KR20180036349A - Low Frequency Antenna Module and keyless entry system including the same - Google Patents

Abstract

A low frequency antenna module which can increase assemblability and productivity, and a keyless entry system having the same are provided. According to an embodiment of the present invention, the low frequency antenna module comprises: a magnetic core having a coil arrangement groove dent inwards in a height direction by a predetermined depth formed on one surface; a coil wound around a virtual line parallel with the height direction of the magnetic core, and arranged to be inserted into the coil arrangement groove; and a plate magnetic sheet arranged on one surface of the magnetic core to cover at least a part of an opened upper part of the coil arrangement groove.

Description

[0001] The present invention relates to a low-frequency antenna module and a keyless entry system including the low-

The present invention relates to a low frequency antenna module and a keyless entry system including the same, and more particularly, to a low frequency antenna module applicable to a keyless entry system for wirelessly operating locking or opening a door of a car, and a keyless entry system .

As the level of living has improved and the supply of cars has increased, the car has now become a necessity for daily life. As a result, there have been a lot of researches on various techniques for opening and starting a vehicle such as a car, a vehicle anti-theft device and a door of a vehicle. For example, a keyless entry method and a keyless start ).

The keyless entry method is a method in which the driver releases the door lock without operating any key or remote control. When the key is held in the body of the driver, the key is automatically transmitted to the electronic authentication device inside the vehicle and the lock is released when the data is authenticated.

An antenna module used in such a keyless entry system is generally configured such that a coil is wound around a bar-type ferrite core and a plurality of antenna modules are mounted at predetermined positions.

Accordingly, when the reception antenna of the smart key is constituted by a single antenna coil, the communication distance (the distance at which data can be received at the vehicle side) is extremely high depending on the positional relationship with the direction of the magnetic field generated in the transmission antenna of the vehicle And there is a problem that communication can not be performed in the worst case.

That is, the reception antenna built in the smart key has a problem that reception sensitivity becomes worse when the axial direction of the antenna coil and the direction of the magnetic field generated by the transmission antenna of the vehicle are parallel to each other and the reception sensitivity is good and when they are orthogonal to each other.

Therefore, it is necessary to provide a non-directional characteristic so that the signal transmitted from the vehicle at all times can be received in a stable state at the receiving antenna of the smart key regardless of the position of the vehicle with respect to the antenna.

To solve this problem, a three-axis antenna module has been proposed in which three coils are arranged orthogonally to each other so as to receive signals in all directions.

For example, a three-axis antenna module is configured by winding a coil on a bar-shaped magnetic core to form an X-axis and Y-axis antenna module, and winding a coil on a side of a hexahedron formed by the magnetic core to arrange a Z- .

In the case of the antenna module for the Z axis, a method of improving the characteristics of the coil by arranging the coil by machining the groove on the side of the hexahedron has been proposed.

However, cracks are generated or broken in the process of forming the grooves on the side of the hexahedron, and the permeability is changed to fail to satisfy the initial design value. In addition, since a separate processing step is required, there is a problem that productivity is lowered.

KR 10-2010-0079607 A

SUMMARY OF THE INVENTION It is an object of the present invention to provide a low frequency antenna module and a keyless entry system including the low frequency antenna module.

According to an aspect of the present invention, there is provided a magnetic core comprising: a magnetic core having a coil placement groove formed on one surface thereof to be drawn inward at a predetermined depth along a height direction; A coil wound around an imaginary straight line parallel to a height direction of the magnetic core and inserted in the coil disposition groove; And a plate-like magnetic sheet disposed on one surface of the magnetic core so as to cover at least a part of the open top of the coil arrangement groove.

In addition, the width of a part of the entire width of the coil is disposed in a region corresponding to the magnetic sheet so that exposure to the outside is limited, and the remaining width can be exposed to the outside through the open top of the coil placement groove.

In addition, the magnetic sheet may be divided into a plurality of fine pieces.

The magnetic sheet may be a ferrite sheet.

