Glass plate with heating wire

Abstract

A heating wire-provided glass plate comprising: a glass plate having an information acquisition region through which an information acquisition device acquires information about the outside of a vehicle; and a heating wire provided in the information acquisition region. When the glass plate is attached to the body of a vehicle with the glass plate sloped, the information acquisition region has a trapezoidal shape, and has a horizontal upper side and a horizontal lower side, as viewed from the direction of the optical axis of the information acquisition region. Streaks produced due to undulation of the glass plate are arranged and spaced apart from each other in a lateral direction parallel to the upper and lower sides, and each extend in a vertical direction perpendicular to the lateral direction. The heating wire has a vertical crossing part that vertically crosses the information acquisition region. A plurality of the vertical crossing parts are provided and spaced apart from each other in the horizontal direction.

Description

[Technical Field]

[0001] The present disclosure relates to a glass sheet equipped with an electric heating wire. [Background technology]

[0002] Patent Document 1 discloses laminated glass. This laminated glass includes a first glass plate, a second glass plate disposed opposite the first glass plate, and an intermediate layer disposed between the first and second glass plates. The intermediate layer includes a first bus bar, a second bus bar, and a plurality of heating wires connecting the first and second bus bars. The heating wires generate heat when supplied with electricity, removing frosting (water droplets) and ice on the surface of the laminated glass.

[0003] In recent years, various information acquisition devices have been installed in vehicles to assist vehicle driving. The information acquisition device includes, for example, a light-receiving element that receives visible light or infrared light and acquires an image of the outside of the vehicle using the light-receiving element. The laminated glass has an information acquisition area that acquires information using the information acquisition device. An electric heating wire is provided in the information acquisition area to remove fogging and ice. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2017 / 065114 Summary of the Invention [Problem to be solved by the invention]

[0005] The information acquisition device acquires information outside the vehicle through a glass plate attached to the vehicle body in an inclined state.

[0006] Conventionally, the performance of an information acquisition device may be reduced due to streaks caused by undulations in the glass plate and refractive index distribution caused by heat generated by an electric heating wire.

[0007] One aspect of the present disclosure provides a technique that can improve the information acquisition performance of an information acquisition device. [Means for solving the problem]

[0008] A glass plate with an electric heating wire according to one aspect of the present disclosure includes a glass plate having an information acquisition area that acquires information about the outside of the vehicle using an information acquisition device, and an electric heating wire provided in the information acquisition area. When the glass plate is attached to the vehicle body in an inclined state, the information acquisition area has a trapezoidal shape when viewed from the direction of the optical axis of the information acquisition device, and has a horizontal upper side and a horizontal lower side. A plurality of streaks caused by waviness of the glass plate are arranged at intervals in a horizontal direction parallel to the upper side and the lower side, and each extend in a vertical direction perpendicular to the horizontal direction. The electric heating wire has a vertical section that crosses the information acquisition area in the vertical direction. A plurality of the vertical sections are provided at intervals in the horizontal direction. The information acquisition area includes a first outer area, a central area, and a second outer area in this order in the horizontal direction. The heating wires arranged in the first outer area and the second outer area have a higher electrical resistance per wire than the heating wire arranged in the central area. [Effects of the Invention]

[0009] According to one aspect of the present disclosure, the information acquisition performance of an information acquisition device can be improved. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a view of a glass plate with heating wires according to one embodiment, viewed from the direction of the optical axis of an information acquisition device. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 3 is a perspective view showing the optical axis of the information acquisition device of FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 5 is a cross-sectional view showing the propagation path of light passing through the glass plate with heating wires of FIG. [Figure 6] FIG. 6 is a cross-sectional view showing a modification of FIG. [Figure 7]FIG. 7 is a view of a first example of the heating wire pattern as viewed from the Y-axis direction. [Figure 8] FIG. 8 is a view of a second example of the heating wire pattern as viewed from the Y-axis direction. [Figure 9] FIG. 9 is a diagram showing the relationship between the bottom side of the information acquisition area shown in FIG. 8 and the angle of view of the information acquisition device. [Figure 10] FIG. 10 is a view of a third example of the heating wire pattern as viewed from the Y-axis direction. [Figure 11] FIG. 11 is a view of a fourth example of the heating wire pattern as viewed from the Y-axis direction. [Figure 12] FIG. 12 is a view of a fifth example of the heating wire pattern as viewed from the Y-axis direction. [Figure 13] FIG. 13 is a view of the sixth example of the heating wire pattern as viewed from the Y-axis direction. [Figure 14] FIG. 14 is a view of the seventh example of the heating wire pattern as viewed from the Y-axis direction. [Figure 15] FIG. 15 is a view of the eighth example of the heating wire pattern as viewed from the Y-axis direction. [Figure 16] FIG. 16 is a view of the ninth example of the heating wire pattern as viewed from the Y-axis direction. [Figure 17] FIG. 17 is a perspective view showing the incident surface at the midpoint of the right side of the information acquisition area in FIG. [Figure 18] FIG. 18 is a diagram showing a method for measuring perspective distortion. [Figure 19] FIG. 19 is a view of a glass plate with heating wires according to a reference embodiment, viewed from the direction of the optical axis of an information acquisition device. [Figure 20] FIG. 20 is a cross-sectional view showing the propagation path of light passing through a glass plate with heating wires according to a reference embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In each drawing, the same or corresponding components are denoted by the same reference numerals, and their description may be omitted. In each drawing, the X-axis, Y-axis, and Z-axis directions are perpendicular to one another. In the specification, a range of values ​​indicated by "to" means that the values ​​before and after the range are included as the lower and upper limits.

