Vehicle window glass

Abstract

Provided is a vehicle window glass with which it is possible to achieve both good transmittance of radio waves and uniform heat distribution.　A vehicle window glass includes: a laminated glass that has a first glass plate, a second glass plate, and an interlayer film, and that is provided in an opening of a vehicle body; an upper-side bus bar that is provided along the upper side of the laminated glass between a second main surface and a third main surface; a lower-side bus bar that is provided along the lower side of the laminated glass between the second main surface and the third main surface; and a heating unit that is provided between the second main surface and the third main surface and is connected between the upper-side bus bar and the lower-side bus bar. The laminated glass has a first region where a communication unit is located in the width direction of the vehicle body, and a second region other than the first region. The heating unit has a first hot wire that is provided in the first region and is connected between the upper-side bus bar and the lower-side bus bar, and a second hot wire that is provided in the second region and is connected between the upper-side bus bar and the lower-side bus bar. A first pitch of the first hot wire in the width direction of the vehicle body is wider than a second pitch of the second hot wire in the width direction of the vehicle body.

Description

Vehicle window glass

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

[0002] Conventionally, electrically heated windows have been available that are laminated with at least two plies of glazing material and at least one ply of interlayer material extending between the plies of glazing material. The electrically heated window comprises an array of fine, closely spaced wires carried by either one of the two or at least one ply, and electrical connection means for connecting the array to an electrical source so as to pass an electric current through the wires to heat the window. At least some of the wires extend along diverging lines, so that the array extends over substantially the entire transparent portion of the window. It has been disclosed, for example, in U.S. Pat. No. 5,499,499 that the spacing of the wires varies depending on the region of the electrically heated window.

[0003] Japanese Patent Application Publication No. 09-207718

[0004] However, conventional electrically heated windows (vehicle window glass) using wires (heating wires) do not increase the spacing between the wires in some areas to improve radio wave transmittance. Simply increasing the spacing between the wires would result in adverse effects such as a decrease in the heating temperature and uneven heating, so it is not easy to achieve both good radio wave transmittance and uniform heat distribution.

[0005] Therefore, an object of the present invention is to provide a vehicle window glass that can achieve both good radio wave transmission and uniform heat distribution.

[0006] A vehicle window glass according to an embodiment of the present disclosure includes a laminated glass provided in an opening of a vehicle body, the laminated glass including a first glass plate having a first main surface and a second main surface, a second glass plate having a third main surface and a fourth main surface, and an intermediate film provided between the second main surface and the third main surface, an upper bus bar provided along an upper side of the laminated glass between the second main surface and the third main surface, a lower bus bar provided along a lower side of the laminated glass between the second main surface and the third main surface, and an intermediate film provided between the second main surface and the third main surface. and a heating unit connected between the upper bus bar and the lower bus bar, the laminated glass having a first region in which a communication unit is located in the width direction of the vehicle body, and a second region other than the first region, the heating unit having a first heating wire provided in the first region and connected between the upper bus bar and the lower bus bar, and a second heating wire provided in the second region and connected between the upper bus bar and the lower bus bar, and a first pitch of the first heating wires in the width direction of the vehicle body being wider than a second pitch of the second heating wires in the width direction of the vehicle body.

[0007] It is possible to provide a vehicle window glass that can achieve both good radio wave transmission and uniform heat distribution.

[0008] FIG. 1B is a side view showing an example of the configuration of a vehicle equipped with a vehicle window glass of an embodiment. FIG. 1A is an enlarged view of the vehicle window glass and its periphery in FIG. 1A. FIG. 1B is a diagram illustrating the relationship between the polarization direction of radio waves and heat rays. FIG. 1C is a plan view of an example of the configuration of a vehicle window glass of an embodiment. FIG. 1D is a diagram illustrating an example of the configuration of a cross section of the vehicle window glass taken along the arrows A-A in FIG. 3. FIG. 1E is a diagram illustrating an example of a simulation result for transmitted power. FIG. 1F is a plan view of an example of the configuration of a vehicle window glass of a first modified example of an embodiment. FIG. 1G is a plan view of an example of the configuration of a vehicle window glass of a second modified example of an embodiment.

[0009] <Embodiments> Hereinafter, embodiments to which the vehicle window glass of the present disclosure is applied will be described. In the following, the same elements will be given the same reference numerals, and duplicate explanations may be omitted. 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 angle, orthogonal, up and down, left and right, etc., are allowed 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 in an arched shape.

[0010] Examples of the vehicle window glass of the embodiment include a windshield (front glass) attached to the front of the vehicle, a fixed side glass attached to the side of the vehicle, a roof glass attached to the ceiling of the vehicle, and a rear glass attached to the rear of the vehicle. The vehicle window glass is not limited to these examples and may be slidable relative to the vehicle body. Below, as an example, a description will be given of an embodiment in which the vehicle window glass of the embodiment is a windshield (front glass) attached to the front of the vehicle.

[0011] A vehicle equipped with a vehicle window glass according to the embodiment is equipped with a communication device. Radio waves transmitted by the communication device to the outside of the vehicle or received by the communication device from the outside of the vehicle are transmitted through the vehicle window glass according to the embodiment. The radio waves transmitted or received by the communication device are preferably radio waves in the 5.9 GHz or 5.8 GHz band allocated for V2X (Vehicle to X) communication, a millimeter wave band such as that of a fifth-generation mobile communication system (5G), or radio waves in a frequency band of 1 GHz to 30 GHz including Sub-6. The radio waves transmitted or received by the vehicle window glass according to the embodiment may be Long Term Evolution (LTE), LTE-Advanced (LTE-A), or Ultra Mobile Broadband (UMB). Furthermore, the radio waves transmitted or received by the vehicle window glass of the embodiment may be IEEE802.11 (Wi-Fi (registered trademark)), IEEE802.16 (WiMAX (registered trademark)), IEEE802.20, UWB (Ultra-Wideband), Bluetooth (registered trademark), LPWA (Low Power Wide Area), or the like. The frequency of the radio waves transmitted or received by the communication device is more preferably 3 GHz to 6 GHz, and even more preferably 5 GHz to 6 GHz. In the following, unless otherwise specified, radio waves in the 5.9 GHz band for V2X will be used as an example for explanation.

[0012] <Vehicle 10 equipped with vehicle window glass 100> Fig. 1A is a side view showing an example of the configuration of a vehicle 10 equipped with a vehicle window glass 100 according to an embodiment. Fig. 1B is an enlarged view showing the vehicle window glass 100 and its surroundings in Fig. 1A.

[0013] The vehicle window glass 100 is attached to a window frame 11A of a vehicle body 11 of the vehicle 10 as a windshield, for example. The window frame 11A is an example of an opening in the vehicle body 11. A communication device 20 is mounted on the vehicle 10. The communication device 20 is an example of a communication unit. For example, the communication device 20 is attached to an upper portion of a dashboard 12 inside the vehicle or to an interior side of an upper portion of the vehicle window glass 100. The upper portion of the dashboard 12 may be an upper portion inside the dashboard 12 or an upper portion outside the dashboard 12 (e.g., the top surface). While FIG. 1A shows the communication device 20 both at an upper portion of the dashboard 12 and at an interior side of an upper portion of the vehicle window glass 100, the communication device 20 may be provided in at least one of the positions. Furthermore, since the communication device 20 only needs to communicate via the vehicle window glass 100, it may be provided on the interior side of the vehicle window glass 100, above the dashboard 12, or at a position other than the interior side of the upper part of the vehicle window glass 100.

[0014] Additionally, as an example, a configuration in which the communication device 20 is located at the center in the width direction of the vehicle 10 will be described here, but the communication device 20 may be provided on the left or right side in the width direction of the vehicle 10. The width direction of the vehicle 10 is the direction transverse to the traveling direction (forward direction of the vehicle 10), and the left and right sides are, as an example, the left and right sides when the vehicle 10 is viewed facing the traveling direction.

