JP7563143B2 - Vehicle window glass device - Google Patents

Description

This disclosure relates to a vehicle window glass device.

Conventionally, a vehicle window glass is known that includes a conductive member that heats the glass sheet by applying a voltage to a pair of bus bars to prevent fogging or icing, and an antenna provided near the heating area where the conductive member is arranged (see, for example, Patent Documents 1 and 2).

International Publication No. 2016/185898 International Publication No. 2016/096432

However, in window glass having a heated area in which a conductive member for anti-fogging etc. is arranged, depending on the size of the heated area, the area in which the antenna element is arranged may become narrow, and the design freedom of the arrangement position and shape of the antenna element may decrease. In such cases, it is difficult to make an antenna element capable of securing antenna gain in a specified frequency band coexist with the heated area.

This disclosure provides a vehicle window glass device that allows an antenna element capable of ensuring antenna gain in a specified frequency band to coexist with a heating area.

The present disclosure relates to
Glass panels for vehicles;
a first bus bar provided on the glass plate and including an upper portion extending in a direction along an upper edge of the glass plate;
a second bus bar provided on the glass plate and including a lower portion extending in a direction along a lower edge of the glass plate;
an antenna element provided on the glass plate and including a power supply portion adjacent to the first bus bar;
the glass sheet having a heating region extending between the upper and lower portions;
the heating region is a region in which a conductive member through which a direct current flows in a vertical direction when a direct current voltage is applied between the first bus bar and the second bus bar by a power source, and the heating region is heated by heat generated by the conductive member;
The wavelength in air of the radio wave of the predetermined frequency band received by the antenna element is λ,
The wavelength shortening rate of the glass plate in the predetermined frequency band is k,
N ₁ is an integer of 1 or more,
_N2 is an integer of 1 or more;
A length of a first path from the power supply portion through the first bus bar to a first high-frequency termination on the power source side is defined as _D1 ,
A length of a second path, which is different from the first path and extends from the power supply portion through the heating region in a vertical direction, through the second bus bar, and to a second high frequency termination on the side of the power source, is denoted as _D2 ;
the first high-frequency termination is a position where a high-frequency current becomes zero and where an antinode position of a standing wave generated along the first path coincides with the power supply portion,
the second high-frequency termination is a position where a high-frequency current becomes zero and where an antinode position of a standing wave generated along the second path coincides with the power supply portion,
The lengths _D1 and _D2 are
(λ/4-λ/ 9 )×(2× _N1-1 )×k≦ _D1 ≦(λ/4+λ/ 9 )×(2× _N1-1 )×k,
A vehicle window glass device is provided that satisfies at least one of the following conditions: (λ/4−λ/ 9 )×(2×N ₂ −1)×k≦D ₂ ≦(λ/4+λ/ 9 )×(2×N ₂ −1)×k.

This disclosure provides a vehicle window glass device that allows an antenna element capable of ensuring antenna gain in a specified frequency band to coexist with a heating area.

1 is a diagram showing a configuration example of a vehicle window glass device in an embodiment in a plan view of a window glass. 1 is a diagram showing a configuration example (modification) of a vehicle window glass device in an embodiment in a plan view of a window glass. FIG. 1 is a cross-sectional view showing an upper portion of a first structural example of a vehicle window glass device according to an embodiment. 1 is a cross-sectional view showing an upper portion of a first structural example (first modified example) of a vehicle window glass device according to an embodiment. 4 is a cross-sectional view showing an upper portion of a first structural example (second modified example) of a vehicle window glass device in one embodiment. FIG. FIG. 4 is a cross-sectional view showing an upper portion of a second structural example of a vehicle window glass device according to an embodiment. FIG. 11 is a diagram showing an example of a result of actually measuring a change in antenna gain caused by adjustment of lengths D ₁ and D ₂ in a vehicle window glass device according to an embodiment. FIG. 4 is a diagram showing an example of a result of actually measuring a change in antenna gain depending on the presence or absence of a stub in a vehicle window glass device according to an embodiment.

Hereinafter, an embodiment according to the present disclosure will be described with reference to the drawings. For ease of understanding, the scale of each component in the drawings may differ from the actual scale. In directions such as parallel, right angle, orthogonal, horizontal, vertical, up/down, left/right, deviations that do not impair the effect of the embodiment are permitted. The shape of the corners is not limited to right angles, and may be rounded in a bow shape. The X-axis direction, the Y-axis direction, and the Z-axis direction respectively represent directions parallel to the X-axis, the Y-axis, and the Z-axis. The X-axis direction, the Y-axis direction, and the Z-axis direction are mutually perpendicular. The XY plane, the YZ plane, and the ZX plane respectively represent imaginary planes parallel to the X-axis direction and the Y-axis direction, imaginary planes parallel to the Y-axis direction and the Z-axis direction, and imaginary planes parallel to the Z-axis direction and the X-axis direction. "Facing" is not limited to a form in which the entirety faces each other, and may include a form in which a part faces each other.

In this embodiment, the X-axis, Y-axis, and Z-axis directions respectively represent the left-right direction (horizontal direction) of the glass plate, the up-down direction (vertical direction) of the glass plate, and the direction perpendicular to the surface of the glass plate (also called the normal direction).

A suitable example of a vehicle window glass in this embodiment is a windshield that is attached to the front of a vehicle.

Figure 1 is a diagram showing a configuration example of a vehicle window glass device in one embodiment in a plan view of the window glass. The vehicle window glass device 300 shown in Figure 1 includes a window glass 100 that is attached to a window frame 66 formed on a vehicle body. Figure 1 is a plan view showing the window glass 100 attached to the window frame 66 as viewed from inside the vehicle. The window glass 100 illustrated in Figure 1 is a windshield that is attached to the window frame 66 formed in the front part of the vehicle body.

