JP2003177168A - Magnetic sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic sensor which can be heightened in detection accuracy even if an object to be detected is made to be hardly caught when passing in the state integrated into a magnetic discrimination device such as a counter, and in which an external force hardly acts on a magnetoelectric device. <P>SOLUTION: In this magnetic sensor, the magnetoelectric device 2 and leads 3 connected to the magnetoelectric device 2 are sealed with a resin sealing body 4; a magnetic field generation means 6 for generating a bias magnetic field to the magnetoelectric device 2 is assembled to the resin sealing body 4; the top face part 4a of the resin sealing body 4 covering the detection face side of the magnetoelectric device 2 is exposed to the outside; and, on the top face part 4a, an external exposed part on the detection face of the magnetoelectric device 2 is dented lower than an external exposed part nearest to the detection object 12 side on a part apart from the detection face. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to, for example, banknotes and MI.
The present invention relates to a magnetic sensor using a magnetoelectric conversion element capable of recognizing magnetic ink such as CR.

[0002]

2. Description of the Related Art Conventionally, as a magnetic sensor of this type, as disclosed in, for example, Japanese Patent Laid-Open No. 52-96877, a chip (magnetoelectric conversion element) on which a magnetoresistive pattern is formed and a bias magnetic field are generated. It is well known that a magnet as a magnetizing means is assembled to a magnet holder and sealed in a metal package or the like in a state in which a gap between the magnetoelectric conversion element and the height direction is provided on the top surface portion.

By the way, in recent years, magnetic sensors using magnetoelectric conversion elements have been used in POS cash registers and counters of ATMs, department stores, convenience stores and the like of banks, and magnetic ink of banknotes, MICR of checks and gift certificates, etc. It is used to read magnetic information and make authenticity decisions.
Since the object to be detected such as banknotes may come into contact with the sensor when reading it, in the magnetic sensor, the metal cap is provided as the metal package as described above, so that undue pressure or impact is not applied to the magnetoelectric conversion element. I was using it. That is, when pressure or shock is applied to the magnetoelectric conversion element from the outside, noise may occur due to the piezo effect, and malfunction may occur. Therefore, the metal cap is provided to prevent the noise.

[0004]

By the way, conventionally, for example, the structure of the reading unit of the magnetic identification device for reading the print information printed with magnetic ink by the magnetoelectric conversion element is as shown in FIGS. It was

More specifically, as shown in FIG. 7, a conventional magnetic sensor 1 having a magnetoelectric conversion element is soldered to a printed circuit board 13 to detect an object 12 such as a bill or a check.
Front housing portion 14 and rear housing portion 15 that secure a moving passage of
It was located between and. Above the magnetic sensor 1, there is provided a rotating roller 16 that transports the detected body 12 so as to pass over the magnetic sensor 1. Object 12
The transfer path R is formed between the upper surfaces of the casings 14 and 15 and the guide plates 17 and 18 facing the upper surfaces.

In the case of such a conventional structure, the magnetic sensor 1
Since it is necessary to secure a sufficient space for disposing the magnetic sensor 1, the magnetic sensor 1 can be installed with a margin between the front and rear housing portions 14 and 15. Therefore, the front and rear surfaces of the magnetic sensor 1 and the front and rear housing portions 14 are arranged. There will be some gap between 15 and 15. When the body 12 to be detected is transferred in such a state and the magnetic sensor 1 reads the magnetic ink or the like, the tip of the body 12 to be detected is a metal package 20 (metal cap or metal cap) of the magnetic sensor 1. There was a high risk of contact with the upper edge of the case). Then, due to the contact, the detected body 12 rubs to generate wear powder from the detected body 12, and the wear powder is generated by the magnetic sensor 1.
When the wear powder reaches the transfer path of the detection object, the tip of the detection object in contact with the abrasion powder becomes unstable. ,
The object to be detected sometimes rushed into the upper end of the front surface of the metal package 20 of the magnetic sensor 1. Due to the rush, a jamming phenomenon in which the detected object is bent in a crumpled state occurs, which may cause a problem such as clogging of the detected object or breakage of the detected object (see FIG. 8). ).

