Vehicle window glass

Abstract

The vehicle window glass of the present application includes: a glass sheet; a light-shielding layer laminated to a peripheral edge portion of the glass sheet; a defogger having at least a portion disposed in a light-transmitting region of the glass sheet surrounded by the light-shielding layer; and a first antenna disposed at a position below the defogger in the glass sheet, wherein a width in a vertical direction of a portion of the light-shielding layer laminated to an upper end portion of the glass sheet is 25 to 200 mm, wherein when a shortest length in a horizontal direction of the light-transmitting region is set as a1, a length in the vertical direction of the light-transmitting region is set as b1, and a wavelength of a radio wave received by the first antenna is set as λ, a1 + b1 ≥ 0.5λ is satisfied.

Description

Technical Field

[0001] This invention relates to a window glass for vehicles. Background Technology

[0002] Various antennas are installed on the surface of vehicle windows (especially rear windows) used in automobiles. For example, antennas are installed for receiving broadcasts of various media such as FM radio, AM radio, and digital television broadcasts. For example, Patent Document 1 describes an antenna for receiving FM radio, AM radio, and digital television broadcasts.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent No. 51098305 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] However, in the window glass of Patent Document 1, various antennas are installed above the defroster. On the other hand, the antenna receivers are mostly located below the window glass. Therefore, if the antenna is installed above the defroster, the wiring connecting the antenna and the receiver needs to be extended, which may adversely affect the reception performance. The present invention was made to solve the above problems, and its object is to provide a vehicle window glass that can improve the antenna reception performance.

[0008] Technical solutions for solving technical problems

[0009] Item 1. A window glass for a vehicle, comprising:

[0010] glass plate;

[0011] A light-shielding layer is stacked on the periphery of the aforementioned glass plate;

[0012] A demister, at least a portion of which is disposed in the light-transmitting area of ​​the glass plate surrounded by the light-shielding layer; and

[0013] The first antenna is positioned below the demister on the aforementioned glass plate.

[0014] In the aforementioned light-shielding layer, the portion stacked at the upper end of the glass plate has a vertical width of 25–200 mm.

[0015] When the horizontal length of the central part of the glass plate in the above-mentioned light-transmitting area in the vertical direction is set as a1, the vertical length of the central part of the glass plate in the horizontal direction is set as b1, and the wavelength of the center frequency of the radio wave received by the first antenna is set as λ, a1+b1≥0.5λ is satisfied.

[0016] Item 2. According to the vehicle window glass described in Item 1, wherein,

[0017] The aforementioned first antenna includes:

[0018] First connection point;

[0019] Second connection point;

[0020] The first element extending from the aforementioned first connection point; and

[0021] The second element extending from the aforementioned second connection point,

[0022] The first element includes: a first portion extending downward from the first connection point; a second portion extending horizontally from the lower end of the first portion; a third portion extending upward from the end of the second portion; and a fourth portion extending from the upper end of the third portion toward the first connection point.

[0023] Item 3. The vehicle window glass according to Item 2, wherein the first element further includes a fifth portion, the fifth portion being connected to the upper end of the third portion and extending horizontally in a direction away from the first connection point.

[0024] Item 4. The vehicle window glass described in Item 2 or 3, wherein the first antenna is a digital television antenna, and when the wavelength shortening rate of the glass is κ, the total length of the first part to the fourth part is in the range of 0.75κ·λ to 1.30κ·λ.

[0025] Item 5. The vehicle window glass according to Item 3, wherein the first antenna is a digital television antenna, and when the wavelength shortening rate of the glass is κ, the total length of the first part to the fifth part is in the range of 0.95κ·λ to 1.33κ·λ.

[0026] Item 6. The vehicle window glass according to any one of items 2 to 5, wherein, at a position above the fourth portion of the first element, at least one non-powered element extending in the horizontal direction is further included.

[0027] Item 7. According to any one of items 1 to 6, the vehicle window glass, wherein,

[0028] It also includes the second line,

[0029] The first antenna and the second antenna are arranged at their horizontal centers, separated by the glass plate.

