Patent Application
20240291154
The present invention relates to a vehicle antenna device.
In recent years, a thermal/optical added value has been given to vehicle openings, particularly to vehicle window glass, such as by coating with a (transparent) conductive film such as a Low-E or a heat-ray reflective film, or by providing a light control film that can electrically (actively) change a visible light transmittance.
On the other hand, when a dielectric such as glass is coated with a conductive film, a desired antenna gain from a glass antenna that receives predetermined broadcast band by disposing a linear conductor pattern on a vehicle window glass such as in a conventional vehicle window glass cannot be obtained. As an example of using a conductive film coating as an antenna, for example, Japanese Unexamined Patent Application, First Publication No. 2019-140669 (hereinafter referred to as “Patent Document 1”) is known.
Patent Document 1 describes that a conductive film heated by applying a voltage between a pair of bus bars is provided, and an antenna element including the conductive film functions as an antenna capable of receiving terrestrial digital television broadcast band, digital audio broadcast (DAB) band, and FM broadcast band. Also, in Patent Document 1, the antenna element can also function as an antenna capable of receiving AM broadcast band by providing a lattice portion of a region in which a resistance is increased by removing an area around a conductor portion of the conductive film.
However, as an antenna using such a conductive film, in a case of realizing an antenna that receives AM broadcast band, there is a problem in that the number of man-hours required for processing the conductive film such as, for example, providing the lattice portion increases, and the process becomes complicated.
The invention provides a vehicle antenna device capable of easily receiving AM broadcast band using a conductive film in a vehicle window glass that uses a conductive film.
A vehicle antenna device according to one aspect of the invention includes a dielectric substrate having a first main surface and a second main surface, and a conductive film provided on a side of the second main surface and having an area of 0.025 m2 or more in a plan view of the dielectric substrate. The conductive film has a sheet resistance value of 1.5×103Ω/□ or lower, and AM broadcast band are receivable from a feeding point electrically connected to the conductive film.
In the vehicle antenna device according to one aspect of the invention, the feeding point may be disposed at a center portion of the conductive film at a distance of 150 mm or more from an end side of the dielectric substrate in a plan view of the dielectric substrate. In the vehicle antenna device according to one aspect of the invention, an outer edge of the conductive film may be substantially quadrangular in a plan view of the dielectric substrate.
In the vehicle antenna device according to one aspect of the invention, the feeding point electrically connected to the conductive film is a first feeding point, and the vehicle antenna device includes an antenna provided on a side of the first main surface and receiving radio waves of at least one of frequencies of a VHF band and a UHF band, an antenna electrode disposed inside an outer edge of a void area provided inside the conductive film in a plan view of the dielectric substrate, an antenna conductor connected to the antenna and disposed on the side of the first main surface, and a filter allowing a signal in a frequency band of radio waves of at least one of frequencies of the VHF band and the UHF band to pass and blocking a signal in a frequency band of AM broadcast band between the conductive film and a ground conductor. The antenna conductor may be electrically connected to the antenna electrode, and radio waves of at least one of frequencies of the VHF band and the UHF band may be receivable by a signal received using the antenna electrode as a second feeding point.
In the vehicle antenna device according to one aspect of the invention, the antenna conductor and the antenna electrode may be electrically connected by capacitive coupling.
In the vehicle antenna device according to one aspect of the invention, the antenna conductor and the antenna electrode may be directly connected by a connection conductor disposed in a through hole of the dielectric substrate.
In the vehicle antenna device according to one aspect of the invention, the dielectric substrate is a first dielectric substrate, and the vehicle antenna device includes a second dielectric substrate disposed on the side of the second main surface of the first dielectric substrate parallel to the second main surface, and an intermediate film disposed between the first dielectric substrate and the second dielectric substrate. The second dielectric substrate may include a third main surface on a side of the first dielectric substrate and a fourth main surface on a side opposite to a side of the third main surface, the conductive film may be disposed between the first dielectric substrate and the second dielectric substrate, and the antenna electrode may be disposed on a side of the fourth main surface.
In the vehicle antenna device according to one aspect of the invention, the conductive film may be disposed in contact with the second main surface.
In the vehicle antenna device according to one aspect of the invention, the intermediate film may include a first intermediate film and a second intermediate film, and the conductive film may be sandwiched between the first intermediate film and the second intermediate film.
In the vehicle antenna device according to one aspect of the invention, the conductive film may be a light control film containing a conductor.
In the vehicle antenna device according to one aspect of the invention, the conductive film may be disposed in contact with the third main surface or the fourth main surface.
In the vehicle antenna device according to one aspect of the invention, the intermediate film may include a first intermediate film and a second intermediate film, the conductive film may include a first conductive film and a second conductive film, the first conductive film and the second conductive film may be disposed at two positions among a position on the second main surface, a position between the first intermediate film and the second intermediate film, a position on the third main surface, and a position on the fourth main surface, and may be disposed in order from a side close to the first dielectric substrate, and the second conductive film may have a second void area disposed to overlap a first void area which is the void area of the first conductive film in a plan view of the first dielectric substrate.
In the vehicle antenna device according to one aspect of the invention, the first conductive film may be disposed in contact with the second main surface, and the second conductive film may be sandwiched between the first intermediate film and the second intermediate film.
In the vehicle antenna device according to one aspect of the invention, the first conductive film may be a conductor for heat ray reflection, and the second conductive film may be a light control film containing a conductor.
In the vehicle antenna device according to one aspect of the invention, the conductive film may include a third conductive film disposed in contact with the fourth main surface, and the third conductive film may be a conductor for a low emissivity film.
In the vehicle antenna device according to one aspect of the invention, the first conductive film may be sandwiched between the first intermediate film and the second intermediate film, and the second conductive film may be disposed in contact with the fourth main surface.
In the vehicle antenna device according to one aspect of the invention, the first conductive film may be a light control film containing a conductor, and the second conductive film may be a conductor for a low emissivity film.
In the vehicle antenna device according to one aspect of the invention, the antenna may be capable of receiving a frequency of FM broadcast band, the vehicle antenna device may include an AM amplifier and an FM amplifier, a signal in a frequency band of AM broadcast band may be input to the AM amplifier from the first feeding point, and a signal in a frequency band of FM broadcast band may be input to the FM amplifier from the second feeding point.
