Vehicle window glass

Abstract

To provide a vehicle window glass having an antenna capable of receiving both VHF band and UHF band radio waves with a relatively simple configuration.SOLUTION: A vehicle window glass 101 includes a glass plate 10 and an antenna 20A provided on the glass plate. The antenna includes a feeding portion 21, a first element 30 electrically connected to the feeding portion and extending to a first open end 35, a second element 40 electrically connected to the feeding portion 21 and extending to a second open end 45, and a third element 50 electrically connected to the feeding portion 21 and extending to a third open end 55. The first element 30 includes a first portion 31 extending in a first direction (+Y) and a second portion 32 extending in a second direction (-Y) opposite to the first direction (+Y) by folding back from the first portion 31. The antenna includes the first element 30, the second element 40, and the third element 50 arranged in this order in a third direction (+X) different from the first direction (+Y) and the second direction (-Y).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to vehicle glazings. [Background technology]

[0002] In recent years, antennas that integrate multiple antenna elements capable of receiving signals in multiple frequency bands, such as AM broadcast waves, FM broadcast waves, terrestrial digital television broadcast waves, and DAB (Digital Audio Broadcasting), have been put to practical use as antennas mounted on vehicles such as automobiles.For example, a glass antenna is known that includes a first antenna connected to a first power feeder and receiving FM broadcast waves and DAB Band III radio waves, a second antenna connected to a second power feeder and receiving AM broadcast waves, and a third antenna connected to a third power feeder and receiving radio waves in the TV broadcast band (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-142162 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology of Patent Document 1 requires a plurality of antennas with different power feed points to receive radio waves in both the VHF and UHF bands, resulting in a complex antenna configuration.

[0005] The present disclosure provides a vehicle window glass equipped with an antenna that can receive radio waves in both the VHF band and the UHF band with a relatively simple configuration. [Means for solving the problem]

[0006] The present disclosure provides: A glass plate and an antenna provided on the glass plate, which receives radio waves in a first frequency band, radio waves in a second frequency band lower than the first frequency band, and radio waves in a third frequency band lower than the second frequency band; the first frequency band is a band included in the UHF band, the second frequency band and the third frequency band are bands included in the VHF band, the antenna has a power feed portion, a first element extending from a first connection end electrically connected to the power feed portion to a first open end opposite the first connection end, a second element extending from a second connection end electrically connected to the power feed portion to a second open end opposite the second connection end, and a third element extending from a third connection end electrically connected to the power feed portion to a third open end opposite the third connection end, the first element includes a first portion extending in a first direction and a second portion folded back from the first portion and extending in a second direction opposite to the first direction; the second element includes a third portion extending in the first direction; the third element includes a fourth portion extending in the first direction; The present invention provides a vehicle window glass in which the first element, the second element, and the third element are arranged in a third direction different from the first direction and the second direction in the order of the first element, the second element, and the third element, or the order of the second element, the first element, and the third element. [Effects of the Invention]

[0007] According to the technique of the present disclosure, it is possible to provide a vehicle window glass equipped with an antenna that can receive radio waves in both the VHF band and the UHF band with a relatively simple configuration. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a plan view showing an example of the configuration of a vehicle window glass equipped with an antenna according to a first embodiment. [Figure 2]FIG. 10 is a plan view showing an example of the configuration of a vehicle window glass equipped with an antenna according to a second embodiment. [Figure 3] FIG. 11 is a plan view showing an example of the configuration of a vehicle window glass equipped with an antenna according to a third embodiment. [Figure 4] FIG. 10 is a plan view showing an example of the configuration of a vehicle window glass equipped with an antenna according to a fourth embodiment. [Figure 5] FIG. 11 is a plan view showing an example of the configuration of a vehicle window glass equipped with an antenna according to a fifth embodiment. [Figure 6] FIG. 13 is a plan view showing an example of the configuration of a vehicle window glass equipped with an antenna according to a sixth embodiment. [Figure 7] 10 is a plan view showing an example of a configuration of a window glass mounting structure in which a vehicle window glass equipped with an antenna according to a third embodiment is mounted on a window frame of a vehicle. FIG. [Figure 8] 10A and 10B are diagrams showing an example of reflection characteristics of the antenna of the third embodiment in the bands of terrestrial digital television broadcast waves, DAB Band III, and FM broadcast waves. [Figure 9] 10A and 10B are diagrams showing an example of the reflection characteristics of an antenna in the band of terrestrial digital television broadcast waves when the length of the branch element and the position of the branch point are changed. [Figure 10] FIG. 10 is a diagram showing an example of the reflection characteristics of the antenna in the DAB Band III band when the length of the branch element and the position of the branch point are changed. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, each embodiment according to the present disclosure will be described with reference to the drawings. Note that for ease of understanding, the scale of each part in the drawings may differ from the actual scale. Deviations in directions such as parallel, right-angled, orthogonal, horizontal, vertical, up-down, and left-right are permitted to the extent that they do not impair the effects of the embodiments. The shape of the corners is not limited to right angles and may be rounded like an arch. The X-axis and Y-axis directions represent directions parallel to the X-axis and Y-axis, respectively. The X-axis and Y-axis directions are perpendicular to each other. The XY plane represents an imaginary plane parallel to the X-axis and Y-axis directions, respectively.

[0010] Examples of the vehicle window glass in this embodiment include a rear window attached to the rear of the vehicle, a windshield attached to the front of the vehicle, a side window attached to the side of the vehicle, etc. The vehicle window glass is not limited to these examples.

[0011] Fig. 1 is a plan view showing an example of the configuration of a vehicle window glass equipped with an antenna according to the first embodiment. The window glass 101 shown in Fig. 1 is an example of a vehicle window glass, and is attached to a window frame 210 formed on a vehicle body. The window glass 101 includes a glass plate 10 and an antenna 20A. Fig. 1 shows a part of the window glass 101 in a plan view from the normal direction of the surface of the glass plate 10.

[0012] The window frame 210 is a conductive portion that can be grounded and is also called a flange. The window frame 210 has a frame edge 211 that forms an opening that is covered by the window glass 101. A portion of the window frame 210 and a portion of the frame edge 211 are shown in FIG.

[0013] The glass plate 10 is an example of a glass plate for a vehicle, and is a transparent or translucent plate-shaped dielectric. The glass plate 10 has an outer peripheral edge 12 that is attached to a window frame 210. A portion of the outer peripheral edge 12 is shown in FIG. 1. The glass plate 10 is attached to the window frame 210 so that the outer peripheral edge 12 overlaps with the window frame 210 in a plan view from inside the vehicle.