The window frame 66 has an upper frame 66a, a lower frame 66b, a left frame 66c, and a right frame 66d to form an opening covered by the window glass 100. The upper frame 66a is a window frame part that extends in the X-axis direction on the positive side of the Y-axis direction relative to the opening, and is, for example, a flange on the ceiling side of the vehicle body. The lower frame 66b is a window frame part that extends in the X-axis direction on the negative side of the Y-axis direction relative to the opening, and is, for example, a flange on the dash panel side of the vehicle body. The left frame 66c is a window frame part that extends in the Y-axis direction on the negative side of the X-axis direction relative to the opening, and is, for example, a flange on the A-pillar on the front left side of the vehicle body. The right frame 66d is a window frame part that extends in the Y-axis direction on the positive side of the X-axis direction relative to the opening, and is, for example, a flange on the A-pillar on the front right side of the vehicle body.

The window glass 100 comprises a glass plate 1, a first bus bar 3, a second bus bar 4, and an antenna element 30.

The glass plate 1 is an example of a glass plate for a vehicle. The glass plate 1 is a transparent or semi-transparent plate-shaped dielectric material attached to the window frame 66. The glass plate 1 has an outer periphery including an upper edge 1a, a lower edge 1b, a left edge 1c, and a right edge 1d. The upper edge 1a is a glass edge extending in the X-axis direction on the positive side of the Y-axis direction, and is attached to the upper frame 66a. The lower edge 1b is a glass edge extending in the X-axis direction on the negative side of the Y-axis direction, and is attached to the lower frame 66b. The left edge 1c is a glass edge extending in the Y-axis direction on the negative side of the X-axis direction, and is attached to the left frame 66c. The right edge 1d is a glass edge extending in the Y-axis direction on the positive side of the X-axis direction, and is attached to the right frame 66d.

The glass plate 1 has a principal surface 22 and a principal surface 12 on the opposite side of the principal surface 22 in the Z-axis direction. The principal surface 22 is the surface on the positive side in the Z-axis direction (inside the vehicle in this example), and the principal surface 12 is the surface on the negative side in the Z-axis direction (outside the vehicle in this example).

The first busbar 3 is a strip-shaped electrode provided on the glass plate 1. The first busbar 3 includes upper portions 71, 79 that extend in a direction along the upper edge 1a of the glass plate 1 (e.g., in a substantially horizontal direction). The first busbar 3 is conductively connected to one electrode terminal (e.g., the negative terminal 402) of the power source 400 mounted on the vehicle.

The second busbar 4 is a strip-shaped electrode provided on the glass plate 1. The second busbar 4 includes lower portions 72, 70 that extend in a direction along the lower edge 1b of the glass plate 1 (e.g., in a substantially horizontal direction). The second busbar 4 is conductively connected to the other electrode terminal (e.g., the positive terminal 401) of the power source 400 mounted on the vehicle.

The first bus bar 3 may be conductively connected to the positive terminal 401 of the power source 400, and the second bus bar 4 may be conductively connected to the negative terminal 402 of the power source 400.

The glass plate 1 has a heating region 2 extending between the upper portions 71, 79 and the lower portions 72, 70. The heating region 2 is an area in which a conductive member 26 is disposed, and is heated by the heat generated by the conductive member 26. The heating region 2 has vertical sides 6a, 6b, which are a pair of sides facing each other in the X-axis direction.

The conductive member 26 is provided on the glass plate 1 and is located between the upper portions 71, 79 and the lower portions 72, 70. The conductive member 26 is a member through which a direct current flows vertically between the upper portions 71, 79 and the lower portions 72, 70 when a direct current voltage is applied between the first bus bar 3 and the second bus bar 4 by the power source 400, and generates heat when the direct current flows vertically. The heating area 2 is heated by the heat generated by the conductive member 26 that electrically connects the upper portions 71, 79 and the lower portions 72, 70. By heating the heating area 2, it is possible to melt snow, melt ice, and prevent fogging in the heating area 2 and its neighboring areas on the glass plate 1.

The conductive member 26 is, for example, as seen in an enlarged view in FIG. 1, a plurality of heating wires extending in the Y-axis direction and spaced apart in the X-axis direction. The plurality of heating wires are, for example, wavy linear conductors extending from the first bus bar 3 toward the second bus bar 4. The heating wires are formed, for example, from copper, aluminum, chromium, molybdenum, nickel, titanium, palladium, indium, tungsten, gold, platinum, silver, or an alloy containing a plurality of any of these metals.

The conductive member 26 may be a transparent or semi-transparent conductive film placed on the inner layer or surface of the glass plate 1, a heating wire placed on the inner layer or surface of the glass plate 1, or a silver-based print formed on the surface of the glass plate 1.

When the conductive member 26 is a conductive film, antimony-doped tin oxide, bismuth-doped tin oxide, fluorine-doped tin oxide, or the like can be used as the material for the conductive film.

The conductive member 26 may be disposed on the inner layer or outer surface of the glass plate 1. The conductive member 26 is disposed on the same layer (inner layer or outer surface) as the first bus bar 3 and the second bus bar 4. However, the conductive member 26 may be disposed on a layer different from at least one of the first bus bar 3 and the second bus bar 4, as long as electrical connection with the first bus bar 3 and the second bus bar 4 is ensured via the auxiliary member.

The heating area 2 in which the conductive member 26 is arranged may be separated into a plurality of heating areas aligned in the X-axis direction. In the example shown in FIG. 1, the heating area 2 includes a first heating area 2a and a second heating area 2b aligned in the X-axis direction with a gap 9 extending in the Y-axis direction as a longitudinal direction. The first heating area 2a has upper edges 6e and 6f conductively connected to the upper portion 71, a lower edge 6g conductively connected to the lower portion 72, and a pair of vertical edges 6a and 6c opposed to each other in the X-axis direction. The second heating area 2b has an upper edge 6h conductively connected to the upper portion 79, a lower edge 6i conductively connected to the lower portion 70, and a pair of vertical edges 6b and 6d opposed to each other in the X-axis direction.

In the example shown in FIG. 1, the heating area 2 is divided into a plurality of heating areas, and therefore the first busbar 3 and the second busbar 4 are also divided. The first busbar 3 includes a first upper busbar 3a and a second upper busbar 3b, and the second busbar 4 includes a first lower busbar 4a and a second lower busbar 4b.