Therefore, in order to prevent such a jamming phenomenon from occurring, as shown in FIG. 9, a plate-like cover 19 is provided over the upper surfaces of the front and rear casing parts 14 and 15.
Is proposed. In this case, the object to be detected is restricted by the cover 19 so as not to enter the magnetic sensor 1. However, when the cover 19 is provided in this manner, the magnetoelectric conversion element 2 of the magnetic sensor 1 and
Since the metal package 20 of the magnetic sensor 1 and the cover 19 are interposed between the detection target 12 and the detection target 12,
There is a problem in that the reading distance of the magnetic information by the magnetoelectric conversion element 2 becomes longer, and the S / N ratio becomes smaller accordingly, and the detection accuracy lowers.

The present invention has been made in view of the above-mentioned circumstances, and for example, in a state where it is incorporated in a magnetic identification device such as a bill counting machine, even if the object to be detected does not easily get caught when passing through it, it is detected. The problem to be solved is to provide a magnetic sensor that can be made highly accurate and in which an external force is less likely to act on the magnetoelectric conversion element.

[0009]

According to a first aspect of the present invention, there is provided a magnetic sensor in which a magnetoelectric conversion element and a lead connected to the magnetoelectric conversion element are sealed with a resin encapsulant, and the magnetoelectric conversion element is sealed. In the top surface portion of the resin sealing body that covers the detection surface side, the recessed step portion is formed on the magnetic detection portion of the magnetoelectric conversion element.

According to the magnetic sensor of the first aspect, in the top surface portion of the resin sealing body on the side having the detection surface of the magnetoelectric conversion element sealed with the resin sealing body, the magnetic detection portion of the magnetoelectric conversion element. Since the concave step portion is formed on the upper side, a gap is provided from the portion closest to the detected body side of the portion deviated from the detection surface to the vicinity of the detection surface of the magnetoelectric conversion element. Due to the structure in which the air gap is provided in this way, even if an external force such as an impact when the detected body passes through acts on the top surface portion of the resin sealing body of the magnetoelectric conversion element, it is generated by the external force. Since the stress is prevented from being transmitted to the magnetoelectric conversion element, the generation of piezo noise in the magnetoelectric conversion element is suppressed.

Further, since the top surface portion is not covered with a case, even when a cover for preventing a jamming phenomenon is provided in the path through which the object to be detected passes, unlike the conventional case. , The gap of the thickness of the cover only occurs between the object to be detected and the detection surface of the magnetoelectric conversion element of the magnetic sensor, and in addition to the thickness of the cover as in the conventional case, the thickness of the case of the magnetic sensor, Therefore, the detection surface of the magnetic sensor can be detected in a state closer to the detected body side than in the conventional case.

Therefore, as compared with the prior art, the magnetic sensor of the present invention can detect the magnetic information by the magnetoelectric conversion element at a position close to the object to be detected, so that the S / N ratio of the detection signal can be made higher. The detection accuracy is high.

Further, since the cover member for covering the top surface portion of the resin sealing body is not provided, the manufacturing process can be simplified and the material cost can be reduced, so that the cost can be reduced.

In the magnetic sensor according to the second aspect of the present invention, the magnetoelectric conversion element and the lead connected to the magnetoelectric conversion element are sealed with a resin encapsulant to cover the detection surface side of the magnetoelectric conversion element. In the top surface portion of the resin sealing body, an opening is formed on the magnetic detection portion of the magnetoelectric conversion element.

According to another aspect of the magnetic sensor of the present invention, in the top surface portion of the resin encapsulation body on the side having the detection surface of the magnetoelectric conversion element encapsulated with the resin encapsulation body, the magnetic detection portion of the magnetoelectric conversion element is present. Since the opening is formed above, a space is provided from the portion closest to the detected body side of the portion deviated from the detection surface to the vicinity of the detection surface of the magnetoelectric conversion element. Due to the structure in which the air gap is provided in this way, even if an external force such as an impact when the detected body passes through acts on the top surface portion of the resin sealing body of the magnetoelectric conversion element, it is generated by the external force. Since the stress is prevented from being transmitted to the magnetoelectric conversion element, the generation of piezo noise in the magnetoelectric conversion element is suppressed.