[0030] The first antenna and the second antenna described above have asymmetrical shapes about the center.

[0031] Item 8. The vehicle window glass according to Item 7, wherein the first antenna and the second antenna are configured to receive broadcast waves in the UHF band.

[0032] Item 9. The vehicle window glass described in Item 7, wherein the first antenna and the second antenna are configured to receive horizontally polarized waves.

[0033] Item 10. A vehicle window glass according to any one of items 7 to 9, wherein the defroster includes a pair of manifolds and a plurality of heating wires extending between the pair of manifolds and arranged parallel in the vertical direction.

[0034] The first antenna is positioned below the lowest heating wire.

[0035] The second heating element is positioned between the bottommost heating element and the second heating element from the bottom.

[0036] Item 11. According to any one of items 7 to 10, the vehicle window glass, wherein,

[0037] The aforementioned second line includes:

[0038] Third connection point;

[0039] Fourth connection point;

[0040] The third element extending from the aforementioned third connection point; and

[0041] The fourth element extending from the aforementioned fourth connection point,

[0042] The aforementioned third element includes a sixth portion extending upward from the aforementioned third connection point, and a seventh portion extending horizontally from the upper end of the aforementioned sixth portion.

[0043] Item 12. The vehicle window glass described in Item 2 or 3, wherein,

[0044] The first antenna mentioned above is a DAB antenna.

[0045] When the wavelength shortening rate of the glass is κ, the total length from the first part to the fourth part is in the range of 0.22κ·λ to 0.32κ·λ.

[0046] Item 13. The vehicle window glass described in Item 3, wherein,

[0047] The first antenna mentioned above is a DAB antenna.

[0048] When the wavelength shortening rate of the glass is κ, the total length from the first part to the fifth part is in the range of 0.32κ·λ to 0.43κ·λ.

[0049] Invention Effects

[0050] The vehicle window glass according to the present invention can improve the antenna's receiving performance. Attached Figure Description

[0051] Figure 1 This is a front view illustrating one embodiment of applying the vehicle window glass of the present invention to the rear window of a car equipped with a digital television antenna.

[0052] Figure 2 yes Figure 1 An enlarged view of the lower part of the rear window.

[0053] Figure 3 This is a front view illustrating one embodiment of applying the vehicle window glass of the present invention to the rear window of a car equipped with a DAB antenna.

[0054] Figure 4 yes Figure 3 An enlarged view of the lower part of the rear window.

[0055] Figure 5 This is a schematic diagram of a testing machine used to study the dimensions of the light-transmitting area.

[0056] Figure 6 It is a chart showing the dimensions of the light-transmitting area from an experiment.

[0057] Figure 7 This is a diagram showing the first digital television antenna in Embodiments 1 to 5.

[0058] Figure 8 These are graphs showing the receiving performance of Examples 1 to 5.

[0059] Figure 9 This is a schematic diagram of the first digital television antenna in Examples 6-10.

[0060] Figure 10 These are graphs showing the receiving performance of Examples 6 to 10.

[0061] Figure 11A This is a diagram showing the first digital television antenna of Embodiment 11.

[0062] Figure 11B This is a diagram showing the first digital television antenna of Embodiment 12.

[0063] Figure 11C This is a diagram showing the first digital television antenna of Embodiment 13.

[0064] Figure 12 These are graphs showing the receiving performance of Examples 11-14.

[0065] Figure 13 This is a diagram showing the DAB antennas of embodiments 15 to 21.

[0066] Figure 14 These are graphs showing the receiving performance of Examples 15-21.

[0067] Figure 15 This is a diagram showing the DAB antennas of embodiments 22 to 25.

