JP2012175579A - Glass antenna, window pane and antenna device with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a glass antenna in which the installation space for a ground member can be secured easily while suppressing distortion that occurs around a ground section.SOLUTION: A glass antenna provided on a glass pane 12 of a vehicle comprises antenna conductors 1-4, non-feeding conductors 5 and 6, a power feeding section 16 and a ground section 17 which is disposed away from the feeding section 16. The feeding section 16 is a portion for connecting the antenna conductors 1-4 to a signal processing circuit, and the ground section 17 is a portion for connecting the non-feeding conductors 5 and 6 to a car body. The ground section 17 includes a ground part 17A and a ground part 17B which is disposed away from the feeding section 16 with respect to the ground part 17A, and the ground part 17A and the ground part 17B are connected by a plurality of linear elements 7A and 7B.

Description

  The present invention relates to a glass antenna provided on a window glass of a vehicle, a window glass provided with a glass antenna, and an antenna device provided with them.

  It is known to provide a glass antenna that functions as an antenna on a window glass that is attached to a window frame of a vehicle. FIG. 1 is a plan view of a glass antenna disclosed in Patent Document 1. FIG. As shown in FIG. 1, the glass antenna 100 provided on the window glass 12 includes an antenna conductor composed of antenna elements 1 to 4, a power feeding unit 16 connected to the antenna conductor, and parasitic elements 5 and 6. And a grounding portion 17 connected to the parasitic element. The power feeding part 16 is a part for electrically connecting the antenna conductor to the signal processing circuit, and the ground part 17 is a part for electrically connecting the parasitic conductor to the vehicle body of the vehicle.

International Publication No. 2010/119856 Pamphlet

  However, depending on the route of the wiring connecting the glass antenna and the vehicle body, the shape of the window frame on the vehicle body side and the surrounding area, etc., it is possible to secure a space for installing a grounding member for connecting the ground portion to the vehicle body. It can be difficult. For example, as shown in FIG. 2, in the case of a vehicle in which the coaxial cable 44 for connecting the glass antenna and the receiver on the vehicle body is routed so as to pass near the ground portion 17, the coaxial cable 44 is an obstacle. Thus, the ground member cannot be installed in the ground portion 17.

  As a countermeasure for this, for example, as shown in FIG. However, even if the grounding portion 17 is widened to secure the installation space for the grounding member, the area of the grounding portion 17 becomes too large and the conductor is covered when the window glass 12 is heated for bending. The difference in heat absorption generated between the ground portion 17 and the portion not covered with the conductor is increased. As a result, distortion occurs around the ground portion 17.

  Therefore, an object of the present invention is to provide a glass antenna and a window glass, and an antenna device including them, which can easily secure an installation space for a ground member while suppressing distortion generated around the ground portion.

In order to achieve the above object, a glass antenna according to the present invention comprises:
A glass antenna provided on a window glass of a vehicle,
An antenna conductor, a parasitic conductor, a power feeding unit, and a grounding part arranged away from the power feeding unit;
The power feeding part is a part for connecting the antenna conductor to a signal processing circuit, and the ground part is a part for electrically connecting the parasitic conductor to a vehicle body,
The ground portion includes a first ground portion and a second ground portion disposed in a direction away from the power feeding portion with respect to the first ground portion.
The first ground part and the second ground part are connected by a plurality of linear elements.

  Moreover, in order to achieve the said objective, the window glass which concerns on this invention is equipped with this glass antenna.

  In order to achieve the above object, an antenna device according to the present invention includes the window glass and a grounding member for connecting the second grounding part to a vehicle body.

  ADVANTAGE OF THE INVENTION According to this invention, the installation space of an earthing member is easily securable, suppressing the distortion which arises around an earth | ground part.

