JP7318487B2 - Vehicle window glass and vehicle window glass device - Google Patents

Description

The present invention relates to a vehicle window glass and a vehicle window glass device.

Vehicle window glass requires the placement of antenna elements for a wide variety of applications across different frequency bands, such as AM broadcast, FM broadcast, DAB (Digital Audio Broadcast), remote keyless entry, digital terrestrial television broadcast, and 4G communication. be done. On the other hand, for vehicle window glass (especially rear glass), there is a technique for heating a transparent or translucent conductive film formed on the surface of the window glass to prevent the window glass from being iced or fogged. When a conductive film is used for anti-fogging of a window glass, etc., there is an advantage that visibility and appearance are improved as compared with the case where a plurality of parallel heating wires are used. As a vehicle window glass having such a conductive film and an antenna element, a vehicle window glass having a DAB antenna element arranged so as not to overlap the conductive film is known (see, for example, Patent Document 1). ).

WO2016/185898

However, with the conventional technology, it may be difficult to secure an antenna gain in the VHF (Very High Frequency) band.

The present disclosure provides a vehicle window glass and a vehicle window glass device that can secure an antenna gain in the VHF band and have anti-fogging effects.

The technology of the present disclosure is
a glass plate and
a dielectric having a first surface facing the glass plate and a second surface opposite to the first surface;
a planar conductor provided between the glass plate and the first surface and having a conductive film, and a first bus bar and a second bus bar connected to the conductive film;
a first extension conductor having one end connected to the first bus bar and extending to the second surface;
a second extension conductor having one end connected to the second bus bar and extending to the second surface;
At least one power feeder provided on the second surface side,
the planar conductor generates heat by applying a voltage between the first bus bar and the second bus bar;
The power supply unit faces the planar conductor through the dielectric and outputs a received signal of at least a VHF band radio wave,
When the central wavelength of the frequency band of the radio wave to be received is λ, and the wavelength shortening rate of the glass plate is k, the longest distance _D1A from the first bus bar to the tip of the first extension conductor is 1. /8 × λ × k or more and 3/8 × λ × k or less,
A vehicle glazing and a vehicle glazing device are provided.

According to the technology of the present disclosure, it is possible to provide a vehicle window glass and a vehicle window glass device that can secure an antenna gain in the VHF band and also have an anti-fogging effect.

1 is an exploded perspective view showing a configuration example of a vehicle window glass in one embodiment; FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows one structural example of the windowpane for vehicles in one Embodiment by planar view. BRIEF DESCRIPTION OF THE DRAWINGS It is the elements on larger scale which show by planar view the example of 1 structure of the window glass for vehicles in one Embodiment. FIG. 4 is a schematic diagram showing a folded portion of an extension conductor in plan view. BRIEF DESCRIPTION OF THE DRAWINGS It is the elements on larger scale which show by planar view the example of 1 structure of the window glass for vehicles in one Embodiment. FIG. 4 is a diagram showing an example of measurement results of antenna gain in the FM broadcast wave band; FIG. 4 is a diagram showing an example of measurement results of antenna gain for Band III of DAB. FIG. 4 is a diagram showing an example of measurement results of antenna gain in the FM broadcast wave band; FIG. 4 is a diagram showing an example of measurement results of antenna gain for Band III of DAB. FIG. 4 is a diagram showing an example of measurement results of antenna gain in the FM broadcast wave band; FIG. 4 is a diagram showing an example of measurement results of antenna gain for Band III of DAB.

Hereinafter, embodiments according to the present disclosure will be described with reference to the drawings. For ease of understanding, the scale of each member in the drawings may differ from the actual scale. In directions such as parallel, right angle, orthogonal, horizontal, vertical, up and down, left and right, misalignment to the extent that the effects of the embodiment are not impaired is allowed. The shape of the corners is not limited to right angles, and may be arcuately rounded. The direction parallel to the X-axis (X-axis direction), the direction parallel to the Y-axis (Y-axis direction), and the direction parallel to the Z-axis (Z-axis direction) are the left-right direction (horizontal direction) of the glass plate, and the direction parallel to the glass plate. The vertical direction of the plate (longitudinal direction) and the direction perpendicular to the surface of the glass plate (also referred to as the normal direction). The X-axis direction, the Y-axis direction, and the Z-axis direction are orthogonal to each other.

A rear glass attached to the rear portion of a vehicle is suitable as the vehicle window glass in the present embodiment. However, the vehicle window glass may be a windshield attached to the front of the vehicle, a side glass attached to the side of the vehicle, a roof glass attached to the ceiling of the vehicle, or the like.

FIG. 1 is an exploded perspective view showing one configuration example of a vehicle window glass according to one embodiment. In FIG. 1 , the positive side in the Z-axis direction represents the outside of the vehicle, and the negative side in the Z-axis direction represents the inside of the vehicle. The window glass 101 has a laminated glass structure in which a glass plate 10 arranged on the outside of the vehicle and a glass plate 20 arranged on the inside of the vehicle are bonded together with an intermediate film 40 interposed therebetween. FIG. 1 shows the components of the windowpane 101 separated in the direction normal to the surface of the glass plate 10 or the glass plate 20 .

The windowpane 101 includes a glass plate 10 arranged on the outside of the vehicle, a glass plate 20 arranged on the inside of the vehicle, and a planar conductor 50 arranged inside the laminated glass.

The glass plate 10 and the glass plate 20 are transparent plate-like dielectrics. Either one or both of the glass plate 10 and the glass plate 20 may be translucent. The glass plate 10 is an example of a first glass plate, and the glass plate 20 is an example of a second glass plate.