In the vehicle antenna device according to one aspect of the invention, the filter may be a capacitor, and a capacitance of the capacitor may be 5 pF to 150 pF.
In the vehicle antenna device according to one aspect of the invention, the antenna may be disposed to be surrounded by a cover member protruding outward from the side of the first main surface of the dielectric substrate.
In the vehicle antenna device according to one aspect of the invention, the dielectric substrate may be a glass substrate.
In the vehicle antenna device according to one aspect of the invention, the dielectric substrate may be attached to a roof of a vehicle parallel to a horizontal surface of the vehicle.
According to the aspects of the invention, the vehicle antenna device can easily receive AM broadcast band using a conductive film in a vehicle window glass that uses a conductive film.
Hereinafter, a vehicle antenna device according to an embodiment of the invention will be described with reference to the drawings.
In the description of the embodiment, the phrase “a side of a first main surface”, the phrase “a side of a second main surface”, the phrase “a side of a third main surface”, and the phrase “a side of a fourth main surface” will be used. The meaning of each of these phrases includes a position on a surface of the main surface or a position away from the main surface in a space facing the main surface. For example, in a relative positional relationship between an optionally selected member A and the main surface, the phrase “the member A is disposed on a side of the main surface” not only means a case in which the member A and the main surface are in direct contact with each other, but also means a case in which the member A is disposed such that the member A is spaced apart from the main surface. Also, in a case in which the main surface and the member A are spaced apart from each other, an inclusion may or may not be between the main surface and the member A.
As shown in
The vehicle glass 10 is, for example, a roof glass mounted on a roof of a vehicle. The vehicle glass 10 is attached to a roof of the vehicle parallel (including substantially parallel) to a horizontal surface of the vehicle. Here, a configuration example of the vehicle glass 10 will be described with reference to
As shown in
A shape of the vehicle glass 10 may be a curved shape or a planar shape (non-curved shape). Also, the vehicle glass 10 may have, for example, a single curved shape that is curved in either a vertical direction or a horizontal direction (with respect to one side of a frame) when it is attached to the vehicle. The vehicle glass 10 may have a compound curved shape that is curved in both the vertical direction and the horizontal direction. Further, the single curved shape may be a shape curved only in one arbitrary direction. The compound curved shape may be a shape curved in two or more arbitrary different directions. Further, in a case in which the vehicle glass 10 has a curved shape, a minimum value of a radius of curvature of the vehicle glass 10 is preferably 500 mm or more and 100,000 mm or less.
The glass substrate 11 is an example of a dielectric substrate and has a first main surface F1 and a second main surface F2.
In the present embodiment, a main surface of the glass substrate 11 on an outer side of the vehicle is the first main surface F1. A main surface on a side opposite to the first main surface F1 is the second main surface F2.
The antenna conductor 12 is an electrode connected to the antenna 21 and is disposed on the side of the first main surface F1. The antenna conductor 12 is formed, for example, on the side of the first main surface F1 of the glass substrate 11 to be in contact with the glass substrate 11 (on the glass substrate 11). Here, a configuration example of the antenna conductor 12 will be described with reference to
Returning to the description of
The conductive film 13 is provided on the side of the second main surface F2 with respect to the glass substrate 11. In order for the conductive film 13 to function as an AM antenna that receives AM broadcast band, an area of the glass substrate 11 in a plan view is preferably 0.025 m2 or more, more preferably 0.050 m2 or more, still more preferably 0.100 m2 or more, yet still more preferably 0.250 m2 or more, and particularly preferably 0.500 m2. An outer edge of the conductive film 13 is, for example, substantially quadrangular in a plan view of the glass substrate 11 in accordance with, for example, a shape of the glass substrate 11.
The conductive film 13 functions as an AM antenna and functions as an antenna ground for the antenna 21.
Also, the conductive film 13 preferably has a sheet resistance value of 1.5×103Ω/□ (ohm/square) or lower. The sheet resistance value of the conductive film 13 is more preferably 1.0×103Ω/□ or lower, still more preferably 500Ω/□ or lower, particularly preferably 300Ω/□ or lower, and most preferably 200Ω/□ or lower.
Also, the conductive film 13 has a void area VA therein in a plan view of the glass substrate 11.
The void area VA is disposed not to overlap the antenna conductor 12 and the antenna electrode 15 in a thickness direction of the vehicle glass 10.
Also, as shown in
Returning to the description of
Further, a distance between the antenna conductor 12 and the antenna electrode 15 is approximately 5 mm. In order for a signal at a frequency in a VHF band or a signal at a frequency in a UHF band to be capacitively coupled, a distance of a dielectric between conductors need only be less than 30 mm, is preferably 20 mm or less, and is more preferably 10 mm or less. As described above, since a thickness of the vehicle glass 10 is typically approximately 2 mm to 5 mm when a laminated glass to be described later is also included, the distance between the antenna conductor 12 and the antenna electrode 15 is sufficient for capacitive coupling. In this way, if the thickness of the vehicle glass 10 is less than 30 mm, capacitive coupling between the antenna conductor 12 and the antenna electrode 15 is possible, and it can be configured as a circuit that amplifies a signal received by the antenna 21 with the amplifier 30.
In
Further, a disposition of the shielding layer 17 is optionally selected. Also, the shielding layer 17 may not be disposed. Further, in a case in which the shielding layer 17 is disposed, the shielding layer 17 may be formed in a state without the void area, that is, the shielding layer 17 may be formed in a so-called “flat shape”. In that case, the shielding layer 17 may be formed (in a flat shape) on the second main surface F2 of the glass substrate 11. The reason for this is because, since a thickness of the shielding layer 17 is approximately 5 μm to 25 μm, even in a case in which a structure having the shielding layer 17 interposed therein is employed, a change in coupling capacitance between the antenna conductor 12 and the antenna electrode 15 is small, and capacitive coupling between the antenna conductor 12 and the antenna electrode 15 is possible regardless of the presence or absence of the shielding layer 17. In the following description, unless otherwise specified, description will be made assuming that the shielding layer 17 having a void area is formed in the vehicle antenna device 1.