[0015] The vehicle 10 is, for example, an automobile such as an EV (Electric Vehicle), a PHEV (Plug-in Hybrid Electric Vehicle), a HV (Hybrid Vehicle), a gasoline-powered vehicle, or a diesel-powered vehicle. The vehicle 10 may also be a train or steam locomotive. The vehicle 10 is an example of a moving body that transports passengers.

[0016] The communication device 20 is, for example, a wireless transceiver for V2X communication, and is a device that transmits and receives data to and from other vehicles outside the vehicle 10, pedestrians (with communication terminals such as smartphones), various infrastructures, networks, etc. Note that the communication device 20 is not limited to a communication device for V2X communication, and may be a device that only transmits or receives data.

[0017] The communication device 20 transmits and receives vertically polarized or circularly polarized radio waves. FIG. 1B shows, as an example, a configuration in which the communication device 20 is provided on the top of the dashboard 12. The communication device 20 has an antenna 21 facing upward. FIG. 1B shows, with dots, an area (radio wave propagation area 21A) through which radio waves transmitted from the antenna 21 propagate. The radio wave propagation area 21A is also an area through which radio waves received by the antenna 21 propagate. The portion where the radio wave propagation area 21A intersects with the vehicle window glass 100 is a portion through which radio waves pass through the vehicle window glass 100. Note that the terms "vertically polarized wave" and "circularly polarized wave" refer to the direction of polarization when the antenna 21 of the communication device 20 is oriented horizontally to transmit or receive radio waves horizontally.

[0018] <Relationship between the polarization direction of radio waves and heat rays> Figure 2 is a diagram explaining the relationship between the polarization direction of radio waves and heat rays. Figure 2 uses an XYZ coordinate system. The X-axis direction, Y-axis direction, and Z-axis direction represent directions parallel to the X-axis, Y-axis direction, and Z-axis direction, respectively. The X-axis direction, Y-axis direction, and Z-axis direction are perpendicular to each other.

[0019] Figures 2(A) to 2(C) show a vehicle window glass 1 parallel to the XY plane. The vehicle window glass 1 is, for example, a laminated glass used as a windshield (front glass). Heating wires 2 extending along the Y-axis direction are provided in the intermediate layer at a constant pitch in the X-axis direction. For example, the heating wires 2 are tungsten wires. For example, the pitch between the heating wires 2 in the X-axis direction is approximately 2 mm. Within the XY plane, the heating wires 2 extend along the Y-axis direction while curving sinusoidally with respect to the Y-axis direction. However, because the amplitude of the sine wave is very small, the heating wires 2 are shown as straight lines in Figures 2(A) to 2(C).

[0020] As an example, the −Z-axis direction side of the vehicle window glass 1 is the interior side of the vehicle, and the +Z-axis direction side is the exterior side of the vehicle. The X-axis direction corresponds to the width direction of the vehicle, the +Y-axis direction side is the upper side, and the −Y-axis direction side is the lower side.

[0021] The heating wire 2 may function as a de-icer that efficiently melts ice or snow adhering to the outer surface of the vehicle window glass 1. When the heating wire 2 functions as a de-icer, the value of the current passed through the heating wire 2 may be set higher (for example, about twice as high) than when the heating wire 2 functions as a defogger that removes fogging (water droplets) on the surface of the vehicle window glass 1. For this reason, when the heating wire 2 is made to function as a de-icer, it is thicker than when the heating wire 2 is made to function as a defogger, and the impact on the visibility of the vehicle window glass 1 is greater.

[0022] The heating wire 2 is provided along the vertical direction of the vehicle (Y-axis direction). The reason for providing the heating wire 2 along the vertical direction of the vehicle is to prevent the heating wire 2 from overlapping with the contours of horizontal objects on the ground in the field of view of the vehicle occupants. In other words, if the heating wire 2 were provided along the width direction of the vehicle (X-axis direction), the heating wire 2 would overlap with the contours of horizontal objects in the field of view of the vehicle occupants, potentially affecting the field of view of the occupants. In particular, when the heating wire 2 is used as a de-icer, the heating wire 2 is thick and has a significant impact on the field of view of the vehicle window glass 1. To prevent such an impact, the heating wire 2 of the vehicle window glass 1, particularly when used as a windshield, is provided along the vertical direction of the vehicle.

[0023] A case will be considered in which a communication device is placed inside a vehicle equipped with a comparative vehicle window glass 1 having such a heating wire 2, and radio waves transmitted by the communication device pass through the vehicle window glass 1. Note that although the radio waves transmitted by the communication device will be considered here, the same applies to radio waves received by the communication device.

[0024] 2A shows a case where the radio waves transmitted by the communication device are vertically polarized waves. The electric field of the radio waves is vertical, which is the same as the extension direction (Y-axis direction) of the heating wire 2. Therefore, the vertically polarized radio waves are absorbed by the heating wire 2, and the electric field of the radio waves propagating to the outside of the vehicle window glass 1 is significantly reduced.

[0025] 2B shows a case where the radio waves transmitted by the communication device are horizontally polarized. The electric field of the radio waves is horizontal, which is perpendicular to the extension direction (Y-axis direction) of the heating wire 2, so the horizontally polarized radio waves are transmitted through the heating wire 2 without being absorbed by it. Therefore, the electric field of the radio waves propagating to the outside of the vehicle window glass 1 is hardly reduced.

[0026] 2C shows a case where the radio wave transmitted by the communication device is a circularly polarized wave. Because the electric field of the radio wave rotates with respect to the XY plane, the vertical component is absorbed by the heat ray 2, but the horizontal component passes through without being absorbed by the heat ray 2. For this reason, in the case of a circularly polarized radio wave, the electric field of the radio wave propagating to the outside of the vehicle window glass 1 is reduced to some extent.

[0027] As described above, horizontally polarized radio waves (FIG. 2(B)) are transmitted through the heat rays 2 with almost no absorption, whereas vertically polarized radio waves are absorbed to a large extent by the heat rays 2 and have a very low transmittance. Furthermore, circularly polarized radio waves are absorbed to some extent by the heat rays 2, and therefore have a lower transmittance than horizontally polarized radio waves.

[0028] Generally, radio waves transmitted or received by a communication device mounted on a vehicle are often vertically polarized waves. In general, radio waves transmitted or received by a communication device mounted on a vehicle may be circularly polarized waves, but are rarely horizontally polarized waves.

[0029] The radio waves transmitted and received by the communication device 20 provided in the vehicle 10 on which the vehicle window glass 100 of this embodiment is mounted may be vertically polarized or circularly polarized, but the following describes, as an example, a configuration in which the communication device 20 transmits and receives vertically polarized radio waves. The following describes a vehicle window glass 100 that can achieve both good radio wave transmittance and uniform heat distribution.

[0030] In Figure 3 and subsequent figures, an XYZ coordinate system, which is an orthogonal coordinate system, is used, as in Figure 2. The X-axis direction, Y-axis direction, and Z-axis direction represent directions parallel to the X-axis, Y-axis, and Z-axis, respectively. The X-axis direction, Y-axis direction, and Z-axis direction are perpendicular to one another. The XY plane, YZ plane, and ZX plane represent imaginary planes parallel to the X-axis direction and Y-axis direction, imaginary planes parallel to the Y-axis direction and Z-axis direction, and imaginary planes parallel to the Z-axis direction and X-axis direction, respectively. Planar view means viewing from an XY plane.