A magnetic sensor according to a third aspect of the present invention is the magnetic sensor according to the first or second aspect, wherein the resin sealing body is provided on the opposite side to the side where the magnetoelectric conversion element is arranged. A recessed space portion for mounting a magnetizing means for generating a bias magnetic field for the magnetoelectric conversion element is provided, and the recessed space portion has an inner diameter that becomes smaller toward the rear side where the magnetizing means is mounted. It is characterized in that it is configured in a shape.

According to the magnetic sensor of the third aspect, since the magnetizing means is mounted in the recessed space portion having the recessed shape, the mounting work is easy and the magnetizing state is maintained in the mounted state. Since the means is easily regulated by the peripheral wall on the back side of the recessed space portion so as not to be displaced,
The mounting position accuracy is also good. That is, as a conventional magnetic sensor, in a block in which a magnetoelectric conversion element and a lead are simply resin-molded, a magnet serving as a magnetizing means is attached and attached to a back surface opposite to a side where the magnetoelectric conversion element is provided. Although the ones are known, the magnetizing means can be assembled with higher positional accuracy in the positional relationship with the magnetoelectric conversion element, as compared with such ones.

If the inner peripheral surface of the recessed space portion is formed into a smooth tapered surface, the magnetizing means can be inserted more smoothly.

A magnetic sensor according to a fourth aspect of the present invention is the magnetic sensor according to the third aspect, wherein the magnetizing means mounted in the recessed space portion and the resin sealing body are bonded to each other. The resin agent is made of a harder material than the resin encapsulant.

According to the magnetic sensor of the fourth aspect, since the magnetizing means and the resin sealing body are bonded with the resin agent harder than the resin sealing body, the resin sealing is performed. The stress in the direction of the normal to the top surface of the body is once dispersed at the boundary between the resin sealing body and the hard adhesive, and is further dispersed between the adhesive and the magnetizing means. The stress dispersion effect is higher than when the same resin or a resin having a lower rigidity than the sealing resin is used for adhesion.

A magnetic sensor according to a fifth aspect of the present invention is the magnetic sensor according to the third or fourth aspect, in which the magnetic sensor is magnetized in a state of being assembled to the resin sealing body. It is characterized by being

According to the magnetic sensor of the fifth aspect, it is possible to change the magnetization amount of the magnetizing means while measuring the electrical characteristics such as the input resistance and the output voltage of the magnetoelectric conversion element.
Thereby, the characteristics of the magnetic sensor can be adjusted within a desired setting range.

A magnetic sensor according to a sixth aspect of the present invention is the magnetic sensor according to any one of the first to fifth aspects,
The resin encapsulant is characterized by being made of at least one of highly flexible polyamide resin, silicone resin, and epoxy resin.

According to the magnetic sensor of the sixth aspect, the rush impact pressure of the object to be detected can be compared by forming the resin sealing body with at least one of highly flexible polyamide resin, silicon resin and epoxy resin. Even when acting on the resin sealing body, the force is easily dispersed and shock-absorbed, and it is possible to further suppress the generation of piezo noise in the magnetoelectric conversion element.

Further, by forming the resin sealing body with at least one of polyamide resin, silicon resin and epoxy resin having low thermal conductivity, an apparatus for reading magnetic information from the detection object when the detection object passes through The generation of thermal noise due to the temperature difference from the object to be detected can be suppressed from occurring in the magnetoelectric conversion element.

According to a seventh aspect of the present invention, there is provided a magnetic sensor in which a magnetoelectric conversion element and a lead connected to the magnetoelectric conversion element are sealed with a resin encapsulant to generate a bias magnetic field for the magnetoelectric conversion element. Assembled to the resin sealing body,
The top surface portion of the resin sealing body that covers the detection surface side of the magnetoelectric conversion element is exposed to the outside, and the stress generated by the external force acting on the top surface portion is only in a position avoiding the magnetoelectric conversion element. It is characterized in that the resin encapsulant is configured to operate.

According to the magnetic sensor of the seventh aspect, since the resin encapsulant is constructed so that the stress generated by the external force acting on the top surface portion acts only on the portion avoiding the magnetoelectric conversion element. Generation of piezo noise in the conversion element is suppressed.