[0014] Antenna 20A is an example of an antenna and is provided on glass plate 10. Antenna 20A is configured to be able to receive radio waves in a first frequency band F1, a second frequency band F2 that is lower than the first frequency band F1, and a third frequency band F3 that is lower than the second frequency band F2, and resonates at frequencies in each of these frequency bands.

[0015] The shape of the antenna 20A is suitable for transmitting and receiving radio waves in the VHF (Very High Frequency) band with frequencies of 30 MHz to 300 MHz and the UHF (Ultra High Frequency) band with frequencies of 300 MHz to 3 GHz. For example, the first frequency band F1 is set to the UHF band (470 MHz to 710 MHz) for terrestrial digital television broadcast waves, the second frequency band F2 is set to the VHF band (170 MHz to 240 MHz) for DAB Band III, and the third frequency band F3 is set to the VHF band (76 MHz to 108 MHz) for FM broadcast waves.

[0016] The antenna 20A includes a power supply portion 21, a first element 30, a second element 40, and a third element 50.

[0017] The power supply unit 21 is an electrode for power supply. The power supply unit 21 is provided near the outer peripheral edge 12 of the glass plate 10 so as to be located near the frame side 211 when the window glass 101 is attached to the window frame 210. The power supply unit 21 is electrically connected to one end of a power supply line (for example, one end of a signal line of a coaxial cable) via a conductive member such as a connector. The other end of the power supply line is connected to a communication device such as a receiver. The shape of the power supply unit 21 is preferably a rectangular shape such as a square, an approximately square, a rectangle, or an approximately rectangular shape, or a polygonal shape, for example, from the viewpoint of implementation, but is not limited to these, and other shapes such as a circle, an approximately circle, an ellipse, or an approximately ellipse may also be used.

[0018] The first element 30 is a linear conductor extending from a first connection end 39, which is an end electrically connected to the power supply unit 21, to a first open end 35, which is an end opposite to the first connection end 39. The first element 30 includes a first portion 31 extending in a first direction (in this example, the positive Y-axis direction) and a second portion 32 folding back from the first portion 31 and extending in a second direction (in this example, the negative Y-axis direction) opposite to the first direction. Note that the second portion 32 is not limited to the form shown in FIG. 1 in which it folds back and extends from the end of the first portion 31, but may fold back and extend from partway through the first portion 31.

[0019] 1, the first portion 31 is a linear element having a first end (first connection end 39) connected to the power supply unit 21 and a second end connected to the end of the second portion 32, and extending linearly from the first end to the second end. On the other hand, the second portion 32 is a linear element having a third end connected to the second end of the first portion 31 and a fourth end (first open end 35) opposite the third end, and extending in a bent manner from the third end to the fourth end.

[0020] 1, second portion 32 includes a direction change portion 32a extending from first portion 31 in a direction different from the first direction (in this example, the positive Y-axis direction) and an extension portion 32b extending from direction change portion 32a in a second direction (in this example, the negative Y-axis direction). Extension portion 32b extends along first portion 31 to first open end 35.

[0021] 1, the second portion 32 is folded back on the side opposite to the third element 50 side with respect to the first portion 31, but it may also be folded back on the third element 50 side with respect to the first portion 31. In this case, it is preferable that the extending portion 32b of the second portion 32 is located between the first portion 31 of the first element 30 and the third portion 43 of the second element 40.

[0022] Furthermore, the first element 30 may further include a portion extending in a direction different from the first direction and the second direction, and may include, for example, a portion extending from the middle or end of the extending portion 32b.

[0023] The second element 40 is a linear conductor extending from a second connection end 49, which is an end electrically connected to the power supply unit 21, to a second open end 45, which is an end opposite to the second connection end 49. The second element 40 includes a third portion 43 extending in a first direction (in this example, the positive Y-axis direction).

[0024] In the example shown in Figure 1, the third portion 43 is a linear element that has a fifth end (second connection end 49) connected to the power supply portion 21 via the first connection element 61 and a sixth end (second open end 45) opposite the fifth end, and extends linearly from the fifth end to the sixth end.

[0025] The second element 40 may further include a portion extending in a direction different from the first direction, for example, a portion extending from the middle or end of the third portion 43.

[0026] The third element 50 is a linear conductor extending from a third connection end 59, which is an end electrically connected to the power supply unit 21, to a third open end 55, which is an end opposite to the third connection end 59. The third element 50 includes a fourth portion 54 extending in the first direction (in this example, the positive Y-axis direction).

[0027] In the example shown in Figure 1, the fourth portion 54 is a linear element that has a seventh end (third connection end 59) connected to the power supply portion 21 via the first connection element 61 and the second connection element 62, and an eighth end (third open end 55) opposite the seventh end, and extends linearly from the seventh end to the eighth end.

[0028] The third element 50 may further include a portion extending in a direction different from the first direction, for example, a portion extending from the middle or end of the fourth portion 54.

[0029] 1, the first element 30, the second element 40, and the third element 50 are arranged in the order of the first element 30, the second element 40, and the third element 50 in a third direction (in this example, the positive X-axis direction) that is different from the first and second directions. In the example shown in FIG. 1, the first portion 31, the third portion 43, and the fourth portion 54 are arranged in the order of the first portion 31, the third portion 43, and the fourth portion 54 in the positive X-axis direction.

[0030] As described above, antenna 20A includes multiple elements (first element 30, second element 40, and third element 50), which makes it easy to tune antenna 20A so that it resonates in both the UHF and VHF bands. Furthermore, first element 30 includes first portion 31 extending in a first direction and second portion 32 folding back from first portion 31 and extending in a second direction opposite to the first direction, which makes it even easier to tune antenna 20A so that it resonates in both the UHF and VHF bands. Furthermore, first element 30, second element 40, and third element 50 are electrically connected to a single power supply 21, which makes it possible for antenna 20A to receive radio waves in both the UHF and VHF bands with a relatively simple configuration.

[0031] When the third direction (in this example, the positive X-axis direction) is approximately perpendicular to the first direction (in this example, the positive Y-axis direction), it is easier to tune antenna 20A so that it resonates in both the UHF band and the VHF band, compared to a configuration in which the third direction is not perpendicular to the first direction.