[0031] In this embodiment, the X-axis direction, the Y-axis direction, and the Z-axis direction respectively represent the left-right direction (horizontal direction) of the vehicle window glass 100, the up-down direction (vertical direction) of the vehicle window glass 100, and the direction perpendicular to the surface of the vehicle window glass 100 (normal direction). The X-axis direction, the Y-axis direction, and the Z-axis direction are perpendicular to one another.

[0032] <Overall Configuration of Vehicle Window Glass 100> Figure 3 is a plan view showing an example of the configuration of the vehicle window glass 100. The vehicle window glass 100 includes a laminated glass 110, an upper bus bar 120T, a lower bus bar 120B, a lead bus bar 120L, and a heating wire 130. There are two of each of the upper bus bar 120T, the lower bus bar 120B, and the lead bus bar 120L. The heating wire 130 is an example of a heating unit, and may function as a de-icer that efficiently melts ice or snow attached to the outer surface of the vehicle window glass 100. The current value passed through the heating wire 130 functioning as a de-icer may be higher than the current value passed through the heating wire 130 to a conductor functioning as a defogger that removes fogging (water droplets) attached to the surface of the vehicle window glass 100.

[0033] Fig. 3 shows the vehicle window glass 100 as seen from the exterior side of the vehicle body 11. Fig. 3 shows the top bus bar 120T, the bottom bus bar 120B, the lead bus bar 120L, and the heating wire 130 in a see-through manner. Fig. 3 also shows a communication device 20 in addition to the vehicle window glass 100. The communication device 20 is provided in the center in the left-right direction above the dashboard 12 of the vehicle window glass 100 in a plan view. A radio wave propagation region 21A shown in Fig. 3 is the portion where the radio wave propagation region 21A in Fig. 1B intersects with the vehicle window glass 100, and represents a transmission region through which radio waves pass through the vehicle window glass 100.

[0034] In the following description, the laminated glass 110 is assumed to have a first region A1 and a second region A2. The first region A1 is a region in the width direction of the vehicle body 11 where the communication device 20 is located. In FIG. 3 , as an example, the first region A1 is a region in the laminated glass 110 in the X direction where the radio wave propagation region 21A (transmission region) exists. The second region A2 is a region in the laminated glass 110 other than the first region A1 in the X direction. In the following description, as an example, the first region A1 is located in the center of the vehicle body 11 in the width direction, and two second regions A2 are located on both sides of the first region A1. However, the first region A1 may be located at an end of the vehicle body 11 in the width direction. In this case, there may be only one second region A2.

[0035] Figure 4 is a diagram showing an example of the cross-sectional configuration of the vehicle window glass 100 as viewed from the arrow A-A in Figure 3. In addition to the vehicle window glass 100, Figure 4 also shows a window frame 11A of a vehicle body 11. The window frame 11A is formed in a flange shape along the outer edge of the vehicle window glass 100. The outer edge of the vehicle window glass 100 is the outer edge of the vehicle window glass 100 in a plan view. The outer edge of the vehicle window glass 100 is the outer edge of the laminated glass 110.

[0036] 3 and 4, the X-axis direction is the left-right direction of the vehicle 10, and the Y-axis direction is the up-down direction of the vehicle window glass 100. When the vehicle window glass 100 is attached to a window frame 11A formed in the vehicle body 11, the +Z-axis direction side of the vehicle window glass 100 is the exterior side of the vehicle body 11, and the −Z-axis direction side of the vehicle window glass 100 is the interior side of the vehicle body 11.

[0037] <Laminated Glass 110> The laminated glass 110 includes a glass plate 111, a glass plate 112, an interlayer film 113, and a ceramic layer 114. As shown in FIG. 4 , the laminated glass 110 is formed by bonding the glass plate 111 provided on the exterior side of the vehicle body 11 to the glass plate 112 provided on the interior side of the vehicle body 11 via the interlayer film 113 disposed between the glass plates 111 and 112. A ceramic layer 114 is provided on the interior-side main surface 111B of the glass plate 111 and the interior-side main surface 112B of the glass plate 112. An upper bus bar 120T, a lower bus bar 120B, a lead bus bar 120L, and a heating element 130 are provided on the interior-side main surface 112B of the glass plate 112. The ceramic layer 114 is an example of a shielding layer. For example, the two ceramic layers 114 have the same shape in a plan view.

[0038] <Glass Plates 111 and 112> The glass plate 111 is an example of a first glass plate, and the glass plate 112 is an example of a second glass plate. The laminated glass 110 is bonded to the window frame of the vehicle body 11 with an adhesive such as a urethane resin. Note that, here, a form in which the vehicle window glass 100 is a windshield (front glass) attached to the front of the vehicle 10 will be described, but the laminated glass 110 may also be attached to, for example, a door of the vehicle 10 and provided so as to be slidable relative to the vehicle body 11.

[0039] The glass plates 111 and 112 are transparent, flat glass plates. The glass plate 111 has an outdoor-side main surface 111A and an indoor-side main surface 111B. The main surface 111A is an example of a first main surface, and the indoor-side main surface 111B is an example of a second main surface. The glass plate 112 has an outdoor-side main surface 112A and an indoor-side main surface 112B. The main surface 112A is an example of a third main surface, and the indoor-side main surface 112B is an example of a fourth main surface.

[0040] The glass plates 111 and 112 may be inorganic glass or organic glass. Examples of inorganic glass that can be used include, without particular limitation, soda-lime glass, aluminosilicate glass, borosilicate glass, alkali-free glass, and quartz glass. Among these, soda-lime glass is particularly preferred from the viewpoints of manufacturing cost and formability. The forming method of the glass plates 111 and 112 is not particularly limited. For example, in the case of inorganic glass, glass plates formed by a float method or the like are preferred.

[0041] When the glass plates 111 and 112 are inorganic glass, they may be either untempered glass or tempered glass. Untempered glass is produced by forming molten glass into a plate shape and slowly cooling it. Tempered glass is produced by forming a compressive stress layer on the surface of untempered glass, and may be either air-cooled tempered glass or chemically tempered glass.

[0042] When the tempered glass is physically tempered glass (e.g., air-cooled tempered glass), the glass surface may be tempered by a process other than slow cooling, such as rapidly cooling a uniformly heated glass sheet from a temperature near its softening point during bending, thereby generating a compressive stress layer on the glass surface due to a temperature difference between the glass surface and the interior of the glass. When the tempered glass is chemically tempered glass, the glass surface may be tempered by generating compressive stress on the glass surface using an ion exchange method or the like after bending. Furthermore, glass that absorbs ultraviolet or infrared rays may be used as the glass sheets 111 and 112. The glass sheets 111 and 112 are preferably transparent, but may also be colored to the extent that transparency is not impaired.

[0043] The laminated glass 110 may have a curved shape such that the exterior side is convex when attached to the vehicle 10. The laminated glass 110 may have a single-curve shape bent in only one direction, or may have a complex-curve shape bent in two directions (for example, the up-down direction when the laminated glass 110 is attached to the vehicle 10 and the left-right direction perpendicular to the up-down direction). Gravity forming, press forming, roller forming, or the like is used to bend the laminated glass 110. When the laminated glass 110 is bent to a predetermined curvature, the radius of curvature of the laminated glass 110 may be 1,000 mm or more and 100,000 mm or less.