Further, the magnetic sheet may be attached to one surface of the magnetic core through an adhesive layer.

The magnetic core may include a pair of connection terminals for electrical connection with the outside, and both ends of the coil may be connected to the pair of connection terminals, respectively.

For example, the pair of connection terminals may be formed so as to surround the upper surface, the side surface, and the lower surface of the magnetic core, and the magnetic core may include an inclined surface formed between the coil placement groove and the connection terminal And the inclined surface may be inclined upward from the coil arrangement groove toward the connection terminal side.

As another example. The pair of connection terminals may be formed on a surface opposite to the one surface of the magnetic core having the coil disposition groove formed therein. The magnetic core may be led inwardly so as to insert a lead portion drawn out from the coil to a predetermined length And the wire arrangement groove may be formed to be connected from the coil arrangement groove to the connection terminal.

Further, the entire depth of the coil disposition groove may be formed to have the same size as the total height of the coil.

Meanwhile, the low-frequency antenna module may be embedded in a smart key, embedded in a portable terminal, or embedded in a wearable device such as a smart watch.

In another embodiment, the low-frequency antenna module of the receiver and the transmitter constituting the keyless entry system may be embedded in the receiver to implement a keyless entry system.

According to the present invention, since the antenna module can be configured through assembly, it is possible to prevent breakage and deformation of the magnetic core, which may occur during processing, thereby enhancing reliability and increasing work productivity.

1 is a schematic view of a low-frequency antenna module according to an embodiment of the present invention,
FIG. 2 is a sectional view of FIG. 1,
Fig. 3 is a sectional view of Fig. 1,
4 is a schematic view illustrating a low-frequency antenna module according to another embodiment of the present invention.
FIG. 5 is an illustration of the separation of FIG. 4,
Fig. 6 is a sectional view of Fig. 4,
7 is a plan view showing a case where a magnetic sheet applied to the low frequency antenna module according to the present invention is divided into a plurality of micro pieces.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art to which the present invention pertains. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same reference numerals are assigned to the same or similar components throughout the specification.

1 and 4, the low-frequency antenna modules 100 and 200 according to an embodiment of the present invention include a magnetic core 110, a coil 120, and a magnetic sheet 130. [

The magnetic core 110 covers the coil 120 and shields an electromagnetic field generated from the coil 120 to serve as an inductor core.

For this, the magnetic core 110 may be made of sintered ferrite such as Mn-Zn, Ni-Zn, or Ni-Cu-Zn, but not limited thereto, and dust cores may be used. It is noted that any material having magnetism can be used. In addition, the magnetic core 110 may be a soft magnetic alloy having an amorphous or nanocrystal structure.

The magnetic core 110 may have a coil placement groove 113 for receiving the coil 120 on one side thereof.

The coil arrangement groove 113 may be formed in the shape of a receiving groove having a predetermined width and depth inwardly from one side of the magnetic core 110. The coil arrangement groove 113 may include a coil 120 wound in a predetermined shape, And may be formed in a closed loop shape corresponding to the shape of the closed loop. For example, the coil disposition groove 113 may be formed in a closed loop shape having a circular shape, a polygonal shape, an elliptical shape, and a cross-sectional shape in which they are mutually combined.

Accordingly, when the coil 120 is inserted into the coil disposition groove 113, the inner side surface, the outer side surface, and the bottom surface of the coil 120 may be surrounded by the magnetic core 110.

The upper surface of the magnetic core 110 may be in the Z-axis direction (direction parallel to the height direction of the magnetic core 110) And a second protrusion 112 protruding from the hollow portion of the first protrusion 111 at a predetermined height in the Z-axis direction. The first protrusion 111 protrudes from the first protrusion 111 at a predetermined height, The outer rim of the second protrusion 112 is spaced apart from the inner rim of the first protrusion 111 by a predetermined distance so that the first protrusion 111 and the second protrusion 112 are spaced apart from each other, (See Figs. 2 and 5).