The first busbar 3 may further include vertical portions connected to the upper portions 71 and 79. In the first busbar 3 shown in FIG. 1, the first upper busbar 3a includes a vertical portion 73 connected to the upper portion 71, and the second upper busbar 3b includes a vertical portion 76 connected to the upper portion 79. The upper portion 71 is a conductor portion connected to the upper edges 6e and 6f of the first heating area 2a, and the vertical portion 73 is a conductor portion that extends away from the vertical side 6a, which is one side edge of the first heating area 2a, in a direction along the left edge 1c, which is one side edge of the glass sheet 1. The upper portion 79 is a conductor portion connected to the upper edge of the second heating area 2b, and the vertical portion 76 is a conductor portion that extends away from the vertical side 6b, which is one side edge of the second heating area 2b, in a direction along the right edge 1d, which is the other side edge of the glass sheet 1.

Since the first bus bar 3 includes vertical portions 73 and 76 that are connected to the upper portions 71 and 79, respectively, a portion of the wiring line that electrically connects the upper portions 71 and 79 of the first bus bar 3 to the power source 400 can be provided on the glass plate 1 side, rather than on the vehicle body side. This allows the harness wired on the vehicle body side to be reduced.

As shown in FIG. 1, the first bus bar 3 may further include a horizontal portion 74 connected to the vertical portion 73, and may further include a horizontal portion 77 connected to the vertical portion 76. The horizontal portion 74 is a conductive portion that extends in a direction along the lower edge 1b of the glass sheet 1 in a region away from the first heating region 2a. The horizontal portion 77 is a conductive portion that extends in a direction along the lower edge 1b of the glass sheet 1 in a region away from the second heating region 2b. The presence of the horizontal portion 74 or the horizontal portion 77 can further reduce the harness depending on the position of the terminal of the harness to be wired to the vehicle body side.

In the example shown in FIG. 1, the glass plate 1 has a number of electrodes 51, 52, 55, and 56 to which terminals of a number of harnesses electrically connected to a power source 400 are electrically connected.

The electrode 51 is a negative electrode for electrically connecting the terminal of the ground harness 53, which is electrically connected to the negative terminal 402, to the first upper bus bar 3a. The electrode 51 is electrically connected to the upper portion 71 via the horizontal portion 74 and the vertical portion 73.

The electrode 52 is a negative electrode for electrically connecting the terminal of the ground harness 54, which is electrically connected to the negative terminal 402, to the second upper bus bar 3b. The electrode 52 is electrically connected to the upper portion 79 via the horizontal portion 77 and the vertical portion 76.

The electrode 55 is a positive electrode for electrically connecting the terminal of the power harness 57, which is electrically connected to the positive terminal 401, to the first lower bus bar 4a. The first lower bus bar 4a has a connection bus bar 75 that is connected to the lower portion 72. The electrode 55 is electrically connected to the lower portion 72 via the connection bus bar 75.

The electrode 56 is a positive electrode for electrically connecting the terminal of the power harness 58, which is electrically connected to the positive terminal 401, to the second lower bus bar 4b. The second lower bus bar 4b has a connection bus bar 78 that is connected to the lower portion 70. The electrode 56 is electrically connected to the lower portion 70 via the connection bus bar 78.

The antenna element 30 is provided on the glass plate 1 and includes a power supply portion 35 adjacent to the first bus bar 3. The antenna element 30 is an antenna that ensures its antenna gain by picking up the current flowing along the first bus bar 3 with the power supply portion 35. In the example shown in FIG. 1, the power supply portion 35 is adjacent to the upper portion 71 of the first bus bar 3. The antenna element 30 is formed to be able to receive radio waves in a predetermined frequency band W, and resonates at a frequency in the predetermined frequency band W. The antenna element 30 may be a radiating element that receives vertically polarized waves, or a radiating element that receives horizontally polarized waves. The antenna element 30 is suitable for transmitting and receiving radio waves in the VHF (Very High Frequency) band, for example, with a frequency of 30 MHz to 300 MHz. Radio waves in the VHF band include radio waves in the DAB (Digital Audio Broadcast) Band III band (170 MHz to 240 MHz), FM broadcast waves, and the like.

Here, the wavelength in air of radio waves of a predetermined frequency band W received by the antenna element 30 is λ, the wavelength shortening rate of the glass plate 1 of the predetermined frequency band W is k, _N1 is an integer equal to or greater than 1, and _N2 is an integer equal to or greater than 1. Also, the length of a first path from the power supply 35 along at least a part of the first bus bar 3 to a first high-frequency terminal on the side of the power source 400 is _D1 . Furthermore, unlike the first path, the length of a second path from the power supply 35 to a second high-frequency terminal on the side of the power source 400 along the vertical direction of the heating region 2 and along at least a part of the second bus bar 4 is _D2 . In this case, the lengths _D1 and _D2 are expressed as
(λ/4 - λ/8) x (2 x N ₁ -1) x k≦D ₁ ≦ (λ/4 + λ/8) x (2 x N ₁ -1) x k
... Formula 1a
(λ/4-λ/8)×(2×N ₂ -1)×k≦D ₂ ≦(λ/4+λ/8)×(2×N ₂ -1)×k
...Formula 2a
When at least one of the above conditions is satisfied, and preferably when both conditions are satisfied, the antenna gain of the antenna element 30 in the predetermined frequency band W can be improved. The first high-frequency termination and the second high-frequency termination are positions where the high-frequency current becomes zero. When the path length _D1 from the first high-frequency termination to the power supply unit 35 is an odd multiple of λ/4 (including a margin defined by "±λ/8 × odd multiple"), the position of the antinode of the standing wave generated along the first path almost coincides with the power supply unit 35. Similarly, when the path length _D2 from the second high-frequency termination to the power supply unit 35 is an odd multiple of λ/4 (including a margin defined by "±λ/8 × odd multiple"), the position of the antinode of the standing wave generated along the second path almost coincides with the power supply unit 35. In this way, when one or both of _D1 and _D2 satisfy the above conditional expressions, a strong current flows in the power supply unit 35 close to the first bus bar 3 or in its vicinity, so that the antenna gain of the antenna element 30 in the predetermined frequency band W can be improved. Therefore, in the vehicle window glass device 300 of this embodiment, even if the heating area 2 has a relatively large area, the antenna element 30 capable of ensuring antenna gain in the predetermined frequency band W can coexist with the heating area 2. In addition, in the formulas 1a and 2a, λ may be the wavelength in air of radio waves of some frequencies included in the predetermined frequency band W, or preferably, may be the wavelength in air of radio waves of all frequencies included in the predetermined frequency band W.