The feeding point 16 is an exposed portion at which the conductive film 13 is exposed. The feeding point 16 is electrically connected to the conductive film 13. The vehicle antenna device 1 is capable of receiving AM broadcast band from the feeding point 16. The feeding point 16 is disposed at a center portion of the conductive film 13 at a distance of 150 mm or more inward from an end side of the glass substrate 11 in a plan view of the glass substrate 11. Further, even in a case in which the shielding layer 17 is formed in a flat shape without a void area as described above, the feeding point 16 need only be electrically connected by capacitive coupling. Further, the feeding point 16 is preferably at a distance of 200 mm or more inward from the end side of the glass substrate 11, and more preferably at a distance of 300 mm or more inward from the end side of the glass substrate 11.
Also, the feeding point 16 is formed in a square loop shape in a plan view of the glass substrate 11. That is, an outer edge and an inner edge of the feeding point 16 have a square shape. Further, the “loop shape” may be a closed loop that is continuous throughout one circumference, or may be a shape having notches at one or more locations. In a case in which the feeding point 16 has a notch, when a length of one circumference in the closed loop is standardized as “100”, a length of the notch portion may be, for example, 40 or less, 30 or less, or 20 or less. Also, the length of the notch portion based on the above-described standardization may be, for example, 1 or more, 2 or more, or 5 or more.
The feeding point 16 is an example of a first feeding point that receives AM broadcast band, and the antenna electrode 15 is an example of a second feeding point that receives FM broadcast band.
Returning to the description of
The antenna 21 is, for example, an antenna for receiving a frequency band of FM broadcast band, an antenna for receiving a frequency band of digital audio broadcast (DAB) band, an antenna for receiving a frequency band of digital terrestrial television broadcast band, an antenna for receiving a global navigation satellite system (GNSS) of 1.2 GHz band or 1.6 GHz band, an antenna for receiving a satellite digital audio radio service (SDARS) of 2.3 GHz band, or the like.
Here, the frequency band of FM broadcast band (hereinafter referred to as “FM band”) is 76 MHz (megahertz) to 108 MHZ, and the frequency band of DAB Band III broadcast band (hereinafter referred to as “DAB band”) is 174 MHz to 240 MHz. Also, the frequency band of digital terrestrial television broadcast band (hereinafter referred to as “DTV band”) is 470 MHz to 710 MHz. The antenna 21 may be capable of receiving a plurality of frequency bands among the frequency band of FM broadcast band, the frequency band of DAB broadcast band, the frequency band of DTV band, the frequency band of GNSS, and the frequency band of SDARS.
The antenna 21 is disposed on an outer side of the vehicle glass 10 and is connected to the antenna conductor 12.
The antenna cover 22 (cover member) is a protrusion-shaped cover that is grounded on the roof of the vehicle. The antenna cover 22 houses the antenna 21 therein. The antenna cover 22 is, for example, a shark fin antenna cover.
The amplifier 30 amplifies a received signal of AM broadcast band received using the conductive film 13 as an AM antenna and a received signal of FM broadcast band received by the antenna 21, and outputs the amplified signal to, for example, a receiver. An input terminal of the amplifier 30 for AM broadcast band is connected to the feeding point 16, and an input terminal for FM broadcast band is connected to the antenna electrode 15. An output of the amplifier 30 is supplied to the receiver via a transmission line such as a coaxial cable CB. Details of the amplifier 30 will be described later.
The high pass filter 40 is disposed between the conductive film 13 and a ground which is a vehicle body (ground conductor). The high pass filter 40 allows a signal in a frequency band of radio waves of at least one of frequencies of the VHF band and the UHF band to pass and blocks a signal in a frequency band of AM broadcast band between the conductive film 13 and the vehicle body. That is, the high pass filter 40 grounds the conductive film 13 to the vehicle body in the VHF band or higher, and makes the conductive film 13 in an electrically floating state (high impedance state) in the AM band.
The high pass filter 40 is, for example, a capacitor C1. The capacitance of the capacitor C1 is preferably 5 pF to 150 pF, more preferably 5 pF to 100 pF.
A capacitor C1 is a capacitor element connected between conductive film 13 and the vehicle body. Further, the capacitor C1 may be inside the amplifier 30.
Next, an equivalent circuit of the vehicle antenna device 1 of the present embodiment shown in
As shown in
In the vehicle antenna device 1 of the present embodiment, the conductive film 13 functions as an AM antenna and functions as an antenna ground for the antenna 21. The conductive film 13 is connected to a ground of the amplifier 30 and a signal ground of the output signal via the capacitor C1 in at least one of the VHF band and UHF band. The ground of the amplifier 30 and the signal ground of the output signal are connected to a vehicle body BD. Further, a capacitance between the vehicle body BD and the conductive film 13 is defined as an antenna capacitance (C3).
The conductive film 13 is connected to an input signal line of the AM amplifier 31 through the feeding point 16. A received signal received by the conductive film 13 as an AM antenna is input to the AM amplifier 31 as an input signal.
Also, the conductive film 13 is electrically disconnected from the ground of the amplifier 30 and the signal ground of the output signal by the capacitor C1 in a frequency band of AM broadcast band.
Also, the antenna 21 is connected to an input signal line of the FM amplifier 32 via a capacitor C2.
The capacitor C2 is a capacitance formed by the antenna conductor 12 to which the antenna 21 is connected and the antenna electrode 15. The capacitor C2 electrically connects the antenna conductor 12 and the antenna electrode 15 by capacitive coupling.
Then, a received signal received by the antenna 21 is input to the FM amplifier 32 as an input signal by capacitive coupling of the capacitor C2.
The AM amplifier 31 amplifies the received signal of the AM broadcast band received by the conductive film 13 and outputs the amplified signal to the signal mixer 33.
The FM amplifier 32 amplifies a received signal having a frequency of the VHF band or higher (for example, FM broadcast band) received by the antenna 21, and outputs the amplified signal to the signal mixer 33. Further, the signal having a frequency of the VHF band or higher refers to, for example, one or more signals having a frequency of at least one of the VHF band frequency and the UHF band frequency.
The signal mixer 33 outputs a received signal, which is a mixture of a received signal of AM broadcast band output by the AM amplifier 31 and a received signal of a frequency in the VHF band or higher (for example, FM broadcast band) output by the FM amplifier 32, to a receiving device (not shown in the drawings) via the coaxial cable CB.