At this time, the depth and width of the coil placement groove 113 may be equal to or greater than the entire width and two of the coil 120. Accordingly, when the coil 120 is inserted into the coil disposition groove 113 so that the second protrusion 112 is positioned on the hollow portion side of the coil 120, the inner side surface of the coil 120, And the outer surface may be interfaced with the magnetic core 110.

The entire width and the total thickness of the coil 120 may be the same as the diameter of the coil 120. When the coil 120 is wound so as to overlap the plurality of layers, .

Since the magnetic material core 110 according to the present invention is configured such that the coil disposition groove 113 is open at the top, the sintering operation using the mold can be performed, thereby improving the productivity. In addition, since the conventional process of polishing or cutting a part of the magnetic core 110 to form the receiving groove for disposing the coil 120 is omitted, the process is simplified, and the magnetic core (not shown) Such as cracking or breakage, of the semiconductor device 110.

The coil 120 is for generating a signal in a predetermined frequency band to perform low frequency communication, and a conductive member having a predetermined wire diameter may be wound a plurality of times in a loop shape having a hollow portion having a predetermined area inside .

For example, the coil 120 may be wound a plurality of times about a virtual straight line parallel to the height direction of the magnetic core 110, and then inserted into the coil placement groove 113.

Accordingly, the low-frequency antenna modules 100 and 200 according to the present invention can stably receive signals transmitted in the Z-axis direction parallel to the height direction of the magnetic core 110.

Here, the coil 120 may be made of an enameled wire that is enameled outside of a copper wire having a predetermined wire diameter. However, the material of the coil is not limited thereto, and it can be used as long as the conductive material is covered with an insulating layer.

The magnetic core 110 is provided with a pair of connection terminals 114 and 214 connected to both ends of the coil 120 inserted in the coil placement groove 113 so that power can be supplied from the outside .

Accordingly, when the low-frequency antenna modules 100 and 200 according to the present invention are mounted on a circuit board (not shown), the connection terminals 114 and 214 formed on the lower surface of the magnetic core 110 are electrically connected to the circuit board A power source provided from the outside can be supplied to the coil 120 side through the circuit board and the connection terminals 114 and 214. [ Here, on one side of the circuit board, connection terminals (not shown) corresponding to the connection terminals 114 and 214 may be formed.

For example, the pair of connection terminals 114 may be formed in a substantially 'C' shape so as to surround the upper surface, the side surface, and the lower surface of the magnetic core 110 (see FIG. 3). Here, the upper surface of the magnetic core 110 may be the upper surface of the second protrusion 112.

At this time, a slope 115 may be formed on one surface of the magnetic core 110 between the coil placement groove 113 and the connection terminal 114, and the slope 115 may be formed in the coil placement groove 113 And may be formed so as to be upwardly inclined at a predetermined angle toward the connection terminal 114 (see FIG. 2).

Specifically, the inclined surface 115 may be formed on the upper surface of the second protrusion 112, and the connection terminal 114 formed on the upper surface of the coil placement groove 113 and the second protrusion 112, As shown in FIG.

The lead portion 121 of the coil 120 drawn out from the body of the coil 120 is disposed on the inclined surface 115 so that the end portion of the lead portion 121 is smoothly connected Terminal 114 as shown in FIG.

As another example, the pair of connection terminals 214 may be formed on the bottom surface of the magnetic core 110. Here, the bottom surface of the magnetic core 110 may be opposite to the top surface of the magnetic core 110 on which the coil placement groove 113 is formed (see FIG. 4).

At this time, a wire arrangement groove 215 may be formed on the side of the magnetic core 110 so that a lead portion 121 drawn out from the body of the coil 120 may be inserted therein. The wire arrangement groove 215 may be formed to be connected from the coil arrangement groove 113 to the connection terminal 214 formed on the lower surface of the magnetic core 110 (refer to FIG. 5).

Specifically, the wire arrangement groove 215 may be formed at a predetermined depth to be connected to the upper surface of the second protrusion 112 and the side surface of the magnetic core 110.