The glass plate 10 has a plate surface 11 and a plate surface 12 opposite to the plate surface 11 in the Z-axis direction. The plate surface 11 represents the surface inside the vehicle, and the plate surface 12 represents the surface outside the vehicle. In particular, the plate surface 12 corresponds to the outer surface of the laminated glass on the vehicle exterior side. The glass plate 10 has a transmissive region 14 that transmits visible light. A light shielding film 13 for shielding visible light is provided outside the transmissive region 14 . The light shielding film 13 will be described later.

The glass plate 20 has a plate surface 21 facing the plate surface 11 of the glass plate 10 and a plate surface 22 opposite to the plate surface 21 in the Z-axis direction. The plate surface 21 represents the surface outside the vehicle, and the plate surface 22 represents the surface inside the vehicle. In particular, the plate surface 22 corresponds to the outer surface of the laminated glass on the vehicle interior side. The plate surface 21 is an example of a first surface, and the plate surface 22 is an example of a second surface.

The intermediate film 40 is a transparent or translucent dielectric interposed between the glass plate 10 and the glass plate 20 . The glass plate 10 and the glass plate 20 are bonded by the intermediate film 40 . Examples of the intermediate film 40 include thermoplastic polyvinyl butyral (PVB), ethylene vinyl acetate copolymer (EVA), and the like. It should be noted that the dielectric constant of the intermediate film 40 is preferably 2.4 or more and 3.5 or less.

FIG. 1 shows a configuration in which a planar conductor 50 is arranged between a glass plate 10 and a glass plate 20. As shown in FIG. In the embodiment shown in FIG. 1, the planar conductor 50 is provided between the plate surface 11 of the glass plate 10 and the plate surface 21 of the glass plate 20, and is formed by one conductor surface that is not separated. there is

The planar conductor 50 has a conductive film 55 and a pair of bus bars 51 and 52 connected to the conductive film 55 . The busbar 51 is an example of a first busbar, and the busbar 52 is an example of a second busbar. Planar conductor 50 (especially conductive film 55 ) generates heat by applying a voltage between bus bar 51 and bus bar 52 . Anti-icing and anti-fogging of the window glass 101 can be realized by the heat generation of the planar conductor 50 .

The busbar 51 is a strip electrode connected to the left edge of the planar conductor 50 , and the busbar 52 is a strip electrode connected to the right edge of the planar conductor 50 . A pair of bus bars 51 and 52 are arranged between the plate surface 11 and the plate surface 21 . The pair of busbars 51 and 52 have a lower sheet resistance (also called surface resistivity or surface resistivity) than the conductive film 55 . For the pair of busbars 51 and 52, for example, metal foil or thin film of copper, silver, or the like is used.

Window glass 101 has a positive electrode 37 connected to bus bar 51 via flat wire 53 and a negative electrode 38 connected to bus bar 52 via flat wire 54 . The positive electrode 37 is an example of a first electrode, and the negative electrode 38 is an example of a second electrode. 1, the positive electrode 37 is a rectangular element provided on the left edge of the plate surface 22 as viewed from the inside of the vehicle and formed in a rectangular shape with the Y-axis direction as the longitudinal direction. It is a rectangular element provided at the right edge of the plate surface 22 when viewed and formed in a rectangular shape with the Y-axis direction as the longitudinal direction. However, the shape of positive electrode 37 and negative electrode 38 may be other shapes such as circular or other polygonal.

When the bus bar 51 is provided on the left edge of the plate surface 21 as seen from the inside of the vehicle, one end 53 a of the flat wire 53 is connected to the bus bar 51 and the other end 53 b of the flat wire 53 is connected to the positive electrode 37 . Similarly, when the bus bar 52 is provided on the right edge of the plate surface 21 as viewed from the vehicle interior, one end 54 a of the flat wire 54 is connected to the bus bar 52 and the other end 54 b of the flat wire 54 is connected to the negative electrode 38 . be done.

By applying a voltage between the positive electrode 37 and the negative electrode 38, a voltage is applied between the busbars 51 and 52, so that the planar conductor 50 generates heat, and the windowpane 101 is protected from ice and fog. can be realized. Since the positive electrode 37 and the negative electrode 38 are exposed on the side of the plate surface 22, even if the pair of bus bars 51 and 52 are sandwiched between the pair of glass plates 10 and 20 and are not exposed, the pair of bus bars 51 and 52 are exposed. can be applied via flat wires 53 and 54 to .

The conductive film 55 is a transparent or translucent conductor arranged between the intermediate film 40 and the glass plate 20, and is, for example, a metal film such as an Ag film, or a metal oxide film such as an ITO (indium tin oxide) film. , a resin film containing conductive fine particles, or a laminate of a plurality of types of films. The conductive film 55 may be formed by coating a resin film such as polyethylene terephthalate by vapor deposition or the like.

The conductive film 55 is sandwiched between the pair of bus bars 51 and 52 in plan view of the plate surface 22 and functions as a heater that heats the window glass 101 . The conductive film 55 heats the windowpane 101 by applying a DC voltage between the pair of busbars 51 and 52 , thereby preventing the windowpane 101 from freezing and fogging. For example, one bus bar 51 provided on the left edge of the planar conductor 50 as seen from the inside of the vehicle is connected to the positive electrode side of the DC power supply via a flat wire 53, and is connected to the right side of the planar conductor 50 as seen from the inside of the vehicle. The other bus bar 52 provided at the edge is connected to the negative side of the DC power supply via a flat wire 54 .