It is a top view of the conventional glass antenna 100 provided with the earthing | grounding part 17. FIG. It is a perspective view of a feed structure. It is a top view of the glass antenna 200 which expanded the area | region of the earthing | grounding part 17 of FIG. It is a top view of the glass antenna 300 which is one Embodiment of this invention. 4 is a cross-sectional view showing an example of a structure in which a ground portion 17B is electrically connected to a vehicle body via a ground member 31. FIG. 3 is a perspective view of a ground member 31. FIG.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. Note that, in the drawings for explaining the embodiments, when directions are not particularly described, the directions on the drawings are referred to, and the directions of the drawings correspond to the directions of symbols and numbers. Further, the directions such as parallel and right angles allow a deviation that does not impair the effects of the present invention. In addition, these drawings are views of the interior of the vehicle with the window glass attached to the vehicle, but may be referred to as a view of the exterior of the vehicle. For example, when the window glass is a windshield attached to the front portion of the vehicle, the left-right direction on the drawing corresponds to the vehicle width direction. Further, in the present invention, the power feeding part and the ground part are arranged side by side along the reference direction, but the reference direction can be freely set by the installation area of the glass antenna, and particularly if it is a window glass for a vehicle, It is preferable to set the direction parallel to the edge of the window glass, the horizontal direction or the vertical direction. In the form described below, the horizontal plane when the vehicle window glass is mounted on the vehicle is the reference direction. In addition, this invention is not limited to a windshield, The rear glass attached to the rear part of a vehicle, and the side glass attached to the side part of a vehicle may be sufficient.

  FIG. 4 is a plan view of a glass antenna 300 for a vehicle that is an embodiment of the present invention. The glass antenna 300 includes an antenna conductor, a parasitic conductor disposed in the vicinity of the antenna conductor, a power feeding unit 16 and a ground unit 17 (17A, 17A, 17A, 17A 17B) is an antenna provided on the vehicle window glass 12 in a plane.

  The glass antenna 300 includes, as an antenna conductor pattern, for example, an antenna element 1 that is a first element, an antenna element 2 that is a second element, an antenna element 3 that is a third element, and a fourth element. An antenna element 4 is provided. Further, the glass antenna 300 includes, for example, a parasitic element 5 that is a first parasitic element and a parasitic element 6 that is a second parasitic element as a parasitic conductor pattern.

  The power feeding part 16 is a part for connecting an antenna conductor to a signal processing circuit (not shown), and the ground part 17 is a part for electrically connecting a non-feeding conductor to a vehicle body made of metal. The vehicle body opening edge 15a is an end portion of a vehicle body flange forming a window opening to which the window glass 12 is attached. The power feeding unit 16 and the ground unit 17 may be located in the vicinity of the edge of the window glass 12 or in the vicinity of the vehicle body opening edge 15a. Here, “electrically connected” includes that the conductors are in direct contact with each other to be connected in a direct current, and that the conductors are separated from each other by a predetermined distance to form a capacitor and are electrically connected at a high frequency. .

  The ground unit 17 includes a ground unit 17A that is a first ground unit, and a ground unit 17B that is a second ground unit disposed in a direction away from the power feeding unit 16 with respect to the ground unit 17A. The ground portion 17A and the ground portion 17B are connected by a plurality of linear elements (in FIG. 4, two linear elements 7A and 7B are illustrated).

  Therefore, according to the glass antenna 300 illustrated in FIG. 4, the ground portion 17 can be separated into the ground portion 17A and the ground portion 17B with the same potential, so that the ground portion 17 can be connected to the vehicle body. An installation space for the ground member can be easily secured.