Next, antenna characteristics of the vehicle antenna device 1 of the present embodiment will be described with reference to
In
In
As indicated by the solid line W1 in
Also,
As indicated by the solid line W3 in
In
Also, in
As shown in
Next, antenna characteristics with respect to the grounded capacitance and the antenna capacitance (C3) of the vehicle antenna device 1 of the present embodiment will be described with reference to
In
Also, in
As shown in
Next, antenna characteristics in a case in which the conductive film 13 has a high resistance will be described with reference to
In
As shown in
As described above, the vehicle antenna device 1 of the present embodiment includes the glass substrate 11 (dielectric substrate) and the conductive film 13. The glass substrate 11 has the first main surface F1 and the second main surface F2. The conductive film 13 is provided on the side of the second main surface F2, and has an area of 0.025 m2 or more in a plan view of the glass substrate 11. The conductive film 13 has a sheet resistance value of 1.5×103Ω/□ or lower. The sheet resistance value of the conductive film 13 is preferably 1.0×103Ω/□ or lower, more preferably 500Ω/□ or lower, and particularly preferably 200Ω/□ or lower. The vehicle antenna device 1 is capable of receiving AM broadcast band from the feeding point 16 electrically connected to the conductive film 13.
Therefore, according to the vehicle antenna device 1 of the present embodiment, a coating such as, for example, a conductive film for heat ray reflection (heat ray reflective film) and a conductive film for low emissivity (Low-E coat) can be used as an antenna for AM broadcast band. Therefore, in the vehicle glass 10 (vehicle window glass) using the conductive film 13, the vehicle antenna device 1 of the present embodiment can easily receive AM broadcast band using the conductive film 13.
Further, since it is easier to obtain an antenna gain in the frequency band of AM broadcast band as an area of the conductive film 13 becomes larger, an area of the glass substrate 11 in a plan view is preferably 0.025 m2 or more. Also, since it is easier to obtain an antenna gain in the frequency band of AM broadcast band as the sheet resistance value of the conductive film 13 becomes lower, a sheet resistance value of 1.5×103Ω/□ or lower is preferable. Therefore, the vehicle antenna device 1 of the present embodiment can obtain a sufficient antenna gain in the frequency band of AM broadcast band.
Also, in the present embodiment, the feeding point 16 is disposed at a center portion of the conductive film 13 at a distance of 150 mm or more from an end side of the glass substrate 11 in a plan view of the glass substrate 11. Also, an outer edge of the conductive film 13 is substantially quadrangular in a plan view of the glass substrate 11.
Therefore, the vehicle antenna device 1 of the present embodiment can easily receive AM broadcast band using the conductive film 13 in, for example, a roof antenna.
Also, in the present embodiment, the feeding point 16 electrically connected to the conductive film 13 is the first feeding point. The vehicle antenna device 1 includes the antenna 21, the antenna electrode 15, the antenna conductor 12, and the high pass filter 40. The antenna 21 is provided on the side of the first main surface F1 and receives radio waves of at least one of the frequencies of the VHF band and the UHF band. The antenna electrode 15 is disposed inside the outer edge of the void area VA provided inside the conductive film 13 in a plan view of the glass substrate 11. The antenna conductor 12 is connected to the antenna 21 and is disposed on the side of the first main surface F1. The high pass filter 40 allows a signal in a frequency band of radio waves of at least one of frequencies of the VHF band and the UHF band to pass and blocks a signal in a frequency band of AM broadcast band between the conductive film 13 and the ground conductor. The antenna conductor 12 is electrically connected to the antenna electrode 15. The vehicle antenna device 1 is capable of receiving radio waves of at least one of the frequencies of the VHF band and the UHF band by a signal received using the antenna electrode 15 as a second feeding point.
Therefore, according to the vehicle antenna device 1 of the present embodiment, the conductive film 13 can be used both as a receiving antenna (AM antenna) of a frequency band of AM broadcast band and as an antenna ground for the antenna 21, and a large area can be secured as the antenna ground. Therefore, the vehicle antenna device 1 of the present embodiment can easily receive AM broadcast band using the conductive film 13, and can obtain a sufficient antenna gain of radio waves of at least one of the frequencies of the VHF band and the UHF band. Also, a sufficient antenna gain can be obtained for the antenna 21 without mechanical processing such as drilling holes in the glass substrate 11.
Also, in the present embodiment, the antenna conductor 12 and the antenna electrode 15 are electrically connected by capacitive coupling.
Therefore, in the vehicle antenna device 1 of the present embodiment, a received signal of the antenna 21 can be taken out from the antenna electrode 15 without performing drilling processing on the glass substrate 11, and the antenna 21 can be installed at any location on the vehicle glass 10.
Also, in the present embodiment, the antenna 21 is capable of receiving a frequency of FM broadcast band. The vehicle antenna device 1 includes the AM amplifier 31 and the FM amplifier 32. A signal in the frequency band of AM broadcast band is input to the AM amplifier 31 from the feeding point 16 (first feeding point). A signal in the frequency band of FM broadcast band is input to the FM amplifier 32 from the antenna electrode 15 (second feeding point). Therefore, the vehicle antenna device 1 of the present embodiment can appropriately receive signals in both the frequency band of AM broadcast band and the frequency band of FM broadcast band.
Also, in the present embodiment, the high pass filter 40 is the capacitor C1. A capacitance of the capacitor C1 is 5 pF to 150 pF. Also, the capacitance of the capacitor C1 is more preferably 5 pF to 100 pF.
Therefore, the vehicle antenna device 1 of the present embodiment can realize the high pass filter 40 with a simple configuration of the capacitor C1.
Also, in the present embodiment, the antenna 21 is disposed to be surrounded by the antenna cover 22 (cover member) that protrudes outward from the side of the first main surface F1 of the glass substrate 11. Also, the dielectric substrate is the glass substrate 11. Also, the glass substrate 11 may be attached to the roof of the vehicle parallel to a horizontal surface of the vehicle, but may also be applied as a side glass or a rear glass. Therefore, according to the vehicle antenna device 1 of the present embodiment, a sufficient antenna gain can be obtained, for example, in the roof glass without mechanical processing of the glass substrate 11.
Next, a vehicle antenna device 1a of a second embodiment will be described with reference to the drawings. In the present embodiment, a modified example of a case in which an antenna conductor 12a and an antenna electrode 15a are directly connected by a connection conductor 18 will be described.