The window glass 101 includes a power supply electrode 33 arranged on the outer surface of the laminated glass on the vehicle interior side. The feeding electrode 33 is an example of a feeding section, and is, for example, a conductor pattern provided on the plate surface 22 side. FIG. 1 shows a form in which the feeding electrode 33 is a rectangular element formed in a rectangular shape with the X-axis direction as the longitudinal direction. However, the shape of the feeding electrode 33 may be other shapes such as circular or other polygonal shapes.

The feeding electrode 33 faces the planar conductor 50 through the glass plate 20 so that the planar conductor 50 receives at least VHF radio waves. The feeding electrode 33 faces the planar conductor 50 through the glass plate 20 so that at least a part of the planar conductor 50 functions as a radiation conductor for receiving at least VHF radio waves. output the received signal. The received signal includes, for example, a received signal of at least one of radio waves in the FM broadcast wave band and DAB Band III.

The feeding electrode 33 is capacitively coupled with the planar conductor 50 because it faces the planar conductor 50 via the dielectric glass plate 20 . The capacitive coupling portion between the feeding electrode 33 and the planar conductor 50 functions as a shortening capacitor that shortens the electrical length of the planar conductor 50, which has a conductor length sufficiently longer than the wavelength of the VHF band. As a result, since the planar conductor 50 can be used as part of an antenna for receiving radio waves in the VHF band, it is possible to ensure antenna gain in the VHF band (for example, FM broadcast wave band).

Even if the planar conductor 50 is not grounded at least with respect to the received signal of the radio wave of the VHF band, the antenna gain of the VHF band is ensured. In this case, the window glass 101 does not need to be provided with a grounding electrode for receiving VHF radio waves. As a result, among the plurality of wirings connected to the window glass 101, the ground wiring for receiving the VHF band can be reduced.

FIG. 1 shows a configuration in which the feed electrode 33 is provided on the left upper edge of the plate surface 22 . However, the power supply electrode 33 may be arranged at another location such as the upper left edge of the plate surface 22 as long as it faces at least a portion of the planar conductor 50 with the glass plate 20 interposed therebetween.

The VHF band represents a frequency band from 30 MHz to 300 MHz. Radio waves in the VHF band include, for example, FM broadcast waves and DAB Band III radio waves. Therefore, the feeding electrode 33 may face the planar conductor 50 through the glass plate 20 so that the planar conductor 50 receives at least FM broadcast waves. Alternatively, the feeding electrode 33 may face the planar conductor 50 via the glass plate 20 so that the planar conductor 50 receives at least DAB Band III radio waves.

Also, the feeding electrode 33 may be formed to receive at least UHF (Ultra high Frequency) band radio waves. In other words, the feeding electrode 33 may be formed to function as a radiation conductor for receiving at least UHF band radio waves in addition to receiving VHF band radio waves. By forming the feeding electrode 33 in this way, it is possible to configure an antenna for both the VHF band and the UHF band.

The UHF band represents a frequency band from 300 MHz to 3 GHz. UHF band radio waves include digital terrestrial television broadcast waves and radio waves for mobile communications. Therefore, the feeding electrode 33 may be configured to receive at least terrestrial digital television broadcast waves, or may be configured to receive at least mobile communication radio waves, in addition to receiving VHF band radio waves. .

At least part of the power supply electrode 33 faces at least one of the bus bar 51 and the conductive film 55 with the glass plate 20 interposed therebetween. A first input section of an amplifier 60 is connected to the feeding electrode 33 . A signal obtained by receiving radio waves at the planar conductor 50 is input to the first input portion of the amplifier 60 via capacitive coupling between the planar conductor 50 and the feeding electrode 33 , and the radio waves are transmitted from the feeding electrode 33 . The received signal is also input to the first input of amplifier 60 . A signal input to the first input section is output from the amplifier 60 via the bandpass filter.

The window glass 101 may further include a power supply electrode 35 arranged on the outer surface of the laminated glass on the vehicle interior side. The feeding electrode 35 is an example of a feeding section, and is, for example, a conductor pattern provided on the plate surface 22 side. FIG. 1 shows a form in which the feed electrode 35 is a rectangular element formed in a rectangular shape with the X-axis direction as the longitudinal direction. However, the shape of the feeding electrode 35 may be other shapes such as circular or other polygonal shapes.

A diversity antenna can be configured by configuring the feeding electrode 35 in the same manner as the feeding electrode 33 described above. A description of the configuration of the power supply electrode 35 is omitted by citing the above description.

At least part of the power supply electrode 35 faces at least one of the bus bar 52 and the conductive film 55 with the glass plate 20 interposed therebetween. A first input section of an amplifier 61 is connected to the feeding electrode 35 . A signal obtained by receiving radio waves at the planar conductor 50 is input to the first input portion of the amplifier 61 via capacitive coupling between the planar conductor 50 and the feeding electrode 35, and the radio waves are transmitted from the feeding electrode 35. A received signal is also input to the first input of the amplifier 61 . A signal input to the first input section is output from the amplifier 61 via the bandpass filter.

The window glass 101 may further include a power supply electrode 32 arranged on the outer surface of the laminated glass on the vehicle interior side. The power supply electrode 32 is an example of a power supply part, and is, for example, a conductor pattern provided on the plate surface 22 side. FIG. 1 shows a mode in which the power supply electrode 32 is a rectangular element provided at the upper edge of the plate surface 22 when viewed from the inside of the vehicle and formed in a rectangular shape with the X-axis direction as the longitudinal direction. However, the shape of the feeding electrode 32 may be other shapes such as circular or other polygonal shapes.

The feeding electrode 32 faces the planar conductor 50 through the glass plate 20 so that the planar conductor 50 receives at least radio waves in the MF (Medium Frequency) band. That is, the feeding electrode 32 faces the planar conductor 50 through the glass plate 20 so that at least a portion of the planar conductor 50 functions as a radiation conductor for receiving at least MF band radio waves.