[0012] As shown in FIG. 2 , the laminated glass 1 includes a first glass plate 2, a second glass plate 3 facing the first glass plate 2, and an interlayer film 4 bonding the first glass plate 2 and the second glass plate 3 together. The first glass plate 2 is located closer to the exterior side of the vehicle than the second glass plate 3, and the second glass plate 3 is located closer to the interior side of the vehicle than the first glass plate 2. In this embodiment, the second glass plate 3 is located closer to the interior side of the vehicle than the first glass plate 2, but it may also be located closer to the exterior side of the vehicle than the first glass plate 2. The number of glass plates constituting the laminated glass 1 may be three or more. When the number of glass plates constituting the laminated glass 1 is three or more, the number of interlayer films may be two or more. When the number of glass plates constituting the laminated glass 1 is three, it is preferable that the thickness of the glass plate on the interior side of the vehicle be smaller than the thickness of the glass plate on the exterior side of the vehicle and the thickness of the middle glass plate.

[0013] The first glass plate 2 may be made of either inorganic glass or organic glass. Examples of inorganic glass include soda lime glass and aluminosilicate glass. The inorganic glass may be either untempered glass or tempered glass. Untempered glass is made by forming molten glass into a plate shape and slowly cooling it. Tempered glass is made by forming a compressive stress layer on the surface of untempered glass. Tempered glass may be either physically tempered glass (e.g., air-cooled tempered glass) or chemically tempered glass. On the other hand, examples of organic glass include transparent resins such as polycarbonate, acrylic resin, polyvinyl chloride, and polystyrene. An example of an acrylic resin is polymethyl methacrylate. Like the first glass plate 2, the second glass plate 3 may be made of either inorganic glass or organic glass.

[0014] The first glass sheet 2 is formed so as to convexly face the exterior of the vehicle. Gravity forming, press forming, or the like is used to bend the first glass sheet 2. When the first glass sheet 2 is physically tempered glass, the glass surface may be strengthened by rapidly cooling the uniformly heated glass sheet from a temperature near its softening point during bending, and generating compressive stress on the glass surface due to the temperature difference between the glass surface and the interior of the glass. When the first glass sheet 2 is chemically tempered glass, the glass surface may be strengthened after bending by generating compressive stress on the glass surface using an ion exchange method or the like. Note that the second glass sheet 3 is also formed so as to convexly face the exterior of the vehicle, similar to the first glass sheet 2.

[0015] The first glass plate 2 is located closer to the vehicle exterior than the second glass plate 3, and therefore has a thickness of 1.8 mm or more to prevent scratches from flying stones. The thickness of the first glass plate 2 is 3.0 mm or less from the viewpoints of light weight and formability. The thickness of the first glass plate 2 may be constant or may vary depending on the position.

[0016] The second glass sheet 3 is disposed closer to the interior of the vehicle than the first glass sheet 2, and may therefore be thinner than the first glass sheet 2. From the viewpoint of ease of handling, the thickness of the second glass sheet 3 is 0.3 mm or more. From the viewpoints of light weight and formability, the thickness of the second glass sheet 3 is 2.3 mm or less. The thickness of the second glass sheet 3 may be constant or may vary depending on the position.

[0017] The interlayer film 4 is formed from a common resin, such as a thermoplastic resin such as polyvinyl butyral resin (PVB), ethylene-vinyl acetate copolymer resin (EVA), urethane, or ionomer resin. The interlayer film 4 exhibits adhesive properties when heated. The interlayer film 4 may have either a single-layer structure or a multi-layer structure. For example, the interlayer film 4 may have one or more layers selected from a sound-insulating layer, a colored transparent layer, an ultraviolet-blocking layer, and an infrared-blocking layer.