[0068] Figure 16 These are graphs showing the receiving performance of Examples 22-25. Detailed Implementation

[0069] Hereinafter, an embodiment of the vehicle window glass of the present invention will be described with reference to the accompanying drawings. Figure 1 This is a front view of the rear window of a car, which is the part of the vehicle window glass to which this embodiment is applied, as viewed from outside the vehicle. Furthermore, for ease of explanation, the following will sometimes use... Figure 1 Based on the orientation, Figure 1 The vertical direction is called the up-down direction or the vertical direction. Figure 1 The left and right directions are referred to as left and right directions or horizontal directions, but this orientation does not limit the invention. For example, the terms "vertical direction" and "horizontal direction" in the following description include not only the strict vertical and horizontal directions, but also directions that deviate slightly from these.

[0070] <1. Rear Glass>

[0071] like Figure 1 As shown, in this embodiment, the rear glass has a light-shielding layer 2, a defogger 3, a first digital television antenna 4, and a second digital television antenna 5 disposed on the glass plate 1. The components will be described in turn below.

[0072] <1-1. Glass Plate>

[0073] Glass panel 1 can utilize commonly known automotive glass panels. For example, glass panel 1 can be made of heat-absorbing glass, ordinary transparent glass or green glass, dark privacy glass, or UV green glass. However, such glass panel 1 needs to achieve visible light transmittance according to the safety standards of the country where the automobile is used. For example, adjustments can be made to ensure that solar radiation absorption rate, visible light transmittance, etc., meet safety standards. The following examples illustrate the composition of transparent glass and heat-absorbing glass.

[0074] (Transparent glass)

[0075] SiO2: 70-73% by mass

[0076] Al2O3: 0.6–2.4% by mass

[0077] CaO: 7–12% by mass

[0078] MgO: 1.0–4.5% by mass

[0079] R₂O: 13–15% by mass (R is an alkali metal)

[0080] Total iron oxide (T-Fe2O3) converted to Fe2O3: 0.08–0.14% by mass

[0081] (Heat-absorbing glass)

[0082] The composition of heat-absorbing glass can be, for example, as follows: based on the composition of transparent glass, the ratio of total iron oxide (T-Fe2O3) converted to Fe2O3 is 0.4 to 1.3% by mass, the ratio of CeO2 is 0 to 2% by mass, the ratio of TiO2 is 0 to 0.5% by mass, and the skeletal components of the glass (mainly SiO2 and Al2O3) are reduced, while the increase in T-Fe2O3, CeO2 and TiO2 is reduced.

[0083] The type of glass plate 1 is not limited to transparent glass or heat-absorbing glass, and can be appropriately selected according to the embodiment. For example, glass plate 1 can also be a resin window made of acrylic, polycarbonate, etc.

[0084] In addition, such glass plate 1 can be made of a single glass plate or laminated glass made of multiple glass plates sandwiching an interlayer film such as resin.

[0085] <1-2. Light-shielding layer>

[0086] In this embodiment, the light-shielding layer 2 is formed along the periphery of the inner side of the glass panel 1, forming a rectangular light-transmitting area 20 surrounded by the light-shielding layer 2. Thus, the interior of the vehicle is not visible from the outside through the area where the light-shielding layer 2 is formed. On the other hand, the interior of the vehicle can be seen from the outside or from the inside of the vehicle through the light-transmitting area 20 where the light-shielding layer 2 is not formed. This allows, for example, components such as wiring disposed on the inner side of the light-shielding layer 2 to be invisible from the outside. The material of the light-shielding layer 2 can be chosen appropriately depending on the embodiment, as long as it can block the view from the outside. Dark ceramic materials such as black, brown, gray, and dark blue can also be used. Alternatively, sheet materials can be used.

[0087] When black ceramic is chosen as the material for the light-shielding layer 2, for example, black ceramic is laminated onto the inner side of the glass plate 1 using methods such as screen printing, and the ceramic laminated together with the glass plate 1 is heated. Then, when the ceramic solidifies, the light-shielding layer 2 is completed. The ceramic used in the light-shielding layer 2 can be made of various materials; for example, ceramics with the compositions shown in Table 1 below can be used in the light-shielding layer 2.