[0028]

DETAILED DESCRIPTION OF THE INVENTION The details of the present invention will be described below with reference to the embodiments shown in the drawings.

1 to 4 relate to an embodiment of the present invention. FIG. 1 is a perspective view showing an appearance of a magnetic sensor, and FIG.
A perspective view showing a state in which a resin sealing body of a magnetic sensor is seen through,
FIG. 3 is a vertical cross-sectional front view showing the magnetic sensor, and FIG. 4 is a vertical cross-sectional side view showing a main part of a magnetic identification device including the magnetic sensor.

As shown in FIG. 1 to FIG. 3, a magnetic sensor 1 includes a magnetoelectric conversion element 2, leads 3 ... And magnetoelectric conversion elements which are respectively connected to electrodes on the detection surface of the magnetoelectric conversion element 2 with gold wires or the like. 2, a resin sealing body 4 for sealing 2 and a magnet 6 as a magnetizing means mounted in a state of being inserted into a recessed space portion 5 formed in the resin sealing body 4. There is.

More specifically, the magnetoelectric conversion element 2 is configured as a rectangular chip (pellet) in plan view on which a magnetoresistive pattern is formed. And four leads 3
One of the leads 3 is provided with a pad 7 on which a chip is placed, and the chip of the magnetoelectric conversion element 2 is bonded and fixed onto the pad 7. The electrodes connected to the magnetoresistive pattern in the magnetoelectric conversion element 2 and the leads 3 are electrically joined by a wedge bonder with a wire of φ25 μm of gold or aluminum. Then, the chip of the magnetoelectric conversion element 2 and a part of the lead 3 are molded and sealed with a polyamide resin, and after sealing, in the resin-sealed body 4 made of this molded and sealed resin material, The magnet 6 as a magnetizing means is fixedly adhered to the back surface side opposite to the surface on the side where the detection surface on which the magnetoresistive pattern 2 is formed is located. As shown in FIGS. 2 and 3, the magnet 6 has a cylindrical shape and is inserted into the recessed space portion 10 formed on the back surface side of the resin encapsulant 4 to be hard resin (for example, epoxy). It is fixedly adhered by an adhesive 11 made of resin.

As shown in FIG. 3, the recessed space portion 10 has an inner peripheral surface shape with a gradual slope in the inner recess, that is, a hole shape having a truncated cone shape. The resin molding of the resin sealing body 4 is performed such that the bottom surface position of the recessed space portion 10 in the resin sealing body 4 accurately corresponds to the position of the magnetoelectric conversion element 2 on the front side. As a result, the positional deviation of the insertion position of the magnet 6 when the magnet 6 is assembled into the resin sealing body 4 is also corrected by the guide by the inner peripheral surface of the recessed space portion 10 associated with the insertion, and finally the optimum mounting position is obtained. The magnet 6 will be located at. For example, the magnet 6 is φ4
Assuming a cylindrical shape of × 2.5 mm, the inner space of the bottom surface of the recessed space portion 10, which is a hole for inserting a magnet, is φ4.1 mm, and there is a margin of 0.1 mm. However, if the assembling accuracy of the jig for mounting the magnet 6 is ± 0.2 mm and the inner diameter of the opening of the recessed space portion 10 is φ4.1 mm, the magnet 6 will be inserted into the recessed space portion during assembly. There is a possibility that something that does not fit in 10 may occur. On the other hand, for example, if the entire inner diameter of the recessed space portion 10 is increased to φ4.3 (φ4.1 + insertion allowance 0.2 mm), the positional deviation margin becomes 0.3 mm, and the defective insertion can be eliminated. However, the gap between the magnet 6 and the inner peripheral surface of the recessed space portion 10 becomes large, the amount of adhesive increases, and the strict magnet position accuracy also deteriorates somewhat. On the other hand, in the present embodiment, for example, the inner diameter of the bottom of the recessed space portion 10 is φ4.1 mm, the inner diameter of the opening portion is φ4.3 mm, and the inner peripheral surface is recessed by about 4.6 degrees. By providing the tapered taper, the insertion of the magnet 6 becomes easy, the positional accuracy of the inserted magnet 6 becomes good, and the amount of adhesive can be reduced.