[0044] Furthermore, when the laminated glass 110 is installed in the vehicle 10, the thickness of the glass plate 111 located on the exterior side and the thickness of the glass plate 112 located on the interior side may be the same or different. The thickness of the glass plate 111 is preferably 1.0 mm or more and 3.0 mm or less. A thickness of 1.0 mm or more of the glass plate 111 provides sufficient strength, such as resistance to stone chips, while a thickness of 3.0 mm or less prevents the mass of the laminated glass 110 from becoming too large, which is preferable in terms of fuel efficiency of the vehicle 10. The thickness of the glass plate 112 is preferably 0.3 mm or more and 2.3 mm or less. A thickness of 0.3 mm or more of the glass plate 112 provides good handling, while a thickness of 2.3 mm or less prevents the mass from becoming too large. The thicknesses of the glass plates 111 and 112 are preferably 1.8 mm or less, as this allows the laminated glass 110 to achieve both lightweight and sound insulation, making it preferable. Note that when the thickness of the glass plate 112 is 1.0 mm or less, the glass plate 112 may be chemically strengthened glass. When the glass plate 112 is chemically strengthened glass, it is preferable that the compressive stress value of the glass surface is 300 MPa or more, and the depth of the compressive stress layer is 2 μm or more.

[0045] When the glass plates 111 and 112 are made of organic glass, examples of the material for the organic glass include transparent resins such as polycarbonate and acrylic resins (for example, polymethyl methacrylate).

[0046] <Interlayer 113> The interlayer 113 is a transparent or semi-transparent dielectric material having dielectric properties and interposed between the glass plates 111 and 112 as shown in FIG. 4 . The glass plates 111 and 112 are joined by the interlayer 113. Examples of materials for the interlayer 113 include thermoplastic polyvinyl butyral (PVB) and ethylene vinyl acetate copolymer (EVA). The interlayer 113 may be transparent or colored. The interlayer 113 may also be composed of two or more layers of film.

[0047] Since the upper bus bar 120T, the lower bus bar 120B, and the lead bus bar 120L are provided in the portions where the ceramic layer 114 exists in a plan view, the intermediate film 113 is provided in the following portions.

[0048] The intermediate film 113 is arranged, for example, between the glass plates 111 and 112 in areas where the ceramic layer 114, the upper bus bar 120T, the lower bus bar 120B, the lead bus bar 120L, and the heating wire 130 are not present in a planar view.

[0049] In addition, the intermediate film 113 is disposed, for example, between the glass plate 111 and the heating wire 130 in a portion where the ceramic layer 114 is not present in a plan view and the heating wire 130 is present.

[0050] In addition, in the area where the ceramic layer 114 is present in a planar view and the upper bus bar 120T, the lower bus bar 120B, or the lead bus bar 120L is present, the intermediate film 113 is arranged, for example, between the ceramic layer 114 and the upper bus bar 120T, the lower bus bar 120B, or the lead bus bar 120L.

[0051] Furthermore, the intermediate film 113 is disposed, for example, between the glass plate 111 and the heating wire 130 in a portion where the ceramic layer 114 is present in plan view and the heating wire 130 is present.

[0052] In addition, when the ceramic layer 114 is present in a planar view but the upper bus bar 120T, the lower bus bar 120B, the lead bus bar 120L, and the heating wire 130 are not present, the intermediate film 113 is, for example, arranged between the ceramic layer 114 and the glass plate 112.

[0053] <Ceramic Layer 114> The ceramic layer 114 is, for example, a fired product of a dark-colored ceramic paste, and is formed by applying and firing a ceramic color paste containing a fusible glass frit containing a black pigment. The ceramic layer 114 is formed to prevent deterioration of the adhesive due to ultraviolet rays when the vehicle window glass 100 is bonded to the vehicle 10, and to improve the appearance by preventing the connection between the vehicle window glass 100 and the vehicle body 11 from being visible from the outside of the vehicle 10. The ceramic layer 114 is provided on the peripheral portion of the laminated glass 110 in a planar view. The peripheral portion of the laminated glass 110 refers to a peripheral portion of the laminated glass 110 that is slightly inside the outer edge of the laminated glass 110 and follows the outer edge of the laminated glass 110 in a planar view. The peripheral portion of the laminated glass 110 refers to the peripheral portions of the glass sheets 111 and 112, and the outer edge of the laminated glass 110 refers to the outer edges of the glass sheets 111 and 112.

[0054] The ceramic layer 114 is provided in one layer on the peripheral portion of the room-side main surfaces 111B and 112B of the glass plates 111 and 112. As an example, the ceramic layer 114 provided on the glass plate 111 and the ceramic layer 114 provided on the glass plate 112 have the same shape in a plan view and are also provided at the same position in a plan view. Note that the ceramic layer 114 may be provided only on the room-side main surface 111B of the glass plate 111, or may be provided only on the room-side main surface 112B of the glass plate 112.

[0055] <Top bus bar 120T> The top bus bar 120T is a bus bar extending along the top edge of the laminated glass 110. The top edge of the laminated glass 110 corresponds to the edge of the outer edge of the laminated glass 110 that extends along the X-axis direction on the +Y-axis direction side. In a plan view, the top bus bar 120T is provided between the glass plates 111 and 112 in a region that overlaps with the ceramic layer 114. The top bus bar 120T is provided along the top edge of the laminated glass 110 across the first region A1 and the second region A2 in the X-axis direction.

[0056] The top bus bar 120T is divided into left and right halves at the center in the X-axis direction of the vehicle window glass 100. The left end of the left top bus bar 120T is connected to the lead bus bar 120L provided on the left side of the vehicle window glass 100. The right end of the right top bus bar 120T is connected to the lead bus bar 120L provided on the right side of the vehicle window glass 100.

[0057] The top bus bar 120T may not be divided into left and right halves at the center in the X-axis direction of the vehicle window glass 100, but may be a single top bus bar 120T extending between the left and right ends of the vehicle window glass 100. In this case, one lead bus bar 120L may be connected to either one of the two ends of one top bus bar 120T.

[0058] <Bottom bus bar 120B> The bottom bus bar 120B is a bus bar that extends along the bottom side of the laminated glass 110. The bottom side of the laminated glass 110 corresponds to the side of the outer edge of the laminated glass 110 that extends along the X-axis direction on the -Y-axis direction side. In a plan view, the bottom bus bar 120B is provided between the glass plates 111 and 112 in a region that overlaps with the ceramic layer 114. The bottom bus bar 120B is provided along the bottom side of the laminated glass 110, spanning the first region A1 and the second region A2 in the X-axis direction.

[0059] The bottom bus bar 120B is divided into left and right halves at the center in the X-axis direction of the vehicle window glass 100. A positive (+) terminal 121P is connected to each of the left and right bottom bus bars 120B. The terminal 121P is exposed to the outside of the laminated glass 110 from a side surface of the intermediate film 113, and is connected to a power source such as the positive terminal of a battery of the vehicle 10 via a switch or the like.

[0060] The bottom bus bar 120B may not be divided into left and right halves at the center in the X-axis direction of the vehicle window glass 100, but may be a single bottom bus bar 120B extending between the left and right ends of the vehicle window glass 100. In this case, it is sufficient that one terminal 121P is connected to one bottom bus bar 120B.

[0061] <Lead bus bars 120L> The lead bus bars 120L are provided on the outer edge of the vehicle window glass 100, one on the +X-axis direction side (left side) and one on the −X-axis direction side (right side), and are connected to two top bus bars 120T that are separated left and right at the center in the X-axis direction of the vehicle window glass 100. The two lead bus bars 120L extend to the bottom side of the vehicle window glass 100, and a negative (−) terminal 121M is connected to the end on the bottom side. The terminal 121M is exposed to the outside of the laminated glass 110 from a side surface of the interlayer film 113, and is connected to the negative terminal of a power source such as a battery of the vehicle 10 via a switch or the like.

[0062] <Heat wire 130> The heat wire 130 includes a first heat wire 131 and a second heat wire 132. The first heat wire 131 and the second heat wire 132 are connected to the upper-side bus bar 120T and the lower-side bus bar 120B, and extend along the Y-axis direction between the upper-side bus bar 120T and the lower-side bus bar 120B.

