JP2018152739A - antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna, an antenna module and a window glass each having improvable reception performance.SOLUTION: The antenna according to the present invention is an antenna placed on a glass plate, and comprises: a first feeding part; a second feeding part; a first antenna element connected to the first feeding part and having at least one antenna conductor; a second antenna element connected to the second feeding part and having at least one antenna conductor; and a third antenna element connected to the second feeding part or the second antenna element and having a plurality of looped antenna conductors.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an antenna, an antenna module, and a window glass.

  Conventionally, various methods have been proposed to improve the reception performance of an antenna disposed on a window glass of an automobile or the like. For example, it is conceivable to prepare an amplifier that matches the frequency of the broadcast wave to be received. At this time, it is desirable to prepare an amplifier suitable for each frequency in the reception frequency range. However, preparation of such an amplifier requires cost. Therefore, for example, in the antenna of Patent Document 1, a conductor extending in the horizontal direction is provided as an impedance adjustment element to improve reception performance.

JP2015-50637A

  However, in the antenna disclosed in Patent Document 1, since the element for adjusting the impedance is only the conductor extending in the horizontal direction, the antenna does not sufficiently contribute to the improvement of the reception performance. In particular, for media with a wide frequency band such as digital television broadcast waves, further improvement in reception performance is desired. The present invention has been made to solve the above problems, and an object of the present invention is to provide an antenna, an antenna module, and a window glass that can improve reception performance.

Item 1. An antenna disposed on a glass plate, comprising: a first feeding unit; a second feeding unit; a first antenna element connected to the first feeding unit and having at least one antenna conductor; and the second feeding unit. A second antenna element having at least one antenna conductor, and a third antenna element having a plurality of loop-shaped antenna conductors connected to the second feeder or the second antenna element. Antenna.

Item 2. Item 2. The antenna according to Item 1, wherein the second power feeding unit of the first power feeding unit and the second power feeding unit is grounded.

Item 3. Item 3. The antenna according to Item 1 or 2, wherein the plurality of antenna conductors of the first antenna element are arranged substantially parallel to the horizontal direction.

Item 4. Item 4. The antenna according to any one of Items 1 to 3, wherein the third antenna element is connected to the second antenna element.

Item 5. Item 5. The antenna according to any one of Items 1 to 4, wherein each antenna conductor of each third antenna element is formed in a rectangular shape.

Item 6. When the wavelength of the broadcast wave that can be received by the antenna is λ1 to λ2, the dielectric constant of the glass plate is α, and L = λ2 / 4 × α, the horizontal length of the third antenna element is L ± Item 6. The antenna according to any one of Items 1 to 5, which is 30 mm.

Item 7. The antenna element further includes a fourth antenna element connected to the one antenna conductor of the third antenna element, and at least one of the plurality of antenna conductors in the third antenna element has at least one portion extending in a horizontal direction. Item 7. The antenna according to any one of Items 1 to 6, wherein the fourth antenna element extends so as to extend the portion in the horizontal direction.

Item 8. Item 8. The antenna according to Item 7, wherein a length of the fourth antenna element in a horizontal direction is 30 to 50 mm.

Item 9. Item 9. The antenna according to any one of Items 1 to 8, further comprising a fifth antenna element that is not connected to the power feeding units and the antenna elements and extends in a horizontal direction.

Item 10. Item 10. The antenna according to Item 9, wherein the length of the fifth antenna element is 100 to 150 mm.

Item 11. Item 10. The antenna according to Item 9, wherein the fifth antenna element is arranged in a range within 10 mm upward and within 30 mm downward with respect to a tip portion of the second antenna element.

Item 12. The antenna according to any one of Items 1 to 11, wherein the antenna is configured to receive a broadcast wave in a frequency range of 200 MHz or higher.

Item 13. Item 13. The antenna according to Item 12, wherein the first antenna element and the second antenna element extend in a horizontal direction and are configured to receive a broadcast wave of a digital television.

Item 14. Item 14. The antenna according to Item 13, wherein a length of the third antenna element in a horizontal direction is 70 to 130 mm.

Item 15. 15. An antenna according to any one of Items 1 to 14, and an amplifier connected to the antenna, amplifying and outputting a signal received by the antenna, and having an input impedance of 50 to 100Ω set Antenna module.

Item 16. Item 15. A window glass comprising a glass plate and at least one antenna according to any one of Items 1 to 14 disposed on the glass plate.

Item 17. The first power feeding unit and the second power feeding unit are arranged in a horizontal direction, and the first antenna element extends in a direction opposite to the second power feeding unit across the first power feeding unit. Item 16. The window glass according to Item 16, wherein the second antenna element extends in a direction opposite to the first power supply unit across the second power supply unit, and constitutes a windshield.

Item 18. The glass plate is formed in a rectangular shape having long sides in the horizontal direction, and an imaginary line connecting the first power feeding unit and the second power feeding unit is substantially parallel to a long side of the glass plate. Window glass as described in 1.

Item 19. Item 19. The window glass according to Item 17 or 18, wherein the antenna is disposed in a region within 80 mm downward from the uppermost portion of the glass plate.

Item 20. The window glass according to any one of Items 17 to 19, wherein the two antennas are disposed at both ends of the glass plate in a horizontal direction.

  The “horizontal direction” in each of the above inventions does not indicate only a strict horizontal direction, but for example, a slight inclination is allowed according to the inclination of an automobile or a glass plate. This also applies to the following description.

  With the window glass according to the present invention, the reception performance can be further improved.