The lengths D ₁ and D ₂ are more preferably:
(λ/4-λ/9)×(2×N ₁ -1)×k≦D ₁ ≦(λ/4+λ/9)×(2×N ₁ -1)×k
Formula 1b
(λ/4-λ/9)×(2×N ₂ -1)×k≦D ₂ ≦(λ/4+λ/9)×(2×N ₂ -1)×k
...Formula 2b
When at least one of the above is satisfied, the antenna gain of the antenna element 30 in the predetermined frequency band W can be improved, and it is more preferable to satisfy both of them. In addition, in the formula 1b and the formula 2b, λ may be the wavelength in the air of radio waves of some frequencies included in the predetermined frequency band W, or preferably, may be the wavelength in the air of radio waves of all frequencies included in the predetermined frequency band W.

The lengths _D1 and _D2 are more preferably:
(λ/4 - λ/10) x (2 x N ₁ -1) x k≦D ₁ ≦ (λ/4 + λ/10) x (2 x N ₁ -1) x k
...Formula 1c
(λ/4−λ/10)×(2×N ₂ −1)×k≦D ₂ ≦(λ/4+λ/10)×(2×N ₂ −1)×k
...Formula 2c
When at least one of the above is satisfied, the antenna gain of the antenna element 30 in the predetermined frequency band W can be improved, and it is more preferable to satisfy both of them. In addition, in the formulas 1c and 2c, λ may be the wavelength in the air of radio waves of some frequencies included in the predetermined frequency band W, or preferably, may be the wavelength in the air of radio waves of all frequencies included in the predetermined frequency band W.

1 , the power supply portion 35 is close to the first busbar 3 but is not in contact with the first busbar 3. Therefore, the length from the power supply portion 35 to the first busbar 3 within the length _D1 is defined as the shortest distance between the power supply portion 35 and the first busbar 3. Similarly, the length from the power supply portion 35 to the first busbar 3 within the length _D2 is defined as the shortest distance between the power supply portion 35 and the first busbar 3.

In the example shown in FIG. 1, the power supply unit 35 is arranged in the upper region 8 described below in a plan view of the window glass 100, but this is not limited to this. The power supply unit 35 may be arranged to overlap at least a portion of the first bus bar 3 (e.g., the first upper bus bar 3a) or at least a portion of the heating region 2 (first heating region 2a) in a plan view of the window glass 100.

1, the "at least a part of the first busbar 3" included in the first path is the first upper part 71a, the vertical part 73, and the horizontal part 74 of the upper part 71. Also, in the example shown in FIG. 1, the first high-frequency termination on the side of the power source 400 is the negative terminal 402. However, when a filter 403 that attenuates a high-frequency signal having a frequency included in a predetermined frequency band W is inserted in series into the ground harness 53, the first high-frequency termination on the side of the power source 400 is the input end 403a of the filter 403. The filter 403 may be disposed on the glass plate 1, or more specifically, may be inserted in series into the vertical part 73. In this case, the first high-frequency termination on the side of the power source 400 is the input end 403a of the filter 403.

In a configuration in which the heating region 2 is not separated by the gap 9, the "at least a part of the first busbar 3" included in the first path may be the second upper portion 71b of the upper portion 71, the upper portion 79, the vertical portion 76, and the horizontal portion 77. When a filter 406 that attenuates a high-frequency signal having a frequency included in a predetermined frequency band W is inserted in series into the ground harness 54, the first high-frequency termination on the side of the power source 400 is the input end 406a of the filter 406. The filter 406 may be disposed on the glass plate 1, and more specifically, may be inserted in series into the vertical portion 76 or the horizontal portion 77. In this case, the first high-frequency termination on the side of the power source 400 is the input end 406a of the filter 406.

1, the second path passes through the vertical direction of the heating region 2 and at least a part of the second bus bar 4. The "at least a part of the second bus bar 4" included in the second path is a part of the lower part 72 and the connection bus bar 75. In the example shown in FIG. 1, the second high-frequency terminal on the side of the power source 400 is the positive terminal 401. However, when a filter 405 that attenuates a high-frequency signal having a frequency included in a predetermined frequency band W is inserted in series into the power harness 57, the second high-frequency terminal on the side of the power source 400 is the input end 405a of the filter 405. The filter 405 may be disposed on the glass plate 1, or more specifically, may be inserted in series into the connection bus bar 75. In this case, the second high-frequency terminal on the side of the power source 400 is the input end 405a of the filter 405.

In addition, in a configuration in which the heating region 2 is not separated by the gap 9, "at least a part of the second bus bar 4" included in the second path may be a part of the right part of the lower part 70 and the connecting bus bar 78. When a filter 404 that attenuates a high-frequency signal having a frequency included in a predetermined frequency band W is inserted in series into the power harness 58, the second high-frequency termination on the side of the power source 400 is the input end 404a of the filter 404. The filter 404 may be disposed on the glass plate 1, or more specifically, may be inserted in series into the connecting bus bar 78. In this case, too, the second high-frequency termination on the side of the power source 400 is the input end 404a of the filter 404.

Filters 403, 404, 405, and 406 may be, for example, LC filters having an inductor L and a capacitor C.

In the example shown in FIG. 1, the antenna element 30 is provided in at least a part of the upper region 8. The upper region 8 is the region between the upper frame 66a (upper edge of the opening) of the window frame 66 and the upper parts 71, 79 of the first busbar 3, within the entire region of the glass plate 1 when viewed in a plan view. The antenna element 30 is disposed in the antenna region 5 within the upper region 8.

The antenna element 30 may have a line element 37 electrically connected to the power supply 35. In this case, the length of the line element 37 is formed to be suitable for receiving radio waves in a specified frequency band W, thereby further improving the antenna gain of the antenna element 30 in the specified frequency band W.