[0088] [Table 1]

[0089] Pigment *1 quality% 10 Resin (cellulose resin) quality% 10 Organic solvent (pine oil) quality% 10 Glass adhesive *2 quality% 70 Viscosity dPs 150

[0090] *1. Main components: copper oxide, chromium oxide, iron oxide, and manganese oxide

[0091] *2. Main components: bismuth borosilicate, zinc borosilicate

[0092] The width d of the horizontal center of the portion of the light-shielding layer 2 along the upper end of the glass plate 1 can be, for example, 25 to 200 mm. In addition, the vertical length b1 of the horizontal center of the light-transmitting area 20 of the glass plate 1 can be, for example, 300 to 1200 mm, and the horizontal length a1 of the vertical center of the light-transmitting area 20 of the glass plate 1 can be, for example, 500 to 1500 mm.

[0093] Furthermore, in this embodiment, the following equation (1) is satisfied. Wherein, λ is the wavelength of the center frequency of the broadcast wave received by the digital television antennas 4 and 5, which will be described later.

[0094] a1+b1≥0.5λ (1)

[0095] <1-3. Demister>

[0096] Next, the demister 3 will be described. For example... Figure 1 As shown, the defogger 3 includes a pair of power supply busbars 31a and 31b extending vertically along both sides of the glass panel 1. Between the two busbars 31a and 31b, a plurality of heating wires 32 are arranged parallel to each other at predetermined intervals. Power supplied from the busbars 31a and 31b generates heat on the surface of the glass panel 1 for defogging. The two busbars 31a and 31b are formed within the light-shielding layer 2 and are not visible from outside the vehicle.

[0097] The lowermost heating wire 321 in the heating wire 32 is formed by three parts: a first part 321a on the right, a second part 321b on the left, and a third part 321c connecting the first part 321a and the second part 321b. The first part 321a and the second part 321b extend in a generally horizontal direction from each of the busbars 31a and 31b to near the center of the light-transmitting area 20. The third part 321c extends obliquely, connecting the first part 321a and the second part 321b. With this shape, the gap between the second heating wire 322 extending horizontally from the bottom and the first part 321a is narrow, and the gap between the second heating wire 322 and the second part 321b from the bottom is wide. Hereinafter, the gap between the second heating wire 322 and the first part 321a from the bottom will be referred to as the first gap 301, and the gap between the second heating wire 322 and the second part 321b from the bottom will be referred to as the second gap 302. In addition, the second part 321b is formed in the light-shielding layer 2.

[0098] <1-4. First Digital Television Antenna>

[0099] Figure 2 This is a magnified view of the area near the lower end of the rear window. (For example...) Figure 1 and Figure 2 As shown, the first digital television antenna 4 is positioned below the first portion 321a of the lowest heating wire 321. More specifically, the first digital television antenna 4 includes: a first connection point 41 connected to the central conductor of the coaxial cable or the input of an amplifier circuit; a second connection point 42 directly connected to the outer conductor of the coaxial cable or connected via an amplifier circuit; a first element 43 extending from the first connection point 41; a second element 44 extending from the second connection point 42; and one or more unpowered elements 45 not connected to the first connection point 41 or the second connection point 42.

[0100] The first connection point 41 is disposed near the center of the glass plate 1, and the second connection point 42 is disposed to its right. The first element 43 has a first portion 431 extending from the first connection point 41 toward the glass extension (below), a second portion 432 extending horizontally to the right from the lower end of the first portion 431, a third portion 433 extending upward from the right end of the second portion 432, a fourth portion 434 extending to the left from the upper end of the third portion 433, and a fifth portion 435 extending to the right from the upper end of the third portion 433. The second portion 432 is disposed at a position closer to the glass extension (below) than the second connection point 42 and the second element 44, and extends to a position to the right of the second element 44. In addition, as Figure 1 As shown, the second part 432 is formed in the light-shielding layer 2.

[0101] The total length of the first portion 431 to the fifth portion 435 of the first element 43 can be, for example, 0.95κ·λ to 1.33κ·λ, thereby improving the receiving performance. Furthermore, κ is the inherent wavelength shortening rate of the glass, typically a value of 0.6 to 0.7.