[0032] When the glass plate 10 is attached to the window frame 210 of a vehicle, if the first direction and the second direction are approximately parallel to a direction perpendicular to a horizontal plane (vertical direction), the receiving sensitivity (antenna gain) of the antenna 20A for vertically polarized waves is improved. This is because the extending directions of the first portion 31, the extending portions 32b of the second portion 32, the third portion 43, and the fourth portion 54 can be made closer to the vertical direction.

[0033] Alternatively, if the first direction and the second direction are approximately parallel to a direction parallel to a horizontal plane (horizontal direction) when the glass plate 10 is attached to the window frame 210 of a vehicle, the reception sensitivity (antenna gain) of the antenna 20A for horizontally polarized waves is improved. This is because the extending directions of the first portion 31, the extending portions 32b of the second portion 32, the third portion 43, and the fourth portion 54 can be made closer to the horizontal direction.

[0034] Here, the path length from the power supply unit 21 to the first open end 35 via the first section 31 and the second section 32 is defined as L1, the path length from the power supply unit 21 to the second open end 45 via the third section 43 is defined as L2, and the path length from the power supply unit 21 to the third open end 55 via the fourth section 54 is defined as L3.

[0035] When path length L1 is shorter than path length L3, the resonant frequency of antenna 20A in the third frequency band F3 in the VHF band can be easily tuned by adjusting L3, and the resonant frequency of antenna 20A in the first frequency band F1 in the UHF band can be easily tuned by adjusting L1. Furthermore, when path length L2 is shorter than path length L3, the resonant frequency of antenna 20A in the third frequency band F3 in the VHF band can be easily tuned by adjusting L3, and the resonant frequency of antenna 20A in the second frequency band F2 in the VHF band can be easily tuned by adjusting L2.

[0036] In the example shown in FIG. 1 , the antenna 20A has both a first connection element 61 and a second connection element 62. In this example, the first connection element 61 is a linear element that electrically connects the second connection end 49 of the second element 40 to the power supply unit 21, and the second connection element 62 is a linear element that electrically connects the third connection end 59 of the third element 50 to the power supply unit 21. The second connection element 62 may be an element that connects the third element 50 to the second element 40, or may connect the third connection end 59 of the third element 50 to the second connection end 49 of the second element 40, as shown in FIG. 1 . In this example, the third connection end 59 is electrically connected to the power supply unit 21 via the second connection element 62 and the first connection element 61.

[0037] If at least one of the first connection element 61 and the second connection element 62 has a portion extending in the third direction (in this example, the positive X-axis direction), it is possible to ensure a certain degree of spacing between the first portion 31, the third portion 43, and the fourth portion 54. This makes it possible to prevent the tuning of the resonance frequencies by the first element 30, the second element 40, and the third element 50 from affecting each other. In the example shown in FIG. 1 , the first connection element 61 extends in the third direction from the power supply portion 21 to the second connection end 49, and the second connection element 62 extends in the third direction from the second connection end 49 to the third connection end 59.

[0038] When the distance W1 between the fourth portion 54 and the portion of the first portion 31, the second portion 32, or the third portion 43 that is closest to the fourth portion 54 is 5 mm or more and 200 mm or less, the antenna gain of the antenna 20A in the third frequency band F3 (for example, the band of FM broadcast waves) is improved. In the example shown in FIG. 1, the distance W1 corresponds to the shortest distance between the third portion 43 and the fourth portion 54.

[0039] If the distance W1 is less than 5 mm, the capacitive coupling between the fourth portion 54 and the portion closest to the fourth portion 54 becomes strong, which tends to reduce the antenna gain of the antenna 20A in the third frequency band F3. On the other hand, if the distance W1 exceeds 200 mm, it becomes difficult to miniaturize the antenna 20A. In order to improve the antenna gain of the antenna 20A in the third frequency band F3, the distance W1 is preferably 10 mm or more, more preferably 15 mm or more, and even more preferably 20 mm or more. Furthermore, in order to achieve a miniaturized antenna 20A, the distance W1 is preferably 150 mm or less, more preferably 100 mm or less, and even more preferably 50 mm or less.

[0040] When the distance W2 between the extension portion 32b of the second portion 32 in the second direction (in this example, the negative Y-axis direction) and the first portion 31 is 1 mm or more and 30 mm or less, the antenna gain in the first frequency band F1 (e.g., the band of terrestrial digital television broadcast waves) is improved.

[0041] If the spacing W2 is less than 1 mm, it becomes difficult to form the first element 30. If the spacing W2 exceeds 30 mm, the antenna gain for the first frequency band F1 is likely to decrease. To facilitate the formation of the first element 30, the spacing W2 is preferably 2 mm or more, and more preferably 3 mm or more. Furthermore, in terms of ensuring the antenna gain for the first frequency band F1, the spacing W2 is preferably 25 mm or less, more preferably 20 mm or less, even more preferably 15 mm or less, and particularly preferably 10 mm or less.

[0042] The length of the first portion 31 is D1, the wavelength in the air of radio waves in the second frequency band F2 is λ2, and the wavelength shortening rate of the glass plate 10 is k. In the example shown in FIG. 1, the length D1 corresponds to the path length from the first end (first connection end 39) connected to the power supply unit 21 to the second end to which the end of the second portion 32 is connected. In this case, D1 is 0.10×λ2×k≦D1≦0.24×λ2×k...Equation 1a If formula 1a is satisfied, tuning of the resonant frequency in the first frequency band F1 can be easily performed. This is because, when D1 is adjusted within a range that satisfies formula 1a, the change in the resonant frequency in the first frequency band F1 is large, whereas the change in the resonant frequency in the second frequency band F2 is small.

[0043] D1 facilitates tuning of the resonant frequency in the first frequency band F1. 0.11×λ2×k≦D1≦0.23×λ2×k...Equation 1b It is preferable that the following is satisfied: 0.12×λ2×k≦D1≦0.22×λ2×k...Equation 1c It is more preferable to satisfy the following.

[0044] Also, D1 is the center wavelength in air of the radio wave of the second frequency band F2, λ 2C In this case, in order to facilitate tuning of the resonance frequency in the first frequency band F1, 0.13×λ 2C ×k≦D1≦0.20×λ 2C ×k...Formula 1d It is more preferable that 0.14×λ2C ×k≦D1≦0.19×λ 2C ×k...Formula 1e It is particularly preferable that the following is satisfied.