For example, when the length of the line element 37 is L _A , the length L _A is expressed as follows:
1/8×λ×k≦L _A ≦1/4×λ×k
...Formula 3a
If the above condition is satisfied, the antenna gain of the antenna element 30 in a predetermined frequency band W can be improved. Preferably, the length L _A satisfies the following condition:
5/32×λ×k≦L _A ≦7/32×λ×k
...Formula 3b
When the above is satisfied, it is possible to further improve the antenna gain of the antenna element 30 in the predetermined frequency band W. In addition, in the formulas 3a and 3b, λ may be the wavelength in the air of radio waves of some frequencies included in the predetermined frequency band W, or preferably, may be the wavelength in the air of radio waves of all frequencies included in the predetermined frequency band W.

The antenna region 5 may be a horizontally elongated region in which the horizontal length is longer than the vertical length when the glass plate 1 is viewed in plan. In particular, in the case of an antenna element 30 having a linear element 37, the antenna region 5 is preferably a horizontally elongated, approximately rectangular region of the smallest area that encompasses the entire antenna element 30. The antenna region 5 is provided between the upper frame 66a of the window frame 66 and the first bus bar 3. By making the antenna region 5 a horizontally elongated region that includes the power supply portion 35 and the linear element 37, the height of the antenna element 30 in the Y-axis direction can be reduced, so that the heating region 2 can be expanded while maintaining the antenna gain of the antenna element 30.

In the example shown in FIG. 1, the power supply unit 35 is arranged outside the heating area 2 in a plan view of the glass plate 1, but may be arranged to overlap the heating area 2. In the example shown in FIG. 1, the linear element 37 is arranged outside the heating area 2 in a plan view of the glass plate 1, but may be arranged to overlap the heating area 2.

The first heating region 2a includes a first upper edge 6f extending in a direction along the upper edge 1a of the glass plate 1, and a second upper edge 6e extending in a direction along the upper edge 1a, further away from the upper edge 1a than the first upper edge 6f. The upper portion 71 of the first upper busbar 3a extends along each of the first upper edge 6f and the second upper edge 6e. As a result, as shown in FIG. 1, a crank portion 7 is formed in the upper portion 71 of the first upper busbar 3a, and a recessed region 81 is formed in the upper region 8. In the example shown in FIG. 1, the antenna element 30 is provided in the recessed region 81.

The recessed region 81 may be a region in the upper region 8 that extends from the end of the crank portion 7 on the first upper side 6f side to the positive side in the Y-axis direction and reaches the upper frame 66a (upper side of the opening) of the window frame 66, and is bounded by a line segment. Alternatively, the recessed region 81 may be a rectangular region in the upper region 8 whose vertical length is the height of the crank portion 7 in the Y-axis direction and whose horizontal length is the combined length of the crank portion 7 and the first upper portion 71a in the X-axis direction.

The upper portion 71 of the first busbar 3 has a crank portion 7, a first upper portion 71a extending from the crank portion 7 to one side, and a second upper portion 71b extending from the crank portion 7 to the other side.

The crank portion 7 is formed in a crank shape by having a third upper portion 71c, a first bent portion 91 formed at the connection between the first upper portion 71a and the third upper portion 71c, and a second bent portion 92 formed at the connection between the second upper portion 71b and the third upper portion 71c.

By forming the recessed region 81 in the upper region 8, a region other than the recessed region 82 is formed in the upper region 8, so that the length in the Y-axis direction of the region other than the recessed region 82 can be made shorter than the length in the Y-axis direction of the recessed region 81. This allows the length in the Y-axis direction of the first heated region 2a connected to the second upper portion 71b to be relatively longer, so that the antenna gain of the antenna element 30 in the specified frequency band W can be ensured while further suppressing the deterioration of the anti-fogging and anti-icing effects of the glass plate 1.

The recessed area 81 may be located in the upper center of the glass plate 1, as in the modified example shown in FIG. 2. In the example shown in FIG. 2, the first upper side 6f and the second upper portion 71b extend in a direction along the upper edge 1a, farther from the upper edge 1a than the second upper side 6e and the first upper portion 71a.

In the example shown in FIG. 1, at least a part of the vertical portion 73 is capacitively coupled to the window frame 66 (more specifically, the metal part of the left frame 66c) to which the glass plate 1 is attached. This improves the antenna gain of the antenna element 30 in a specified frequency band W. Note that "capacitively coupled" refers to a portion where the distance between the vertical portion 73 and the window frame 66 (more specifically, the metal part of the left frame 66c) is greater than 0 mm and less than or equal to 30 mm.

For example, the length of the portion of the first bus bar 3 that is capacitively coupled with the window frame 66 (more specifically, the metal portion of the left frame 66c) is defined as _DC , and P is an integer equal to or greater than 1. In this case, the length _DC is expressed as follows:
(λ/4-λ/8)×(2P-1)×k≦D _C ≦(λ/4+λ/8)×(2P-1)×k
...Formula 4a
If the above condition is satisfied, the antenna gain of the antenna element 30 in a predetermined frequency band W can be improved. Preferably, the length D _C is
(λ/4-λ/9)×(2P-1)×k≦D _C ≦(λ/4+λ/9)×(2P-1)×k
...Formula 4b
When the above is satisfied, it is possible to further improve the antenna gain of the antenna element 30 in the predetermined frequency band W. In addition, in the formulas 4a and 4b, λ may be the wavelength in the air of radio waves of some frequencies included in the predetermined frequency band W, or preferably, may be the wavelength in the air of radio waves of all frequencies included in the predetermined frequency band W.

The vehicle window glass device 300 may also include a connection element that is provided on the glass plate 1 and attenuates a high-frequency signal having a frequency included in the predetermined frequency band W. The connection element has one end electrically connected to the first bus bar 3 or the second bus bar 4 and an open end opposite the one end, and is arranged in a region that does not overlap with the heating region 2 in a plan view of the glass plate 1. The connection element may be directly connected to the first bus bar 3 or the second bus bar 4. The connection element 43 illustrated in FIG. 1 is a branch element having one end 41 connected to the vertical portion 73, which is the middle portion of the first bus bar 3, and an open end 42 opposite the one end 41. By providing such a connection element 43, the antenna gain of the antenna element 30 in the predetermined frequency band W can be improved.