[0102] In this embodiment, as an example, two unpowered elements 45 are formed. Both are formed by straight lines extending in the horizontal direction and are arranged in a manner where two of each are arranged in the horizontal direction above the fourth portion 434 of the first element 43.

[0103] The second element 44 extends horizontally to the right from the second connection point 42 and is disposed below the fourth portion 434 of the first element 43. In this embodiment, the second element 44 and the fourth portion 434 are formed in an overlapping manner in the horizontal direction, but they can also be separated in the horizontal direction without overlapping.

[0104] Furthermore, the car equipped with this rear window has an amplifier circuit (not shown) for digital television broadcasting waves. The first connection point 41 is connected directly or via the central conductor of a coaxial cable (not shown) to the signal input section of this amplifier circuit. On the other hand, the second connection point 42 is electrically connected to the circuit board of the amplifier circuit. This is also the case in the second digital television antenna 5, which will be described later. In addition, the first connection point 41 and the second connection point 42 are sometimes also connected to the two ends of the input section of a balanced circuit, such as a balun or balun transformer circuit. The amplifier circuit is located near the center below the glass plate 1.

[0105] <1-5. Second Digital TV Antenna>

[0106] like Figure 1 and Figure 2 As shown, the second digital television antenna 5 is disposed in the aforementioned second gap 302. More specifically, the second digital television antenna 5 includes a third connection point 51, a fourth connection point 52, a third element 53 extending from the third connection point 51, a fourth element 54 extending from the fourth connection point 52, and one or more unpowered elements 55.

[0107] The third connection point 51 is located near the center of the glass plate 1, and the fourth connection point 52 is located to its left. The third element 53 has a sixth portion 531 extending upward from the third connection point 51 and a seventh portion 532 extending horizontally to the left from the upper end of the sixth portion 531.

[0108] The fourth element 54 extends horizontally to the left from the fourth connection point 52. Additionally, the seventh part 532 extends to a position further to the left than the fourth element 54.

[0109] In this embodiment, a non-powered element 55 is formed. This non-powered element 55 is formed by a straight line extending in the horizontal direction and is positioned to the left of the seventh part 532.

[0110] <1-6 Materials>

[0111] The aforementioned defogger 3 and digital television antennas 4 and 5 are constructed by combining wires, but they can also be formed by layering conductive materials with a predetermined pattern on the surface of the glass plate 1. As long as the material is conductive, it can be appropriately selected in the embodiment; examples include silver, gold, and platinum. Specifically, for example, it can be formed by printing conductive ink containing silver powder, glass frit, etc., onto the surface of the glass plate 1 and then firing it.

[0112] <1-7 Manufacturing Method>

[0113] Next, the manufacturing method of the window glass according to this embodiment will be described. The glass plate 1 of the window glass in this embodiment can be formed by heating the glass to its softening point and then forming it into any desired shape through a stamping process or a weight bending process in which the glass plate 1 bends due to its own weight.

[0114] Here, during the forming of the glass plate 1 in each process, the glass plate 1 is heated to near its softening point in a heating furnace. Before being fed into the heating furnace, the glass plate 1 is formed into a flat plate shape, and inks for the aforementioned materials, such as conductive inks, are printed on the surface of the glass plate 1. Then, by feeding the glass plate 1 into the heating furnace, the glass plate 1 can be formed, and the conductive ink printed on the glass plate 1 is fired to form the demister 3 and each digital television antenna 4, 5. In addition, the colored ceramic paste that forms the light-shielding layer 2 is printed onto the glass plate 1 before heating, just like the conductive ink that forms the antennas 4, 5, etc., which is formed on the flat plate. Furthermore, by layering and printing the colored ceramic paste and various conductive inks, it is also possible to form a layer of light-shielding layer and conductive layer on the glass surface.

[0115] <2. Characteristics>

[0116] As described above, the following effects can be obtained according to this embodiment.