In addition, since a perspective view of the vehicle antenna device 1a of the present embodiment is the same as that of the first embodiment shown in
As shown in
Further, in
The connection conductor 18 is a conductor disposed in a through hole of the glass substrate 11.
The antenna conductor 12a and the antenna electrode 15a of the present embodiment are directly connected by the connection conductor 18.
Other configurations of the present embodiment are the same as those of the first embodiment shown in
Further, in the present embodiment, a signal in a frequency band of AM broadcast band is input to the AM amplifier 31 of the amplifier 30 from the feeding point 16 (first feeding point). Further, a signal in a frequency band of FM broadcast band is input to an FM amplifier 32 of the amplifier 30 from the antenna electrode 15a (second feeding point).
As described above, in the present embodiment, the antenna conductor 12a and the antenna electrode 15a are directly connected by the connection conductor 18 disposed in the through hole of the glass substrate 11.
Therefore, according to the vehicle antenna device 1a of the present embodiment, a sufficient antenna gain of an antenna 21 can be obtained with minimal mechanical processing of the glass substrate 11 as in the first embodiment.
Next, a vehicle antenna device 1b of a third embodiment will be described with reference to the drawings. In the present embodiment, a modified example in a case of using a laminated glass will be described.
Further, since a perspective view of the vehicle antenna device 1b of the present embodiment is the same as that of the first embodiment shown in
As shown in
The vehicle glass 10b is, for example, a laminated glass. The vehicle glass 10b includes two glass substrates 11 (11-1 and 11-2), an antenna conductor 12, a conductive film 13, an intermediate film 14, an antenna electrode 15, a signal electrode 16a, and a connection conductor 18a.
The glass substrate 11-1 (an example of a first dielectric substrate) and the glass substrate 11-2 (an example of a second dielectric substrate) are glass substrates for the laminated glass adhered together by the intermediate film 14. Each of the glass substrate 11-1 and the glass substrate 11-2 is an example of a dielectric substrate. Further, the glass substrate 11-1 may also be referred to as a first glass substrate. The glass substrate 11-2 may also be referred to as a second glass substrate.
In the present embodiment, a main surface of the glass substrate 11-1 on an outer side of a vehicle is a first main surface F1. A main surface on a side opposite to the side of the first main surface F1 is a second main surface F2. Further, a main surface of the glass substrate 11-2 on the side of the glass substrate 11-1 is a third main surface F3. A main surface on a side opposite to the third main surface F3 is a fourth main surface F4.
The glass substrate 11-2 is disposed parallel to the second main surface F2 to face the side of the second main surface F2 of the glass substrate 11-1. The conductive film 13 and the intermediate film 14 are sandwiched between the glass substrate 11-1 and the glass substrate 11-2. The conductive film 13 is disposed to be in contact with the second main surface F2 as shown in
Also, the intermediate film 14 may have a configuration in which a plurality of layers are laminated. In this case, the conductive film 13 may be disposed to be inserted between layers of the plurality of intermediate films 14. In this case, as the conductive film 13, a conductor contained in a light control film capable of controlling a visible light transmittance when an AC voltage is applied may be exemplified. The light control film has a pair of resin substrates, a pair of indium tin oxide (ITO) films, a transparent conductive polymer, a laminated film of a metal layer and a dielectric layer, a conductive film 13 such as a silver nanowire and a silver or copper metal mesh, and a light control layer sandwiched between a pair of conductive films 13. In the light control film, the ITO films are provided on main surfaces of the resin substrates. Since the main surfaces of the pair of resin substrates face each other, the pair of ITO films also face each other. The light control layer is a molecular layer such as liquid crystal having optical anisotropy. The conductive film 13 may be a conductive film included in a solar cell panel.
In
The intermediate film 14 is an adhesive layer such as, for example, a transparent polyvinyl butyral (PVB) film, an ethylene vinyl acetate copolymer (EVA) film, and a cycloolefin polymer (COP) film. The intermediate film 14 is disposed between the glass substrate 11-1 and the glass substrate 11-2. The intermediate film 14 adheres the glass substrate 11-1, the conductive film 13, and the glass substrate 11-2 together. The laminated glass is formed by a laminated structure adhered by the intermediate film 14.
In the present embodiment, the antenna electrode 15 is disposed inside an outer edge of a void area VA in a plan view of the glass substrate 11-2 (11). The antenna electrode 15 is disposed on the side of the second main surface F2 and is electrically connected to the antenna conductor 12. The antenna electrode 15 is disposed in contact with, for example, the fourth main surface F4 of the glass substrate 11-2. The antenna electrode 15 is formed to face the antenna conductor 12. The glass substrate 11-1, the intermediate film 14, and the glass substrate 11-2 are sandwiched between the antenna electrode 15 and the antenna conductor 12. In the present embodiment, the antenna conductor 12 and the antenna electrode 15 are disposed to be electrically connected by capacitive coupling. Here, the antenna electrode 15 functions as a second feeding point.
Further, thicknesses of the glass substrate 11-1, the intermediate film 14, and the glass substrate 11-2 are, for example, approximately 2 mm, approximately 1 mm, and approximately 2 mm, respectively. A distance between the antenna conductor 12 and the antenna electrode 15 is approximately 5 mm. In order for a signal at a frequency in a VHF band or a signal at a frequency in a UHF band to be capacitively coupled, a distance of a dielectric between conductors need only be less than 30 mm, is preferably 20 mm or less, and is more preferably 10 mm or less. Since a thickness of the vehicle glass 10b is typically approximately 5 mm as described above, the distance between the antenna conductor 12 and the antenna electrode 15 is sufficient for capacitive coupling. In this way, if a thickness of the vehicle glass 10b, which is a laminated glass, is less than 30 mm, capacitive coupling between the antenna conductor 12 and the antenna electrode 15 is possible. It can be configured as a circuit that amplifies a signal received by the antenna 21 with the amplifier 30.
The signal electrode 16a is an electrode disposed on the side of the fourth main surface F4 of the glass substrate 11-2, and functions as a feeding point of the conductive film 13 functioning as an AM antenna that receives AM broadcast band. The signal electrode 16a is disposed to be electrically connected to the conductive film 13 by the connection conductor 18a. In this way, the signal electrode 16a is disposed at a position overlapping the conductive film 13 in a plan view of the glass substrate 11-2 (11).