For example, when the length of the connection element 43 is L _S , the length L _S is expressed as follows:
(λ/4-λ/8)×k≦L _S ≦(λ/4+λ/8)×k
...Formula 5a
If the length L _{S satisfies the following condition, the connection element 43 functions as a stub, thereby improving the antenna gain of the antenna element 30 in a predetermined frequency band W. Preferably, the length L S} satisfies the following condition:
(λ/4-λ/9)×k≦L _S ≦(λ/4+λ/9)×k
...Formula 5b
When the above is satisfied, it is possible to further improve the antenna gain of the antenna element 30 in the predetermined frequency band W. In addition, in the formulas 5a and 5b, λ may be the wavelength in the air of radio waves of some frequencies included in the predetermined frequency band W, or preferably, may be the wavelength in the air of radio waves of all frequencies included in the predetermined frequency band W.

In a configuration in which one end 41 of the connection element 43 is electrically connected to the first bus bar 3, "at least a part of the first bus bar 3" included in the first path is the first upper portion 71a and the vertical portion 73 of the upper portion 71, and the first high-frequency termination on the power source 400 side is the one end 41. That is, in a configuration in which one end 41 of the connection element 43 is electrically connected to the first bus bar 3, _D1 corresponds to the path length from the power supply 35 to the one end 41. Note that, similarly, in a configuration (not shown) in which one end of the connection element is electrically connected to the second bus bar 4, _D2 corresponds to the path length from the power supply 35 to the one end of the connection element.

Figure 3 is a cross-sectional view showing the upper part of a first structural example of a vehicle window glass device in one embodiment. The vehicle window glass device 300A shown in Figure 3 is an example of the vehicle window glass device 300 shown in Figure 1. In Figure 3, when the glass plate 1 is attached to the window frame 66 formed in the vehicle body 62, the positive side in the Z-axis direction represents the vehicle interior side, and the negative side in the Z-axis direction represents the vehicle exterior side. In the example shown in Figure 3, the glass plate 1 is a laminated glass in which a glass plate 10 arranged on the vehicle exterior side and a glass plate 20 arranged on the vehicle interior side are bonded together via an intermediate film 40. The intermediate film 40 is sandwiched between the glass plate 10 and the glass plate 20.

The glass plate 1 is attached to the window frame 66 by, for example, bonding the peripheral portion of the main surface 22 of the glass plate 20 to the flange-shaped window frame 66 with an adhesive 65 such as urethane resin. The window frame 66 has a metal portion 63 that faces at least a portion of the peripheral portion of the main surface 22 when viewed from above the glass plate 1 in the Z-axis direction. The inner edge 64 of the metal portion 63 forms an opening that is covered by the glass plate 1 when viewed from above the glass plate 1 in the Z-axis direction.

The glass plate 10 and the glass plate 20 are transparent plate-shaped dielectrics. Either 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 sheet 10 has a main surface 11 and a main surface 12 opposite to the main surface 11 in the Z-axis direction. The main surface 11 represents the surface facing the inside of the vehicle, and the main surface 12 represents the surface facing the outside of the vehicle. In particular, the main surface 12 corresponds to the outer surface of the laminated glass facing the outside of the vehicle.

The glass plate 20 has a main surface 21 facing the main surface 11 of the glass plate 10, and a main surface 22 opposite the main surface 21 in the Z-axis direction. The main surface 21 represents the surface facing the outside of the vehicle, and the main surface 22 represents the surface facing the inside of the vehicle. In particular, the main surface 22 corresponds to the outer surface of the laminated glass facing the inside of the vehicle.

The intermediate film 40 is a transparent or semi-transparent dielectric material having dielectric properties and interposed between the glass plate 10 and the glass plate 20. The glass plate 10 and the glass plate 20 are joined by the intermediate film 40. Examples of the intermediate film 40 include thermoplastic polyvinyl butyral (PVB) and ethylene vinyl acetate copolymer (EVA).

The power supply unit 35 is, for example, a power supply electrode connected to the main surface 22. The power supply unit 35 has a power supply point 36 to which one end of the power supply line 32 is connected, and is connected to the input of the amplifier 61 via the power supply line 32. The amplifier 61 may be mounted on the power supply unit 35. A signal obtained by receiving radio waves at the antenna element 30 is input to the input of the amplifier 61 via the power supply point 36 of the power supply unit 35. The signal input to the input of the amplifier 61 is filtered by a bandpass filter and amplified by an amplifier circuit, and then output from the amplifier 61.

The conductive member 26 is disposed between the glass plate 10 and the glass plate 20. In the example shown in FIG. 3, the conductive member 26 is disposed between the glass plate 10 and the intermediate film 40, and contacts the main surface 11. The glass plate 20 has a main surface 22 opposite the intermediate film 40. The antenna element 30 is disposed on the main surface 22. In the example shown in FIG. 3, all of the line elements 37 and the power supply portion 35 are disposed on the main surface 22.

The conductive member 26 may be disposed between the intermediate film 40 and the glass plate 20, as illustrated in FIG. 4, or may be in contact with the main surface 21. The conductive member 26 may be disposed between the first intermediate film 40A and the second intermediate film 40B, as illustrated in FIG. 5. The first intermediate film 40A is a dielectric intermediate film disposed between the glass plate 10 and the conductive member 26, and the second intermediate film 40B is a dielectric intermediate film disposed between the conductive member 26 and the glass plate 20. The materials of the first intermediate film 40A and the second intermediate film 40B may be the same or different, but it is preferable that these materials are the same because the physical properties such as the thermal expansion coefficient are equivalent.

Figure 6 is a cross-sectional view showing the upper part of a second structural example of a vehicle window glass device in one embodiment. The vehicle window glass device 300B shown in Figure 6 is an example of the vehicle window glass device 300 shown in Figure 1. The description of the configuration of Figure 6 that is similar to that of Figures 3, 4, and 5 will be omitted by incorporating the above description of Figures 3, 4, and 5.