[0117] (1) The two digital television antennas 4 and 5 are positioned below or at the bottom of the defogger 3, thus shortening the wiring (transmission cable) to the amplifier circuit compared to positioning them above the defogger 3. For example, if the digital television antennas 4 and 5 are positioned above the defogger 3, the wiring length is at least a1+b1. Furthermore, the inventors have confirmed that when the length of a1+b1 is 0.5λ or more, the reception performance deteriorates. In addition, if the width d of the center of the portion of the light-shielding layer 2 along the upper end of the glass plate 1 is 25 to 200 mm, as in this embodiment, it is difficult to position the antennas.

[0118] (2) In this embodiment, the two digital television antennas 4 and 5 are asymmetrical about the horizontal centerline. Therefore, the received frequency band can be varied, and broadcast waves of a wider frequency band can be received.

[0119] (3) The two digital television antennas 4 and 5 are capable of receiving digital television broadcast waves in the UHF band. They are also capable of receiving horizontally polarized waves. In particular, the first digital television antenna 4 is configured to receive broadcast waves in the lower frequency band (e.g., 470MHz to 575MHz) of the frequency band 470MHz to 710MHz used in broadcast services, as the first element 43 is formed in a generally U-shape from the first connection point 41 as described above. On the other hand, the second digital television antenna 5 is configured such that the third element 53 extends upwards from the third connection point 51, making it suitable for receiving broadcast waves in the higher frequency band (e.g., 575 to 710MHz).

[0120] <3. Variations>

[0121] The present invention has been described above as one embodiment, but the present invention is not limited to the above embodiment. Various modifications can be made without departing from its spirit. In addition, the following variations can be appropriately combined.

[0122] (1) In the first element 43 of the first digital television antenna 4, the fifth part 435 may not be required, as long as at least the first part 431 to the fourth part 434 are provided. In this case, in order to improve the receiving performance, it is preferable that the total length of the first part 431 to the fourth part 434 is 0.75κ·λ to 1.30κ·λ as described above.

[0123] (2) In the first digital television antenna 4, the power-free element 45 is not necessary and may be omitted. However, if it is included, its shape, position, and number are not particularly limited. For example, the power-free element can be formed by straight lines extending in the horizontal direction and arranged above the fourth part 434 of the first element 43 in a manner of two vertically and two horizontally. The shape of the second element 44 is not particularly limited and can be any shape other than a straight line.

[0124] (3) The shape of the second digital television antenna 5 is not particularly limited. For example, at least one linear element may be added to the third element 53. That is, at least one linear element can be connected to the sixth part 531 in a manner parallel to the seventh part 532. The shape of the fourth element 54 is also not particularly limited and can be any shape other than a straight line. In addition, the unpowered element 55 is not necessary and may be omitted, but if it is included, its shape, position, and number are not particularly limited. When unpowered elements are included, they can be arranged in parallel at intervals in the vertical direction, located to the left of the third element 53. By including multiple unpowered elements and multiple elements in the sixth part 531, the reception performance can be improved.

[0125] (4) The shape of the demister 3 in the above embodiment is an example, and the number of heating wires 22 is not particularly limited. Furthermore, to improve receiving sensitivity, additional heating wires extending in the vertical direction can be added. Also, in the above embodiment, a portion of the demister 3 is located in the light-shielding layer 2, but the portion disposed in the light-shielding layer can be appropriately determined. Therefore, the entire demister 3 can be disposed in the light-transmitting area 20. Alternatively, the shape of the demister 3 can be the reverse of the shape described in the above embodiment. That is, the first gap 301 can be disposed on the left side, and the second gap 302 on the right side. Correspondingly, the first digital television antenna 4 can be disposed on the left side, and the second digital television antenna 5 on the right side.

[0126] (5) In the above embodiment, a light-shielding layer 2 is formed on the glass plate 1, but a shielding member can also be provided at the periphery of the glass plate, either together with the light-shielding layer or without a light-shielding layer. When a shielding member is provided in this way, a defogger 3 and digital television antennas 4 and 5 can be mainly arranged in the light-transmitting area surrounded by the shielding member. Furthermore, the inventors have discovered that in the light-transmitting area 20 surrounded by the shielding member, when the horizontal length at the center of the vertical direction of the glass plate 1 is set to a2, and the vertical length at the center of the horizontal direction of the glass plate 1 is set to b2, if a2 + b2 ≥ 0.5λ, the receiving performance decreases. Moreover, a2 and b2 can be set in the same way as a1 and b1 as described above.