As described above, the adhesive 11 is harder than the resin material of the resin encapsulation body 4 and has a high rigidity, so that the resin encapsulation body 4 will be described later. The stress exerted on the top surface portion 4a by the external force in the normal direction is
When the resin material of the same resin as the resin material of the resin sealing body 4 is used as the adhesive because it is dispersed once at the boundary surface between the resin sealing body 4 and the adhesive 11, The effect of dispersing stress is higher than that when a resin material having a rigidity lower than that of the resin material of the body 4 is used as the adhesive.

As shown in FIGS. 1 to 3, the top surface portion 4a of the resin encapsulant 4 has a mold wall thickness of 80 μm on the magnetoresistive pattern of 0.1 μm.
A concave step D having a depth of mm is provided. The concave step D is formed so as to form a groove over the front and rear ends of the resin encapsulation body 4, and a detection magnetic resistance pattern for detection of the magnetoelectric conversion element 2 is formed. A void is created above the resin portion covering the surface. In this embodiment, the external dimensions of the magnetic sensor 1 are
The length is 6.4 mm × width 4.58 mm × height 2.5 mm (height 4.0 mm when the magnet 6 is mounted).

The magnetic sensor 1 is, as shown in FIG. 4, an object to be detected 1 which is a thin piece such as a bill or a check.
The magnetic identification device for reading the print information printed with the two magnetic inks.

The reading unit of the magnetic identification device will be described in detail. As shown in FIG. 4, the magnetic sensor 1 is arranged in a space S between the front housing portion 14 and the rear housing portion 15 which is soldered to the printed circuit board 13 and secures a moving path for the detected body 12. Has been done. Above the magnetic sensor 1, there is provided a rotating roller 16 that transports the detected body 12 so as to pass over the magnetic sensor 1. The transfer passage R of the detected body 12 is formed between the upper surfaces of the housing portions 14 and 15 and the guide plates 17 and 18 facing the upper surfaces.

Then, as shown in FIG.
In the passage R through which the sheet is transferred, one casing cover 19 forming a flat passage surface on each of the casings 14 and 15 and the magnetic sensor 1 (in the case of this embodiment, a plate thickness of 0.1 mm Are used).

Further, as shown in FIG. 4, the top surface portion 4a of the resin sealing body 4 of the magnetic sensor 1 is exposed to the outside, that is, a cover or a case for covering the top surface portion 4a, Since no cap or the like is provided, the flat surface H of the upper surface of the top surface portion 4a is
Is opposed to and abuts the lower surface of the casing cover 19. The flat surface H constitutes a position regulation portion in which the position of the resin sealing body 4 is regulated with respect to the detected body 12 side. In this case, the flat surface H is brought into contact with the housing cover 19 and its position is regulated. Therefore, the height of the magnetic sensor 1 itself can be made lower than that of the conventional one because there is no cover for covering the top surface portion 4a, and the entire reading unit can be made compact.

Then, due to the concave step D formed on the top surface portion 4a of the resin sealing body 4, a gap is created between the mold resin on the detection surface of the magnetoelectric conversion element 2 and the housing cover 19. Due to this air gap, the stress in the direction perpendicular to the detection surface due to the impact or vibration at the time of entering the object to be detected does not directly act on the magnetoelectric conversion element 2 forming the detection surface, so the stress on the magnetoelectric conversion element 2 becomes extremely small, and the piezo noise Can be suppressed.

Further, since there is no case, the gap between the object to be detected and the object to be detected is small through the one-plate housing, which is different from the case where the object to be detected 12 is directly read in the case as in the conventional case. There is an advantage that it can be used with the same S / N ratio, and since there is no case, the cost can be reduced and the product can be supplied at a low price.

As a resin material forming the resin encapsulating body 4, a highly flexible polyamide resin is used for encapsulation so that the rush impact pressure of the object to be detected is dispersed and the generation of piezo noise is suppressed. There is. In mass production, polyamide resin is
Since it can be processed by the hot melt casting method, the die cost can be reduced, which is advantageous for high-mix low-volume production.