At least a part of the antenna element 30 and the conductive member 26 are disposed between the glass plate 10 and the glass plate 20. In the example shown in FIG. 6, the conductive member 26 is disposed between the glass plate 10 and the intermediate film 40 as in FIG. 3, and is in contact with the main surface 11. The conductive member 26 may be disposed between the glass plate 20 and the intermediate film 40 as in FIG. 4, or may be disposed between the intermediate film 40A and the intermediate film 40B as in FIG. 5. The line element 37, which is a part of the antenna element 30, is disposed between the glass plate 20 and the intermediate film 40 and is in contact with the main surface 21. The signal obtained by receiving the radio wave with the line element 37 is input to the input section of the amplifier 61 through the capacitive coupling between the line element 37 and the power supply section 35. The line element 37 may be disposed on the main surface 11, or may be disposed between the intermediate film 40A and the intermediate film 40B as in FIG. 5.

FIG. 7 is a diagram showing an example of a result of actually measuring a change in antenna gain caused by adjustment of lengths D ₁ and D ₂ in a vehicle window glass device according to an embodiment.

The dimensions of each part of the vehicle window glass device 300 in the "no adjustment" state shown in FIG. 7 are as follows, in units of mm:
_D1 : 1265
_D2 : 1196
Length L _A of the linear element 37: 155
Here, the path length _D1 is the path length from the power supply unit 35 through the vertical portion 73 of the first bus bar 3 to the electrode 51, and the electrode 51 is defined as the first high-frequency termination. The path length _D2 is the path length from the power supply unit 35 through (the conductive member 26 of) the heating region 2 to the electrode 55, and the electrode 55 is defined as the second high-frequency termination. The length L _A (=155 mm) satisfies the above formula 3a at all frequencies in the Band III band (170 MHz to 240 MHz). k was 0.64.

Here, referring to the antenna gain of the antenna element 30 without "adjustment", it was found that the antenna gain decreased near 230 MHz. Since k=0.64 at this time, at the wavelength λ of 230 MHz, _D1 (=1265 mm) without "adjustment" did not satisfy the above formula 1a, and _D2 (=1196 mm) without "adjustment" did not satisfy the above formula 2a.

On the other hand, " _D1 adjustment" shown in FIG. 7 is the antenna gain of the antenna element ₃₀ when only _D1 is adjusted to 1470 mm (length that satisfies formula 1a at wavelength λ at 230 MHz) compared to "no adjustment". " _D2 adjustment" shown in FIG. 7 is the antenna gain of the antenna element 30 when only D2 is adjusted to 1035 mm (length that satisfies formula 2a at wavelength λ at 230 MHz) compared to "no adjustment". " _D1 , _D2 adjustment" shown in FIG. 7 is the antenna gain of the antenna element 30 when _D1 is adjusted to 1470 mm and _D2 is adjusted to 1035 mm compared to "no adjustment". As shown in FIG. 7, by adjusting the length of _D1 or _D2 , or both _D1 and _D2 to a length that satisfies formula 1a or formula 2a, the antenna gain around 230 MHz was improved.

Figure 8 shows an example of the results of actual measurements of the change in antenna gain depending on whether or not a stub (specifically, a connection element 43) is present for a vehicle window glass device in one embodiment.

The dimensions of each part of the vehicle window glass device 300 without stubs shown in FIG. 8 are as follows, in units of mm:
_D1 : 1205
_D2 : 1748
Length L _A of the line element 37: 170
The length L _A (=170 mm) satisfies the above formula 3a at all frequencies in the Band III band (170 MHz to 240 MHz). k was 0.64.

Here, referring to the antenna gain of the antenna element 30 without a stub, it was found that the antenna gain decreased near 220 MHz. Since k=0.64 at this time, at the wavelength λ of 220 MHz, _D1 (=1205 mm) without a stub did not satisfy the above formula 1a, and _D2 (=1748 mm) without a stub did not satisfy the above formula 2a.

On the other hand, "stub addition" shown in Fig. 8 is the antenna gain of the antenna element 30 when one end 41 of the connection element 43 with a length L _S of 220 mm is connected to a location where the length D ₁ of the first path from the power supply 35 to the one end 41 of the connection element 43 is 1080 mm. In the "stub addition", the first high-frequency termination can be determined by the connection element 43, and the first high-frequency termination corresponds to the one end 41 of the connection element 43. Furthermore, the length D ₁ (= 1080 mm) corresponds to "a length of 5 times λ/4" that satisfies the formula 1a at the wavelength λ at 220 MHz. The length L _S (= 220 mm) corresponds to "a length of λ/4" that satisfies the formula 5a at the wavelength λ at 220 MHz. As shown in FIG. 8, by adjusting the length _D1 to a length that satisfies the formula 1a and by adjusting the length _L2S to a length that satisfies the formula 5a, the antenna gain near 220 MHz was improved.

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

The vehicle window glass is not limited to the windshield, but may be window glass attached to other parts of the vehicle body. For example, the vehicle window glass may be rear glass attached to a window frame at the rear of the vehicle body, side glass attached to a window frame at the side of the vehicle body, roof glass attached to a window frame in the roof of the vehicle body, etc.

REFERENCE SIGNS LIST 1 glass plate 1a upper edge 1b lower edge 1c left edge 1d right edge 2 heating region 2a first heating region 2b second heating region 3 first bus bar 3a first upper bus bar 3b second upper bus bar 4 second bus bar 4a first lower bus bar 4b second lower bus bar 5 antenna region 6a, 6b, 6c, 6d vertical sides 6e, 6f upper side 6g lower side 7 crank portion 8 upper region 9 gap 10, 20 glass plate 11, 12, 21, 22 principal surface 26 conductive member 30 antenna element 32 power supply line 35 power supply portion 36 power supply point 37 line element 40 intermediate film 40A first intermediate film 40B second intermediate film 41 one end 42 open end 43 connection element Description of the Reference Signs 51, 52, 55, 56 Electrode 53, 54 Ground harness 57, 58 Power harness 61 Amplifier 62 Vehicle body 63 Metal part 64 Inner edge 65 Adhesive 66 Window frame 66a Upper frame 66b Lower frame 66c Left frame 66d Right frame 70, 72 Lower portion 71, 79 Upper portion 71a First upper portion 71b Second upper portion 71c Third upper portion 73, 76 Vertical portion 74, 77 Horizontal portion 75, 78 Connection bus bar 81 Recessed region 82 Region 91 First bent portion 92 Second bent portion 100 Window glass 300, 300A, 300B Vehicle window glass device 400 Power source 401 Positive electrode terminal 402 Negative electrode terminal 403, 404, 405, 406 Filter 403a, 404a, 405a, 406a Input terminal

