above or has the effects not described above. There are also cases where only some of the described problems are solved or only some of the described effects are achieved.

(About magnetic sensing element)
The magnetic sensing element is not limited to the Hall element 20, and any element including a magnetoresistive element can be used.

(About magnetic collector)
The magnetic current collectors 30 and 40 are not limited to ferrite, and any magnetic material containing iron oxide, chromium oxide, or cobalt can be used. Further, the number, shape, or arrangement position of the current collectors 30 and 40 can be arbitrarily changed except when they are projected. For example, a plurality of current collectors 30 are spaced apart on the magnetic detection side of the magnetic sensing element. Or close up.
In addition, the concentrating member 30 used is a conical shape, but is not limited thereto, and may be a pyramid shape or a shape capable of forming a magnetic field distribution so as to improve the detection efficiency of the magnetic sensing element. It may be the same as. The first surface 31 of the magnetism collecting body 30 is a flat surface. However, the present invention is not limited to this, and a conical shape with a sharp tip may be used, or a shape with a rounded tip may be used.

It is a principal part perspective view of the magnetic detection apparatus which concerns on embodiment of this invention. It is sectional drawing of FIG. It is a figure for defining the code | symbol used for description of the shape and position of a magnetic collector. It is a graph which shows the output of a Hall element in each position at the time of moving a magnet laterally with respect to a Hall element, and is a graph at the time of setting L1 = 1.0 mm of mutual distance between a Hall element and a magnetic current collector. is there. It is a graph which shows the output of a Hall element in each position at the time of moving a magnet sideways with respect to a Hall element, and is a graph at the time of setting mutual distance L1 = 1.5mm of a Hall element and a magnetic collector. is there. It is a graph which shows the output of a Hall element in each position at the time of moving a magnet sideways with respect to a Hall element, and is a graph at the time of setting mutual distance L1 = 2.0mm of a Hall element and a magnetic collector. is there. It is a graph which shows the output of a Hall element in each position at the time of moving a magnet sideways with respect to a Hall element, and is a graph at the time of setting mutual distance L1 = 3.0 mm of a Hall element and a magnetic collector. is there. It is a graph which shows the output of a Hall element in each position at the time of changing the mutual distance L3 of a magnetic collector and a magnet. It is a table | surface which shows the change of the detection output improvement rate by the shape of a magnetic collector. It is a figure which shows the magnetic collector used for the experiment of FIGS. 11-21, (a) is a cone-shaped large magnetic collector, (b) is a cone-shaped small magnetic collector, (c) is a cylindrical small collector. (D) shows a large cylindrical magnetic current collector. It is a graph which shows the output of a Hall element in each position at the time of moving a magnet laterally with respect to a Hall element or a magnetic current collector, and is a graph when there is no magnetic current collector. It is a graph which shows the output of a Hall element in each position at the time of moving a magnet laterally with respect to a Hall element or a current collector, and is a graph at the time of arranging a cone-shaped large current collector in the positive direction. . It is a graph which shows the output of a Hall element in each position at the time of moving a magnet laterally with respect to a Hall element or a current collector, and is a graph at the time of arranging a cone-shaped large current collector in the reverse direction. . It is a graph which shows the output of a Hall element in each position at the time of moving a magnet laterally with respect to a Hall element or a magnetic current collector, and is a graph at the time of arranging a cone-shaped small magnetic current collector in the positive direction. . It is a graph which shows the output of a Hall element in each position at the time of moving a magnet laterally with respect to a Hall element or a magnetic current collector, and is a graph at the time of arranging a cylindrical small magnetic current collector. It is a graph which shows the output of a Hall element in each position at the time of moving a magnet laterally with respect to a Hall element or a current collector, and is a graph at the time of arranging a cylindrical large-sized current collector. It is a graph which shows the output difference at the time of arrange | positioning a magnetic collector with respect to the output of a Hall element when there is no magnetic collector, and is a graph at the time of arrange | positioning a conical large magnetic collector in the positive direction. It is a graph which shows the output difference at the time of arrange | positioning a magnetic collector with respect to the output of a Hall element when there is no magnetic collector, and is a graph at the time of arrange | positioning a conical large magnetic collector in the reverse direction. It is a graph which shows the output difference at the time of arrange | positioning a magnetic collector with respect to the output of a Hall element when there is no magnetic collector, and is a graph at the time of arrange | positioning a conical small magnetic collector in the positive direction. It is a graph which shows the output difference at the time of arrange | positioning a magnetic collector with respect to the output of a Hall element when there is no magnetic collector, and is a graph at the time of arrange | positioning a cylindrical small magnetic collector. It is a graph which shows the output difference at the time of arrange | positioning a magnetic collector with respect to the output of a Hall element in case there is no magnetic collector, and is a graph at the time of arrange | positioning a cylindrical large magnetic collector.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Magnetic detection apparatus 10 Board | substrate 20 Hall element 21 Magnetic detection side surface 30, 40 Current collector 31, 41 First surface 32, 42 Second surface 50 First housing 60 Second housing 70 Magnet

Claims (4)

A magnetic sensing element;
A magnetic current collector disposed on the magnetic detection side of the magnetic sensing element,
The area of the first surface facing the magnetic sensing element in the magnetic current collector is smaller than the area of the second surface located on the opposite side of the magnetic current collector from the first surface;
Magnetic detection device characterized by the above. Reducing the area of the first surface of the magnetism collector relative to the area of the magnetic sensing side surface of the magnetic sensing element;
The magnetic detection device according to claim 1. Disposing a second magnetic current collector on the side opposite to the magnetic detection side of the magnetic sensing element;
The magnetic detection device according to claim 1, wherein: The second magnetic current collector is formed in a columnar shape or a prismatic shape along a direction from the magnetic sensing element to the second magnetic current collector,
The magnetic detection device according to claim 3.

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