Alternatively, the feeding electrode 32 may face the planar conductor 50 via the glass plate 20 so that the planar conductor 50 receives at least radio waves in the MF band and the HF (High Frequency) band. That is, the feeding electrode 32 faces the planar conductor 50 through the glass plate 20 so that at least a portion of the planar conductor 50 functions as a radiation conductor for receiving radio waves in at least the MF band and the HF band.

By providing such a feeding electrode 32, a shared antenna capable of receiving radio waves in the MF band (or MF band and HF band) can be constructed. The MF band represents a frequency band from 300 kHz to 3 MHz. Examples of MF band radio waves include AM broadcast waves. The HF band represents a frequency band of 3 MHz or more and 30 MHz or less, and is also called SW (Short Wave) band. Therefore, the feeding electrode 32 and the planar conductor 50 may be formed to receive at least AM broadcast waves. The AM broadcast wave is preferably 15 dBμV or more, and more preferably 18 dBμV or more, because appropriate reception sensitivity can be obtained.

In FIG. 1 , at least part of the power supply electrode 32 faces at least part of the upper edge of the conductive film 55 with the glass plate 20 interposed therebetween when viewed from the inside of the vehicle. A second input section of an amplifier 60 is connected to the feeding electrode 32 . Therefore, a signal obtained by receiving radio waves at the planar conductor 50 is input to the second input section of the amplifier 60 via capacitive coupling between the planar conductor 50 and the feeding electrode 32 . Also, a signal obtained by receiving radio waves with the planar conductor 50 may be extracted without the capacitive coupling between the planar conductor 50 and the feeding electrode 32 . For example, in FIG. 2, radio waves are received by the planar conductor 50 from wiring connected to the first choke coil 81 (or the second choke coil 83), the capacitor 82 (or the capacitor 84), or the choke transformer 86. A structure for extracting the obtained signal is conceivable. Details of FIG. 2 will be described later.

In FIG. 1, the window glass 101 may further include a power supply electrode 39 arranged on the outer surface of the laminated glass on the vehicle interior side. The power supply electrode 39 is an example of a power supply portion, and is, for example, a conductor pattern provided on the plate surface 22 side. FIG. 1 shows a form in which the power supply electrode 39 is a rectangular element provided at the upper edge of the plate surface 22 when viewed from the inside of the vehicle and formed in a rectangular shape with the X-axis direction as the longitudinal direction. However, the feed electrode 39 may be provided on the side edge of the plate surface 22 or may be provided on the lower edge. Furthermore, the shape of the feed electrode 39 may be other shapes such as circular or other polygonal shapes.

The feeding electrode 39 may be formed to receive at least UHF band radio waves. In other words, the feeding electrode 39 itself may be formed so as to function as a radiation conductor that receives at least UHF band radio waves. A UHF antenna for three channels using the feeding electrodes 33, 35, and 39 can be configured.

At least part of the power supply electrode 39 may or may not face the conductive film 55 with the glass plate 20 interposed therebetween. The power supply electrode 39 may be a conductor pattern located outside the conductive film 55 in plan view. A signal obtained by receiving radio waves at the feeding electrode 39 is input to the second input section of the amplifier 61 .

The glass plate 10 has a light shielding film 13 that shields visible light. The light shielding film 13 is provided on the outer peripheral edge of the glass plate 10 . The light shielding film 13 includes a pair of bus bars 51, 52, a positive electrode 37, a negative electrode 38, power supply electrodes 32, 33, 35, 39, and stubs 71, 72, 73, 74 in the thickness direction of the glass plate 10 in plan view. Duplicate. The duplication is not limited to a form in which all are duplicated, but may include a form in which part is duplicated. Specific examples of the light shielding film 13 include ceramics such as a black ceramics film. The pair of busbars 51, 52, positive electrode 37, negative electrode 38, power supply electrodes 32, 33, 35, 39, and stubs 71, 72, 73, 74 have portions overlapping the light shielding film 13 in plan view of the glass plate 10. In this case, when the window glass 101 is viewed from the outside of the vehicle, the overlapping portion becomes difficult to see. Therefore, the design of the window glass 101 and the vehicle is improved.

As described above, in a plan view of the window glass 101 , the pair of bus bars 51 , 52 , the positive electrode 37 , the negative electrode 38 , the power supply electrodes 32 , 33 , 35 , 39 and the stubs 71 , 72 , 73 , 74 overlap the light shielding film 13 . Therefore, it is possible to both improve the appearance and secure the field of view.

For example, at least one of the power supply electrodes 32 , 33 , 35 , 39 and the stubs 71 , 72 , 73 , 74 is coated with a paste containing a conductive metal (for example, silver paste). It may be formed by printing and baking, or may be formed from a metal plate (metal foil).

FIG. 2 is a plan view showing one configuration example of the vehicle window glass according to the embodiment, and is a view of the vehicle window glass attached to the vehicle as viewed from the inside of the vehicle. That is, in FIG. 2, the positive direction of the Y-axis direction corresponds to the direction away from the ground surface when the vehicle window glass is attached to the vehicle.

The inner edge 13 a of the light shielding film 13 is inside the outer edge 50 a of the planar conductor 50 . As a result, the outer edge 50a overlaps the light shielding film 13 in plan view, so that the boundary between the portion with the planar conductor 50 and the portion without the planar conductor 50 is hidden by the light shielding film 13 when viewed from the outside of the vehicle, improving the appearance.