[0018] The thickness of the interlayer film 4 is 0.5 mm or more from the viewpoint of adhesiveness. The thickness of the interlayer film 4 is 3 mm or less from the viewpoint of lightweight and easy handling. The thickness of the interlayer film 4 may be constant or may vary depending on the position. For example, when an image from a head-up display is projected onto the laminated glass 1, the thickness of the interlayer film 4 increases from bottom to top to prevent the occurrence of double images. The interlayer film 4 is formed in a wedge shape, with a wedge angle of, for example, 1.0 mrad or less.

[0019] The laminated glass 1 is obtained by overlapping a first glass plate 2 and a second glass plate 3 with an interlayer film 4 interposed therebetween, preparing a polymer, and then subjecting the prepared polymer to a pressure and heat treatment in an autoclave or the like. Before preparing the polymer, the first glass plate 2 and the second glass plate 3 are heat treated and bent. The manufacturing method of the laminated glass 1 may be any ordinary method, and does not necessarily need to include pressure and heat treatment in an autoclave or the like.

[0020] The laminated glass 1 is used, for example, as a vehicle windshield. In this case, an adhesive is applied to the peripheral edge of the laminated glass 1 to bond the laminated glass 1 to the vehicle body. The adhesive is, for example, urethane. A light-shielding film 5 is formed on the peripheral edge of the laminated glass 1 to prevent deterioration of the adhesive due to ultraviolet rays. The light-shielding film 5 is formed, for example, by firing a black ceramic paste. The black ceramic paste is applied to the first glass sheet 2 or the second glass sheet 3 and fired simultaneously with bending of the first glass sheet 2 or the second glass sheet 3.

[0021] The light-shielding film 5 is formed, for example, on both the second surface 12 and the fourth surface 14 of the first surface 11, the second surface 12, the third surface 13, and the fourth surface 14 of the laminated glass 1. The first surface 11 is the main surface of the first glass plate 2 facing the exterior side of the vehicle. The second surface 12 is the main surface of the first glass plate 2 facing the interior side of the vehicle. The third surface 13 is the main surface of the second glass plate 3 facing the exterior side of the vehicle. The fourth surface 14 is the main surface of the second glass plate 3 facing the interior side of the vehicle. The light-shielding film 5 may be formed on only one of the second surface 12 and the fourth surface 14.

[0022] In addition to the first glass sheet 2, the second glass sheet 3, the interlayer film 4, and the light-shielding film 5, the laminated glass 1 may also include one or more layers selected from the group consisting of a water-repellent layer, an ultraviolet-blocking layer, an infrared-blocking layer, a heat-insulating layer, and a colored transparent layer. The heat-insulating layer has the function of suppressing radiant heat transfer. The colored transparent layer has an anti-glare function that reduces the transmittance of visible light. These functional layers may be located either on the exterior or interior of the laminated glass 1.

[0023] In this embodiment, the laminated glass 1 is used as a windshield of a vehicle, but it may also be used as a rear glass or side glass. The rear glass and side glass only need to have the first glass plate 2, and do not necessarily have the second glass plate 3 and the interlayer film 4. In other words, the rear glass and side glass may be single-pane glass instead of the laminated glass 1.

[0024] The first glass plate 2 has an information acquisition area 21. The information acquisition area 21 is an area where information about the outside of the vehicle is acquired by an information acquisition device 9. The information acquisition device 9 includes, for example, a light receiving element that receives visible light or infrared light, and acquires an image of the outside of the vehicle using the light receiving element. The information acquisition device 9 is, for example, a camera such as a visible light camera or an infrared camera, or a LiDAR (Light Imaging Detection and Ranging). The LiDAR emits laser light, receives reflected light from an object, and measures the distance and direction to the object. The LiDAR scans the laser light over the entire information acquisition area 21.

[0025] As described above, the first glass plate 2 has the information acquisition region 21. The information acquisition region 21 is, for example, an opening in the light-shielding film 5, and is surrounded on all four sides by the light-shielding film 5. Note that the information acquisition region 21 may be surrounded on only three sides (top, left, and right sides) by the light-shielding film 5, and the bottom of the information acquisition region 21 may be open.

[0026] Like the first glass plate 2, the second glass plate 3 also has an information acquisition region 31. The information acquisition region 21 of the first glass plate 2 and the information acquisition region 31 of the second glass plate 3 coincide with each other. Therefore, hereinafter, the information acquisition region 21 of the first glass plate 2 will be described, and a description of the information acquisition region 31 of the second glass plate 3 will be omitted.

[0027] As shown in FIG. 2, the first glass plate 2 and other components are attached to the vehicle body in an inclined state. In this state, the information acquisition area 21, as viewed from the direction of the optical axis 9A of the information acquisition device 9, has a trapezoidal shape as shown in FIG. 1, with a horizontal upper side 22 and a horizontal lower side 23. Note that the trapezoid shape shown in FIG. 1 includes not only a mathematical trapezoid, but also a shape that includes a curved portion and a shape in which the upper side 22 and the lower side 23 intersect at an angle of 10° or less. The X-axis direction parallel to the upper side 22 and the lower side 23 is the horizontal direction, and the Z-axis direction perpendicular to the horizontal direction is the vertical direction. Note that the Y-axis direction is the thickness direction. The positive side of the Y-axis direction is the inside of the vehicle, and the negative side of the Y-axis direction is the outside of the vehicle. When the information acquisition device 9 scans with laser light, the average direction of all scanning directions is the optical axis 9A.