[0127] (6) In the above embodiment, two digital TV antennas are used to receive the broadcast waves of digital TV, but as long as the width d and formula (1) are satisfied at least, it can also be just the first digital TV antenna 4.

[0128] (7) In the above embodiments, the case where the digital television antennas 4 and 5 are located below or at the bottom of the defogger 3 was described, but this also applies to antennas other than digital television antennas. That is, the inventors have confirmed that even for FM antennas, AM antennas, or DAB antennas, if they are located above the defogger 3, the wiring to the receiving device located below the glass plate 1 becomes longer, thus adversely affecting the receiving performance. Therefore, the first antenna of the present invention can also be an FM antenna, AM antenna, or DAB antenna other than a digital television antenna.

[0129] (8) In the case of using a vertically polarized DAB antenna (175-240MHz, center wavelength 207MHz) instead of a digital television antenna, for example, the above-mentioned point that "if the antenna is positioned above the defogger 3, the length of the wiring will be at least a1+b1. If the length of a1+b1 is 0.5λ or more, the reception performance will deteriorate" is also the same in the DAB antenna.

[0130] (9) As an example of vehicle window glass using a DAB antenna, for example, Figure 3 and Figure 4 The type of vehicle window shown. Figure 3 This is a front view of a vehicle window equipped with a DAB antenna. The above... Figure 1 The vehicle window glass shown is Figure 3 The differences are in the shape of the bottom heating wire 321, the shape of the light-shielding layer 2, and the fact that the DAB antenna 6, instead of the digital TV antenna, is located below the defogger.

[0131] First, in this example, the lowermost heating line 321 is composed of a first portion 321d on the right, a second portion 321e on the left, and a third portion 321f connecting the first portion 321d and the second portion 321e. The first portion 321d and the second portion 321e extend generally horizontally from each of the busbars 31a and 31b to near the center of the light-transmitting area 20. The third portion 321f extends vertically in a manner connecting the first portion 321d and the second portion 321e. Using this shape, the gap between the second heating line 322 extending horizontally from the bottom and the first portion 321d is narrow, and the gap between the second heating line 322 extending horizontally from the bottom and the second portion 321e is wide.

[0132] At the center of the lower edge of the light-transmitting area 20 formed by the light-shielding layer 2, a trapezoidal protrusion 21 protruding upwards is formed. Figure 1 The light-shielding layer 2 is different.

[0133] Figure 4 This is a magnified view of the area near the lower end of the rear window. (For example...) Figure 3 and Figure 4 As shown, the DAB antenna 6 is positioned below the first portion 321a of the lowest heating wire 321. More specifically, the DAB antenna 6 includes a first connection point 61 connected to the central conductor of the coaxial cable or the input of an amplifier circuit, and a second connection point 62 directly connected to the outer conductor of the coaxial cable or connected via an amplifier circuit. These two connection points are located on the protrusion 21. An element with six portions is connected to the first connection point 61. Specifically, it includes a first portion 63 extending slightly downward from the first connection point 61, a second portion 64 extending horizontally to the right from the first portion 63, a third portion 65 extending upward from the second portion 64, a fourth portion 66 extending horizontally to the left (towards the first connection point 61) from the upper end of the third portion 65, a fifth portion 67 extending horizontally to the right from the fourth portion 66, and a sixth portion 68 extending horizontally to the right from the second portion 64. The first part 63, the second part 64, and the sixth part 68 are disposed on the light-shielding layer 2, and the lower end of the third part 65 is disposed on the light-shielding layer 2. The left end of the fourth part 66 is disposed on the protrusion 21. The fifth part 67 is disposed on the light-transmitting area 20.