The windowpane device 1010 is an example of a vehicle windowpane device. A windowpane device 1010 includes a windowpane 101 , a first choke coil 81 connected to the positive electrode 37 , and a second choke coil 83 connected to the negative electrode 38 . The first choke coil 81 and the second choke coil 83 block at least received signals of radio waves in the VHF band. As a result, it is possible to suppress the leakage of the high-frequency signal in the VHF band to the DC power supply 80 and the ground side. The first choke coil 81 and the second choke coil 83 block, for example, signals in at least one of the frequency band of FM broadcast waves and DAB Band III among received signals of radio waves in the VHF band.

The side of the first choke coil 81 opposite to the positive electrode 37 may be grounded through a capacitor 82 , and the side opposite to the negative electrode 38 of the second choke coil 83 may be grounded through a capacitor 84 . may be connected to Capacitors 82 and 84 can adjust the wiring impedance. For example, when the planar conductor 50 receives radio waves in the MF band, the capacitors 82 and 84 are preferably set to values that provide high impedance in the MF band.

The first choke coil 81 may be omitted if the wiring connecting the positive electrode 37 and the DC power supply 80 has at least an inductance that cuts off the received signal of the radio waves in the VHF band. The second choke coil 83 may be omitted if the wiring connecting the negative electrode 38 and the ground has at least an inductance that cuts off the received signal of the radio waves in the VHF band.

The windowpane device 1010 further comprises a choke transformer 86 connected to the positive electrode 37 and the negative electrode 38 . The choke transformer 86 blocks at least MF band signals. The choke transformer 86 has a transformer structure having a primary side coil and a secondary side coil. The positive electrode 37 is connected to the positive electrode side of the DC power source 80 via the primary coil, and the negative electrode 38 is connected to the negative electrode side of the DC power source 80 via the secondary coil. Therefore, especially when the planar conductor 50 receives an MF band radio wave, the insertion of the choke transformer 86 allows the reception signal obtained by receiving the MF band radio wave, such as an AM broadcast wave, to be received by the planar conductor 50 . And leakage to the ground side can be suppressed.

The windowpane 101 includes a first extension conductor 75 having one end connected to the first bus bar 51 on the side of the plate surface 21 and the other end extending to the plate surface 22 and a second bus bar 52 on the side of the plate surface 21 at one end. and a second extension conductor 76 having the other end extending to the plate surface 22 .

1 and 2, the first extension conductor 75 includes a flat wire 53 having one end 53a connected to the first bus bar 51 on the plate surface 21 side, and a flat wire 53 having the other end 53b connected to the plate surface 22. and stubs 71 and 72 connected to the positive electrode 37 on the plate surface 22 side. Similarly, in the form shown in FIGS. 1 and 2, the second extension conductor 76 has one end 54a connected to the second bus bar 52 on the plate surface 22 side of the flat wire 54 and the other end 54b of the flat wire 54. It has a negative electrode 38 connected on the plate surface 22 side, and stubs 73 and 74 connected to the negative electrode 38 on the plate surface 22 side.

By extending the first extension conductor 75 and the second extension conductor 76 to the plate surface 22 , even if the pair of bus bars 51 and 52 are arranged between the pair of glass plates 10 and 20 , the pair of bus bars 51 , 52 can be applied with a voltage via a first extension conductor 75 and a second extension conductor 76 .

FIG. 3 is a partially enlarged view showing a configuration example of the vehicle window glass in one embodiment in a plan view, showing an enlarged view of the first extension conductor 75 and its peripheral portion. The first extension conductor 75 is folded back by the flat wire 53 at the outer edge 20 a of the glass plate 20 . FIG. 4 is a schematic plan view showing the folded portion of the first extension conductor 75 folded back by the flat wire 53 as shown in FIG.

Let λ be the center wavelength of the frequency band of radio waves received in the VHF band (hereinafter also referred to as frequency band WH), and k be the wavelength reduction rate of the glass plate 10 . At this time, if the longest distance _D1A from the first bus bar 51 to the tip of the first extension conductor 75 is 1/8×λ×k or more and 3/8×λ×k or less, the frequency band WH ( For example, the antenna gain of Band III) of DAB is improved. From the point of view of improving the antenna gain in the frequency band WH, the maximum distance _D1A is more preferably 3/16×λ×k or more and 3/8×λ×k or less.

For example, when improving the antenna gain of DAB Band III (170 MHz to 240 MHz), the center wavelength λ is 1.46 m, so if k = 0.64, the maximum distance D _1A should be adjusted to 117 mm or more and 350 mm or less. Just do it.

The longest distance D _1A represents the longest central path length from the first busbar 51 to the tip of the first extension conductor 75 . In the case of FIG. 4, the longest distance _D1A is from one end 53a, which is the connection point between the flat wire 53 and the first bus bar 51, through the other end 53b, which is the connection point between the flat wire 53 and the positive electrode 37. It represents the central path length (=L1+L2+L3) to the tip portion 71a of the stub 71. The width of the positive electrode 37 may be the same as or different from at least one of the width of the stub 71 and the width of the stub 72 . The width of the positive electrode 37, the width of the stub 71, and the width of the stub 72 are substantially perpendicular to the direction along the inner edge 13a of the light shielding film 13 on the positive electrode 37 side. Similarly, the width of negative electrode 38 may be the same as or different from at least one of the width of stub 73 and the width of stub 74 . The width of the negative electrode 38, the width of the stub 73, and the width of the stub 74 are substantially orthogonal to the direction along the inner edge 13a of the light shielding film 13 on the negative electrode 38 side. For example, the width of the positive electrode 37 may be wider than the width of the stubs 71 and 72 and the width of the negative electrode 38 may be wider than the width of the stubs 73 and 74 .