[0028] 3, the information acquisition device 9 receives light from an entire rectangular area 9C, which is located on the outer side of the vehicle and has a center 9B at the optical axis 9A, in a cross section perpendicular to the optical axis 9A of the information acquisition device 9. When viewed from the direction of the optical axis 9A, the information acquisition area 21 of the first glass plate 2 is trapezoidal because the first glass plate 2 is attached to the vehicle body in an inclined state. The length of the lower side 23 is longer than the length of the upper side 22.

[0029] As shown in FIG. 4, the first glass plate 2 has undulations in the horizontal direction. These undulations are formed when molten glass is formed into a plate. For example, the float method is used to form molten glass into a plate. In the float method, molten glass is continuously supplied onto the surface of molten metal, and is formed into a strip while flowing on the horizontal surface. The strip-shaped glass does not have undulations in the flow direction, but does have undulations in the width direction. The undulations are waves.

[0030] In FIG. 4, A is the antinode of the wave and B is the node of the wave. The waves are visible as streaks 29 (see FIG. 1). The streaks 29 are caused by undulations, and the pitch P1 of the streaks 29 matches the undulation period. The undulation period is, for example, 5 mm to 50 mm. The undulation amplitude is 0.1 μm to 5 μm. The undulation period and amplitude can be measured using a commercially available surface roughness measuring device.

[0031] The first glass plate 2 has undulations in the horizontal direction but not in the vertical direction. Therefore, as shown in Fig. 1, multiple streaks 29 on the first glass plate 2 are arranged at intervals in the horizontal direction and each extends in the vertical direction. Therefore, as shown in Fig. 5, the phase difference of the undulations between the incident position and the exit position of the light ray L is small, and the variation in the exit direction of the light ray L is small.

[0032] On the other hand, according to the reference embodiment, as shown in Fig. 19, the streaks 29 on the first glass plate 2 are arranged at intervals in the vertical direction and extend horizontally. This means that the first glass plate 2 has waviness in the vertical direction but not in the horizontal direction. Therefore, as shown in Fig. 20, there is a large phase difference in the waviness between the incident position and the exit position of the light ray L, and there is a large variation in the exit direction of the light ray L. The variation in the exit direction is due to the effect of refraction.

[0033] As described above, this embodiment can reduce the variation in the emission direction of light ray L compared to the reference embodiment, thereby reducing the magnitude of perspective distortion. Perspective distortion is a phenomenon in which a perspective image seen through glass is distorted. The magnitude of perspective distortion is measured in accordance with the perspective distortion test (5.12) of Japanese Industrial Standard JIS R3212:2015.

[0034] Like the streaks 29 of the first glass plate 2, the streaks of the second glass plate 3 may be arranged at intervals in the width direction and each may extend vertically. This can further reduce perspective distortion. When the streaks of the second glass plate 3 extend vertically, the streaks 29 of the first glass plate 2 may extend horizontally. It is sufficient that at least one of the streaks 29 of the first glass plate 2 and the streaks of the second glass plate 3 extend vertically. As described above, the window glass may be single-pane glass instead of laminated glass 1, in which case the second glass plate 3 and the interlayer film 4 may not be provided.

[0035] The laminated glass 1 is a glass plate with an electric heating wire, and has an electric heating wire 6 provided in the information acquisition area 21. The material of the electric heating wire 6 is not particularly limited as long as it is an electrically conductive material, and examples thereof include a pure metal selected from the group consisting of gold, silver, copper, aluminum, tin, iron, nickel, chromium, and tungsten, an alloy containing one or more metals selected from this group, carbon, or graphene.

[0036] The heating wire 6 generates heat when power is supplied, and removes frost and ice that has formed on the information acquisition area 21. The heating wire 6 is provided, for example, between the first glass plate 2 and the second glass plate 3, preferably between the interlayer film 4 and the second glass plate 3, and particularly preferably on the surface of the second glass plate 3 facing the interior of the vehicle.

[0037] Alternatively, the heating wire 6 may be disposed between the first glass plate 2 and the second glass plate 3 while being supported by a base film. The base film improves the handleability of the heating wire 6. The base film is formed of a transparent resin, for example, the same material as the interlayer film 4. However, the material of the base film does not have to be one that develops adhesiveness to glass upon heating, and may be, for example, polyethylene terephthalate (PET). In this case, an adhesive layer may be disposed between the base film and the first glass plate 2 or the second glass plate 3.