It is a front view of the windshield of the automobile by which one embodiment of the window glass for vehicles concerning the present invention was mounted. It is sectional drawing of the laminated glass which comprises the windshield which concerns on FIG. It is an enlarged view of FIG. It is a figure which shows the other example of a 3rd antenna element. It is sectional drawing which shows an example of a film antenna. 1 is a diagram illustrating an antenna according to Example 1. FIG. FIG. 6 is a diagram illustrating an antenna according to a second embodiment. It is a figure which shows the antenna which concerns on the comparative example 1. 6 is a diagram showing an antenna according to Comparative Example 2. FIG. 10 is a diagram showing an antenna according to Comparative Example 3. FIG. It is a graph which shows the receiving performance of Examples 1, 2 and Comparative Examples 1-3. 6 is a diagram illustrating an antenna according to Example 3. FIG. 6 is a graph showing the reception performance of Examples 1 and 3. It is a graph which shows the reception performance of Example 3, 4. It is a graph which shows the receiving performance of Examples 3 and 5-11. It is a graph which shows the reception performance of Examples 3, 12, and 13. It is a graph which shows the reception performance of Examples 3, 14, and 15. It is a graph which shows the reception performance of Example 3, 16, and 17. FIG.

  Hereinafter, an embodiment in which a window glass according to the present invention is applied to a windshield of an automobile will be described with reference to the drawings. FIG. 1 is a front view of a windshield of an automobile according to this embodiment. In the following, for convenience of explanation, the vertical direction in FIG. 1 may be referred to as the vertical direction or the vertical direction, and the horizontal direction in FIG. This orientation does not limit the invention.

<1. Windshield>
As shown in FIG. 1, the window glass for a vehicle according to the present embodiment is mounted on a laminated glass 1, a shielding layer 2 laminated on a vehicle inner surface of the laminated glass 1, and a vehicle inner surface. And an antenna 3 for a digital TV antenna. Hereinafter, each member will be described in order.

<1-1. Overview of laminated glass>
FIG. 2 is a sectional view of the laminated glass. As shown in the figure, the laminated glass 1 includes an outer glass plate 11 and an inner glass plate 12, and a resin intermediate film 13 is disposed between the glass plates 11 and 12.
<1-1-1. Glass plate>
As each glass plate 11 and 12, a well-known glass plate can be used, and it can also form with heat ray absorption glass, general clear glass, green glass, or UV green glass. However, these glass plates 11 and 12 need to realize visible light transmittance in accordance with the safety standards of the country where the automobile is used. For example, the required solar radiation absorption rate can be ensured by the outer glass plate 11, and the visible light transmittance can be adjusted by the inner glass plate 12 so as to satisfy safety standards. Below, an example of a composition of clear glass, heat ray absorption glass, and soda-lime-type glass is shown.

(Clear glass)
SiO ₂ : 70 to 73% by mass
Al ₂ O ₃ : 0.6 to 2.4% by mass
CaO: 7 to 12% by mass
MgO: 1.0 to 4.5 mass%
R ₂ O: 13 to 15% by mass (R is an alkali metal)
Fe total iron oxide in terms of _{2 O 3 (T-Fe 2} O 3): 0.08~0.14 wt%

(Heat ray absorbing glass)
The composition of the heat-absorbing glass, for example, based on the composition of the clear glass, the proportion of the total iron oxide in terms of _{Fe 2 O 3 (T-Fe} 2 O 3) and 0.4 to 1.3 wt%, CeO ₂ ratio as 0-2 mass%, the proportion of TiO ₂ and 0 to 0.5 wt%, framework component of the glass (mainly, SiO ₂ and Al ₂ O ₃₎ to T-Fe ₂ O _3, CeO _The composition can be reduced by an increase of ₂ and TiO ₂ .

(Soda-lime glass)
SiO ₂ : 65-80% by mass
Al ₂ O ₃ : 0 to 5% by mass
CaO: 5 to 15% by mass
MgO: 2% by mass or more NaO: 10-18% by mass
K ₂ O: 0 to 5% by mass
MgO + CaO: 5 to 15% by mass
Na ₂ O + K ₂ O: 10 to 20% by mass
SO ₃ : 0.05 to 0.3% by mass
B ₂ O ₃ : 0 to 5% by mass
Fe total iron oxide in terms of _{2 O 3 (T-Fe 2} O 3): 0.02~0.03 wt%

  Although the thickness of the laminated glass which concerns on this embodiment is not specifically limited, From a viewpoint of weight reduction, it is preferable that the sum total of the thickness of the outer side glass plate 1 and the inner side glass plate 2 shall be 2.4-4.6 mm. It is more preferable to set it as 2.6-3.4 mm, and it is especially preferable to set it as 2.7-3.2 mm. Thus, since it is necessary to reduce the total thickness of the outer glass plate 11 and the inner glass plate 12 for weight reduction, the thickness of each glass plate is not particularly limited, For example, the thickness of the outer glass plate 11 and the inner glass plate 12 can be determined as follows.

  The outer glass plate 11 mainly needs durability and impact resistance against external obstacles. For example, when this laminated glass is used as a windshield of an automobile, the outer glass plate 11 has impact resistance performance against flying objects such as pebbles. is necessary. On the other hand, as the thickness is larger, the weight increases, which is not preferable. From this viewpoint, the thickness of the outer glass plate 1 is preferably 1.0 to 3.0 mm, and more preferably 1.6 to 2.3 mm. Which thickness is adopted can be determined according to the application of the glass.

  Although the thickness of the inner side glass plate 12 can be made equivalent to the outer side glass plate 11, for example, thickness can be made smaller than the outer side glass plate 11 for weight reduction of a laminated glass. Specifically, considering the strength of the glass, it is preferably 0.6 to 2.0 mm, more preferably 0.8 to 1.8 mm, and 0.8 to 1.6 mm. Particularly preferred. Furthermore, it is preferable that it is 0.8-1.3 mm. Which thickness is used for the inner glass plate 2 can also be determined according to the purpose of the glass.

  Moreover, the shape of the outer side glass plate 11 and the inner side glass plate 12 which concerns on this embodiment may be a curved shape. However, when the glass plates 11 and 12 have a curved shape, the sound insulation performance decreases when the amount of double is increased. The amount of double is an amount indicating the bending of the glass plate. When a straight line L connecting the center of the upper side and the center of the lower side of the glass plate is set, the largest distance between the straight line L and the glass plate is set. This is defined as a double amount D.