In FIG. 4,
L1: the sum of the conductor length from one end 53a to the other end 53b and the conductor length from the other end 53b to the center of the positive electrode 37 in the longitudinal direction of the flat wire 53 L2: from the center of the positive electrode 37 in the longitudinal direction of the flat wire 53 Conductor length to the tip of the positive electrode 37 in the direction 78 L3: Conductor length in the direction 78 of the stub 71 L4: Conductor length from the center of the positive electrode 37 in the longitudinal direction of the flat wire 53 to the tip of the positive electrode 37 in the direction 79 L5: Conductor length in direction 79 of stub 72 B: L2+L3
C: L4 + L5
represents

As described above, in FIGS. 1 and 2, the capacitive coupling portion between the feeding electrode 33 and the planar conductor 50 causes the planar conductor 50 to move to a desired frequency band lower than the frequency band WH within the VHF band (hereinafter referred to as frequency Since it can be used as a part of an antenna for receiving radio waves in the frequency band WL, it is possible to ensure the antenna gain in the frequency band WL. An example of the frequency band WL is the FM broadcast wave band. On the other hand, a high-frequency signal in a frequency band WH (for example, DAB Band III) higher than the frequency band WL passes through the capacitive coupling portion between the feed electrode 33 and the planar conductor 50 . However, since the high frequency signal in the frequency band WH is cut off by the inductance of the first choke coil 81, wiring, etc., the first extension conductor 75 operates as an open stub for the high frequency signal in the frequency band WH. Therefore, by adjusting the maximum distance _D1A to a length that causes resonance in the frequency band WH (a length of 1/8×λ×k or more and 3/8×λ×k or less), the frequency band WL (for example, FM A broadband antenna that resonates in both the broadcast wave band) and the frequency band WH (eg, Band III of DAB) can be formed on the window glass 101 .

3 and 4, since the size of the positive electrode 37 changes according to the size of the connector connected to the positive electrode 37, at least one of the conductor length L3 of the stub 71 and the conductor length L5 of the stub 72 should be adjusted. , the maximum distance _D1A can be easily adjusted to the desired length.

3 and 4, the first extension conductor 75 has a bent portion 77 in plan view of the plate surface 22 . The bent portion 77 represents a portion where the extension direction of the first extension conductor 75 changes, for example, at least one portion where the extension direction of the first extension conductor 75 changes at an angle of 30° or more and 150° or less. show.

3 and 4 exemplify a form in which the bent portion 77 is a T-shaped portion that branches in directions 78 and 79. FIG. If the bent portion 77 is such a T-shaped portion, the antenna gain in the frequency band WH is improved. Direction 79 represents a direction opposite to direction 78, but need not be completely 180° opposite.

In the first extension conductor 75, the extension distance from the first bus bar 51 to the tip 71a in the direction 78 is the longest distance _D1A , and the extension distance from the first bus bar 51 to the tip 72a in the direction 79 _{is D1B.} and In terms of improving the antenna gain of the frequency band WH (for example, DAB Band III), (D _1A /D _1B ) is preferably 1.0 or more and 3.0 or less, more preferably 1.0 or more and 2.7 or less. It is preferably 1.0 or more and 2.0 or less.

In the case of FIG. 4, the extension distance _D1B is from one end 53a, which is the connection point between the flat wire 53 and the first bus bar 51, via the other end 53b, which is the connection point between the flat wire 53 and the positive electrode 37. The central path length (=L1+L4+L5) to the tip 72a of the stub 72 is represented.

In addition, in the first extension conductor 75, when the extension distance from the first bus bar 51 to the tip portion 71a in the direction 78 is the longest distance _D1A , the direction 78 is an example of the first direction. 79 is an example of the second direction. Conversely, in the case of the configuration in which the extension distance from the first bus bar 51 to the tip portion 72a in the direction 79 of the first extension conductor 75 is the longest distance _D1A , the direction 79 is an example of the first direction, Direction 78 is an example of a second direction.

The bent portion 77 may be an L-shaped portion (C=0) that bends in the direction 78 without bending in the direction 79 . If the bent portion 77 is an L-shaped portion, the antenna gain in the frequency band WH is improved. The bending portion 77 may be an L-shaped portion (B=0) that bends in the direction 79 without bending in the direction 78 .

In the first extension conductor 75 having an L-shaped bent portion 77, the extension distance from the first bus bar 51 to the tip portion 71a in the direction 78 is defined as the longest distance _D1A , and the length from the first bus bar 51 to the bent portion 77 D _1C is the drawing distance of . In terms of improving the antenna gain of the frequency band WH (for example, DAB Band III), (D _1A /D _1C ) is preferably 1.1 or more and 3.8 or less, and more preferably 1.1 or more and 3.5 or less. preferable. The extension distance _D1C represents the conductor length L1 in the case of FIG.

As shown in FIG. 4 , the windowpane 101 may include a first filamentous conductor 91 connected to the distal end portion 71 a of the first extension conductor 75 and thinner than the first extension conductor 75 . The first filamentary conductor 91 has a narrower width than the positive electrode 37 and the stub 71, for example. When the windowpane 101 is provided with the first linear conductor 91, the antenna gain in the frequency band WH (for example, Band III of DAB) is improved. In order to improve the antenna gain in the frequency band WH, the length of the first linear conductor 91 is preferably 30 mm or more and 80 mm or less, and more preferably 40 mm or more and 70 mm or less. In order to improve the antenna gain in the frequency band WH, the first filamentary conductor 91 preferably has a width of 0.3 mm or more and 5 mm or less, more preferably 0.5 mm or more and 4 mm or less.