As the resin material forming the resin sealing body 4, a polyamide resin having a low thermal conductivity is used for sealing, so that the temperature difference between the device and the detection object when the detection object passes. This has the effect of suppressing the generation of thermal noise due to. In mass production, the polyamide resin can be processed by the hot melt casting method, so that the die cost can be reduced, which is advantageous in the production of a large number of small lots.

Next, the step of assembling the magnet into the magnetic sensor and then magnetizing the magnet will be described.

When a magnetized magnet is incorporated in a magnetic sensor, the characteristics of the sensor usually vary due to variations in element characteristics and the distance between the magnet and the element. Therefore, in this embodiment, a magnet member that is not magnetized is magnetized after the sensor is incorporated. By doing so, the amount of magnetization can be changed while measuring the electrical characteristics such as the input resistance and output voltage of the sensor, and the characteristics can be adjusted within a desired setting range.

Further, in the present invention, the resin sealing body on the side where the detection surface of the magnetoelectric conversion element is located is the top surface side, and the term "top surface side" means that the object to be detected is the magnetoelectric conversion element. It does not mean only when it is above the conversion element. That is, for example, even when the detection surface of the magnetoelectric conversion element is used downward or sideways, the resin sealing body on the side having the detection surface of the magnetoelectric conversion element is simply referred to as a top surface portion.

The present invention is not limited to the above-described embodiment, and may be modified or applied as follows, for example, and is not limited to these structures.

(1) In the above embodiment, the resin sealing body is provided so as to cover the detection surface of the magnetoelectric conversion element. However, as shown in FIG. 5, the detection of the magnetoelectric conversion element 2 is performed. The present invention also includes a case where the detection surface is directly exposed to the outside without being covered with the resin sealing body 4. That is, the present invention includes a case where the entire magnetoelectric conversion element is sealed with a resin encapsulant, while the resin is formed in a state where an opening is formed on the detection surface of the magnetoelectric conversion element and the detection surface is exposed to the outside. What is sealed with a sealing body is also included in the present invention.

(2) In the above embodiment, the magnet for magnetic field bias is mounted in the recess formed in the resin encapsulation body and directly assembled to the resin encapsulation body. The magnet may be assembled to the resin-sealed body via an assembly member that is a separate member.

(3) In the above embodiment, the magnet is provided as the magnetizing means for magnetic field bias, but the magnetizing means is not limited to the magnet, and a bias magnetic field is generated by an electromagnet. You may do it.

(4) In the above embodiments, the entire resin encapsulation body is not covered with a cover or a cap, but in the present invention, the detection surface of the magnetoelectric conversion element in the resin encapsulation body is the object to be detected. It is sufficient that at least the top surface portion on the detection surface side that performs the detection action is exposed so as not to be covered with a covering member such as a cover or a cap, and the top surface portion in the resin sealing body is excluded. The part may be covered with a covering member such as a cover or a cap.

(5) In the above embodiment, the groove-shaped concave step is provided on the top surface of the resin encapsulant. However, as shown in FIG. The protrusion T may be distributed to a plurality of locations on the top surface portion 4a of the body 4. That is, no protrusion is provided at the detection surface of the magnetoelectric conversion element 2, and a plurality of protrusions T ... Are provided at other positions, and the end faces of the protrusions T ... Are detected as in the above embodiment. The magnetic sensor 1 may be in contact with the lower surface of the housing cover that partitions the magnetic sensor 1 from the magnetic sensor 1. The protrusion T may be a protrusion extending in one direction.

[0052]

According to the present invention, in the top surface portion of the resin encapsulation body on the side having the detection surface of the magnetoelectric conversion element sealed with the resin encapsulation body, a recess is formed on the magnetic detection portion of the magnetoelectric conversion element. Since the step portion is formed, the air gap is provided from the portion closest to the detected body side of the portion deviated from the detection surface to the vicinity of the detection surface of the magnetoelectric conversion element. Due to the structure in which the air gap is provided in this way, even if an external force such as an impact when the detected body passes through acts on the top surface portion of the resin sealing body of the magnetoelectric conversion element, it is generated by the external force. Since the stress is prevented from being transmitted to the magnetoelectric conversion element, the generation of piezo noise in the magnetoelectric conversion element is suppressed.