[0045] The central wavelength refers to the wavelength of a radio wave having the central frequency of a frequency band.

[0046] The path length from the power supply 21 to the first open end 35 via the first portion 31 and the second portion 32 is defined as L1, the wavelength in air of the radio wave of the first frequency band F1 is defined as λ1, and the wavelength shortening rate of the glass plate 10 is defined as k. In this case, L1 is expressed as follows: 0.48×λ1×k≦L1≦0.99×λ1×k...Equation 2a If formula 2a is satisfied, tuning of the resonant frequency in the first frequency band F1 can be easily performed. This is because, when L1 is adjusted within a range that satisfies formula 2a, the change in the resonant frequency in the first frequency band F1 is large, whereas the change in the resonant frequency in the second frequency band F2 is small.

[0047] L1 facilitates tuning of the resonant frequency in the first frequency band F1. 0.49×λ1×k≦L1≦0.99×λ1×k...Formula 2b It is preferable that the following is satisfied: 0.50×λ1×k≦L1≦0.99×λ1×k...Formula 2c It is more preferable to satisfy the following.

[0048] Also, L1 is the center wavelength in the air of the radio wave of the first frequency band F1, λ 1C In this case, in order to facilitate tuning of the resonance frequency in the first frequency band F1, 0.63×λ 1C ×k≦L1≦0.83×λ 1C ×k...Formula 2d It is more preferable that 0.64×λ 1C ×k≦L1≦0.82×λ 1C ×k...Formula 2e It is particularly preferable that the following is satisfied.

[0049] Let the path length from the power supply unit 21 to the second open end 45 via the third portion 43 be L2, the wavelength of the radio wave in the air in the second frequency band F2 be λ2, and the wavelength shortening rate of the glass plate 10 be k. At this time, L2 satisfies 0.17×λ2×k ≦ L2 ≦ 0.42×λ2×k ··· Equation 3a If satisfied, the resonance frequency tuning in the second frequency band F2 can be facilitated. When L2 is adjusted within the range satisfying Equation 3a, the change in the resonance frequency in the second frequency band F2 is large, while the change in the resonance frequency in the third frequency band F3 is small.

[0050] The path length L2 is preferable in terms of facilitating the resonance frequency tuning in the second frequency band F2 0.18×λ2×k ≦ L2 ≦ 0.41×λ2×k ··· Equation 3b If satisfied, it is preferable 0.19×λ2×k ≦ L2 ≦ 0.40×λ2×k ··· Equation 3c If satisfied, it is more preferable

[0051] Also, when the center wavelength of the radio wave in the second frequency band F2 in the air is λ 2C the path length L2 is preferable in terms of facilitating the resonance frequency tuning in the second frequency band F2 0.21×λ 2C ×k ≦ L2 ≦ 0.36×λ 2C ×k ··· Equation 3d If satisfied, it is even more preferable 0.22×λ 2C ×k ≦ L2 ≦ 0.35×λ 2C ×k ··· Equation 3e If satisfied, it is particularly preferable

[0052] Furthermore, when comparing the length D1 of the first portion 31 and the path length L2 from the power supply unit 21 to the second open end 45 via the third portion 43, in terms of facilitating the resonance frequency tuning in the first frequency band F1 and the second frequency band F2 D1 < L2 ··· Equation 3f If satisfied, it is sufficient D1×1.1 < L2 ··· Equation 3g It is preferable to satisfy, D1×1.2 < L2 ··· Formula 3h It is more preferable to satisfy.

[0053] If the path from the power supply unit 21 to the third open end 55 via the fourth part 54 has an L shape, the resonance frequency in the third frequency band F3 can be easily tuned. The path only needs to have an L shape. For example, the tip of the third element 50 may be bent.

[0054] Let the path length from the power supply unit 21 to the third open end 55 via the fourth part 54 be L3, the wavelength of the radio wave in the air in the third frequency band F3 be λ3, and the wavelength shortening rate of the glass plate 10 be k. At this time, L3 is 0.19×λ3×k ≤ L3 ≤ 0.44×λ3×k ··· Formula 4a When it satisfies, the resonance frequency in the third frequency band F3 can be easily tuned. Adjusting L3 within the range that satisfies Formula 4a results in a large change in the resonance frequency in the third frequency band F3, while the change in the resonance frequency in the second frequency band F2 is small.

[0055] L3 is, in terms of facilitating the tuning of the resonance frequency in the third frequency band F3, 0.21×λ3×k ≤ L3 ≤ 0.43×λ3×k ··· Formula 4b It is preferable to satisfy, 0.23×λ3×k ≤ L3 ≤ 0.41×λ3×k ··· Formula 4c It is more preferable to satisfy.

[0056] Also, when the center wavelength of the radio wave in the third frequency band F3 in the air is λ 3C In terms of facilitating the tuning of the resonance frequency in the third frequency band F3, 0.23×λ 3C ×k ≤ L3 ≤ 0.37×λ 3C ×k ··· Formula 4d It is even more preferable to satisfy, 0.25×λ 3C ×k ≤ L3 ≤ 0.35×λ 3C×k...Formula 4e It is particularly preferable that the following is satisfied.

[0057] FIG. 2 is a plan view showing an example of the configuration of a vehicle window glass equipped with an antenna according to the second embodiment. In the second embodiment, the description of the same configuration as in the above-described embodiments will be omitted by citing the above description. The window glass 102 shown in FIG. 2 includes an antenna 20B. The antenna 20B of the second embodiment has the same configuration as the antenna 20A according to the first embodiment, and therefore has the same effects as those of the antenna 20A described above. The antenna 20B according to the second embodiment differs from the antenna 20A according to the first embodiment in the order in which the first element 30, the second element 40, and the third element 50 are arranged in the third direction.

[0058] 2, the first element 30, the second element 40, and the third element 50 are arranged in the third direction (in this example, the positive X-axis direction) in the order of the second element 40, the first element 30, and the third element 50. In the example shown in FIG. 2, the first portion 31, the third portion 43, and the fourth portion 54 are arranged in the positive X-axis direction in the order of the third portion 43, the first portion 31, and the fourth portion 54.