[0063] The first heating wire 131 and the second heating wire 132 are, for example, round conductors, and for example, made of tungsten wire. The first heating wire 131 and the second heating wire 132 extend along the Y-axis direction while curving sinusoidally in the XY plane. However, because the amplitude of the sine wave is very small, they are shown as straight lines in FIG. 3 .

[0064] A plurality of first heating wires 131 are provided in the first region A1 and are connected between the top bus bar 120T and the bottom bus bar 120B. The first pitch of the first heating wires 131 in the width direction of the vehicle body 11 is wider than the second pitch of the second heating wires 132 in the width direction of the vehicle body 11. For example, the first pitch of the first heating wires 131 is preferably 3 mm to 8 mm, and more preferably 3.5 mm to 5 mm. The second pitch of the second heating wires 132 is, for example, 2 mm. The pitch between adjacent first heating wires 131 is preferably the same between the top bus bar 120T and the bottom bus bar 120B.

[0065] The first area A1 is an area where the communication device 20 is present, and is an area where radio waves transmitted or received by the communication device 20 pass through the vehicle window glass 100. Therefore, by making the first pitch of the first heating wires 131 wider than the second pitch of the second heating wires 132, a configuration is realized in which vertically polarized radio waves are less likely to be absorbed by the first heating wires 131. By providing such first heating wires 131 within the first area A1, the transmittance of the radio waves transmitted or received by the communication device 20 through the vehicle window glass 100 is increased.

[0066] Furthermore, the first heating wire 131 is thicker than the second heating wire 132. As an example, the thickness of the first heating wire 131 is preferably 0.025 mm or more and 0.03 mm or less. The thickness of the second heating wire 132 is preferably 0.02 mm or more and 0.025 mm or less. Because the first pitch in the X-axis direction of the first heating wires 131 in the first region A1 is wider than the second pitch in the X-axis direction of the second heating wires 132 in the second region A2, the first heating wires 131 are made thicker than the second heating wires 132 to obtain a heat generation distribution equivalent to that in the second region A2. The heat generation distribution refers to both the height of the heat generation temperature itself and the planar distribution of the heated region.

[0067] By making it easier for current to flow through the first heating wire 131 than through the second heating wire 132, the heat generation amount per first heating wire 131 is made greater than the heat generation amount per second heating wire 132, and the heat generation distribution of the laminated glass 110 in the first region A1 is made equivalent to the heat generation distribution of the laminated glass 110 in the second region A2. In this way, the first region A1 is ensured to function satisfactorily as a de-icer that efficiently melts ice or snow adhering to the outer surface of the vehicle window glass 100, or as a defogger that removes fogging (water droplets) on the surface of the vehicle window glass 100.

[0068] Here, a case will be described in which the first heating wire 131 is thicker than the second heating wire 132. However, even if the first heating wire 131 and the second heating wire 132 have the same thickness, as long as a sufficient de-icer or defogger function can be obtained within the first area A1, the first heating wire 131 and the second heating wire 132 may have the same thickness.

[0069] A plurality of second heating wires 132 are provided in the second region A2 and are connected between the top bus bar 120T and the bottom bus bar 120B. The second pitch of the second heating wires 132 in the width direction of the vehicle body 11 is, for example, 2 mm. The second heating wires 132 are similar to the heating wires 2 of the comparative vehicle window glass 1 (see FIGS. 2A to 2C ), and within the second region A2, they ensure sufficient function as a de-icer that efficiently melts ice or snow adhering to the outer surface of the vehicle window glass 100, or as a defogger that removes fogging (water droplets) from the surface of the vehicle window glass 100. Note that the pitch between adjacent second heating wires 132 is preferably the same between the top bus bar 120T and the bottom bus bar 120B. Furthermore, the pitch between adjacent first heating wires 131 and second heating wires 132 may be the same as the pitch between adjacent first heating wires 131, or the pitch between adjacent second heating wires 132 may be the same as the pitch between adjacent second heating wires 132.

[0070] The first heating wire 131 and the second heating wire 132 are connected to the upper bus bar 120T and the lower bus bar 120B, respectively, and therefore the same amount of power is supplied to them. Because the first heating wire 131 is thicker than the second heating wire 132, a larger current flows through the first heating wire 131 than through the second heating wire 132, and the amount of heat generated by each first heating wire 131 is greater than the amount of heat generated by each second heating wire 132.

[0071] In this way, the heat generation distribution within the first area A1 and the second area A2 can be made equal, and by making the first pitch of the first heating wire 131 wider than the second pitch of the second heating wire 132, the transparency of the radio waves transmitted or received by the communication device 20 in the first area A1 can be increased.

[0072] <Simulation Results for Transmitted Power> Figure 5 is a diagram showing an example of a simulation result for transmitted power. As an example, a simulation was performed under the following conditions: the thickness of the first heating wire 131 was set to 0.025 mm, the thickness of the second heating wire 132 was set to 0.02 mm, and the second pitch of the second heating wire 132 in the width direction of the vehicle body 11 was set to 2 mm; and the first pitch of the first heating wire 131 in the width direction of the vehicle body 11 was set to 2 mm, 4 mm, 6 mm, and 8 mm. Note that the result when the first pitch was 2 mm is for reference only, as the first pitch was equal to the second pitch.

[0073] 5, the horizontal axis represents frequency (GHz) and the vertical axis represents radio wave transmittance (dB). The radio wave transmittance represents the power of radio waves transmitted through the vehicle window glass 100 (transmitted power) relative to the transmission power of the communication device 20.

[0074] Simulations were performed with the first pitch set to 2 mm, 4 mm, 6 mm, and 8 mm, and it was found that at frequencies of 7 GHz or higher, the transmittance was equivalent for all first pitches, and there was almost no decrease in transmitted power relative to the transmitted power.

[0075] Under the condition of a frequency of 6 GHz, improvements were observed in the transmitted power when the first pitch was 4 mm, 6 mm, and 8 mm compared to the transmitted power when the first pitch was 2 mm. Therefore, it was found that in the 5.9 GHz and 5.8 GHz bands that can be used for V2X, sufficient transmitted power can be obtained if the first pitch is 4 mm or more.

[0076] Furthermore, even under the condition of a frequency of 6 GHz or less, improvements were observed in the transmitted power when the first pitch was 4 mm, 6 mm, and 8 mm compared to the transmitted power when the first pitch was 2 mm. The larger the first pitch, the smaller the degree of decrease in transmitted power tended to be.

[0077] Furthermore, it has been found that a first pitch of 6 mm or 8 mm provides good radio wave permeability but reduces heat distribution. For this reason, it is preferable that the frequency of the radio waves transmitted or received by the communication device 20 is 6 GHz or less and that the first pitch is 4 mm or less. From this perspective, in the simulation of heat generation amount described below, the pitches between the heating wires in the X-axis direction are set to 2.5 mm and 3.6 mm.

[0078] <Simulation results for heat generation amount> A simulation for heat generation amount was also performed. Because the heat generation amount is proportional to the density of the power supplied to the heating wire of the laminated glass, the tendency of the heat generation amount of the laminated glass used for the simulation was analyzed by calculating the average value of the power density of the heating wire (hereinafter referred to as average power density).

[0079] The simulation laminated glass was made by equalizing the pitch in the X-axis direction of all heating wires 130 in the first region A1 and the second region A2 of the laminated glass 110 of the embodiment. The average power density was calculated for three types of simulation laminated glass with different heating wire thicknesses and pitches. The three types of simulation laminated glass were as follows.

[0080] The first laminated glass had heating wires with a pitch of 2.5 mm in the X-axis direction and a thickness of 0.025 mm (25 μm). The first laminated glass corresponds to the laminated glass whose entirety corresponds to the second region A2 of the laminated glass 110 of the embodiment.