  For example, even if there is no space for installing a grounding member in the grounding portion 17A due to physical interference with other parts such as the vehicle body, wiring, and connectors, the grounding is achieved by changing the lengths and extending directions of the plurality of linear elements. By adjusting the position of the portion 17B, the installation location of the ground member can be freely determined as a location that can be easily connected to the vehicle body. Then, since the ground portion 17A and the ground portion 17B are connected by the linear elements, the areas of the ground portions 17A and 17B do not become too large. In addition to the linear elements, distortion occurring around the ground portions 17A and 17B can be suppressed. Although not shown, the vehicle body side ground member made of a conductive material is electrically connected to the vehicle body flange so as to protrude from the vehicle body opening edge 15a toward the inner surface of the window glass 12 so as to cover the ground portion 17B. Connected to and provided. By providing such a vehicle body-side ground member, the ground member can be easily connected to the vehicle body. Further, the vehicle body flange may be formed so that the vehicle body opening edge 15a protrudes toward the inner surface of the window glass 12 so as to cover the ground portion 17B.

  Next, the configuration of one embodiment of the present invention will be described in more detail.

  In FIG. 4, the antenna element 1 extends from the power feeding portion 16 in a first direction (right direction in the drawing) that is parallel to the reference direction and toward the opposite side of the ground portion 17. The antenna element 2 is connected to the first terminal end 1g (that is, the terminal opposite to the power supply unit 16), which is the terminal of the extension of the antenna element 1 in the first direction, and is orthogonal to the antenna element 1 and the window glass. 12 extends in the second direction (downward in the drawing), which is the direction toward the inside with respect to the outer periphery of 12. The antenna element 2 may extend linearly in the second direction starting from the terminal end 1g, or may be curved and extended in the second direction. The antenna element 3 starts in the third direction (left direction in the drawing) that is the direction opposite to the first direction, starting from the second terminal end 2g that is the terminal end of the extension of the antenna element 2. Stretch. And the 3rd termination | terminus part 3g which is the termination | terminus of the extending | stretching to the 3rd direction of the antenna element 3 is located in a 1st direction side with respect to the below-mentioned antenna element 5 (namely, with respect to the antenna element 5). Located on the right area). The antenna element 4 extends in the first direction starting from a point on the antenna element 2. The starting point of the antenna element 4 in FIG. 4 extends in the first direction starting from the terminal end 2g and starting from the terminal end 4g.

  Although the antenna element 4 may not be provided, the glass antenna provided with the antenna element 4 improves the average sensitivity of the glass antenna as compared with the case where the antenna element 4 is not provided.

  The parasitic element 5 is an element that extends at least partially in the second direction from the ground portion 17A. The parasitic element 6 extends from a point parallel to the reference direction and on the parasitic element 5 as a starting point. The parasitic element 6 is preferably extended in the horizontal direction through the terminal end 5g in order to improve the antenna gain. In the case of FIG. 4, in the third direction (leftward in the drawing) starting from the terminal end 5g. It extends | stretches by making the termination | terminus part 6g into an end point.

  Although the parasitic element 6 may not be provided, the glass antenna provided with the parasitic element 6 improves the average sensitivity of the glass antenna as compared with the case where the parasitic element 6 is not provided.

  Here, the “termination part” may be an end point of extension of the parasitic element or the antenna element, or may be in the vicinity of the end point which is a conductor portion before the end point.

  Further, the antenna gain of the glass antenna 300 is improved by connecting the ground portion 17A and the ground portion 17B by at least two of the plurality of linear elements. Preferably it is 3 or more. In the case of FIG. 4, each of the two linear elements 7A and 7B is connected to the sides of the ground portion 17A and the ground portion 17B that face each other.

  The linear elements 7A and 7B extend linearly in the same direction (in other words, in the same direction as the reference direction) as the direction in which the power feeding portion 16 and the ground portion 17 are separated from each other. By extending the linear element in the same direction as the separation direction of the power feeding unit 16 and the ground unit 17, the entire glass antenna 300 can be further compared with the case where the ground unit 17 B is provided by extending the linear element in the other direction. Can be reduced in height. In addition, the linear element does not need to extend | stretch linearly, and may be curving and extending | stretching.