The connection conductor 18a is a conductor penetrating the glass substrate 11-2. The connection conductor 18a directly connects the conductive film 13 and the signal electrode 16a electrically.
Other configurations of the present embodiment are the same as those of the first embodiment shown in
Further, in the present embodiment, a signal in a frequency band of AM broadcast band is input to an AM amplifier 31 of the amplifier 30 from the signal electrode 16a (first feeding point). Also, a signal in a frequency band of FM broadcast band is input to an FM amplifier 32 of the amplifier 30 from the antenna electrode 15 (second feeding point).
As described above, in the present embodiment, the glass substrate 11 is the glass substrate 11-1 (first dielectric substrate). The vehicle antenna device 1b includes the glass substrate 11-2 disposed on the side of the second main surface F2 of the glass substrate 11-1 parallel to the second main surface F2, and the intermediate film 14 disposed between the glass substrate 11-1 and the glass substrate 11-2. The glass substrate 11-2 has the third main surface F3 on the side of the glass substrate 11-1 and the fourth main surface F4 on a side opposite to the third main surface F3. The conductive film 13 is disposed between the glass substrate 11-1 and the glass substrate 11-2, and the antenna electrode 15 is disposed on the side of the fourth main surface F4. The conductive film 13 is disposed in contact with, for example, the second main surface F2.
Therefore, according to the vehicle antenna device 1b of the present embodiment, even in a case in which the laminated glass including the glass substrate 11-1 (first dielectric substrate) and the glass substrate 11-2 is used, the same effects as in the first embodiment described above are achieved, and AM broadcast band can be easily received using the conductive film 13 in the vehicle glass 10b using the conductive film 13. Also, the vehicle antenna device 1b of the present embodiment can obtain a sufficient antenna gain for the antenna 21 with minimal mechanical processing of the glass substrate 11.
Next, a vehicle antenna device 1c of a fourth embodiment will be described with reference to the drawings. In the present embodiment, a modified example in which a laminated glass is used, and a conductive film 13a, which is a light control film, is provided will be described.
Further, since a perspective view of the vehicle antenna device 1c of the present embodiment is the same as that of the first embodiment shown in
As shown in
The vehicle glass 10c is, for example, a laminated glass. The vehicle glass 10c includes two glass substrates 11 (11-1 and 11-2), an antenna conductor 12, the conductive film 13a, intermediate films 14 (14-1 and 14-2), and an antenna electrode 15, a signal electrode 16a, and a connection conductor 18a.
Further, in
Further, in the present embodiment, the intermediate film 14 includes the intermediate film 14-1 (first intermediate film) and the intermediate film 14-2 (second intermediate film).
The intermediate film 14-1 and the intermediate film 14-2 are, for example, a PVB film, an EVA film, a COP film, or the like, but it is preferable that the same material be used for the intermediate film 14-1 and the intermediate film 14-2.
The conductive film 13a is a light control film containing a conductor. The conductive film 13a is sandwiched between the intermediate film 14-1 and the intermediate film 14-2. In
Also, the connection conductor 18a of the present embodiment is a conductor penetrating the glass substrate 11-2. The connection conductor 18a directly connects the conductive film 13a and the signal electrode 16a electrically.
Further, in the present embodiment, the conductive film 13a, which is a light control film, functions as an AM antenna and functions as an antenna ground for an antenna 21. A signal in a frequency band of AM broadcast band received by the conductive film 13a, which is a light control film, is input to an AM amplifier 31 of the amplifier 30 from the signal electrode 16a (first feeding point). Also, a signal in a frequency band of FM broadcast band is input to an FM amplifier 32 of the amplifier 30 from the antenna electrode 15 (second feeding point).
Also, a choke coil 50 is connected to the conductive film 13a, which is a light control film, to prevent leakage of a received signal of AM broadcast band.
As described above, in the present embodiment, the intermediate film 14 includes the intermediate film 14-1 (first intermediate film) and the intermediate film 14-2 (second intermediate film). The conductive film 13a is sandwiched between the intermediate film 14-1 and the intermediate film 14-2. The conductive film 13a is a light control film containing a conductor.
Therefore, according to the vehicle antenna device 1c of the present embodiment, the conductive film 13a is disposed between the glass substrate 11-1 (first dielectric substrate) and the glass substrate 11-2 (second dielectric substrate). Therefore, for example, even if the conductive film 13a is a light control film, the same effects as in the third embodiment described above are achieved, and AM broadcast band can be easily received using the conductive film 13a in the vehicle glass 10c that uses the conductive film 13a which is a light control film. Also, according to the vehicle antenna device 1c of the present embodiment, since the conductive film 13a, which is a light control film, functions as an antenna ground for the antenna 21, a sufficient antenna gain can be obtained for the antenna 21 with minimal mechanical processing of the glass substrate 11.
Next, a vehicle antenna device 1d of a fifth embodiment will be described with reference to the drawings. In the present embodiment, a modified example in which a laminated glass is used, and a conductive film 13b, which is a conductive film for heat ray reflection (heat ray reflective film) or a conductive film for low emissivity (Low-E coat), is provided will be described.
Further, since a perspective view of the vehicle antenna device 1d of the present embodiment is the same as that of the first embodiment shown in
As shown in
The vehicle glass 10d is, for example, a laminated glass. The vehicle glass 10d includes two glass substrates 11 (11-1 and 11-2), an antenna conductor 12, the conductive film 13b, an intermediate film 14, an antenna electrode 15, a signal electrode 16a, and a connection conductor 18a.
Further, in
The conductive film 13b is, for example, a conductive film for heat ray reflection (heat ray reflective film) or a conductive film for low emissivity (Low-E coat). The conductive film 13b is disposed in contact with a third main surface F3 of the glass substrate 11-2 between the intermediate film 14 and the glass substrate 11-2. Further, the conductive film 13b may be disposed in contact with a fourth main surface F4 of the glass substrate 11-2.
Also, the connection conductor 18a of the present embodiment is a conductor penetrating the glass substrate 11-2. The connection conductor 18a directly connects the conductive film 13b and the signal electrode 16a electrically.