[0038] The heating wire 6 may be arranged on the interior side of the vehicle on the fourth surface 14 of the laminated glass 1. Alternatively, the heating wire 6 may be arranged on the interior side of the vehicle on the fourth surface 14 of the laminated glass 1 while being supported by a base film. As described above, if the window glass is a single-pane glass rather than a laminated glass 1, the heating wire 6 is arranged on the interior side of the first glass sheet 2.

[0039] As shown in Fig. 7 and other figures, the heating wire 6 has a vertical section 61 that cuts across the information acquisition area 21 in the vertical direction. A plurality of vertical sections 61 are provided at intervals in the horizontal direction, and each extends in the vertical direction. The vertical sections 61 are provided parallel to the streaks 29. As will be described in more detail later, the vertical sections 61 only need to cut across the information acquisition area 21 in the vertical direction, and may be provided at an angle to the streaks 29.

[0040] The longitudinal section 61 may be a straight line, but may also be a wavy line such as a sinusoidal curve as shown in FIG. 7 to suppress the generation of light beams. Light beams are a phenomenon in which streaks of light are visible, and are caused by the diffraction and interference of light. If the phases of adjacent longitudinal sections 61 are shifted, the generation of light beams can be further suppressed.

[0041] When the heating wire 6 generates heat, the temperature of the interlayer 4 and other components rises, causing the refractive index to decrease. Since multiple vertical sections 61 are arranged at intervals in the horizontal direction, low refractive index and high refractive index sections are arranged in the horizontal direction. From the perspective of perspective distortion, the horizontal variation in the refractive index is equivalent to the occurrence of undulations in the horizontal direction.

[0042] According to this embodiment, since the refractive index varies in the horizontal direction, the magnitude of perspective distortion can be reduced compared to when the refractive index varies in the vertical direction. This is because undulations in the horizontal direction can suppress the influence of refraction compared to undulations in the vertical direction, and can reduce the magnitude of perspective distortion.

[0043] As shown in Figure 4, the horizontal pitch P2 of the vertical cross-sections 61 is preferably 25 mm or less. If P2 is 25 mm or less, the interlayer film 4 is heated more uniformly, the refractive index difference is reduced, and the magnitude of perspective distortion is reduced. P2 is more preferably 10 mm or less, even more preferably 5 mm or less, and particularly preferably 2.5 mm or less.

[0044] P2 may be half the value (P1 / 2) of the horizontal pitch P1 of the streaks 29, and the vertical section 61 may be located at an antinode A or a node B of the waviness of the first glass plate 2. If P2 is half the value of P1, then when the phase of the waviness of the first glass plate 2 and the phase of the waviness of the second glass plate 3 match, as shown in FIG. 4, the vertical section 61 can be located at the node B. For example, a ray of light L parallel to the Y-axis direction is refracted because it is obliquely incident at node B, whereas it is not refracted because it is perpendicularly incident at antinode A. When the heating wire 6 is energized, the temperature of node B is high, so the refractive index at node B is small, the amount of refraction at node B is small, and the magnitude of perspective distortion is small.

[0045] Furthermore, if P2 is half the value of P1, then when the phase of the waviness of the first glass plate 2 and the phase of the waviness of the second glass plate 3 are shifted by π (half a wavelength) as shown in Figure 6, the vertical cross-section 61 can be placed at the antinode A. Since the antinode A acts as a convex or concave lens, it focuses or diverges parallel light due to the lens effect. When the heating wire 6 is energized, the temperature of the antinode A is high, so the refractive index of the antinode A is small, the amount of refraction of the lens is small, and the magnitude of perspective distortion is small.

[0046] As shown in FIG. 7 , the laminated glass 1 has a first bus bar 7 that supplies a first potential to one end of the heating wire 6, and a second bus bar 8 that supplies a second potential different from the first potential to the other end of the heating wire 6. Either the first potential or the second potential may be higher. The first bus bar 7 and the second bus bar 8 are made of copper, aluminum, or the like, and are connected to the heating wire 6 with a conductive adhesive such as solder, supplying voltage to the heating wire 6 and current to the heating wire 6. The first bus bar 7 and the second bus bar 8 may be made of the same material as the heating wire 6 and formed integrally without using a conductive adhesive such as solder.

[0047] The multiple heating wires 6 electrically connected to the first bus bar 7 and the second bus bar 8 have the same length and the same electrical resistance. "The multiple heating wires 6 have the same length" means that the difference between the maximum and minimum lengths of the multiple heating wires 6 is 5% or less of the average length. The multiple heating wires 6 can be supplied with the same voltage and current, and can be supplied with the same power (the product of voltage and current). This reduces uneven heating.