[0059] In the example shown in FIG. 2 , the antenna 20B has both a first connection element 61 and a second connection element 62. In this example, the first connection element 61 is a linear element that electrically connects the first connection end 39 of the first element 30 to the power supply unit 21, and the second connection element 62 is a linear element that electrically connects the third connection end 59 of the third element 50 to the power supply unit 21. The second connection element 62 may be an element that connects the third element 50 to the first element 30, or may connect the third connection end 59 of the third element 50 to the first connection end 39 of the first element 30, as shown in FIG. 2 . In this example, the third connection end 59 is electrically connected to the power supply unit 21 via the second connection element 62 and the first connection element 61.

[0060] 2, the first connection element 61 extends in the third direction from the power supply portion 21 to the first connection end 39, and the second connection element 62 extends in the third direction from the first connection end 39 to the third connection end 59. In addition, in the example shown in FIG. 2, the interval W1 corresponds to the shortest distance between the first portion 31 and the fourth portion 54.

[0061] FIG. 3 is a plan view showing an example of the configuration of a vehicle window glass equipped with an antenna according to the third embodiment. In the third embodiment, the description of the same configuration as in the above-described embodiments will be omitted by citing the above description. The window glass 103 shown in FIG. 3 includes an antenna 20C. The antenna 20C according to the third embodiment has the same configuration as the antenna 20A according to the first embodiment, and therefore has the same effects as those of the antenna 20A described above. The antenna 20C according to the third embodiment differs from the antenna 20A according to the first embodiment in that it includes a branch element 70.

[0062] In FIG. 3, branch element 70 is a linear conductor branching from branch point 76 in fourth portion 54 of third element 50, and has an open end 75 at the end opposite branch point 76. Providing branch element 70 makes it easier to tune antenna 20C so that it resonates in both the UHF and VHF bands. In the example shown in FIG. 3, branch element 70 includes portion 77 extending in the third direction (in this example, the positive X-axis direction). Branch element 70 is, for example, a linear element extending linearly in the third direction from branch point 76 to open end 75.

[0063] The length of the branch element 70 is L S In the example shown in FIG. 3, the wavelength of the radio wave in the first frequency band F1 in the air is λ1, and the wavelength shortening rate of the glass plate 10 is k. S corresponds to the path length from the branch point 76 to the open end 75. In this case, L S teeth, 0.11×λ1×k≦L S ≦0.50×λ1×k...Equation 5a If the above equation is satisfied, tuning of the resonance frequency in the first frequency band F1 can be easily performed. S This is because, when the frequency is adjusted, the change in the resonant frequency in the first frequency band F1 is large, whereas the change in the resonant frequency in the second frequency band F2 is small.

[0064] L S is advantageous in that it facilitates tuning of the resonant frequency in the first frequency band F1. 0.11×λ1×k≦L S ≦0.49×λ1×k...Equation 5b It is preferable that the following is satisfied: 0.11×λ1×k≦L S ≦0.48×λ1×k...Equation 5c It is more preferable to satisfy the following.

[0065] Also, L S The central wavelength in air of the radio wave of the first frequency band F1 is λ 1C In this case, in order to facilitate tuning of the resonance frequency in the first frequency band F1, 0.14×λ 1C ×k≦L S ≦0.42×λ 1C ×k...Formula 5d It is more preferable that 0.14×λ 1C ×k≦L S ≦0.41×λ 1C ×k...Formula 5e It is particularly preferable that the following is satisfied.

[0066] The path length from the power supply unit 21 to the branch point 76 is L C In the example shown in FIG. 3, the wavelength of the radio wave in the first frequency band F1 in the air is λ1, and the wavelength shortening rate of the glass plate 10 is k. C corresponds to the path length from the power supply unit 21 to the branch point 76 via the third connection end 59. C teeth, 0.11×λ1×k≦L C ≦0.50×λ1×k...Equation 6a If the above equation is satisfied, tuning of the resonance frequency in the first frequency band F1 can be easily performed. C This is because, when the frequency is adjusted, the change in the resonant frequency in the first frequency band F1 is large, whereas the change in the resonant frequency in the second frequency band F2 is small.

[0067] L C is advantageous in that it facilitates tuning of the resonant frequency in the first frequency band F1. 0.11×λ1×k≦L C ≦0.49×λ1×k...Equation 6b It is preferable that the following is satisfied: 0.11×λ1×k≦L C ≦0.48×λ1×k...Equation 6c It is more preferable to satisfy the following.

[0068] Also, L C The central wavelength in air of the radio wave of the first frequency band F1 is λ 1C In this case, in order to facilitate tuning of the resonance frequency in the first frequency band F1, 0.14×λ 1C ×k≦L C ≦0.42×λ 1C ×k...Formula 6d It is more preferable that 0.14×λ 1C ×k≦L C ≦0.41×λ 1C ×k...Formula 6e It is particularly preferable that the following is satisfied.

[0069] By positioning the branch point 76 of the branch element 70 at a location that satisfies Equations 5a and 6a, the branch element 70 functions as a "λ / 4 stub" attached approximately k×(λ1 / 4) from the power supply unit 21. By having the branch element 70 function as a "λ / 4 stub," it is possible to suppress the appearance of high-order resonant frequencies generated by the third element 50 in the third frequency band F3, making it easier to tune the resonant frequency in the first frequency band F1.

[0070] FIG. 4 is a plan view showing an example of the configuration of a vehicle window glass equipped with an antenna according to the fourth embodiment. In the fourth embodiment, the description of the same configuration as in the above-described embodiments will be omitted by citing the above description. The window glass 104 shown in FIG. 4 includes an antenna 20D. The antenna 20D according to the fourth embodiment has the same configuration as the antenna 20A according to the first embodiment, and therefore has the same effects as those of the antenna 20A described above. The antenna 20D according to the fourth embodiment differs from the antenna 20A according to the first embodiment in that it includes a branch element 80.

[0071] In Fig. 4, branch element 80 is a linear conductor branching from branch point 86 in second connection element 62, and has an open end 85 at the end opposite branch point 86. Providing branch element 80 makes it easier to tune antenna 20D so that it resonates in both the UHF and VHF bands. In the example shown in Fig. 4, branch element 80 includes portion 87 extending in a third direction (in this example, the positive X-axis direction). Branch element 80 is, for example, a linear element that extends from branch point 86 via portions 88 and 87 to open end 85, bending in an L shape.