FIG. 5 is a partially enlarged view showing a configuration example of a vehicle window glass in one embodiment in plan view, showing an enlarged view of the second extension conductor 76 and its peripheral portion. The second extension conductor 76 is folded back by the flat wire 54 at the outer edge 20 a of the glass plate 20 .

The same configuration as the first extension conductor 75 provided on the left edge of the windowpane 101 can also be applied to the second extension conductor 76 provided on the right edge of the windowpane 101 . For example, if the longest distance _D2A from the second bus bar 52 to the tip portion 73a of the second extension conductor 76 is 1/8×λ×k or more and 3/8×λ×k or less, the frequency band WH ( For example, the antenna gain of Band III) of DAB is improved. From the point of view of improving the antenna gain in the frequency band WH, the maximum distance _D2A is more preferably 3/16×λ×k or more and 3/8×λ×k or less.

As shown in FIG. 5 , the windowpane 101 may include a second filamentous conductor 92 connected to the distal end portion 73 b of the second extension conductor 76 and thinner than the second extension conductor 76 . When the windowpane 101 is provided with the second linear conductor 92, the antenna gain in the frequency band WH (for example, Band III of DAB) is improved. In order to improve the antenna gain in the frequency band WH, the length of the second filamentary conductor 92 is preferably 30 mm or more and 80 mm or less, and more preferably 40 mm or more and 70 mm or less. In order to improve the antenna gain in the frequency band WH, the second filamentary conductor 92 preferably has a width of 0.3 mm or more and 5 mm or less, more preferably 0.5 mm or more and 4 mm or less.

As shown in FIG. 5 , the windowpane 101 may include a third wire conductor 93 connected to the feed electrode 35 and thinner than the feed electrode 35 . When the windowpane 101 is provided with the third filamentous conductor 93, the antenna gain in the UHF band (for example, digital terrestrial television broadcast waveband) is improved. Similarly, connecting a wire conductor thinner than the feed electrode 33 to the feed electrode 33 (see FIGS. 1 and 2) also improves the antenna gain in the UHF band (for example, digital terrestrial television broadcast wave band).

As shown in FIG. 5 , the windowpane 101 may include a fourth wire conductor 94 connected to the feed electrode 39 and thinner than the feed electrode 39 . When the windowpane 101 is provided with the fourth linear conductor 94, the antenna gain in the UHF band (for example, digital terrestrial television broadcast waveband) is improved.

FIG. 1 shows a form in which a planar conductor 50 is formed on a plate surface 21 of a glass plate 20. As shown in FIG. For example, the planar conductor 50 is formed on the conductive film coated on the plate surface 21 of the glass plate 20 by vapor deposition.

However, the planar conductor 50 may be formed on the plate surface 11 of the glass plate 10 . For example, the planar conductor 50 is formed on a conductive film coated on the plate surface 11 of the glass plate 10 by sputtering. Between the planar conductor 50 and the feeding electrode 32, not only the glass plate 20 but also the intermediate film 40 may be present. Alternatively, the planar conductor 50 may be sandwiched between intermediate films.

Further, the vehicle window glass according to the present disclosure is not limited to laminated glass. In this case, the dielectric that exists between the planar conductor 50 and the feeding electrode 32 may not have the same size as the glass plate 10. A dielectric film or the like may be used.

Table 1 shows average values of antenna gain (unit: dB) measured in the frequency bands used in Europe and Japan for the window glass 101 . FM (87-108 MHz) and DAB (170-240 MHz) were selected as the frequency band used in Europe, and FM (76-108 MHz) was selected as the frequency band used in Japan. ANT1 represents the antenna gain of the signal obtained from the feeding electrode 33, and ANT2 represents the antenna gain of the signal obtained from the feeding electrode 35. FIG. "No stub" indicates a form in which the windowpane 101 has no stubs 71, 72, 73, 74 and the maximum distance _D1A does not satisfy 1/8 x λ x k or more and 3/8 x λ x k or less. "With stubs" indicates a form in which the windowpane 101 has stubs 71, 72, 73, and 74 and the longest distance _D1A satisfies 1/8 x λ x k or more and 3/8 x λ x k or less.

As shown in Table 1, the antenna gain (band average gain) of DAB (170 to 240 MHz) was improved in "with stub" as compared to "without stub".

6 to 11 show the relationship between the conductor length A of the feeding electrode 33, the conductor length B including the stub 71, and the conductor length C including the stub 72. In horizontal polarization, The results of measuring the antenna gain of the obtained signal are shown. Note that the conductor length L1 (see FIG. 4) is 144 mm in any case.

FIG. 6 is a diagram showing an example of measurement results of antenna gain in the FM broadcast wave band when A is fixed at 40 mm, C is fixed at 35 mm, and B is varied. FIG. 7 is a diagram showing an example of the measurement results of the DAB antenna gain when A is fixed at 40 mm, C is fixed at 35 mm, and B is varied. As shown in FIGS. 6 and 7, the results show that the stubs 71 and 72 do not significantly change the antenna gain in the FM broadcast wave band and are effective in improving the DAB frequency characteristics and antenna gain. . At this time, as shown in Table 2, (D _1A /D _1B ) is 1.0 or more and 3.0 or less, and the longest distance D _1A is 1/8×λ×k or more and 3/8×λ×k or less. Met.

FIG. 8 is a diagram showing an example of measurement results of antenna gain in the FM broadcast wave band when A is fixed at 40 mm, B is fixed at 35 mm, and C is varied. FIG. 9 is a diagram showing an example of the measurement results of the DAB antenna gain when A is fixed at 40 mm, B is fixed at 35 mm, and C is varied. As shown in FIGS. 8 and 9, the stubs 71 and 72 did not significantly change the antenna gain in the FM broadcast wave band, and the result was that they had the effect of improving the DAB frequency characteristics and antenna gain. . At this time, as shown in Table 3, (D _1A /D _1B ) is 1.0 or more and 3.0 or less, and the longest distance D _1A is 1/8×λ×k or more and 3/8×λ×k or less. Met.