  In addition, the curved glass plate does not have a large difference in sound transmission loss (STL) in the range of the doubly amount of 30 to 38 mm, but the frequency band of 4000 Hz or less compared to the planar glass plate. It can be seen that the sound transmission loss is reduced. Therefore, when producing a curved glass plate, it is preferable that the amount of double is small. Specifically, the amount of double is preferably less than 30 mm, more preferably less than 25 mm, and particularly preferably less than 20 mm.

  Here, an example of a method for measuring the thickness when the glass plate is curved will be described. First, about a measurement position, it is two places up and down on the center line extended in the up-down direction at the center of the left-right direction of a glass plate. The measuring instrument is not particularly limited, and for example, a thickness gauge such as SM-112 manufactured by Teclock Co., Ltd. can be used. At the time of measurement, it is arranged so that the curved surface of the glass plate is placed on a flat surface, and the end of the glass plate is sandwiched by the thickness gauge and measured.

<1-1-2. Intermediate layer>
Subsequently, the intermediate film 13 will be described. The intermediate film 13 is formed of at least one layer. For example, as shown in FIG. 2, the intermediate film 13 can be configured by three layers in which a soft core layer 131 is sandwiched between harder outer layers 132. However, it is not limited to this configuration, and may be formed of a plurality of layers including the core layer 131 and at least one outer layer 132 disposed on the outer glass plate 11 side. For example, two layers of the intermediate film 13 including the core layer 131 and one outer layer 132 disposed on the outer glass plate 11 side, or an even number of outer layers 132 each having two or more layers on both sides around the core layer 131. Alternatively, the intermediate film 13 may be disposed, or the intermediate film 13 may be configured such that the odd outer layer 132 is disposed on one side and the even outer layer 132 is disposed on the other side with the core layer 131 interposed therebetween. When only one outer layer 132 is provided, the outer layer 132 is provided on the outer glass plate 11 side as described above, but this is to improve the resistance to breakage against an external force from outside the vehicle or outside. Further, when the number of outer layers 132 is large, the sound insulation performance is also enhanced.

  The hardness of the core layer 131 is not particularly limited as long as it is softer than the outer layer 132. For example, the material can be selected based on the Young's modulus. Specifically, at a frequency of 100 Hz and a temperature of 20 degrees, it is preferably 1 to 20 MPa, more preferably 1 to 18 MPa, and particularly preferably 1 to 14 MPa. In such a range, it is possible to prevent the sound transmission loss from being lowered in a low frequency range of approximately 3500 Hz or less.

  On the other hand, the Young's modulus of the outer layer 132 is preferably large in order to improve the sound insulation performance in the high frequency region, as will be described later, 560 MPa or more, 600 MPa or more, 650 MPa or more, 700 MPa or more at a frequency of 100 Hz and a temperature of 20 degrees. It can be set to 750 MPa or more, 880 MPa or more, or 1300 MPa or more. On the other hand, the upper limit of the Young's modulus of the outer layer 132 is not particularly limited, but can be set from the viewpoint of workability, for example. For example, it is empirically known that when it becomes 1750 MPa or more, workability, particularly cutting becomes difficult. Moreover, it is preferable to make the Young's modulus of the outer layer on the outer glass plate 11 side larger than the Young's modulus of the outer layer on the inner glass plate 12 side. Thereby, the damage resistance performance with respect to the external force from the outside of a vehicle or the outdoors improves.

  The material constituting each of the layers 131 and 132 is not particularly limited, but it is necessary that the material has at least a Young's modulus in the above range. For example, these layers 131 and 132 can be formed of a resin material. Specifically, the outer layer 132 can be made of polyvinyl butyral resin (PVB). Polyvinyl butyral resin is preferable because it is excellent in adhesiveness and penetration resistance with each glass plate. On the other hand, the core layer 131 can be composed of an ethylene vinyl acetate resin (EVA) or a polyvinyl acetal resin that is softer than the polyvinyl butyral resin that constitutes the outer layer 132. By sandwiching the soft core layer 131 in between, the sound insulation performance can be greatly improved while maintaining the same adhesion and penetration resistance as the single-layer resin intermediate film.

  In general, the hardness of the polyvinyl acetal resin is controlled by (a) the degree of polymerization of the starting polyvinyl alcohol, (b) the degree of acetalization, (c) the type of plasticizer, (d) the addition ratio of the plasticizer, etc. Can do. Therefore, by appropriately adjusting at least one selected from these conditions, a hard polyvinyl butyral resin used for the outer layer 132 and a soft polyvinyl butyral resin used for the core layer 131 even if the same polyvinyl butyral resin is used. Can be made separately. Furthermore, the hardness of the polyvinyl acetal resin can also be controlled by the type of aldehyde used for acetalization, coacetalization with a plurality of aldehydes, or pure acetalization with a single aldehyde. Although it cannot generally be said, the polyvinyl acetal resin obtained by using an aldehyde having a large number of carbon atoms tends to be softer. Therefore, for example, when the outer layer 132 is made of polyvinyl butyral resin, the core layer 131 has an aldehyde having 5 or more carbon atoms (for example, n-hexylaldehyde, 2-ethylbutyraldehyde, n-heptylaldehyde, n-octylaldehyde) can be used as the polyvinyl acetal resin obtained by acetalization with polyvinyl alcohol. In addition, when a predetermined Young's modulus is obtained, it is not limited to the said resin.