[0081] The second laminated glass had heating wires with a pitch of 3.6 mm in the x-axis direction and a thickness of 0.025 mm (25 μm), i.e., the second laminated glass was a glass in which the pitch of the heating wires in the x-axis direction of the first laminated glass was widened.

[0082] The third laminated glass had heating wires with a pitch of 3.6 mm in the X-axis direction and a thickness of 0.03 mm (30 μm). That is, the third laminated glass had thicker heating wires than the second laminated glass. The third laminated glass corresponds to the laminated glass whose entirety is the first region A1 of the laminated glass 110 of the embodiment.

[0083] For these three types of laminated glass used for simulation, the average power density of the heat rays in the left and right halves was calculated, and the following results were obtained. The left half of the laminated glass is the part where the heat rays are provided on the +X side of the center of the width of the laminated glass in the X axis direction. The right half of the laminated glass is the part where the heat rays are provided on the -X side of the center of the width of the laminated glass in the X axis direction.

[0084] The average power density of the heat ray of the first laminated glass is 650 (W / m 2 ), the right half is 662 (W / m 2 The average power density of the heat wire of the second laminated glass was 469 (W / m 2 ), the right half is 470 (W / m 2 The average power density of the second laminated glass, which had a configuration in which the pitch in the X-axis direction was increased without changing the thickness of the heating wires compared to the first laminated glass, was reduced by about 30% compared to the average power density of the heating wires of the first laminated glass.

[0085] The average power density of the third laminated glass in the heat ray is 630 (W / m 2 ), the right half is 641 (W / m 2 The average power density of the third laminated glass, which had a configuration in which the heating wires were thicker and the pitch in the X-axis direction was wider than that of the first laminated glass, was about 3% lower than the average power density of the heating wires of the first laminated glass, but the values ​​obtained were approximately the same.

[0086] In the laminated glass 110 of the vehicle window glass 100 of the embodiment, the configuration in the first region A1 corresponds to the third laminated glass for the simulation, and the configuration in the second region A2 corresponds to the first laminated glass for the simulation.

[0087] Therefore, it was confirmed that the laminated glass 110 of the vehicle window glass 100 of the embodiment can obtain an average power density similar to that of the first laminated glass for the simulation even in the first region A1. In other words, it was confirmed that the laminated glass 110 of the vehicle window glass 100 of the embodiment can achieve both good radio wave transmittance and heat distribution in the first region A1 where the communication device 20 is located in the width direction of the vehicle body 11.

[0088] <Effects> The vehicle window glass 100 includes a laminated glass 110, an upper bus bar 120T, a lower bus bar 120B, and a heating wire 130. The laminated glass 110 has a glass plate 111 having a principal surface 111A and a principal surface 111B, a glass plate 112 having a principal surface 112A and a principal surface 112B, and an interlayer provided between the principal surface 111B and the principal surface 112A, and is provided in an opening of the vehicle body 11. The upper bus bar 120T is provided along the upper edge of the laminated glass 110, between the principal surface 111B and the principal surface 112A. The lower bus bar 120B is provided along the lower edge of the laminated glass 110, between the principal surface 111B and the principal surface 112A. The heating wires 130 are provided between the main surfaces 111B and 112A and are connected between the top bus bar 120T and the bottom bus bar 120B. The laminated glass 110 has a first region A1 in which the communication device 20 is located in the width direction of the vehicle body 11, and a second region A2 other than the first region A1. The heating wires 130 include a first heating wire 131 provided in the first region A1 and connected between the top bus bar 120T and the bottom bus bar 120B, and a second heating wire 132 provided in the second region A2 and connected between the top bus bar 120T and the bottom bus bar 120B. A first pitch of the first heating wires 131 in the width direction of the vehicle body 11 is wider than a second pitch of the second heating wires 132 in the width direction of the vehicle body 11.

[0089] Therefore, good radio wave transmission can be ensured within the first area A1, and uniform heat distribution can be obtained in the first area A1 and the second area A2.

[0090] Therefore, it is possible to provide a vehicle window glass 100 that can achieve both good radio wave transmission and uniform heat distribution.

[0091] Furthermore, since the first heating wire 131 is thicker than the second heating wire 132, a larger current flows through the first heating wire 131. As a result, good radio wave permeability is ensured within the first area A1, and a more uniform heat distribution is obtained in the first area A1 and the second area A2.

[0092] Furthermore, since the first region A1 is located at the center or end of the width of the vehicle body 11, in accordance with a configuration in which the communication device 20 is located at the center or end of the width of the vehicle body 11, it is possible to achieve both good radio wave transparency within the first region A1 and uniform heat distribution in the first region A1 and the second region A2.

[0093] The first pitch and the second pitch are constant between the top bus bar 120T and the bottom bus bar 120B. This ensures good radio wave permeability in the first area A1 between the top bus bar 120T and the bottom bus bar 120B, and achieves uniform heat distribution in the first area A1 and the second area A2.

[0094] Furthermore, since the frequency of the radio waves transmitted or received by the communication device 20 is 6 GHz or less and the first pitch is 4 mm or less, the first heating wire 131 with a first pitch of 4 mm or less can ensure good radio wave permeability within the first area A1 for radio waves of 6 GHz or less, and an even heat distribution is obtained in the first area A1 and the second area A2.

[0095] Furthermore, since the radio waves transmitted or received by the communication device 20 are vertically polarized or circularly polarized, the transmittance of the radio waves can be reliably improved by widening the first pitch of the first heating wire 131 extending in the vertical direction (Y-axis direction) between the upper bus bar 120T and the lower bus bar 120B.

[0096] <First Modification> Fig. 6 is a plan view showing an example of the configuration of a vehicle window glass 100M1 according to a first modification of the embodiment. The vehicle window glass 100M1 includes a laminated glass 110, an upper bus bar 120TC, an upper bus bar 120TS, a lower bus bar 120BC, a lower bus bar 120BS, a lead bus bar 120L, a lead bus bar 120LC, and a heating wire 130M1. The upper bus bar 120TC is an example of a first upper bus bar, and the upper bus bar 120TS is an example of a second upper bus bar. The lower bus bar 120BC is an example of a first lower bus bar, and the lower bus bar 120BS is an example of a second lower bus bar.

[0097] The vehicle window glass 100M1 has a configuration in which an upper bus bar 120TS and a lower bus bar 120BS corresponding to the upper bus bar 120T and the lower bus bar 120B of the vehicle window glass 100 are arranged in two second regions A2, one each, and an upper bus bar 120TC and a lower bus bar 120BC are added to the first region A1. That is, the upper bus bar and the lower bus bar are divided between the first region A1 and the second region A2. A lead bus bar 120LC is connected to the upper bus bar 120TC.

[0098] The heating wire 130M1 includes a first heating wire 131M1 arranged in the first region A1 and a second heating wire 132 arranged in the second region A2, and the first heating wire 131M1 and the second heating wire 132 are equal in thickness. The first pitch of the first heating wire 131M1 in the X-axis direction is equal to the first pitch of the first heating wire 131 shown in Figure 3 in the X-axis direction, and therefore the first pitch of the first heating wire 131M1 in the X-axis direction is wider than the second pitch of the second heating wire 132 in the X-axis direction. The second heating wire 132 is the same as the second heating wire 132 shown in Figure 3.

[0099] For example, the lead bus bar 120LC is provided on the peripheral edge of the laminated glass 110, extending from the +Y-axis direction side of the top bus bar 120TS on the -X-axis direction side to the -X-axis direction side of the lead bus bar 120L. A negative (-) terminal 121MC is connected to the lead bus bar 120LC. For example, the terminal 121MC is provided at an end of the laminated glass 110 near a corner on the -X-axis direction side and the -Y-direction side. A positive (+) terminal 121PC is connected to the bottom bus bar 120BC. The terminal 121PC is located at the center of the laminated glass 110 in the x-axis direction, at the end on the -Y-direction side. The terminals 121PC and 121MC are exposed to the outside of the laminated glass 110 from the side surface of the interlayer film 113 and are connected to the positive and negative terminals, respectively, of a power source such as a battery of the vehicle 10 via a switch or the like.