[0072] The length of the branch element 80 is L S In the example shown in FIG. 4, the wavelength of the radio wave in the first frequency band F1 in the air is λ1, and the wavelength shortening rate of the glass plate 10 is k. S corresponds to the path length from the branch point 86 to the open end 85. In this case, L S As in the third embodiment, satisfying the above formula 5a, preferably formula 5b, more preferably formula 5c, even more preferably formula 5d, and particularly preferably formula 5e, makes it easy to tune the resonant frequency in the first frequency band F1.

[0073] The path length from the power supply unit 21 to the branch point 86 is L C In the example shown in FIG. 4, the wavelength of the radio wave in the first frequency band F1 in the air is λ1, and the wavelength shortening rate of the glass plate 10 is k. Ccorresponds to the path length from the power supply unit 21 to the branch point 86 via the second connection end 49. C As in the third embodiment, satisfying the above formula 6a, preferably formula 6b, more preferably formula 6c, even more preferably formula 6d, and particularly preferably formula 6e, makes it possible to easily tune the resonant frequency in the first frequency band F1.

[0074] The branch element 80 may function as a "λ / 4 stub" as in the third embodiment. Furthermore, the branch element 80 has a portion that is capacitively coupled to the flange (window frame 210), thereby improving its function as a "λ / 4 stub" and increasing the antenna gain. In the example shown in FIG. 4, it is preferable that the portion 87 is capacitively coupled to the flange. The distance at which the branch element 80 and the flange are capacitively coupled may be 150 mm or less, preferably 100 mm or less, and more preferably 50 mm or less. The lower limit of this distance may be greater than 0 mm.

[0075] FIG. 5 is a plan view showing an example of the configuration of a vehicle window glass equipped with an antenna according to the fifth embodiment. In the fifth embodiment, the description of the same configuration as in the above-described embodiments will be omitted by citing the above description. The window glass 105 shown in FIG. 5 includes an antenna 20E. The antenna 20E of the fifth embodiment has the same configuration as the antenna 20A according to the first embodiment, and therefore has the same effects as those of the antenna 20A described above. The antenna 20E according to the fifth embodiment differs from the antenna 20A according to the first embodiment in that it has a first connection element 61 but does not have a second connection element 62.

[0076] 5, the first connecting element 61 is a linear element that electrically connects the first connecting end 39 of the first element 30 to the power supply portion 21. The first connecting element 61 may also be an element that connects the first element 30 to the second element 40.

[0077] FIG. 6 is a plan view showing an example of the configuration of a vehicle window glass equipped with an antenna according to the sixth embodiment. In the sixth embodiment, the description of the same configuration as in the above-described embodiments will be omitted by citing the above description. The window glass 106 shown in FIG. 6 includes an antenna 20F. The antenna 20F according to the sixth embodiment has the same configuration as the antenna 20A according to the first embodiment, and therefore has the same effects as those of the antenna 20A described above. The antenna 20F according to the sixth embodiment differs from the antenna 20A according to the first embodiment in that it has a second connection element 62 but does not have a first connection element 61.

[0078] 6, the second connecting element 62 is a linear element that electrically connects the third connecting end 59 of the third element 50 to the power supply unit 21. The second connecting element 62 may be an element that connects the third element 50 to the second element 40.

[0079] Fig. 7 is a plan view showing an example of a window glass mounting structure in which a vehicle window glass equipped with an antenna according to the third embodiment is mounted on a window frame of a vehicle. Fig. 7 shows an antenna 20C according to the third embodiment, but the explanation of Fig. 7 can also be applied to antennas according to the other embodiments. Fig. 7 is a view showing a window glass 103 mounted on a window frame 210 formed in a vehicle body 200 as viewed from inside the vehicle.

[0080] The vehicle window glass according to this embodiment is particularly suitable for use in a window glass (for example, a side window) that is installed substantially parallel to a vertical direction perpendicular to a horizontal plane, because it improves the receiving sensitivity (antenna gain) of both vertically polarized waves and horizontally polarized waves. Fig. 7 illustrates an example in which the window glass 103 is used in a side window. The glass plate 10 is an example of a glass plate for a side window.

[0081] The window frame 210 has frame sides 211a, 211b, 211c, and 211d to form an opening that is covered by the glass pane 10. The glass pane 10 has an outer peripheral edge 12 that includes glass bezels 12a, 12b, 12c, and 12d. The glass bezels 12a, 12b, 12c, and 12d are attached to the corresponding frame sides 211a, 211b, 211c, and 211d, respectively. When the window glass 103 attached to the window frame 210 is viewed from inside the vehicle, the glass bezels 12a, 12b, 12c, and 12d are hidden by the vehicle body 200 or the window frame 210, but are shown by solid lines in FIG. 7 for convenience.

[0082] The window frame 210 includes a corner 13 between frame sides 211a and 211c. When the power supply unit 21 is provided in a region 14 adjacent to the corner 13, an element extending from the power supply unit 21 is positioned close to at least one of the frame sides 211a and 211c when the glass plate 10 is attached to the window frame 210. This allows the element extending from the power supply unit 21 to be capacitively coupled to at least one of the frame sides 211a and 211c, thereby improving the reception sensitivity (antenna gain of the antenna 20C) of vertically polarized waves or horizontally polarized waves. The distance over which the element extending from the power supply unit 21 is capacitively coupled to the frame sides 211a and 211c is, for example, greater than 0 mm and not greater than 150 mm. The distance is preferably greater than 0 mm and not greater than 100 mm, and more preferably greater than 0 mm and not greater than 50 mm.

[0083] For example, in FIG. 7, if the Y-axis direction is approximately parallel to the vertical direction, the vicinity region 14 is the vicinity region of the lower left corner 13 of the glass plate 10. The first element 30, which extends approximately parallel to the vertical direction, is close to the frame side 211c, which is also approximately parallel to the vertical direction. This improves the reception sensitivity of horizontally polarized waves in the first frequency band F1 (for example, horizontally polarized terrestrial digital television broadcast waves). On the other hand, the second element 40 and the third element 50, which extend approximately parallel to the vertical direction, are farther from the frame side 211c than the first element 30. This improves the reception sensitivity of vertically polarized waves in the second frequency band F2 (for example, vertically polarized DAB Band III broadcast waves).

[0084] The outer edge of the vicinity region 14 includes a corner 13, a portion of a frame side 211a connected to the corner 13, a portion of a frame side 211c connected to the corner 13, an imaginary side 14b facing the portion of the frame side 211a, and an imaginary side 14d facing the portion of the frame side 211c. The frame side 211a is an example of a first side of a window frame to which a glass plate is attached, and the glass bezel 12c is an example of a second side of a window frame to which a glass plate is attached.