[0048] The pattern of the heating wire 6 is not limited to the pattern shown in Fig. 7. The pattern of the heating wire 6 will be described below with reference to Figs.

[0049] The heating wires 6 shown in FIG. 8 are arranged at intervals in the horizontal direction, similar to the heating wires 6 shown in FIG. 7, but are arranged over a wider area than the heating wires 6 shown in FIG. 7. This is because the length of the lower side 23 of the information acquisition area 21 is long. The length of the lower side 23 is, for example, 50 mm or more. If the length of the lower side 23 is 50 mm or more, the angle of view γ of the information acquisition device 9 is large as shown in FIG. 9, so the angle of incidence of the light ray L is large near both ends of the information acquisition area 21 in the horizontal direction, and the influence of refraction is significant. Therefore, the effect of applying the technology disclosed herein is significantly achieved. The length of the lower side 23 is preferably 70 mm or more, more preferably 100 mm or more, even more preferably 150 mm or more, even more preferably 200 mm or more, and particularly preferably 300 mm or more. The length of the lower side 23 is preferably 400 mm or less.

[0050] FIG. 10 shows three heating wires 6, each arranged in a zigzag pattern across the entire horizontal direction of the information acquisition area 21. The number of heating wires 6 is not limited to three and may be any number. Each of the heating wires 6 has a U-shaped folded portion 62 in addition to a vertical section 61. The folded portion 62 has a different radius of curvature from the other folded portions 62 so as not to interfere with the other folded portions 62, and bypasses the other folded portions 62 to electrically connect the upper ends or lower ends of the multiple vertical sections 61. Because the heating wires 6 are arranged in a zigzag pattern across the entire horizontal direction of the information acquisition area 21, it is only necessary to provide the first bus bar 7 and the second bus bar 8 at the left or right end of the information acquisition area 21, thereby shortening the horizontal lengths of the first bus bar 7 and the second bus bar 8.

[0051] A horizontal portion 63 shown in Fig. 11 may be provided instead of the U-shaped folded portion 62 shown in Fig. 10. The horizontal portion 63 supplies the same potential to the upper ends or lower ends of the multiple vertical portions 61. By providing the horizontal portion 63 shown in Fig. 11 instead of the U-shaped folded portion 62, the length of the portion of the heating wire 6 that extends outside the information acquisition area 21 can be shortened. This makes it possible to reduce wasted power.

[0052] The heating wire 6 shown in FIG. 12 is a single wire, and is arranged in a zigzag pattern across the entire horizontal direction of the information acquisition area 21. Each heating wire 6 has a vertical section 61 as well as a U-shaped folded section 62. The folded section 62 electrically connects the upper ends or lower ends of two adjacent vertical sections 61. If there is only one heating wire 6, the folded section 62 does not need to bypass another folded section 62. This allows the length of the folded section 62 to be shortened, and the length of the portion of the heating wire 6 that extends outside the information acquisition area to be shortened. This reduces wasted power.

[0053] The ratio of the total length of the heating wire 6 outside the information acquisition area 21 to the total length of the heating wire 6 both inside and outside the information acquisition area 21 is preferably 0% or more and 20% or less. If this ratio is 20% or less, wasted power can be minimized. This ratio is more preferably 15% or less, and particularly preferably 10% or less.

[0054] 13, multiple heating wires 6 are provided at intervals in the horizontal direction, and have electrical resistances that vary depending on their horizontal positions. The information acquisition area 21 includes, in the horizontal direction, a first outer area 21a, a central area 21b, and a second outer area 21c, in this order. The incident angle of light ray L is larger in the first outer area 21a and the second outer area 21c than in the central area 21b, and therefore they are more susceptible to refraction.

[0055] Therefore, the heating wires 6 arranged in the first outer region 21a and the second outer region 21c have a higher electrical resistance per wire than the heating wires 6 arranged in the central region 21b. For the same voltage, the higher the electrical resistance, the smaller the amount of heat generated. Therefore, the first outer region 21a and the second outer region 21c experience smaller temperature changes than the central region 21b, and the change in refraction due to temperature changes can be reduced.

[0056] The heating wires 6 arranged in the first outer region 21a and the second outer region 21c shown in Fig. 13 have smaller cross-sectional areas than the heating wires 6 arranged in the central region 21b. The cross-sectional area is the area of ​​a cross section perpendicular to the longitudinal direction. The smaller the cross-sectional area, the higher the electrical resistance. The heating wires 6 arranged in the first outer region 21a and the second outer region 21c have at least one of the wire width and thickness (wire width in Fig. 13) smaller than the heating wires 6 arranged in the central region 21b.

[0057] Since information acquisition area 21 is divided into three areas 21a, 21b, and 21c, three first bus bars 7 and three second bus bars 8 may be provided as shown in Fig. 13. Note that the number of first bus bars 7 and second bus bars 8 is not limited to three, and may be, for example, five first bus bars 7 and five second bus bars 8 as shown in Fig. 14, seven or more first bus bars 7 and seven second bus bars 8, or even one first bus bar 7 and one second bus bar 8.