  The total thickness of the intermediate film 13 is not particularly limited, but is preferably 0.3 to 6.0 mm, more preferably 0.5 to 4.0 mm, and 0.6 to 2.0 mm. It is particularly preferred. Moreover, the thickness of the core layer 131 is preferably 0.1 to 2.0 mm, and more preferably 0.1 to 0.6 mm. On the other hand, the thickness of each outer layer 132 is preferably larger than the thickness of the core layer 131, and specifically, it is preferably 0.1 to 2.0 mm, and preferably 0.1 to 1.0 mm. Is more preferable. In addition, the total thickness of the intermediate film 13 can be made constant, and the thickness of the core layer 131 can be adjusted therein.

  In addition, the thickness of the core layer 131 and the outer layer 132 of the intermediate film 13 does not need to be constant over the entire surface, and may be a wedge shape for laminated glass used for a head-up display, for example. In this case, the thickness of the core layer 131 and the outer layer 132 of the intermediate film 13 is measured at the position where the thickness is the smallest, that is, the lowermost side portion of the laminated glass. When the intermediate film 13 is wedge-shaped, the outer glass plate and the inner glass plate are not arranged in parallel, but such arrangement is also included in the glass plate in the present invention. That is, in the present invention, for example, the arrangement of the outer glass plate 11 and the inner glass plate 12 when the intermediate film 13 using the core layer 131 and the outer layer 132 whose thickness is increased at a change rate of 3 mm or less per 1 m is used. including.

  The method for producing the intermediate film 13 is not particularly limited. For example, the resin component such as the polyvinyl acetal resin described above, a plasticizer, and other additives as necessary are blended and kneaded uniformly, and then each layer is collectively And a method of laminating two or more resin films prepared by this method by a pressing method, a laminating method or the like. The resin film before lamination used in a method of laminating by a press method, a laminating method or the like may have a single layer structure or a multilayer structure. Further, the intermediate film 13 can be formed of a single layer in addition to the above-described plural layers.

<1-2. Shielding layer>
As shown in FIG. 1, a shielding layer 2 made of dark ceramic such as black is laminated on the periphery of the laminated glass 1. This shielding layer 2 shields the field of view from inside or outside the vehicle, and is laminated along the four sides of the laminated glass. That is, the shielding layer 2 includes an upper side portion 21, a left side portion 22, a right side portion 23, and a lower side portion 24 along the four sides of the laminated glass 1. The inner edge of the connection part of the upper side part 21 and the left side part 22, and the upper side part 21 and the right side part 23 is formed in circular arc shape. And the circular vehicle verification 5 is affixed on the inner surface of the laminated glass 1 along the inner edge of the connection part of the upper side part 21 and the left side part 22. FIG.

  Further, the upper side portion 21 is formed in a band shape, and a first region 211 extending from the center of the laminated glass 1 to the vicinity of both sides, and a second region extending from both sides of the first region 211 and connected to the left side portion 22 or the right side portion 23. 212. The vertical width of the second region 212 is slightly larger than that of the first region. Thereby, an obliquely extending step is formed on the inner edge of the upper side portion 21 from the first region 211 to the second region 212.

The shielding layer 2 can have various modes such as only the inner surface of the outer glass plate 11, only the inner surface of the inner glass plate 12, or the inner surface of the outer glass plate 11 and the inner surface of the inner glass plate 12. Moreover, although it can form with a ceramic and various materials, it can be set as the following compositions, for example.
* 1, Main component: Copper oxide, Chromium oxide, Iron oxide and Manganese oxide * 2, Main component: Bismuth borosilicate, Zinc borosilicate

  The ceramic can be formed by a screen printing method, but it can also be produced by transferring a firing transfer film to a glass plate and firing. When screen printing is employed, for example, polyester screen: 355 mesh, coat thickness: 20 μm, tension: 20 Nm, squeegee hardness: 80 degrees, mounting angle: 75 °, printing speed: 300 mm / s, drying oven The ceramic can be formed by drying at 150 ° C. for 10 minutes.

  Moreover, the shielding layer 2 can be formed by laminating ceramics and attaching a dark colored resin shielding film.

<1-3. Antenna>
Next, the antenna 3 will be described with reference to FIG. FIG. 3 is an enlarged view of FIG. 1 showing the antenna. As shown in FIG. 1, a pair of digital television antennas are mounted on the windshield according to the present embodiment. Since these antennas are bilaterally symmetrical and basically the same, the antennas arranged on the left side will be described below with reference to FIG.

  As shown in FIG. 3, the antenna 3 includes a first feeding unit 31 and a second feeding unit 32 that are formed in a rectangular shape. Both the first power supply unit 31 and the second power supply unit 32 are arranged in the horizontal direction in the second region 212 on the left side of the upper side portion 21 of the shielding layer 2, and the first power supply unit 31 is arranged on the left side. The 2nd electric power feeding part 32 is arrange | positioned at the right side. Therefore, the imaginary line connecting the center of the first power supply unit 31 and the center of the second power supply unit 32 and the upper edge of the laminated glass 1 are substantially parallel.

  The automobile is also provided with a receiver for digital television (not shown) and an amplifier (not shown) connected to the receiver. The amplifier is connected to the first power feeding unit 31 and the second power via a coaxial cable. The power supply unit 32 is connected. And the 1st electric power feeding part 31 is connected to the signal wire | line (core wire) of a coaxial cable, and the 2nd electric power feeding part 32 is connected to the ground line (external conductor) of a coaxial cable. The input impedance of the amplifier can be set to 50 to 100Ω, for example.

  A first antenna element 33 that extends horizontally toward the left side is connected to the first power feeding portion 31. The first antenna element 33 includes two linear antenna conductors 331 extending along the upper side portion 21. The antenna conductors 331 are arranged in the vertical direction and extend in parallel to each other. A second antenna element 34 that extends horizontally toward the right side is connected to the second power feeding portion 32. The second antenna element 34 includes a first portion 341 that extends horizontally to the vicinity of the boundary between the second region 212 and the first region 211 of the upper side portion 21, a second portion 342 that extends slightly upward from the first portion 341, And a third portion 343 extending horizontally from the upper end of the second portion 342 to the right side. The first portion 341 has a vertical position that is substantially the same as the lower edge of the first region 211, and the third portion 343 extends in the first region 211.