FIG. 10 is a diagram showing an example of measurement results of antenna gain in the FM broadcast wave band when A is fixed at 40 mm and B and C are varied. FIG. 11 is a diagram showing an example of measurement results of the DAB antenna gain when A is fixed at 40 mm and B and C are varied. As shown in FIGS. 10 and 11, the results show that the stubs 71 and 72 do not significantly change the antenna gain in the FM broadcast wave band and have the effect of improving the DAB frequency characteristics and antenna gain. . At this time, as shown in Table 4, (D _1A /D _1B ) is 1.0 or more and 3.0 or less (1.0 fixed), and the longest distance D _1A is 1/8×λ×k or more 3/ It was 8×λ×k or less. Further, when the conductor lengths B and C were each 60 mm or more, an effect of flattening the frequency characteristics of DAB was observed.

Although the embodiments have been described above, the technology of the present disclosure is not limited to the above embodiments. Various modifications and improvements such as combination or replacement with part or all of other embodiments are possible.

10 Glass plate 13 Light shielding film 14 Transmissive area 20 Glass plate 21 Plate surface 22 Plate surfaces 33, 35 Power supply electrode 40 Intermediate film 50 Planar conductor 51 First bus bar 52 Second bus bar 55 Conductive films 71 to 74 Stub 75 First extension conductor 76 second extension conductor 77 bent portion 78 direction 79 direction 91 first wire conductor 92 second wire conductor 93 third wire conductor 101 window glass 1010 window glass device

Claims (18)

a glass plate and
a dielectric having a first surface facing the glass plate and a second surface opposite to the first surface;
a planar conductor provided between the glass plate and the first surface and having a conductive film, and a first bus bar and a second bus bar connected to the conductive film;
a first extension conductor having one end connected to the first bus bar and extending to the second surface;
a second extension conductor having one end connected to the second bus bar and extending to the second surface;
At least one power feeder provided on the second surface side,
the planar conductor generates heat by applying a voltage between the first bus bar and the second bus bar;
The power supply unit faces the planar conductor through the dielectric and outputs a received signal of at least a VHF band radio wave,
When the central wavelength of the frequency band of the radio wave to be received is λ, and the wavelength shortening rate of the glass plate is k, the longest distance _D1A from the first bus bar to the tip of the first extension conductor is 1. /8 x λ x k or more and 3/8 x λ x k or less. The vehicle window glass according to claim 1, wherein the first extension conductor has a bent portion in plan view of the second surface. 3. The vehicle window glass according to claim 2, wherein said bent portion is a T-shaped portion that branches in a first direction and a second direction. In the first extension conductor, the extension distance from the first bus bar to the tip in the first direction is the longest distance _D1A , and the length from the first bus bar to the tip in the second direction is D1A. When the stretching distance is D _1B ,
The vehicle window glass according to claim 3, wherein ( _D1A / _D1B ) is 1.0 or more and 3.0 or less. The vehicle window glass according to claim 2, wherein the bent portion is an L-shaped portion bent in the first direction. In the first extension conductor, the extension distance from the first bus bar to the tip portion in the first direction is defined as the maximum distance _D1A , and the extension distance from the first bus bar to the bent portion is defined as _D1C . When
The vehicle window glass according to claim 5, wherein ( _D1A / _D1C ) is 1.1 or more and 3.8 or less. The vehicle window glass according to any one of claims 1 to 6, further comprising a first wire conductor connected to the tip of the first extension conductor and thinner than the first extension conductor. The vehicle window glass according to claim 7, wherein the first filament conductor extends with a length of 30 mm or more and 80 mm or less. The vehicle window glass according to claim 7 or 8, wherein the first wire conductor has a width of 0.3 mm or more and 5 mm or less. 10. The longest distance _D2A from the second bus bar to the tip of the second extension conductor is 1/8×λ×k or more and 3/8×λ×k or less. The vehicle window glass according to item 1. 11. The vehicle window glass according to claim 10, further comprising a second filament conductor connected to the tip of said second extension conductor and thinner than said second extension conductor. The vehicle window glass according to claim 11, wherein the second filament conductor extends with a length of 30 mm or more and 80 mm or less. The vehicle window glass according to any one of claims 1 to 12, further comprising a third filament conductor connected to said power feeder and thinner than said power feeder. The vehicle window glass according to any one of claims 1 to 13, wherein the received signal includes a received signal of at least one of FM broadcast wave band and DAB Band III radio waves. The glass plate has a transmission region that transmits visible light, and a light shielding film that blocks visible light is provided outside the transmission region,
15. The light shielding film according to any one of claims 1 to 14, wherein the light shielding film overlaps with the power feeding portion, the first bus bar, the second bus bar, the first extension conductor, and the second extension conductor in plan view. The vehicle window glass according to item 1. the glass plate is a first glass plate, the dielectric is a second glass plate,
The vehicle window glass according to any one of claims 1 to 15, having a laminated glass structure in which the first glass plate and the second glass plate are bonded together via an intermediate film. A vehicle window glass according to any one of claims 1 to 16;
a first choke coil connected to the first extension conductor;
a second choke coil connected to the second extension conductor;
The vehicle window glass device, wherein the first choke coil and the second choke coil block at least received signals of radio waves in the VHF band. 18. The vehicle windowpane device according to claim 17, wherein the planar conductor is not grounded at least with respect to received signals of radio waves in the VHF band.

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