[0058] The heating wires 6 arranged in the first outer region 21a and the second outer region 21c shown in Fig. 15 may be longer than the heating wires 6 arranged in the central region 21b. The longer the length of each wire, the higher the electrical resistance per wire. Note that the heating wire 6 shown in Fig. 15 has a folded portion 62, but instead of the folded portion 62, it may have a horizontal portion 63 shown in Fig. 11.

[0059] As is clear from FIG. 2, the incident angle α of the light ray L increases from the upper side 22 to the lower side 23 of the information acquisition area 21, and therefore the light ray is more susceptible to the influence of refraction.

[0060] 16, the horizontal pitch of the vertical sections 61 of the heating wire 6 increases from the upper side 22 to the lower side 23 of the information acquisition area 21. The larger the horizontal pitch of the vertical sections 61, the smaller the temperature change, and the smaller the change in the amount of refraction due to temperature change can be reduced.

[0061] The vertical section 61 shown in FIG. 16 extends vertically in the horizontal center of the information acquisition area 21 and is tilted relative to the vertical direction near the horizontal ends of the information acquisition area 21. The vertical section 61 is parallel to the left side 24 of the information acquisition area 21 near the left side 24, and parallel to the right side 25 of the information acquisition area 21 near the right side 25. By arranging the heating wire 6 in this manner, as shown in FIG. 17, for example, the entire heating wire 6 near the right side 25 of the information acquisition area 21 is included in the plane of incidence LA of the light ray L that enters near the right side 25 of the information acquisition area 21. In other words, the intersection line between the incident surface LA and the first glass plate 2 substantially coincides with the right side 25. As a result, changes in the amount of refraction due to temperature changes can be reduced.

[0062] As described above, the vertical section 61 is inclined with respect to the vertical direction near the horizontal end of the information acquisition area 21. The inclination angle β is, for example, 15° or more, preferably 20° or more, more preferably 30° or more, even more preferably 40° or more, still more preferably 50°, and particularly preferably 60°. The inclination angle β is 70° or less. When the vertical section 61 is a sine curve, the angle between the center line of the amplitude and the vertical line is the inclination angle β.

[0063] 16, the horizontal pitch of the vertical cross-section portions 61 of the heating wire 6 increases from the upper side 22 to the lower side 23 of the information acquisition area 21. Therefore, the density of the vertical cross-section portions 61 decreases from the upper side 22 to the lower side 23 of the information acquisition area 21.

[0064] 16 may become smaller from the upper side 22 to the lower side 23 of the information acquisition area 21. The smaller the cross-sectional area, the greater the electrical resistance per unit length and the greater the amount of heat generated. Therefore, uneven heating can be reduced. [Example]

[0065] In Examples 1 to 10, laminated glass 1 was produced under the same conditions except that the grain direction of the first glass plate 2 and the second glass plate 3 and the pattern of the heating wire 6 were set as shown in Table 1, and the magnitude of perspective distortion of the laminated glass 1 was measured. The size of the laminated glass 1 was the same as the size of the information acquisition area 21, measuring 300 mm in length and 300 mm in width. The thickness of the first glass plate 2 and the thickness of the second glass plate 3 were both 2 mm. The thickness of the interlayer film 4 was 0.76 mm. The wire diameter of the heating wire 6 was 20 μm. The horizontal pitch P1 of the vertical cross-sections 61 of the heating wire 6 at the upper side 22 of the information acquisition area 21 was 3 mm. In both Example 9 and Example 10, the pattern of the heating wire 6 was the pattern shown in Fig. 16, but while the cross-sectional area of ​​the heating wire 6 was constant in Example 9, the cross-sectional area of ​​the heating wire 6 became smaller from the upper side 22 to the lower side 23 of the information acquisition area 21 in Example 10. Example 1 is a comparative example, and Examples 2 to 10 are working examples.

[0066] [Table 1] The magnitude of the perspective distortion shown in Table 1 was measured in accordance with the perspective distortion test (5.12) of Japanese Industrial Standard JIS R3212:2015 using a test apparatus 100 shown in FIG. 18. The test apparatus 100 has a projector 101, a support stand 102, and a screen 103. The projector 101 projects an image of a polka dot pattern consisting of multiple perfect circles arranged in a staggered pattern onto the screen 103 through the laminated glass 1 in an inclined position. The support stand 102 supports the laminated glass 1 in an inclined position. The distance between the laminated glass 1 and the screen 103 was 4 m. The inclination angle θ of the laminated glass 1 was 25°.