The lead part 121 of the coil 120 drawn out from the body of the coil 120 is inserted into the wire arrangement groove 215 and then the end side is connected to the connection terminal 214, It may not protrude from the magnetic core 110 when connected to the connection terminal 214 and may prevent the lead portion 121 from being broken due to external force during twisting or other operations during connection with the connection terminal 214 . As a result, the defect rate of the product can be reduced and the reliability can be increased.

The inclined surface 216 connected to the wire arrangement groove 215 is formed on the bottom surface of the magnetic core 110 in a region corresponding to the pair of connection terminals 214, And the connection terminal 214 can be smoothly soldered.

The magnetic sheet 130 shields an electromagnetic field generated from the coil 120. To this end, the magnetic sheet 130 may be made of a magnetic material so as to shield an electromagnetic field generated from the coil 120. For example, the magnetic sheet 130 may be a ferrite sheet, a polymer sheet, an amorphous ribbon sheet, a nanocrystalline ribbon sheet, or the like. However, it should be noted that the kind of the magnetic sheet 130 is not limited thereto, and any known magnetic material may be used.

The magnetic sheet 130 may be in the form of a plate having a predetermined area, and may be attached to one surface of the magnetic core 110 through an adhesive layer.

At this time, the magnetic sheet 130 may be attached to the magnetic core 110 such that the edge side covers only a part of the entire area of the coil placement groove 113.

That is, the magnetic sheet 130 has a relatively larger area than the first protrusions 111 and has an area that is relatively smaller than the sum of the first protrusions 111 and the coil placement recesses 113 .

Accordingly, when the magnetic sheet 130 is attached to one surface of the magnetic core 110, the edge of the magnetic sheet 130 protrudes from the edge of the first protrusion 111 toward the coil placement groove 113 And covers the entire width of the upper portion of the open upper portion of the coil disposition groove 113. The remaining width of the entire upper width of the coil disposition groove 113 is kept open.

The coil 120 inserted into the coil disposition groove 113 is formed in a region corresponding to the edge side of the magnetic sheet 130 protruding from the rim of the first protrusion 111 of the entire width W The width W1 of the portion to be disposed may be covered by the edge side of the magnetic sheet 130 exceeding the edge of the first protrusion 111 and the remaining width W2 of the entire width of the coil 120, Can be exposed to the outside through the open portion of the coil disposition groove 113, thereby forming a radiation path in which the magnetic field generated in the coil 120 is emitted to the outside (see FIGS. 3 and 6) ).

A portion of the magnetic sheet 130 protruding from the rim of the first protrusion 111 to the upper side of the coil disposition groove 113 is formed by a part of the coil 120 inserted into the coil disposition groove 113 and an adhesive layer It can be directly attached by mediation.

When the coil 120 is inserted into the coil arrangement groove 113, the inner side surface, the outer side surface, and the bottom surface of the coil 120 are connected to the magnetic core 110 And a portion of the upper surface of the coil 120 is surrounded by the magnetic sheet 130 and only a portion corresponding to the remaining width of the upper surface is exposed to the outside, The radiation characteristics of the coil 120 can be improved.

Accordingly, the low-frequency antenna modules 100 and 200 according to the present invention can improve reception sensitivity in a desired direction.

Meanwhile, the magnetic sheet 130 may be divided into a plurality of fine pieces so as to improve flexibility, and the plurality of fine pieces may be irregularly formed (see FIG. 7). In addition, the pair of protective films 132 are attached to both sides of the magnetic sheet 130 via the adhesive member 131, so that the position of the fine pieces can be fixed through the adhesive member 131. Here, at least one of the pair of protective films 132 may be a release film that is removed during the attachment process.

For example, the magnetic sheet 130 may be formed of a ferrite sheet, and the ferrite sheet may be flaked to form a plurality of micro-pieces. As a result, the flexibility of the ferrite sheet having a high brittleness is improved, so that cracking or cracking can be prevented from occurring when the ferrite sheet is attached to the magnetic core 110, and occurrence of cracks or cracks can be minimized. Thus, it is possible to prevent the characteristic of the initial design value from being changed or to minimize the characteristic change.