  A third antenna element 35 is connected to the second power feeding unit 32. The third antenna element 35 includes an L-shaped connecting part 351 having a part extending horizontally to the right side and a part extending downward from the part, and two loop-like parts connected to the lower end of the connecting part 351. A first antenna conductor 352 and a second antenna conductor 353. These antenna conductors 352 and 353 are both formed in a rectangular shape having long sides in the horizontal direction, with the first antenna conductor 352 being disposed on the left side and the second antenna conductor 353 being disposed on the right side. The two antenna conductors 352 and 353 are in contact with each other so that the right side of the first antenna conductor 352 and the left side of the second antenna conductor 353 are common. Hereinafter, the common side is referred to as a vertical portion 354.

  And the lower end of the connection part 351 mentioned above is connected with the upper end of the perpendicular | vertical site | part 354. FIG. Further, the upper region including the upper side of the first antenna conductor 352 and the vicinity of the upper left corner of the second antenna conductor 353 are on the second region 212 of the shielding layer 2, and the other parts of the third antenna element 35 are , And protrudes downward from the upper side 21 of the shielding layer 2.

Here, the horizontal length of the third antenna element 35 will be described. For example, as the wavelength lambda ₁ to [lambda] ₂ of receivable broadcast waves in the antenna 3, the dielectric constant of the glass plate alpha, and _{L = λ 2/4 × α} , the horizontal length of the third antenna element 35 Can be L ± 30 mm.

Specifically, the frequency of the broadcast wave of the digital television are the about 500～720MHz, when the α dielectric constant of the glass plate is 0.65, the wavelength λ ₁ / 4~λ _2/4 is about 68~100mm It becomes. That is, it is the λ _2/4 = 100mm, From the above equation, the horizontal length of the third antenna element 35, 70～130Mm is appropriate.

  By making the length of the third antenna element 35 in the horizontal direction the above L, the impedance mismatch is eliminated, so that a wider band can be expected, and as a result, the reception performance is improved. Note that L is defined by using λ2. This is because the length L is generally determined in consideration of the low frequency side.

  In addition, a fourth antenna element 36 that extends linearly is connected to the right end of the upper side 3531 of the second antenna conductor 353. That is, the fourth antenna element 36 extends so as to extend the upper side 3531 of the second antenna conductor 353, and is disposed below the upper side portion 21 of the shielding layer 2. Although the length L1 of the 4th antenna element 35 is not specifically limited, For example, it can be set as 10-50 mm.

  Furthermore, on the right side of the second antenna element 34, a fifth antenna element 37 extending linearly with a gap in the horizontal direction is provided. That is, since the fifth antenna element 34 is not connected to any of the antenna elements 33 to 36 and the power feeding units 31 and 32 and is not fed, it is provided mainly to improve directivity. The fifth antenna element 37 has substantially the same vertical position as the third portion 343 of the second antenna element 34 and is disposed on the upper side portion 21 of the shielding layer 2. Although the length L2 of the 5th antenna element 37 is not specifically limited, For example, it can be 120-140 mm. Also, the vertical position of the fifth antenna element 37 is not particularly limited. For example, with reference to the tip of the third portion 343 of the second antenna element 34, the upper part is within 30 mm (L3), and the lower part is within 30 mm. It can arrange | position in the position of (L4).

<1-4. Material>
The antenna 3 as described above can be formed by laminating a conductive material having conductivity on the surface of the glass plate 1 so as to have a predetermined linear pattern. Such a material is only required to have conductivity, and can be appropriately selected according to the embodiment. Examples thereof include silver, gold, and platinum. Each of the above members can be formed by printing and baking a conductive silver paste containing silver powder, glass frit and the like on the surface of the glass plate 1.

<2. Windshield manufacturing method>
Next, an example of a windshield manufacturing method will be described. First, after the shielding layer 2 is formed on the inner glass plate 12 formed in a flat plate by screen printing or the like, the antenna 3 is formed by screen printing or the like. Thereafter, the outer glass plate 11 and the inner glass plate 12 are carried into a heating furnace and heated to near the softening point. Thereafter, these are formed into a curved surface shape by press molding. Or each glass plate 11 and 12 can be shape | molded by the curved surface shape by the self-weight bending method etc. which bend by own weight.

  Thus, when the outer glass plate 11 and the inner glass plate 12 are formed, the intermediate film 13 is subsequently sandwiched between the outer glass plate 11 and the inner glass plate 12, put into a rubber bag, and sucked under reduced pressure. While pre-adhering at about 70-110 ° C. Other pre-adhesion methods are possible. For example, the intermediate film 13 is sandwiched between the outer glass plate 11 and the inner glass plate 12 and heated at 45 to 65 ° C. by an oven. Subsequently, this laminated glass is pressed by a roll at 0.45 to 0.55 MPa. Next, this laminated glass is again heated at 80 to 105 ° C. by an oven and then pressed again by a roll at 0.45 to 0.55 MPa. Thus, preliminary adhesion is completed.

  Next, this adhesion is performed. The laminated glass on which the preliminary bonding has been performed is subjected to main bonding by an autoclave, for example, at 100 to 150 ° C. at 8 to 15 atm. Specifically, for example, the main bonding can be performed under the conditions of 14 atm and 145 ° C. Thus, the laminated glass according to the present embodiment is manufactured.

<3. Features>
According to the present embodiment, the following effects can be obtained.
(1) Since the third antenna element 35 has a plurality of loop-shaped antenna conductors 352 and 353, the impedance can be adjusted, and the reception performance can be improved. In particular, since a plurality of loop-shaped antenna conductors 352 and 353 are provided, reception performance in a wide band can be improved even in a medium having a wide frequency band such as a broadcast wave of digital television.