[0085] For example, let S be the area of ​​the opening surrounded by the frame side 211 (in the case of FIG. 7, the area inside the solid line representing the frame side 211), and let S be the area of ​​the neighborhood region 14. R In this case, the area S R teeth, (1 / 100)×S≦S R ≦(1 / 9)×S...Equation 7a It is good to satisfy the following.

[0086] Although the vicinity region 14 is the vicinity region of the lower left corner 13 of the glass plate 10 in FIG. 7, it may be the vicinity region of another corner of the glass plate 10.

[0087] Fig. 8 is a diagram showing an example of the reflection coefficient S11 of the antenna 20C (Fig. 3) of the third embodiment in the bands of terrestrial digital television broadcast waves, DAB Band III, and FM broadcast waves. The reflection coefficient S11 shown in Fig. 8 is a measurement result of an actual vehicle when the window glass 103 equipped with the antenna 20C is applied to the side glass shown in Fig. 7. The surface of the side glass was installed so as to be approximately parallel to the vertical direction perpendicular to the horizontal plane.

[0088] In Figure 8, "FM" represents an antenna in which the first element 30, the second element 40, and the branch element 70 have been deleted from the antenna 20C (Figure 3). "DAB+DTV" represents an antenna in which the third element 50 and the branch element 70 have been deleted from the antenna 20C (Figure 3). "FM+DAB+DTV" represents the antenna 20C (Figure 3). As shown in Figure 8, with the antenna 20C (Figure 3), resonance results were obtained in three frequency bands: terrestrial digital television broadcast waves, DAB Band III, and FM broadcast waves.

[0089] The conditions for the measurements in Figure 8, such as the dimensions of each part (Figure 3), are as follows: W1:30mm W2:5mm D1: 160mm L1: 260mm L2: 270mm L3: 605mm L S :60mm L C :60mm In this case, λ 1C ≒508mm, λ 2C ≒1448mm, λ 3C ≒3259 mm and k=0.67, so D1≒0.165×k×λ 2C and L1 ≒ 0.764 × k × λ 1C and L2≒0.278×k×λ 2C and L3 ≒ 0.277 × k × λ 3C and L S ≒0.176×k×λ 1C and L C ≒0.176×k×λ 1C It was.

[0090] Fig. 9 is a diagram showing an example of the reflection characteristic S11 of the antenna in the band of terrestrial digital television broadcast waves when the length of the branch element 70 and the position of the branch point are changed. Fig. 10 is a diagram showing an example of the reflection characteristic S11 of the antenna in the band of DAB Band III when the length of the branch element 70 and the position of the branch point are changed. To make the function of the branch element 70 easier to understand, an antenna (hereinafter referred to as "antenna A") obtained by removing the first element 30 and the second element 40 from the antenna 20C (Fig. 3) was used for the measurements in Figs. 9 and 10. The reflection coefficient S11 shown in Figs. 9 and 10 is calculated by L S =L C While holding L S and L C The graph shows the results of measurements taken on an actual vehicle when the window glass equipped with antenna A was applied to the side glass shown in FIG. 7, with the distance varied from 50 mm to 230 mm.

[0091] According to Figure 9, L S and L C If L is 50 mm or more (corresponding to the lower limit "0.11 × λ1 × k" defined in the above formulas 5a and 6a), the result shows that resonance occurs in the frequency band of terrestrial digital television broadcast waves. S and L C If L is 140 mm or less (corresponding to the upper limit "0.50 × λ1 × k" defined in the above formulas 5a and 6a), the resonance in the DAB Band III band is suppressed. S and L C When L is adjusted, the change in the resonance frequency in the frequency band of terrestrial digital television broadcasting waves becomes large, while the change in the resonance frequency of DAB Band III becomes small. Therefore, it is possible to adjust L within the range that satisfies Equation 5a and Equation 6a. S and L C By adjusting the above, it was found that tuning of the resonance frequency in the frequency band of terrestrial digital television broadcast waves can be easily achieved.

[0092] Although the embodiments have been described above, the technology of the present disclosure is not limited to the above-described embodiments, and various modifications and improvements are possible, such as combinations with or substitutions for part or all of other embodiments.

[0093] For example, the "end" of an element may be the start or end point of the extension of the element, or the vicinity of the start or end point, which is a conductor portion just before the start or end point. Furthermore, the "end" of an element may be bent or folded back within the scope of the effects of the present invention. Furthermore, the connection between elements may be connected with a curvature.

[0094] The antenna element and electrode are formed, for example, by printing and baking a paste containing a conductive metal (e.g., silver paste) on the interior surface of the window glass. However, the method for forming the antenna element and electrode is not limited to this method. For example, the antenna element or electrode may be formed by providing a linear or foil-shaped body containing a conductive material such as copper on the interior or exterior surface of the window glass. Alternatively, the antenna element or electrode may be attached to the window glass with an adhesive or the like, or may be provided inside the window glass itself.

[0095] Alternatively, a conductor layer forming at least one of an antenna element and an electrode may be provided inside or on the surface of a synthetic resin film, and the synthetic resin film with the conductor layer may be installed on the interior or exterior surface of the window glass.Furthermore, a flexible circuit board on which at least one of an antenna element and an electrode is formed may be installed on the interior or exterior surface of the window glass.

[0096] 7, the glass plate 10 has a light-shielding film 11 along its outer peripheral edge 12, and the electrodes and antenna element may overlap partly or entirely with the light-shielding film 11 in a plan view of the glass plate 10. A specific example of the light-shielding film 11 is a ceramic film such as a black ceramic film. In this case, when the window glass is viewed from outside the vehicle, the overlapping portion with the light-shielding film 11 in a plan view is difficult to see from outside the vehicle, improving the design of the window glass. [Explanation of symbols]

[0097] 10 Glass Plate 11 Light-shielding film 12 outer edge 12a, 12b, 12c, 12d Glass rim 13 Corner 14 Neighborhood Areas 14b and 14d 20A, 20B, 20C, 20D, 20E, 20F Antenna 21 Power supply unit 30 First Element 31 Part 1 32 Part 2 32a Turning point 32b Extension part 35 1st open end 39 First connection end 40 Second Element 43 Part 3 45 2nd open end 49 Second connection end 50 Third Element 54 Part 4 55 3rd open end 59 Third connection end 61 First connecting element 62 Second connecting element 70 Branching Element 75 Open end 76 Branching Point 80 Branching Elements 85 Open end 86 Branching Point 101, 102, 103, 104, 105, 106 Window glass 200 body 210 Window Frame 211,211a,211b,211c,211d Frame side