  The length of the linear elements 7A and 7B is preferably 70 mm or less. With this length, it is possible to reduce the installation area of the glass antenna without separating the ground portion 17A and the ground portion 17B too much, and to shorten the shortest conductor length from the ground portion 17A to the connection point to the vehicle body. As a result, the antenna gain of the glass antenna 300 is improved. More preferably, it is 50 mm or less. The lengths of the linear elements 7A and 7B are preferably 10 mm or more. Depending on the length and the shape of the vehicle body, the installation space for the ground member can be easily secured depending on this length. More preferably, it is 20 mm or more, More preferably, it is 30 mm or more.

  The power supply unit 16, the ground units 17A and 17B, and the linear elements 7A and 7B are arranged along the vehicle body opening edge 15a, thereby reducing the overall height of the glass antenna 300 and reducing the installation space for the ground member. Easy to secure.

  The power supply unit 16 and the antenna conductor connected to the power supply unit 16, the ground units 17A and 17B, the parasitic conductor connected to the ground unit 17A, and the linear elements 7A and 7B are made of conductive metal such as silver paste. It is formed by printing and baking a paste containing a glass on the inner surface of the window glass plate. However, the present invention is not limited to this forming method, and a linear or foil-like body made of a conductive material such as copper may be formed on the vehicle-side surface or the vehicle-outside surface of the window glass, It may be attached by, for example, or may be provided inside the window glass itself.

  The minimum value of each line width (each conductor width) of the plurality of linear elements is preferably 0.4 mm or more, and more preferably 0.6 mm or more in terms of preventing disconnection of the printed element. In addition, the maximum value of each line width is preferably 3.0 mm or less, more preferably 2.8 mm or less, from the viewpoint of suppressing distortion generated during glass bending.

  FIG. 5 is a cross-sectional view showing an example of a structure in which the ground portion 17 </ b> B is electrically connected to the vehicle body via the ground member 31. A radio wave reception signal received by the antenna conductor is transmitted to the signal processing circuit via a conductive member electrically connected to the power supply unit 16 and the ground unit 17A, which are not shown in FIG. On the other hand, a ground member 31 is attached to the ground portion 17B in order to connect the ground portion 17B to the vehicle body. With such a connection structure, the ground portion 17B and the parasitic conductor connected to the ground portion 17B can be securely grounded to the vehicle body via the ground member 31.

  In FIG. 5, 12 is a window glass for a vehicle, 11 is a vehicle body panel (entire figure is omitted) consisting of an inner panel 11a and an outer panel 11b, and its end is L-shaped for installing the window glass 12 on the vehicle body. A flange is formed on the surface. Reference numeral 13 denotes an adhesive (or packing) for bonding the flange of the vehicle body panel 11 and the window glass 12.

  FIG. 6 is a perspective view of the ground member 31. The ground member 31 is an elastic connection member, and is installed with a metal plate 35 having a connection portion 34 electrically connected to the ground portion 17B by soldering or the like, and the metal plate 35 being curved in an arch shape. It consists of an elastic plate 33. In the ground member 31, the metal plate 35 may be bonded to the ground portion 17B with a double-sided adhesive tape or an adhesive, and connected to the ground portion 17B at a high frequency. As shown in FIG. 5, when the window glass 12 is bonded to the end of the vehicle body panel 11 via the adhesive 13, the grounding member 31 installed in the grounding portion 17 </ b> B is elastically deformed by the elastic plate 33. In surface contact with the body panel 11. As a result, the ground portion 17B can be grounded to the vehicle body panel 11 without any special configuration on the vehicle body side.

  On the other hand, the outer surface of the outer panel 11b of the vehicle body panel 11 is usually coated with a paint or the like to form an insulating paint film 32, and a DC connection is not ensured only by contacting the ground member 31. However, since the elastic plate 33 is elastically deformed and the area in contact with the paint film 32 becomes sufficiently large, the grounding member 31 is connected to the outer panel 11b at a high frequency, so that the grounding portion 17B can be grounded to the vehicle body. it can.