Further, since the top surface portion is exposed to the outside, a cover is provided on the magnetic sensor side so as not to come into contact with the magnetic sensor in the path through which the object to be detected passes, as in the conventional case. Even in the case of, the gap corresponding to the thickness of the cover only occurs between the object to be detected and the detection surface of the magnetoelectric conversion element of the magnetic sensor. Since the distance from the object is not widened, the detection surface of the magnetic sensor can be detected in a state closer to the object side than in the conventional case.

Therefore, as compared with the prior art, the magnetic sensor of the present invention can detect magnetic information by the magnetoelectric conversion element at a position close to the object to be detected, so that the S / N ratio of the detection signal can be increased. There is an effect that the detection accuracy becomes high.

[Brief description of drawings]

FIG. 1 is a perspective view showing the appearance of a magnetic sensor.

FIG. 2 is a perspective view showing a state in which a resin sealing body of a magnetic sensor is seen through.

FIG. 3 is a vertical sectional front view showing a magnetic sensor.

FIG. 4 is a vertical sectional side view showing a main part of a magnetic identification device including a magnetic sensor.

FIG. 5 is a vertical sectional front view showing a magnetic sensor according to another embodiment.

FIG. 6 is a perspective view showing the outer appearance of a magnetic sensor according to another embodiment.

FIG. 7 is a vertical sectional side view showing a reading unit of a conventional magnetic identification device.

FIG. 8 is a vertical sectional side view showing a reading unit of a conventional magnetic identification device in a clogged state.

FIG. 9 is a vertical sectional side view showing a reading unit of a conventional magnetic identification device provided with a housing cover.

[Explanation of symbols]

1 Magnetic sensor 2 Magnetoelectric conversion element 3 leads 4 resin encapsulation 4a Top part 6 Magnet (Magnetizer) 10 Recessed space 11 adhesive

Claims (7)

[Claims] 1. A magnetoelectric conversion element and a lead connected to the magnetoelectric conversion element are sealed with a resin encapsulant, and a top surface portion of the resin encapsulant covering the detection surface side of the magnetoelectric conversion element is provided. A magnetic sensor characterized in that a concave step portion is formed on a magnetic detection portion of the magnetoelectric conversion element. 2. A magnetoelectric conversion element and a lead connected to the magnetoelectric conversion element are sealed with a resin encapsulant, and a top surface portion of the resin encapsulant that covers a detection surface side of the magnetoelectric conversion element is formed. A magnetic sensor, wherein an opening is formed on a magnetic detection portion of the magnetoelectric conversion element. 3. The magnetic sensor according to claim 1, wherein a magnetic field for generating a bias magnetic field for the magnetoelectric conversion element is provided on a side of the resin sealing body opposite to a side where the magnetoelectric conversion element is arranged. A recessed space portion for mounting the magnetic means is provided, and the recessed space portion is formed in a deep recessed shape in which the inner diameter becomes smaller toward the rear side where the magnetizing means is mounted. Magnetic sensor. 4. The magnetic sensor according to claim 3, wherein a resin agent for adhering the magnetizing means mounted in the recessed space portion and the resin encapsulant is the resin encapsulant. A magnetic sensor characterized by being made of a hard material. 5. The magnetic sensor according to claim 3, wherein the magnetizing means is magnetized in a state of being assembled with the resin sealing body. 6. The magnetic sensor according to claim 1, wherein the resin encapsulant is made of at least one of highly flexible polyamide resin, silicon resin, and epoxy resin. A magnetic sensor characterized in that. 7. A magnetoelectric conversion element and a lead connected to the magnetoelectric conversion element are sealed with a resin sealing body, and a magnetizing means for generating a bias magnetic field for the magnetoelectric conversion element is provided in the resin sealing body. Assembled against, while exposing the top surface portion of the resin sealing body covering the detection surface side of the magnetoelectric conversion element to the outside, the stress generated by the external force acting on the top surface portion avoids the magnetoelectric conversion element. A magnetic sensor, wherein the resin encapsulant is configured so as to act only on an open portion.