Claims (18)

Glass panels for vehicles;
a first bus bar provided on the glass plate and including an upper portion extending in a direction along an upper edge of the glass plate;
a second bus bar provided on the glass plate and including a lower portion extending in a direction along a lower edge of the glass plate;
an antenna element provided on the glass plate and including a power supply portion adjacent to the first bus bar;
the glass sheet having a heating region extending between the upper and lower portions;
the heating region is a region in which a conductive member through which a direct current flows in a vertical direction when a direct current voltage is applied between the first bus bar and the second bus bar by a power source, and the heating region is heated by heat generated by the conductive member;
The wavelength in air of the radio wave of the predetermined frequency band received by the antenna element is λ,
The wavelength shortening rate of the glass plate in the predetermined frequency band is k,
N ₁ is an integer of 1 or more,
_N2 is an integer of 1 or more;
A length of a first path from the power supply portion through the first bus bar to a first high-frequency termination on the power source side is defined as _D1 ,
A length of a second path, which is different from the first path and extends from the power supply portion through the heating region in a vertical direction, through the second bus bar, and to a second high frequency termination on the side of the power source, is denoted as _D2 ;
the first high-frequency termination is a position where a high-frequency current becomes zero and where an antinode position of a standing wave generated along the first path coincides with the power supply portion,
the second high-frequency termination is a position where a high-frequency current becomes zero and where an antinode position of a standing wave generated along the second path coincides with the power supply portion,
The lengths _D1 and _D2 are
(λ/4-λ/ 9 )×(2× _N1-1 )×k≦ _D1 ≦(λ/4+λ/ 9 )×(2× _N1-1 )×k,
A vehicle window glass device that satisfies at least one of (λ/4−λ/ 9 )×(2×N ₂ −1)×k≦D ₂ ≦(λ/4+λ/ 9 )×(2×N ₂ −1)×k. The lengths _D1 and _D2 are
(λ/4-λ/ 9 )×(2× _N1-1 )×k≦ _D1 ≦(λ/4+λ/ 9 )×(2× _N1-1 )×k,
2. The vehicle window glass _device according to claim 1, wherein both of the following conditions are satisfied: (λ/4-λ/ 9 )x( _2xN2-1 )xk≦D2 _≦ (λ/4+λ/ 9 )x(2xN2-1)xk. The vehicle window glass device according to claim 1 or 2, wherein the antenna element has a linear element electrically connected to the power supply portion. When the length of the linear element is L _A , the length L _A is expressed as follows:
1/8×λ×k≦L _A ≦1/4×λ×k
4. The vehicle window glass device according to claim 3, which satisfies the above. The vehicle window glass device according to any one of claims 1 to 4, wherein the power supply unit is disposed outside the heating area in a plan view of the glass sheet. The heating region includes a first upper side extending in a direction along the upper edge, and a second upper side extending in a direction along the upper edge away from the upper edge than the first upper side,
The vehicle glazing device according to claim 1 , wherein the upper portion extends along each of the first upper edge and the second upper edge. the first bus bar further includes a vertical portion connected to the top portion;
The upper portion is connected to a top edge of the heating area;
7. A vehicle glazing arrangement as claimed in any one of the preceding claims, wherein the vertical portions extend in a direction along a lateral edge of the glass sheet, away from a lateral side of the heating region. The vehicle window glass device according to claim 7, wherein at least a portion of the vertical portion is capacitively coupled to a window frame to which the glass plate is attached. The length of the portion of the first bus bar that is capacitively coupled to the window frame is defined as _DC , where P is an integer equal to or greater than 1. The length _DC is expressed as follows:
9. The vehicle window glass device according to claim 8, which satisfies (λ/4-λ/8)x(2P-1)xk≦D _C ≦(λ/4+λ/8)x(2P-1)xk. the first bus bar further includes a horizontal portion connected to the vertical portion;
10. A vehicle glazing arrangement according to claim 7, wherein the lateral portion extends in a direction along a lower edge of the glass sheet in a region away from the heating region. The vehicle window glass device according to any one of claims 1 to 10, wherein at least one of the first high-frequency terminal and the second high-frequency terminal is disposed on the glass sheet. The vehicle window glass device according to any one of claims 1 to 11, wherein at least one of the first high-frequency terminal and the second high-frequency terminal is a terminal of the power source. a filter for attenuating a high-frequency signal having a frequency included in the frequency band;
12. The vehicle glazing device according to claim 1, wherein at least one of the first high-frequency termination and the second high-frequency termination is the filter. a connection element provided on the glass plate, the connection element having one end electrically connected to the first bus bar or the second bus bar and an open end opposite to the one end;
The connection element is arranged in a region of the glass sheet that does not overlap with the heating region in a plan view,
14. The vehicle glazing device according to claim 13, wherein the first high frequency termination or the second high frequency termination is the one end. When the length of the connection element is L _S , the length L _S is expressed as follows:
(λ/4-λ/8)×k≦L _S ≦(λ/4+λ/8)×k
15. The vehicle window glass device according to claim 14, which satisfies the following: the glass plate is a laminated glass including a first glass plate, a second glass plate, and an interlayer film sandwiched between the first glass plate and the second glass plate;
the conductive member is disposed between the first glass plate and the second glass plate;
the second glass plate has a main surface opposite to the interlayer film,
16. A vehicle glazing arrangement according to any one of the preceding claims, wherein the antenna element is arranged on the main surface. the glass plate is a laminated glass including a first glass plate, a second glass plate, and an interlayer film sandwiched between the first glass plate and the second glass plate;
16. The vehicle window glass device according to claim 1, wherein at least a part of the antenna element and the conductive member are disposed between the first glass plate and the second glass plate. The vehicle window glass device according to any one of claims 1 to 17, wherein the predetermined frequency band is the DAB Band III band.

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