(2) The antenna conductors 352 and 353 of the third antenna element 35 are formed in a rectangular shape. That is, since the wire extending in the horizontal direction and the wire extending in the vertical direction are provided, reception is possible regardless of whether the polarization is horizontal polarization or vertical polarization, which contributes to improvement in reception performance. In particular, the two rectangular antenna conductors 352 and 353 are formed so that the horizontal direction is the longitudinal direction, and are arranged side by side in the horizontal direction, so that the reception performance of horizontal polarization is improved. A big contribution.

(3) Since the antenna 3 is disposed so as to extend in the horizontal direction as a whole, it is possible to prevent the field of view of the windshield from being obstructed. In addition, since most of the antenna 3 can be disposed on the shielding layer 2, it can be difficult to see from the outside of the vehicle, so that the appearance can be improved.

(4) Since the antenna 3 is arranged so as to avoid the vehicle verification 5, it is possible to prevent a decrease in reception performance. This is because the vehicle verification often includes metal, and this metal affects reception performance.

<4. Modification>
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible unless it deviates from the meaning. The following modifications can be combined as appropriate.

<4-1>
In the above embodiment, the first antenna element 33 includes the two antenna conductors 331. However, the number of the antenna conductors 331 is not particularly limited, and may be one or three or more. However, the reception performance can be improved as the number of the antenna conductors 331 of the first antenna element 33 increases. Moreover, each antenna conductor 331 should just extend horizontally as a whole, for example, may be bent in the middle.

<4-2>
In the above embodiment, the second antenna element 34 is configured by a single antenna conductor, but may be configured by a plurality of antenna conductors. Moreover, the 2nd antenna element 34 should just extend horizontally as a whole, for example, may be bent in the middle or may be curved.

<4-3>
In the said embodiment, although the 3rd antenna element 35 has the two loop-shaped antenna conductors 352 and 353, it is not limited to this. That is, the number of loop antenna conductors 352 and 353 may be three or more. Further, the direction in which the antenna conductors 352 and 353 are arranged is not limited. Further, the connecting portion 351 does not have to be connected to the vertical portion 354 and can be directly connected to any one of the antenna conductors 352 and 353.

  Further, the two antenna conductors 352 and 353 are not necessarily in contact with each other. For example, as shown in FIG. 4, the antenna conductors 352 and 353 are arranged with a gap therebetween, and the linear conductor 357 is used. You may connect. At this time, the connecting portion 351 may be connected to the conductor 357 or may be connected to one of the antenna conductors 352 and 353. Furthermore, the antenna conductors 352 and 353 may have a loop shape, and may have a circular shape, an elliptical shape, a polygonal shape, or the like other than the rectangular shape.

  Moreover, in the said embodiment, although the 3rd antenna element 35 is connected to the 2nd electric power feeding part 32 via the connection part 351, it can also be connected to the 2nd antenna element 34, for example. That is, the connection position can be changed as appropriate in accordance with the region where the antenna is mounted. Therefore, the degree of freedom in designing the antenna can be increased and the appearance can be improved.

<4-4>
The fourth antenna element 36 extends from the third antenna element 35, but may extend from any position of the third antenna element 35. Moreover, what is necessary is just to extend in the horizontal direction as a whole, for example, it may be bent in the middle or may curve. Further, the fourth antenna element 36 is not necessarily provided.

<4-5>
The fifth antenna element 37 only needs to extend in the horizontal direction as a whole. For example, the fifth antenna element 37 may be bent or curved in the middle. Further, the position of the fifth antenna element 37 is not particularly limited, and may be not connected to both the feeding portions 31 and 32 and the first to fourth antenna elements 33 to 36. Further, the fifth antenna element 37 is not necessarily provided.

<4-6>
In the above embodiment, a part of the antenna 3 is disposed on the shielding layer 2, but it is also possible to dispose all of the antenna 3 on the shielding layer 2 or not all of the antenna 3 on the shielding layer 2. . However, if it arrange | positions on the shielding layer 2, it will not be visible from the outside of a vehicle and it will improve appearance. Further, as a specific position, the antenna 3 can be arranged in an area within 80 mm downward from the uppermost part of the laminated glass 1.

<4-7>
Although the 2nd electric power feeding part 32 is earth | grounded among the two electric power feeding parts 31 and 32, the 1st electric power feeding part 31 can also be earth | grounded. Moreover, the position of the two electric power feeding parts 31 and 32 is not specifically limited, You may arrange | position by shifting | deviating to an up-down direction.

<4-8>
In the above-described embodiment, the antenna is configured to receive digital television. However, the present invention is applicable to media other than digital television, for example, broadband media having a frequency of 200 MHz or more.

<4-9>
Moreover, the window glass of this invention can also be applied to rear glass and side glass other than the windshield of a motor vehicle.

<4-10>
In the said embodiment, although the antenna 3 is mounted in the glass plate 1, it can also be set as a film antenna, for example. That is, the antenna can be disposed on a film and can be attached to a glass plate such as a windshield.

  The film antenna can have various configurations. For example, the film antenna can be configured as shown in FIG. In this example, the film antenna 50 includes a base film 51 made of a resin such as polyethylene terephthalate or polyethylene, an antenna 3 formed on the first surface of the base film 51 by printing or the like, and covers the antenna 3. The protective layer 52 formed on the first surface of the base film 51 and the adhesive layer 53 applied on the second surface of the base film 51 are provided. The antenna 3 is the one shown in the above embodiment. Further, release paper (not shown) is attached to the adhesive layer 53.

  And such a film antenna 50 is affixed on the laminated glass 1 as follows. First, the release paper is removed from the adhesive layer 53. Next, the exposed adhesive layer 53 is attached to a predetermined portion of the laminated glass 1. At this time, the film antenna 50 can be attached to a position separated by a predetermined distance from the edge of the laminated glass 1 as a reference. However, it is difficult to measure the distance from the edge of the laminated glass 1 when the laminated glass 1 is attached to the automobile. In such a case, the film antenna 50 can be affixed with reference to the edge of the shielding layer 2 or the like.