Claims

1. A glass plate and an antenna provided on the glass plate, the antenna receiving radio waves in a first frequency band, radio waves in a second frequency band lower than the first frequency band, and radio waves in a third frequency band lower than the second frequency band; the first frequency band is a band of terrestrial digital television broadcast waves included in the UHF band, the second frequency band is a DAB Band III band included in the VHF band, the third frequency band is a band of FM broadcast waves included in the VHF band, the antenna has a power feed portion, a first element extending from a first connection end electrically connected to the power feed portion to a first open end opposite the first connection end, a second element extending from a second connection end electrically connected to the power feed portion to a second open end opposite the second connection end, and a third element extending from a third connection end electrically connected to the power feed portion to a third open end opposite the third connection end, When the glass plate is attached to a vehicle, the direction parallel to a horizontal plane is defined as the horizontal direction, and the direction perpendicular to the horizontal direction is defined as the vertical direction. the first element includes a first portion extending in a first direction substantially parallel to the vertical direction, and a second portion folding back from the first portion and extending in a second direction opposite to the first direction, the second element includes a third portion extending in the first direction; the third element includes a fourth portion extending in the first direction; the first element, the second element, and the third element are arranged in a third direction that is approximately parallel to the horizontal direction in the order of the first element, the second element, and the third element, or in the order of the second element, the first element, and the third element.

2. the antenna has at least one of a first connection element and a second connection element; the first connection element electrically connects the first element or the second element to the power supply portion; 2. The vehicle glazing according to claim 1, wherein the second connection element electrically connects the third element to the power supply.

3. 3. The vehicle window glass according to claim 2, wherein at least one of the first connecting element and the second connecting element has a portion extending in the third direction.

4. 4. The vehicle window glass according to claim 1, wherein a distance between the fourth portion and a portion of the first portion, the second portion, and the third portion that is closest to the fourth portion is 5 mm or more and 200 mm or less.

5. The vehicle window glass according to claim 1 , wherein a distance between the first portion and an extending portion of the second portion in the second direction is equal to or greater than 1 mm and equal to or less than 30 mm.

6. The length of the first portion is D １ , the wavelength in air of the radio wave of the second frequency band is λ ２ , where k is the wavelength shortening rate of the glass plate, D １ teeth, 0.10×λ ２ ×k≦D １ ≦0.24×λ ２ ×k The vehicle window glass according to claim 1 , which satisfies the following:

7. The path length from the power supply portion to the first open end via the first portion and the second portion is defined as L １ , the wavelength in air of the radio wave of the first frequency band is λ １ , where k is the wavelength shortening rate of the glass plate, L １ teeth, 0.48×λ １ ×k≦L １ ≦0.99×λ １ ×k The vehicle window glass according to claim 1 , which satisfies the following:

8. The length of the first portion is D １ , the path length from the power supply portion to the second open end via the third portion is L ２ When D １ <L ２ The vehicle window glass according to any one of claims 1 to 7, which satisfies the following:

9. The path length from the power supply portion to the second open end via the third portion is defined as L ２ , the wavelength in air of the radio wave of the second frequency band is λ ２ , where k is the wavelength shortening rate of the glass plate, L ２ teeth, 0.17×λ ２ ×k≦L ２ ≦0.42×λ ２ ×k The vehicle window glass according to any one of claims 1 to 8, which satisfies the following:

10. The vehicle window glass according to claim 1 , wherein a path from the power supply portion to the third open end via the fourth portion has an L-shape.

11. The path length from the power supply portion to the third open end via the fourth portion is defined as L ３ , where the wavelength of the radio wave in the third frequency band in the air is λ3 and the wavelength shortening rate of the glass plate is k, L ３ teeth, 0.19×λ3×k≦L ３ ≦0.44×λ3×k The vehicle window glass according to any one of claims 1 to 10, which satisfies the following:

12. The vehicle window glass according to claim 1 , wherein the antenna includes a branch element that branches from a branch point in the third element and has an open end.

13. The antenna is a second connection element that electrically connects the third element to the power supply; The vehicle window glass according to any one of claims 1 to 11, further comprising: a branch element branching from a branch point in the second connecting element and having an open end.

14. The vehicle window glass according to claim 12 or 13, wherein the branch element includes a portion extending in the third direction.

15. The length of the branch element is L Ｓ , the wavelength in air of the radio wave of the first frequency band is λ １ , where k is the wavelength shortening rate of the glass plate, L Ｓ teeth, 0.11×λ １ ×k≦L Ｓ ≦0.50×λ １ ×k、 The vehicle window glass according to any one of claims 12 to 14, which satisfies the following:

16. The path length from the power supply unit to the branch point is L Ｃ , the wavelength in air of the radio wave of the first frequency band is λ １ , where k is the wavelength shortening rate of the glass plate, L Ｃ teeth, 0.11×λ １ ×k≦L Ｃ ≦0.50×λ １ ×k The vehicle window glass according to any one of claims 12 to 15, which satisfies the following:

17. The vehicle window glass according to claim 1 , wherein the third direction is substantially perpendicular to the first direction.

18. The vehicle window glass according to claim 1 , wherein the power supply unit is provided so as to be located in the vicinity of a corner of a window frame to which the glass plate is attached.

19. The vehicle window glass according to any one of claims 1 to 18, wherein the glass plate is for a side glass.

20. the first element, the second element, and the third element are arranged in the third direction in the order of the first element, the second element, and the third element, The second portion is a direction change portion extending from the first portion in a fourth direction opposite to the third direction; The vehicle window glass according to claim 1 , further comprising: an extension portion extending in the second direction from the direction change portion.

21. The path length from the power supply portion to the first open end via the first portion and the second portion is defined as L １ , the path length from the power supply portion to the third open end via the fourth portion is L ３ When L １ Is L ３ 21. A vehicle glazing according to any one of claims 1 to 20, wherein said glazing is shorter than

22. The path length from the power supply portion to the second open end via the third portion is defined as L ２ When L ２ Is L ３ 22. A vehicle glazing according to claim 21, wherein said glazing is shorter than

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