The low-frequency antenna modules 100 and 200 according to the present invention may be implemented by a Z-axis antenna module, and may be applied together with an X-axis antenna and a Y-axis antenna in which a coil is wound around a conventional bar- .

In addition, the low-frequency antenna modules 100 and 200 may be applied to a keyless entry system including a low-frequency transmitter and a low-frequency receiver.

For example, the low-frequency antenna modules 100 and 200 may be installed in a smart phone, a portable terminal such as a smart phone, or a key fob built in a wearable device such as a smart watch.

Here, the KEY FOB may include a low frequency (LF) receiver including a low frequency antenna module 100, 200, a 3D active immobilizer, and a microcontroller.

Accordingly, low frequency (LF) communication in the 22 kHz band is performed between the key fob mounted on the smart key 10 and the control unit mounted on the vehicle, for example, to wirelessly open the door or steering of the vehicle, At least one of the lock or unlock can be controlled.

In addition, the low-frequency antenna modules 100 and 200 described above can be used as a keyless start system in which a driver can start a vehicle, operate and stop the engine while being electronically authenticated without inserting or manipulating a separate mechanical key, As shown in FIG. It is also noted that the molding type low frequency antenna modules 100 and 200 may be implemented by a low frequency transmitter constituting a keyless entry system.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

100,200: Low frequency antenna module
110: magnetic core 111: first protrusion
112: second projection 113: coil placement groove
114, 214: connection terminal 115:
215: wire placement groove 120: coil
121: lead portion 130: magnetic sheet
131: Adhesive member 132: Protective film

Claims (15)

A magnetic core formed on one surface of the coil arrangement groove to be drawn inward at a predetermined depth along a height direction;
A coil wound around an imaginary straight line parallel to a height direction of the magnetic core and inserted in the coil disposition groove; And
And a plate-like magnetic sheet disposed on one surface of the magnetic core so as to cover at least a part of the open top of the coil disposition groove. The method according to claim 1,
Wherein a width of a part of the entire width of the coil is disposed in a region corresponding to the magnetic sheet so that exposure to the outside is limited and the remaining width is exposed to the outside through an open top of the coil arrangement groove. The method according to claim 1,
Wherein the magnetic sheet is divided into a plurality of minute pieces. The method according to claim 1,
Wherein the magnetic sheet is a ferrite sheet. The method according to claim 1,
Wherein the magnetic sheet is attached to one surface of the magnetic core via an adhesive layer. The method according to claim 1,
Wherein the magnetic core includes a pair of connection terminals for electrical connection with the outside, and both ends of the coil are connected to the pair of connection terminals, respectively. The method according to claim 6,
And the pair of connection terminals are formed to surround the upper surface, the side surface, and the lower surface of the magnetic core. 8. The method of claim 7,
Wherein the magnetic material core includes a coil arrangement groove and an inclined plane formed between the connection terminals, and the inclined plane is inclined upward from the coil arrangement groove toward the connection terminal side. The method according to claim 6,
Wherein the pair of connection terminals are formed on a surface opposite to a surface of the magnetic core on which the coil disposition groove is formed. 10. The method of claim 9,
Wherein the magnetic core includes a wire arrangement groove that is drawn inwardly so that a lead portion drawn out from the coil by a predetermined length can be inserted and arranged, and the wire arrangement groove includes a low frequency Antenna module. The method according to claim 1,
Wherein an entire depth of the coil disposition groove is formed to have the same size as the total height of the coil. A smart key having the molding type low frequency antenna module according to any one of claims 1 to 11. A portable terminal having the molding type low frequency antenna module according to any one of claims 1 to 11 incorporated therein. A wearable device incorporating the molding type low frequency antenna module according to any one of claims 1 to 11. receiving set; And a transmitter, the keyless entry system comprising:
A keyless entry system in which the low-frequency antenna module according to any one of claims 1 to 11 is incorporated in the receiver.

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