  Here, a difference between an antenna (glass antenna) directly provided on the laminated glass shown in the above embodiment and a film antenna will be described. First, regarding the line width, the glass antenna can be set to about 0.8 mm, for example. This is because it is difficult to make the thickness 0.8 mm or less in the above-described screen printing. On the other hand, the film antenna can be about 0.25 mm from the viewpoint of appearance.

  When the line width is large, it is possible to widen the reception performance of the antenna. On the other hand, if the line width is thin, it is easy to break. In this respect, since the glass antenna is difficult to replace, the line width is increased from the viewpoint of preventing disconnection.

<4-11>
In the above embodiment, the amplifier is installed in the vehicle. For example, the amplifier can be directly attached to the power feeding units 31 and 32. That is, it is possible to use a unit in which each of the power feeding units 31 and 32 and the amplifier are integrated, and is connected to a receiver in the vehicle from here. In this case, the input impedance of the amplifier can be set to 50 to 100Ω as described above.

  Examples of the present invention will be described below. However, the present invention is not limited to the following examples.

  FIG. 6 is a window glass according to Example 1, and has the same configuration as that of FIG. 1 of the above embodiment. The unit of the dimension in FIG. 6 is mm. Note that dimensions not described in other drawings are the same as those described in previous drawings. And about the window glass which concerns on all the Examples and comparative examples including this Example 1, the receiving performance in a digital television (450-750 MHz) was evaluated by actually measuring on condition of the following.

  That is, by radiating radio waves from a digital television in a anechoic chamber to a vehicle to which the window glass according to each of the embodiments and comparative examples is attached, and receiving the broadcast wave by the antenna of each window glass, The sensitivity of was measured. A network analyzer (Keysight Technology LLC E5071C) was used to measure the sensitivity of each antenna. Specific conditions for the measurement are as follows.

・ Glass plate mounting angle: 62 ° tilted at the lower edge in the vertical direction, 54 ° tilted at the central point in the vertical direction, and 45 ° tilted at the upper side in the vertical direction with respect to the horizontal direction. Measurement by rotating the vehicle 360 degrees every 3 degrees ・ Frequency resolution: Measurement every 3 MHz in the range of 450 MHz to 750 MHz ・ Elevation angle between the transmission position of the radio wave and the antenna: 1.7 degrees (0 degrees on the ground and the horizontal direction, The zenith direction is 90 degrees)
The sensitivity of each antenna was defined as a relative gain (dBd) with a half-wave dipole antenna as a reference. A through cable was used instead of an amplifier between the receiver and each antenna.

  In other examples and comparative examples to be described later, the dimensions of the antenna are the same as those in Example 1 unless otherwise specified. That is, as will be described later, those not described are the same as the dimensions already described. Unless otherwise specified, it is assumed that the first feeder is connected to the core wire of the coaxial cable, and the second feeder is connected to the ground line of the coaxial cable.

<1. Evaluation of the shape of the third antenna element>
Hereinafter, the reception performance of Examples 1 and 2 and Comparative Examples 1 to 3 will be examined. As shown in FIG. 6, Example 1 has the same configuration as the above embodiment. FIG. 7 shows a second embodiment. In Example 2, four loop-shaped antenna conductors are combined as the third antenna element. That is, two loop antenna conductors are connected in the vertical direction and the horizontal direction so that the long side and the short side are common.

  8 shows Comparative Example 1, FIG. 9 shows Comparative Example 2, and FIG. As shown in FIG. 8, the comparative example 1 is different from the first example in that the third antenna element is not provided in the comparative example 1. Moreover, as shown in FIG. 9, although the comparative example 2 has an L-shaped connection part as a 3rd antenna element, the loop-shaped antenna conductor is not provided. Instead, a linear antenna conductor is provided. Further, as shown in FIG. 10, in Comparative Example 3, only one loop-shaped antenna conductor is provided. That is, the two antenna conductors of the first embodiment are integrated, and one loop antenna conductor having no vertical portion is provided.

  The reception performance in the frequency range of the digital television in Examples 1 and 2 and Comparative Examples 1 to 3 was calculated as shown in FIG. As illustrated in FIG. 11, the first and second embodiments show higher reception performance in almost all frequency ranges than the first to third comparative examples. As for the comparative example, the reception performance was the lowest in Comparative Example 1 in which the third antenna element was not provided. As for the third antenna element, the reception performance of the comparative example 3 having a loop shape was higher than that of the comparative example 2 having a linear shape. However, it was found that Examples 1 and 2 having two or more loop-shaped antenna conductors had higher reception performance than Comparative Example 3 as described above.

<2. Evaluation on presence / absence of fifth antenna element>
As shown in FIG. 12, Example 3 was prepared. The third embodiment is different from the first embodiment in that the fifth antenna element is provided in the third embodiment, and other configurations are the same as those in the first embodiment.

  The results are as shown in FIG. As shown in the figure, the receiving performance of the third embodiment having the fifth antenna element was generally higher than that of the first embodiment.

<3. Evaluation of the number of first antenna elements>
Below, it evaluated about the number of the 1st antenna elements. As Example 4, the first antenna element having one antenna conductor was prepared. That is, the fourth embodiment has only the upper antenna conductor as compared with the first antenna element of the third embodiment. However, the first antenna element of Example 4 is 10 mm longer than the first antenna element of Example 3.

  The result of the reception performance is as shown in FIG. As shown in the figure, in the frequency range of about 500 to 700 MHz, the receiving performance of Example 3 with two antenna conductors was higher than that of Example 4 with one antenna conductor. However, in the other frequency ranges, that is, about 500 MHz or less and about 700 MHz or more, the receiving performance of Example 4 was higher.

<4. Evaluation of length of fourth antenna element>
The length of the fourth antenna element was evaluated. Examples 1 and 5 to 10 in which the length of the fourth athena element was changed were prepared as follows.