  In addition, in the glass antenna of the present invention, when a coaxial cable is used as a signal line routed from the vehicle body side for connection to the signal processing circuit, the inner conductor of the coaxial cable is electrically connected to the power feeding portion 16 on one end side of the coaxial cable. The outer conductor of the coaxial cable is electrically connected to the ground portion 17A. The coaxial cable, the power feeding unit 16 and the ground unit 17A are electrically connected by soldering or the like. The outer conductor of the coaxial cable is electrically connected to the ground portion 17A, and thereby connected to the vehicle body side ground by a ground member connected to the ground portion 17B via the linear elements 7A and 7B. The other end side of the coaxial cable is connected to a signal processing circuit such as an amplifier mounted on the vehicle body side. In this case, on the other end side of the coaxial cable, the inner conductor may be electrically connected to the input portion of the amplifier, and the outer conductor may be electrically connected to the ground portion of the amplifier. The output section of the amplifier is electrically connected to an input section such as a tuner.

  Further, a connector for electrically connecting the inner conductor of the coaxial cable and the power feeding portion 16 and electrically connecting the outer conductor of the coaxial cable and the ground portion 17A is mounted on the power feeding portion 16 and the ground portion 17A. A configuration may be adopted. With such a connector, it becomes easy to attach the inner conductor of the coaxial cable to the power feeding portion 16 and to attach the outer conductor to the ground portion 17A.

  For example, the terminal member shown in FIG. 2 is used. The antenna-side connector 41 is attached so as to straddle the power feeding portion 16 and the ground portion 17A. A metal leg 42 that is a first terminal of the antenna-side connector 41 is attached to the power feeding part 16, and a metal leg 43 that is a second terminal of the antenna-side connector 41 is attached to the ground part 17A. The coaxial cable 44 is connected to the coaxial cable side connector 40.

  FIG. 2 shows a structure in which the coaxial cable side connector 40 is a male type, and the coaxial cable is connected to the feeding portion 16 and the ground portion 17A by fitting the female side antenna side connector 41 in the direction of the arrow. Is shown. When the coaxial cable side connector 40 and the antenna side connector 41 are fitted and connected, the inner conductor of the coaxial cable 44 is connected to the power feeding unit 16 via the metal legs 42, and the outer conductor of the coaxial cable 44 is connected. It is connected to the ground part 17A through the metal leg part 43.

  Further, the signal processing circuit on which an amplifier or the like is mounted may be incorporated in the antenna-side connector 41 as exemplified in FIG. The input part of the amplifier is electrically connected to the metal leg part 42, the output part of the amplifier is electrically connected to the inner conductor of the coaxial cable 44, and the ground part of the amplifier (the ground part of the signal processing circuit 20 and the ground part). Is electrically connected to the outer conductor of the coaxial cable 44 and the metal legs 43. In this case, the other end side of the coaxial cable 44 is connected to a tuner or the like mounted on the vehicle body side. With this configuration, compared with the case where the signal processing circuit is connected via a coaxial cable, the antenna side connector receives the signal before the reception signal is attenuated during transmission of the signal via the coaxial cable. This is preferable because the signal can be amplified.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications, improvements, and modifications can be made to the above-described embodiments without departing from the scope of the present invention. Substitutions can be added.

  For example, the present invention is not limited to the configuration shown in FIG. 4 as long as the antenna conductor, the parasitic conductor, the feeding portion, and the ground portion have a desired antenna gain. Specifically, the shape of the elements of the antenna conductor and the parasitic conductor may be appropriately set according to a desired reception frequency for each vehicle type. If it is the form of FIG. 4, the antenna gain of a terrestrial digital television broadcasting band can be improved. Further, a parasitic conductor may be provided in the ground portion 17B.

  Further, the ground member is not limited to the form shown in FIG. 6 as long as it has a function for connecting the ground portion 17B to the vehicle body side ground. For example, the ground member may be a projecting conductive member that can expand and contract between the ground portion 17B and the vehicle body side portion facing the ground portion 17B in a vehicle-mounted state. Alternatively, when the window glass is attached to the vehicle body, a ground member may be provided in a portion facing the ground portion 17B on the vehicle body side.