Further, in the present embodiment, the conductive film 13b functions as an AM antenna and functions as an antenna ground for an antenna 21. A signal in a frequency band of AM broadcast band received by the conductive film 13b is input to an AM amplifier 31 of the amplifier 30 from the signal electrode 16a (first feeding point). Also, a signal in a frequency band of FM broadcast band is input to an FM amplifier 32 of the amplifier 30 from the antenna electrode 15 (second feeding point).
As described above, in the present embodiment, the conductive film 13b is disposed in contact with the third main surface F3 or the fourth main surface F4. The conductive film 13b is, for example, a conductive film for heat ray reflection (heat ray reflective film) or a conductive film for low emissivity (Low-E coat).
Therefore, according to the vehicle antenna device 1d of the present embodiment, even in a case in which the conductive film 13b is disposed in contact with the third main surface F3 or the fourth main surface F4, the same effects as in the third embodiment described above are achieved, and AM broadcast band can be easily received using the conductive film 13b. Also, in the vehicle antenna device 1d of the present embodiment, since the conductive film 13b functions as an antenna ground for the antenna 21, a sufficient antenna gain can be obtained for the antenna 21 with minimal mechanical processing of the glass substrate 11.
Next, a vehicle antenna device 1e of a sixth embodiment will be described with reference to the drawings. In the present embodiment, a modified example in which a laminated glass is used, and both a conductive film 13 which is a conductive film for heat ray reflection (heat ray reflective film) and a conductive film 13a which is a light control film are provided will be described.
Further, since a perspective view of the vehicle antenna device 1e of the present embodiment is the same as that of the first embodiment shown in
As shown in
The vehicle glass 10e is, for example, a laminated glass. The vehicle glass 10e includes two glass substrates 11 (11-1 and 11-2), an antenna conductor 12, the conductive film 13 and the conductive film 13a, intermediate films 14 (14-1 and 14-2), an antenna electrode 15, a signal electrode 16a, and a connection conductor 18a.
Further, in
The conductive film 13 is, for example, a conductive film for heat ray reflection (heat ray reflective film). The conductive film 13 is disposed in contact with a second main surface F2 of the glass substrate 11-1. A sheet resistance value of the conductive film 13 is, for example, lower than a sheet resistance value of the conductive film 13a.
Also, the conductive film 13a is, for example, a light control film containing a conductor. The light control film is a light control film in which a transmittance of light can be electrically changed, and includes, for example, a transparent conductive film such as ITO. In
Further, the intermediate film 14 of the present embodiment includes the intermediate film 14-1 (first intermediate film) and the intermediate film 14-2 (second intermediate film). The intermediate film 14-1 and the intermediate film 14-2 are, for example, a PVB film, an EVA film, a COP film, or the like, but it is preferable that the same material be used for the intermediate film 14-1 and the intermediate film 14-2.
Also, the connection conductor 18a of the present embodiment is a conductor penetrating the glass substrate 11-2. The connection conductor 18a directly connects the conductive film 13a and the signal electrode 16a electrically. Alternatively, the connection conductor 18a may directly connect the conductive film 13 and the signal electrode 16a electrically.
Further, in the present embodiment, the conductive film 13a which is a light control film or the conductive film 13 for heat ray reflection functions as an AM antenna and functions as an antenna ground for an antenna 21. A signal in a frequency band of AM broadcast band received by the conductive film 13a which is a light control film or the conductive film 13 for heat ray reflection is input to an AM amplifier 31 of the amplifier 30 from the signal electrode 16a (first feeding point). Also, a signal in a frequency band of FM broadcast band is input to an FM amplifier 32 of the amplifier 30 from the antenna electrode 15 (second feeding point).
As described above, in the present embodiment, the intermediate film 14 includes the intermediate film 14-1 and the intermediate film 14-2, and the conductive film includes the conductive film 13 (first conductive film) and the conductive film 13a (second conductive film). The conductive film 13 and the conductive film 13a are disposed at two positions among a position on the second main surface F2, a position between the intermediate film 14-1 and the intermediate film 14-2, a position on a third main surface F3, and a position on a fourth main surface F4, and are disposed in order from a side close to the glass substrate 11-1. The conductive film 13a has the second void area VA2 disposed to overlap the first void area VA1 which is the void area VA of the conductive film 13 in a plan view of the glass substrate 11-1.
Therefore, according to the vehicle antenna device 1e of the present embodiment, even in a case in which both the conductive film 13 and the conductive film 13a are provided, the same effects as in the third embodiment described above are achieved, and AM broadcast band can be easily received using the conductive film 13a or the conductive film 13. Also, in the vehicle antenna device 1e of the present embodiment, since the conductive film 13a or the conductive film 13 functions as an antenna ground for the antenna 21, a sufficient antenna gain can be obtained for the antenna 21 with minimal mechanical processing of the glass substrate 11.
Also, in the present embodiment, the conductive film 13 is disposed in contact with the second main surface F2, and the conductive film 13a is sandwiched between the intermediate film 14-1 and the intermediate film 14-2. The conductive film 13 is, for example, a conductor for heat ray reflection (heat ray reflective film), and the conductive film 13a is, for example, a light control film containing a conductor.
Therefore, the vehicle antenna device 1e of the present embodiment can easily receive AM broadcast band even in a case in which, for example, both the conductor for heat ray reflection (heat ray reflective film) and the light control film are provided.
Next, a vehicle antenna device 1f of a seventh embodiment will be described with reference to the drawings. In the present embodiment, a modified example in which a laminated glass is used, and both a conductive film 13a which is a light control film and a conductive film 13c which is a conductor for a low emissivity film (Low-E coat) are provided will be described.
Further, since a perspective view of the vehicle antenna device 1f of the present embodiment is the same as that of the first embodiment shown in
As shown in
The vehicle glass 10f is, for example, a laminated glass. The vehicle glass 10f includes two glass substrates 11 (11-1 and 11-2), an antenna conductor 12, the conductive film 13a and the conductive film 13c, an intermediate film 14, an antenna electrode 15, and a feeding point 16. Also, as in the fourth embodiment shown in
Further, in
The conductive film 13c is, for example, a conductive film for low emissivity (Low-E coat). The conductive film 13c is disposed in contact with a fourth main surface F4 of the glass substrate 11-2. Further, in a case in which the Low-E coat is provided on the fourth main surface F4, it is preferable for the Low-E coat to be overcoated with an insulating layer such that it is not exposed on the surface. Also, the conductive film 13c has a third void area VA3 disposed to overlap a first void area VA1 in a plan view of the glass substrate 11-1. Further, in a plan view of the glass substrate 11-1, it is preferable that an outer edge of the first void area VA1 and an outer edge of the third void area VA3 coincide, although some deviation therebetween is allowable.