[0067] The magnitude of perspective distortion was determined by measuring the maximum amount of distortion from a perfect circle and converting it into minutes of angle. A rating of "◎" indicates that the magnitude of perspective distortion was 1.5 minutes or less, a rating of "〇" indicates that the magnitude of perspective distortion was greater than 1.5 minutes and less than 2.0 minutes, and a rating of "×" indicates that the magnitude of perspective distortion was greater than 2.0 minutes. The magnitude of perspective distortion was measured at both the horizontal center and horizontal ends of the information acquisition area 21, and was measured both when electricity was not applied and when electricity was applied.

[0068] In Table 1, L0 is the total length of the heating wire 6 both inside and outside the information acquisition area 21, and is the sum of L1 and L2 described below. L1 is the total length of the heating wire 6 inside the information acquisition area 21. On the other hand, L2 is the total length of the heating wire 6 outside the information acquisition area 21. The evaluation "◎" indicates that the ratio of L2 to L0 is 20% or less, and the evaluation "◯" indicates that the ratio of L2 to L0 is greater than 20%.

[0069] As is clear from Table 1, in Examples 2 to 10, unlike Example 1, the streak direction of the first glass plate 2 and the second glass plate 3 was vertical, so the magnitude of the perspective distortion when electricity was applied was 2.0 or less. Also, in Examples 7 to 10, the magnitude of the perspective distortion at the horizontal ends of the information acquisition area 21 when electricity was applied was small, being 1.5 or less. Furthermore, in Examples 4, 5, and 8 to 10, the ratio of L2 to L0 was 20% or less, and little wasted power was consumed.

[0070] The above describes the glass sheet with heating wire according to the present disclosure, but the present disclosure is not limited to the above-described embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. These naturally fall within the technical scope of the present disclosure.

[0071] For example, the ratio of L2 to L0 is preferably 15% or less, and more preferably 10% or less.

[0072] This application claims priority based on Japanese Patent Application No. 2019-213617, filed with the Japan Patent Office on November 26, 2019, the entire contents of which are incorporated herein by reference. [Explanation of symbols]

[0073] 1. Laminated glass 2. First glass plate 3 Second glass pane 4 Interlayer 5. Light-shielding film 6 heating wire 61 Longitudinal section 62 Turned part 63 Horizontal section 7 No. 1 bus bar 8 Second bus bar

Claims

1. a glass plate having an information acquisition area for acquiring information about the outside of the vehicle by an information acquisition device; A heating wire provided in the information acquisition area, When the glass plate is attached to a vehicle body in an inclined state, the information acquisition area has a trapezoidal shape when viewed from the direction of an optical axis of the information acquisition area, and has a horizontal upper side and a horizontal lower side, The streaks caused by the waviness of the glass sheet are arranged at intervals in a horizontal direction parallel to the upper side and the lower side, and each extend in a vertical direction perpendicular to the horizontal direction, The heating wire has a longitudinal section that crosses the information acquisition area in the longitudinal direction, The longitudinal section is provided in a plurality of sections spaced apart from one another in the lateral direction, The information acquisition region includes a first outer region, a central region, and a second outer region in this order in the lateral direction, The glass plate with electric heating wires, wherein the electric heating wires arranged in the first outer region and the second outer region have a larger electric resistance per wire than the electric heating wire arranged in the central region.

2. The glass sheet with heating wire according to claim 1 , wherein the heating wires arranged in the first outer region and the second outer region have a smaller cross-sectional area than the heating wire arranged in the central region.

3. 3 . The glass sheet with heating wires according to claim 1 , wherein the heating wires arranged in the first outer region and the second outer region each have a length longer than the heating wire arranged in the central region. 4 .

4. 4. The glass plate with heating wire according to claim 1, wherein the length of the lower side of the information acquisition region is longer than the length of the upper side, and is 50 mm or more and 400 mm or less.

5. The glass plate with heating wire according to any one of claims 1 to 4, wherein a ratio of a total length of the heating wire outside the information acquisition area to a total length of the heating wire both inside and outside the information acquisition area is 0% or more and 20% or less.

6. The glass sheet with heating wire according to any one of claims 1 to 5, further comprising a first bus bar that supplies a first potential to one end of the heating wire, and a second bus bar that supplies a second potential different from the first potential to the other end of the heating wire.

7. A second glass plate facing the glass plate; an intermediate film that bonds the glass plate and the second glass plate; The glass sheet with heating wire according to any one of claims 1 to 6, wherein the heating wire is provided between the glass sheet and the second glass sheet.

8. The glass sheet with heating wire according to claim 7 , wherein a plurality of streaks caused by waviness of the second glass sheet are arranged at intervals in the horizontal direction and each extend in the vertical direction.

9. The glass plate with heating wire according to any one of claims 1 to 8, wherein the pitch of the vertical sections in the lateral direction is 25 mm or less.

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