[0100] In the vehicle window glass 100M1, the DC power supplied between the terminals 121PC and 121MC is greater than the DC power supplied between the terminals 121P and 121M. More specifically, the voltage value of the DC power supplied between the terminals 121PC and 121MC is greater than the voltage value of the DC power supplied between the terminals 121P and 121M. Therefore, the power supplied to the first heating wire 131M1 in the first area A1 is greater than the power supplied to the second heating wire 132 in the second area A2, and more current flows through the first heating wire 131M1 than through the second heating wire 132.

[0101] Since more current flows through the first heating wire 131M1 than through the second heating wire 132, the amount of heat generated per first heating wire 131M1 is greater than the amount of heat generated per second heating wire 132, and the heat distribution of the laminated glass 110 in the first region A1 can be made equivalent to the heat distribution of the laminated glass 110 in the second region A2.

[0102] This configuration of the vehicle window glass 100M1 makes it possible to make the heat distribution within the first area A1 and the second area A2 equal, and by making the first pitch of the first heating wire 131M1 wider than the second pitch of the second heating wire 132, it is possible to increase the transmittance of radio waves transmitted or received by the communication device 20 in the first area A1.

[0103] As described above, in the vehicle window glass 100M1, the top bus bar 120T has the top bus bar 120TC located in the first region A1 and the top bus bar 120TS located in the second region A2. The bottom bus bar 120B has the bottom bus bar 120BC located in the first region A1 and the bottom bus bar 120BS located in the second region A2. The first heating wire 131M1 is connected between the top bus bar 120TC and the bottom bus bar 120BC, and the second heating wire 132 is connected between the top bus bar 120TS and the bottom bus bar 120BS. The power supplied to the first heating wire 131M1 via the top bus bar 120TC and the bottom bus bar 120BC is greater than the power supplied to the second heating wire 132 via the top bus bar 120TS and the bottom bus bar 120BS.

[0104] As a result, more current flows through the first heating wire 131 than through the second heating wire 132, and the heat generation amount of the first heating wire 131M1 can be made greater than that of the second heating wire 132, thereby achieving a more even heat generation distribution in the first area A1 and the second area A2 while ensuring good radio wave permeability within the first area A1.

[0105] Therefore, it is possible to provide a vehicle window glass 100M1 that can achieve both good radio wave transmittance and more uniform heat distribution.

[0106] As described above, the power supplied to the first heating wire 131M1 in the first region A1 may be greater than the power supplied to the second heating wire 132 in the second region A2, and the first heating wire 131M1 may be thicker than the second heating wire 132. By thickening the first heating wire 131M1 in the first region A1, current flows more easily through the first heating wire 131M1, and the power supplied to the first heating wire 131M1 can be reduced compared to when the first heating wire 131M1 and the second heating wire 132 are the same thickness. In addition, the first pitch of the first heating wire 131M1 in the X-axis direction can be further widened.

[0107] 7 is a plan view showing an example of the configuration of a vehicle window glass 100M2 according to a second modification of the embodiment. The vehicle window glass 100M2 includes a laminated glass 110M, an upper bus bar 120TM, a lower bus bar 120B, a lead bus bar 120L, and a heating wire 130M2. The portion of the upper bus bar 120TM located within the first region A1 is an example of a first portion, and the portion located within the second region A2 is an example of a second portion.

[0108] In the laminated glass 110M, the shape of the ceramic layer 114M in plan view is different from that of the ceramic layer 114 shown in Fig. 3 in order to avoid the camera 30. As an example, the camera 30 is attached to the interior side of the upper part of the vehicle window glass 100M2, and more specifically, it may be attached in place of the communication device 20 shown on the interior side of the upper part of the vehicle window glass 100 in Fig. 1A. The camera 30 is mounted on the vehicle 10 to capture images of the area ahead of the vehicle 10, and as an example, acquires images for an Advanced Driver-Assistance Systems (ADAS) of the vehicle 10.

[0109] The ceramic layer 114M has a convex portion 114MA in the left-right center of the upper part of the laminated glass 110M. The convex portion 114MA protrudes downward from the peripheral edge of the laminated glass 110M2 within the first region A1 and is provided in a portion that surrounds the camera 30 in a plan view. The convex portion 114MA has an opening 114MB located in front of the camera 30. The opening 114MB is a portion where the ceramic layer 114M is not formed and is included in the imaging field of view of the camera 30. The imaging field of view of the camera 30 is the range in which the camera 30 can acquire images.

[0110] As an example, the camera 30 is attached to the laminated glass 110M by fixing the bracket or the like made of resin to the main surface 112B of the glass plate 112 on the interior side with an adhesive or the like. The camera 30 is attached to the laminated glass 110M so that the lens faces forward of the vehicle body 11 through the opening 114MB. The bracket or the like may have ventilation holes or the like, and the internal space of the bracket or the like may be connected to the interior space of the vehicle 10.

[0111] In a vehicle window glass 100M2 including such a laminated glass 110M, the radio wave propagation region 21A is located below the convex portion 114MA of the ceramic layer 114M.

[0112] The top-side bus bar 120TM is bent in a crank shape along the convex portion 114MA of the ceramic layer 114M. More specifically, in the second region A2, the top-side bus bar 120TM extends in the X-axis direction along the top side of the laminated glass 110M, and in the first region A1, the top-side bus bar 120TM is bent in a crank shape along the convex portion 114MA of the ceramic layer 114M. The bottom-side bus bar 120B shown in FIG. 7 is the same as the bottom-side bus bar 120B shown in FIG. 3.

[0113] Therefore, the length in the Y-axis direction between the upper bus bar 120TM and the lower bus bar 120B in the first region A1 is shorter than the length in the Y-axis direction between the upper bus bar 120TM and the lower bus bar 120B in the second region A2.

[0114] The heating wire 130M2 includes a first heating wire 131M2 and a second heating wire 132. The second heating wire 132 is the same as the second heating wire 132 shown in FIG. 3. The first heating wire 131M2 has the same thickness as the second heating wire 132 and is arranged at a first pitch that is the same as the first pitch in the X-axis direction of the first heating wire 131 shown in FIG. 3. The length of the first heating wire 131M2 in the Y-axis direction is shorter than the length of the second heating wire 132 in the Y-axis direction. Therefore, the resistance value between both ends of the first heating wire 131M2 is lower than the resistance value between both ends of the second heating wire 132.

[0115] The first heating wire 131M2 and the second heating wire 132 are connected between the top bus bar 120TM and the bottom bus bar 120B, and therefore the same amount of power is supplied to them. The first heating wire 131M2 is shorter and has a lower resistance than the second heating wire 132, and therefore a larger current flows through the first heating wire 131M2 than through the second heating wire 132. As a result, the amount of heat generated per first heating wire 131M2 is greater than the amount of heat generated per second heating wire 132.

[0116] In this way, the heat distribution within the first area A1 and the second area A2 can be made equal, and by making the first pitch of the first heating wire 131M2 wider than the second pitch of the second heating wire 132, the transparency of the radio waves transmitted or received by the communication device 20 in the first area A1 can be increased.

[0117] As described above, in the vehicle window glass 100M2, the first region A1 is located in the center in the width direction of the vehicle body 11, and the second region A2 is located on both sides of the first region A1 in the width direction of the vehicle body 11. The top bus bar 120TM has a first portion located in the first region A1 and two second portions located in the second region A2 on both sides of the first region A1. The top bus bar 120TM is bent in a crank shape between the first portion and the two second portions, and the first portion is located closer to the bottom edge of the laminated glass 110 than the two second portions are with respect to the top edge of the laminated glass 110.