The feeding point 16 of the present embodiment is a part of the conductive film 13c and is electrically connected to the conductive film 13c. The vehicle antenna device 1f is capable of receiving AM broadcast band from the feeding point 16. The feeding point 16 is disposed at a center portion of the conductive film 13 at a distance of 150 mm or more from an end side of the glass substrate 11-2 in a plan view of the glass substrate 11-2.
Further, in the present embodiment, the conductive film 13c, which is a conductive film for low emissivity (Low-E coat), functions as an AM antenna and functions as an antenna ground for an antenna 21. A signal in a frequency band of AM broadcast band received by the conductive film 13c, which is a conductive film for low emissivity (Low-E coat), is input to an AM amplifier 31 of the amplifier 30 from the feeding point 16 (first feeding point). Also, a signal in a frequency band of FM broadcast band is input to an FM amplifier 32 of the amplifier 30 from the antenna electrode 15 (second feeding point).
As described above, in the present embodiment, the conductive film 13a (first conductive film) is sandwiched between the intermediate film 14-1 and the intermediate film 14-2. The conductive film 13c (second conductive film) is disposed in contact with the fourth main surface F4. The conductive film 13a is, for example, a light control film containing a conductor. The conductive film 13c is a conductor for a low emissivity film (Low-E coat).
Therefore, according to the vehicle antenna device 1f of the present embodiment, for example, even in a case in which both the light control film and the conductor for a low emissivity film (Low-E coat) are provided, AM broadcast band can easily be received.
Next, a vehicle antenna device 1g of an eighth embodiment will be described with reference to the drawings. In the present embodiment, a modified example in which a conductive film 13 and a signal electrode 16b are electrically connected by capacitive coupling will be described.
Further, since a perspective view of the vehicle antenna device 1g of the present embodiment is the same as that of the first embodiment shown in
As shown in
The vehicle glass 10g is, for example, a laminated glass. The vehicle glass 10g includes two glass substrates 11 (11-1 and 11-2), an antenna conductor 12, the conductive film 13, an intermediate film 14, an antenna electrode 15, and the signal electrode 16b. The present embodiment differs from the third embodiment described above in that the connection conductor 18a is not provided.
Further, in
The signal electrode 16b is disposed to be electrically connected to the conductive film 13 by capacitive coupling. That is, the signal electrode 16b is disposed at a position overlapping the conductive film 13 in a plan view of the glass substrate 11-2 (11).
Also, the signal electrode 16b is formed in a square loop shape in a plan view of the glass substrate 11-2 (11). That is, an outer edge and an inner edge of the signal electrode 16b have a square shape.
Further, in the present embodiment, the conductive film 13 functions as an AM antenna and functions as an antenna ground for an antenna 21. A signal in a frequency band of AM broadcast band received by the conductive film 13 is electrically connected to the signal electrode 16b (first feeding point) by capacitive coupling and is input to an AM amplifier 31 of the amplifier 30 from a feeding point 16 (first feeding point). Also, a signal in a frequency band of FM broadcast band is input to an FM amplifier 32 of the amplifier 30 from the antenna electrode 15 (second feeding point).
As described above, in the present embodiment, the conductive film 13 and the signal electrode 16b are configured to be electrically connected by capacitive coupling. Therefore, the vehicle antenna device 1g of the present embodiment can take out the received signal of AM broadcast band from the signal electrode 16b (first feeding point) without performing drilling processing on the glass substrate 11-2 (11) and can receive the AM broadcast band more simply using the conductive film 13.
Further, the invention is not limited to the above-described embodiments and can be modified within a range not departing from the spirit of the invention.
For example, in each of the above-described embodiments, an example in which the antenna portion 20 is a shark fin antenna has been described, but the invention is not limited thereto, and may be, for example, a rod antenna.
Also, in each of the above-described embodiments, an example in which a dielectric substrate is used for the glass substrate 11 has been described, but the invention is not limited thereto, and may be a substrate using another dielectric such as, for example, a plastic substrate (resin substrate).
Also, in the third to eighth embodiments described above, an example in which the vehicle glasses 10b to 10g do not include the shielding layer 17 has been described, but the shielding layer 17 may be provided in the third to eighth embodiments.
Also, in the first and second embodiments described above, an example in which the vehicle glass 10 (10a) includes the shielding layer 17 has been described, but the shielding layer 17 may not be provided in the first and second embodiments.
Also, in each of the embodiments described above, an example in which the capacitor C1 of the high pass filter 40 is formed of a capacitor element has been described, but the capacitor C1 may be formed by capacitive coupling using, for example, the glass substrate 11 or the like between the conductive film 13 (13a, 13b) and the ground line (vehicle body BD). Also, the capacitor C1 may be formed by utilizing an overlap between the conductive film 13 (13a, 13b) and the vehicle body BD. Also, the filter 40 may be configured as a band stop filter.
Also, in the vehicle antenna device 1e of the sixth embodiment shown in
As described above, in a case in which the vehicle antenna device 1e has the third conductive film in contact with the fourth main surface F4, a combination in which the conductive film 13 serving as the first conductive film is a heat ray reflective film, the conductive film 13a serving as the second conductive film is a light control film (a conductor included therein), and the third conductive film is a Low-E coat may be exemplified.
Further, in a case in which the fourth main surface F4 has a Low-E coat, it is preferable for the Low-E coat to be overcoated with an insulating layer such that it is not exposed on the surface. Further, in a case in which the fourth main surface F4 has a Low-E coat, the connection conductor 18a may be omitted in
Further, in the vehicle antenna device 1b of the third embodiment shown in
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021-184698 | Nov 2021 | JP | national |
This is a Continuation Application of International Application No. PCT/JP2022/041507, filed on Nov. 8, 2022, which claims priority to Japanese Patent Application No. 2021-184698 filed on Nov. 12, 2021. The contents of the aforementioned applications are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2022/041507 | Nov 2022 | WO |
| Child | 18657962 | US |