  INDUSTRIAL APPLICABILITY The present invention is used as an antenna for an automobile that receives, for example, terrestrial digital TV broadcast, UHF analog TV broadcast, US digital TV broadcast, European Union digital TV broadcast or People's Republic of China digital TV broadcast. It is preferable. Also used for FM broadcast band in Japan (76-90MHz), FM broadcast band in the US (88-108MHz), TV VHF band (90-108MHz, 170-222MHz), keyless entry system for vehicles (300-450MHz) it can.

  Also, 800 MHz band (810 to 960 MHz) for automobile telephones, 1.5 GHz band (1.429 to 1.501 GHz) for automobile telephones, GPS (Global Positioning System), GPS signals of artificial satellites 1575.42 MHz), VICS (Registered trademark) (Vehicle Information and Communication System: 2.5 GHz).

  Furthermore, ETC communication (Electronic Toll Collection System: non-stop automatic toll collection system, roadside wireless device transmission frequency: 5.795 GHz or 5.805 GHz, roadside wireless device reception frequency: 5.835 GHz or 5.845 GHz), dedicated narrow Area communication (DSRC: Dedicated Short Range Communication, 915 MHz band, 5.8 GHz band, 60 GHz band), microwave (1 GHz to 3 THz), millimeter wave (30 to 300 GHz), and SDARS (Satellite Digital Audio Radio Service (2. 34 GHz, 2.6 GHz)).

1-4 Antenna elements 5, 6 Parasitic element 11 Car body panel 11a Inner panel 11b Outer panel 12 Window glass 13 Adhesive (packing)
15a Car body opening edge 16 Power feeding portion 17 Ground portion 17A First ground portion 17B Second ground portion 20 Signal processing circuit 31 Ground member 32 Paint film 33 Elastic plate 34 Connection portion 35 Metal plate 40 Coaxial cable side connector 41 Antenna side connector 42, 43 Metal legs 44 Coaxial cable 100, 200, 300 Glass antenna for vehicle

Claims (10)

A glass antenna provided on a window glass of a vehicle,
An antenna conductor, a parasitic conductor, a power feeding unit, and a grounding part arranged away from the power feeding unit;
The power feeding part is a part for connecting the antenna conductor to a signal processing circuit, and the ground part is a part for electrically connecting the parasitic conductor to a vehicle body,
The ground portion includes a first ground portion, and a second ground portion disposed in a direction away from the power feeding portion with respect to the first ground portion,
The glass antenna, wherein the first ground part and the second ground part are connected by a plurality of linear elements.   2. The glass antenna according to claim 1, wherein each of the plurality of linear elements has a length of 10 mm to 70 mm.   The glass antenna according to claim 1 or 2, wherein each line width of the plurality of linear elements is 0.4 mm or more and 3.0 mm or less.   The said parasitic conductor is a glass antenna as described in any one of Claim 1 to 3 extended | stretched from the said 1st earth | ground part.   A window glass comprising the glass antenna according to any one of claims 1 to 4. A window glass according to claim 5;
An antenna device, comprising: a ground member for electrically connecting to the vehicle body at the second ground portion.   The antenna device according to claim 6, wherein the ground member is an elastic connection member.   The signal line routed from the vehicle body side is a coaxial cable, the inner conductor of the coaxial cable is electrically connected to the feeding portion, and the outer conductor of the coaxial cable is electrically connected to the first ground portion. The antenna device according to claim 6 or 7.   The power feeding portion and the first ground portion are electrically connected to the inner conductor of the coaxial cable and the power feeding portion, and are electrically connected to the outer conductor of the coaxial cable and the first ground portion. The antenna device according to claim 8, wherein a connector for mounting is mounted.   The antenna device according to claim 9, wherein the connector includes the signal processing circuit.

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