[0118] Therefore, the distance between the top bus bar 120TM and the bottom bus bar 120B in the first region A1 is shorter than the distance between the top bus bar 120TM and the bottom bus bar 120B in the second region A2. That is, the first heating wire 131M2 is shorter and has a lower resistance than the second heating wire 132, so more current flows through the first heating wire 131M2. This ensures good radio wave transparency in the first region A1 while achieving a more uniform heat distribution in the first region A1 and the second region A2.

[0119] Therefore, it is possible to provide a vehicle window glass 100M2 that can achieve both good radio wave transmittance and more uniform heat distribution.

[0120] The first heating wires 131M2 may be thicker than the second heating wires 132. By thickening the first heating wires 131M2 in the first region A1, the resistance of the first heating wires 131M2 is further reduced, making it easier for current to flow and allowing the amount of heat generated per first heating wire 131M2 to be increased compared to when the first heating wires 131M2 and the second heating wires 132 are the same thickness. Therefore, for example, the first pitch of the first heating wires 131M2 in the X-axis direction can be made wider.

[0121] Furthermore, instead of using the top-side bus bar 120TM bent in a crank shape along the convex portion 114MA of the ceramic layer 114M, the following may be done. Like the two top-side bus bars 120TS and one top-side bus bar 120TC of the first modification, the top-side bus bar may be divided into the first region A1 and the second region A2, and the top-side bus bar 120TC in the first region A1 may be positioned further toward the -Y-axis direction than the top-side bus bar 120TS in the second region A2 to avoid the convex portion 114MA of the ceramic layer 114M. In this case, on the bottom side, the bottom-side bus bar 120BC may be provided in the first region A1, and the bottom-side bus bar 120BS may be provided in the second region A2. The power supplied between the top bus bar 120TC and the bottom bus bar 120BC in the first region A1 may be greater than the power supplied between the top bus bar 120TS and the bottom bus bar 120BS in the second region A2. In this case, the thickness of the first heating wires 131M2 in the first region A1 and the second heating wires 132 in the second region A2 may be equal. Because the first heating wires 131M2 in the first region A1 are shorter and have lower resistance than the second heating wires 132 in the second region A2, the first pitch of the first heating wires 131M2 in the X-axis direction can be made wider. Furthermore, if the first heating wires 131M2 are made thicker than the second heating wires 132, the first pitch of the first heating wires 131M2 in the X-axis direction can be made even wider.

[0122] In this case, the top bus bar 120TC is located closer to the bottom of the laminated glass 110 than the top bus bar 120TS with respect to the top edge of the laminated glass 110, so the distance between the top bus bar 120TC and the bottom bus bar 120BC in the first region A1 is shorter than the distance between the top bus bar 120TS and the bottom bus bar 120BS in the second region A2. In other words, the first heating wire 131M1 is shorter and has a lower resistance than the second heating wire 132, so more current flows through the first heating wire 131M1. This ensures good radio wave transparency in the first region A1 while achieving a more uniform heat distribution in the first region A1 and the second region A2.

[0123] Therefore, it is possible to provide a vehicle window glass 100M1 that can achieve both good radio wave transmittance and more uniform heat distribution.

[0124] While exemplary vehicle window panes according to the present disclosure have been described above, the present disclosure is not limited to the specifically disclosed embodiments, and various modifications and variations are possible without departing from the scope of the claims.

[0125] This international application claims priority based on Japanese Patent Application No. 2022-144492, filed on September 12, 2022, the entire contents of which are incorporated herein by reference.

[0126] DESCRIPTION OF SYMBOLS 10 Vehicle 11 Vehicle body 11A Window frame 12 Dashboard 20 Communication device (an example of a communication unit) 21A Radio wave propagation area 100, 100M1, 100M2 Vehicle window glass 110, 110M Laminated glass 111 Glass plate (an example of a first glass plate) 111A Main surface (an example of a first main surface) 111B Main surface (an example of a second main surface) 112 Glass plate (an example of a second glass plate) 112A Main surface (an example of a third main surface) 112B Main surface (an example of a fourth main surface) 113 Interlayer 114, 114M Ceramic layer 114MA Convex portion 114MB Opening 120T, 120TM Top bus bar 120TC Top bus bar (an example of a first top bus bar) 120TS Top bus bar (an example of a second top bus bar) 120B Bottom bus bar 120BC Bottom bus bar (an example of a first bottom bus bar) 120BS Bottom bus bar (an example of a second bottom bus bar) 120L, 120LC Lead bus bar Lead bus bar 130, 130M1, 130M2 Heat wire 131, 131M1, 131M2 First heat wire 132 Second heat wire

Claims

1. a laminated glass provided in an opening of a vehicle body, the laminated glass comprising a first glass plate having a first principal surface and a second principal surface, a second glass plate having a third principal surface and a fourth principal surface, and an interlayer provided between the second principal surface and the third principal surface; an upper bus bar provided along an upper edge of the laminated glass between the second main surface and the third main surface; a lower bus bar provided between the second main surface and the third main surface along a lower side of the laminated glass; a heating section provided between the second main surface and the third main surface and connected between the upper side bus bar and the lower side bus bar; Including, The laminated glass has a first region in a width direction of the vehicle body where a communication unit is located, and a second region other than the first region, A vehicle window glass, wherein the heating portion has a first heating wire provided in the first region and connected between the upper side bus bar and the lower side bus bar, and a second heating wire provided in the second region and connected between the upper side bus bar and the lower side bus bar, and a first pitch of the first heating wire in the width direction of the vehicle body is wider than a second pitch of the second heating wire in the width direction of the vehicle body.

2. The vehicle window glass according to claim 1 , wherein the first heat ray is thicker than the second heat ray.

3. The vehicle window glass according to claim 1 or 2, wherein the first region is located at a center portion or an end portion in a width direction of the vehicle body.

4. the top bus bar includes a first top bus bar located in the first region and a second top bus bar located in the second region; the bottom bus bar includes a first bottom bus bar located in the first region and a second bottom bus bar located in the second region; the first hot wire is connected between the first upper bus bar and the first lower bus bar; the second hot wire is connected between the second upper bus bar and the second lower bus bar, 3. The vehicle window glass according to claim 1, wherein the power supplied to the first heating wire via the first upper bus bar and the first lower bus bar is greater than the power supplied to the second heating wire via the second upper bus bar and the second lower bus bar.

5. The vehicle window glass according to claim 4 , wherein the first upper bus bar is located closer to a lower side of the laminated glass than the second upper bus bar is, with respect to an upper side of the laminated glass.

6. The first region is located at a center portion in a width direction of the vehicle body, The second region is located on both sides of the first region in a width direction of the vehicle body, the top bus bar has a first portion located in the first region and two second portions located in the second region on both sides of the first region, 3. The vehicle window glass according to claim 1, wherein the upper bus bar is bent in a crank shape between the first portion and the two second portions, and the first portion is located closer to a lower edge of the laminated glass than the two second portions are with respect to an upper edge of the laminated glass.

7. 3. The vehicle window glass according to claim 1, wherein the first pitch and the second pitch are constant between the top bus bar and the bottom bus bar.

8. The frequency of the radio waves transmitted or received by the communication unit is a frequency in the 6 GHz band or a frequency of 6 GHz or lower, The vehicle window glass according to claim 1 or 2, wherein the first pitch is 4 mm or less.

9. The vehicle window glass according to claim 1 or 2, wherein the radio waves transmitted or received by the communication unit are vertically polarized waves or circularly polarized waves.