  The result is as shown in FIG. That is, in the frequency range of about 450 to 600 MHz, it has been found that the longer the length of the fourth antenna element, the higher the reception performance. On the other hand, in the frequency range of about 600 to 750 MHz, it was found that the reception performance was higher as the length of the fourth antenna element was shorter.

<5. Evaluation of length of fifth antenna element>
Evaluation on the length of the fifth antenna element was performed. Examples 3 and 12 and 13 in which the length of the fifth athena element was changed were prepared as follows. The distance between the fifth antenna element and the second antenna element is the same as in the third embodiment.

  The results are as shown in FIG. That is, in the frequency range of about 450 to 630 MHz, it was found that the longer the fifth antenna element, the higher the reception performance. On the other hand, in the frequency range of about 630 to 750 MHz, it was found that the shorter the length of the fifth antenna element, the higher the reception performance.

<6. Evaluation of vertical position of fifth antenna element>
Evaluation was made regarding the vertical position of the fifth antenna element. Examples 14 and 15 in which the fifth antenna element is located at a position lower than that of the fifth antenna element in Example 3 were prepared as described below with reference to the vertical position of the fifth antenna element.

  The result is as shown in FIG. That is, in the frequency range of about 450 to 630 MHz, the reception performance of Example 15 was the highest, and the reception performances of Example 3 and Example 14 were almost the same. On the other hand, in the frequency range of about 630 to 750 MHz, it was found that the reception performance of Example 15 in which the fifth antenna element was at the lowest position was the worst, and the reception performance was higher in the order of Example 3 and Example 14. .

<7. Evaluation of the number of antennas>
Example 16 was prepared in which an antenna having the same configuration as that of Example 3 was arranged on the right side of the glass plate. Furthermore, what combined Example 3 and Example 16, ie, Example 17 which arranged the antenna in both the right-and-left edge parts of a glass plate, was prepared. However, for Example 3, the vehicle verification was placed near the antenna. The results are as shown in FIG. As shown in FIG. 18, the reception performance of Example 17 having two antennas was the highest. When Example 3 and Example 16 were compared, the receiving performance was higher in Example 16 in which the antenna was disposed on the left side of the glass plate. This is thought to be influenced by vehicle verification.

1: Glass plate 2: Shielding layer 3: Antenna 31: 1st feeding part 32: 2nd feeding part 33: 1st antenna element 34: 2nd antenna element 35: 3rd antenna element 36: 4th antenna element 37: 1st 5 antenna elements

Claims (20)

An antenna placed on a glass plate,
A first power feeding unit;
A second power feeding unit;
A first antenna element connected to the first feeder and having at least one antenna conductor;
A second antenna element connected to the second feeder and having at least one antenna conductor;
A third antenna element connected to the second feeding part or the second antenna element and having a plurality of loop-shaped antenna conductors;
Equipped with an antenna.   The antenna according to claim 1, wherein the second power feeding unit is grounded among the first power feeding unit and the second power feeding unit.   The antenna according to claim 1 or 2, wherein the plurality of antenna conductors of the first antenna element are arranged in parallel so as to extend in a horizontal direction.   The antenna according to any one of claims 1 to 3, wherein the third antenna element is connected to the second antenna element.   The antenna according to claim 1, wherein each antenna conductor of each third antenna element is formed in a rectangular shape. When the to [lambda] _{2 1} wavelength of receivable broadcast waves lambda in the antenna, the dielectric constant of the glass plate is alpha, is _{L = λ 2/4 × α} ,
The antenna according to claim 1, wherein a length of the third antenna element in the horizontal direction is L ± 30 mm. A fourth antenna element connected to the third antenna element;
At least one of the plurality of antenna conductors in the third antenna element has at least one portion extending in the horizontal direction,
The antenna according to any one of claims 1 to 6, wherein the fourth antenna element extends so as to extend the portion in a horizontal direction.   The antenna according to claim 7, wherein a length of the fourth antenna element in a horizontal direction is 30 to 50 mm.   The antenna according to any one of claims 1 to 8, further comprising a fifth antenna element that is not connected to each of the power feeding units and each of the antenna elements and extends in a horizontal direction.   The antenna according to claim 9, wherein a length of the fifth antenna element is 100 to 150 mm.   10. The antenna according to claim 9, wherein the fifth antenna element is arranged within a range of 30 mm upward and within 30 mm downward with respect to a tip portion of the second antenna element.   The antenna according to claim 1, wherein the antenna is configured to receive a broadcast wave in a frequency range of 200 MHz or higher. The first antenna element and the second antenna element extend in a horizontal direction,
13. An antenna according to claim 12, configured to receive digital television broadcast waves.   The antenna according to claim 13, wherein a length of the third antenna element in a horizontal direction is 70 to 130 mm. An antenna according to any one of claims 1 to 14,
An amplifier connected to the antenna, amplifying and outputting a signal received by the antenna, and an input impedance of 50 to 100Ω is set;
Antenna module equipped with. A glass plate,
At least one antenna according to any of claims 1 to 14, arranged on the glass plate;
Having a window glass. The first power feeding unit and the second power feeding unit are arranged to be aligned in the horizontal direction,
The first antenna element extends in a direction opposite to the second power feeding unit across the first power feeding unit,
The second antenna element extends in a direction opposite to the first power feeding unit across the second power feeding unit,
The window glass of Claim 16 which comprises a windshield. The glass plate is formed in a rectangular shape having long sides in the horizontal direction,
The window glass according to claim 17, wherein an imaginary line connecting the first power feeding unit and the second power feeding unit and a long side of the glass plate are substantially parallel.   The window glass according to claim 17 or 18, wherein the antenna is disposed in an area within 80 mm downward from an uppermost portion of the glass plate.   The window glass according to any one of claims 17 to 19, wherein the two antennas are arranged at both ends of the glass plate in a horizontal direction.