[0134] A component with two parts is connected at the second connection point 62. Specifically, it includes a seventh part 69 extending upward from the second connection point 62 and an eighth part 70 extending horizontally to the right from the upper end of the seventh part 69. The lower end of the seventh part 69 is disposed in the light-shielding layer 2, and the eighth part 70 is disposed in the light-transmitting area 20.

[0135] but, Figure 3 and Figure 4 The shapes of the DAB antenna, defogger, and light-shielding layer shown are examples and can be modified appropriately. For example, Figure 3 and Figure 4 The DAB antenna shown can be modified appropriately. For example, the fifth part 67 and the sixth part 68 (described later) can be removed. Figure 13 ), or remove the sixth part 68 (described later). Figure 15 ).

[0136] Furthermore, the main difference between digital TV antennas and DAB antennas lies in the difference in the wavelength of the received broadcast waves. For example, the total length of the first to fourth sections or the first to fifth sections is as described later; for both digital TV antennas and DAB antennas, the absolute length is preferably within a certain range. Additionally, based on the difference in center wavelength (λ) between the digital TV antenna and the DAB antenna, if their lengths are expressed as multiples of κ·λ, then the coefficient of κ·λ also changes accordingly with the wavelength difference. For example, if the difference in center wavelength between the digital TV antenna and the DAB antenna is approximately three times, then the coefficient of κ·λ will also be approximately three times the difference.

[0137] In addition, Figure 3 Vehicle windows can also be equipped with Figure 1 The digital TV antenna 4, FM antenna, AM antenna, etc. shown are used to replace the DAB antenna 6.

[0138] (10) In the above embodiments, the present invention is applied to the rear glass, but it can also be applied to window glass other than the rear glass.

[0139] Example

[0140] The following describes embodiments of the present invention. However, the present invention is not limited to the following embodiments.

[0141] <1. Research on the size of the light-transmitting area>

[0142] The impact of the transmission cable length connected to the receiving antenna on reception level is evaluated below. First, as... Figure 5 As shown, a 500×500mm glass plate with a thickness of 5mm is prepared, and conductive ink is printed and fired onto the upper center of the plate to create a receiving antenna. This receiving antenna has two connection points, from which linear elements are connected in a horizontally separated manner.

[0143] A transmission cable (coaxial cable) with a total horizontal length of x and a vertical length of y is installed on the receiving antenna (the total length of the transmission cable is x+y). That is, a central conductor is connected at one connection point, and an outer conductor is connected at another connection point. Next, a test wave with a horizontal polarization of 470-710MHz is irradiated from the transmitting antenna (not shown) to the receiving antenna. The signal level received via the transmission cable is used as the transmission characteristic, and a network analyzer is used to measure it.

[0144] The evaluation is based on the variation in receiver gain. The evaluation method is as follows: given a certain cable length, the change in receiver gain is quantified and evaluated when the horizontal length (x) and vertical length (y) are varied.

[0145] The results are as follows Figure 6 As shown, if the total length x+y of the transmission cable increases, the magnitude of the change in receiving gain also increases. That is, a slight change in the state of the transmission cable, resulting in a change in the lengths of x and y, will have a greater impact on the antenna's receiving performance. Since the transmission cable is also a conductor, when it exceeds a certain length, the cable itself begins to function as an antenna, thus increasing the impact on the performance of the original receiving antenna.

[0146] In particular, according to other insights of the inventors, in antennas that receive radio waves of digital television in the 470–710 MHz frequency band, when the receive gain variation exceeds 0.5 dB, adverse effects such as the need for adjustment mechanisms on the circuit side where the connection is made occur, making them less desirable. Figure 6 The results show that the transmission cable length is approximately 0.5 × λ (λ is the wavelength of 590 MHz, the center frequency of the radio wave in the 470–710 MHz range). Therefore, it can be concluded that in vehicle windows with a light-transmitting area satisfying equation (1) above, placing the antenna below the defroster improves reception performance. Furthermore, this study was conducted with a digital television antenna, but the same results were obtained with a DAB antenna.

[0147] <2. Research on the Shape of the First Digital Television Antenna 1>

[0148] The following is about Figure 7 The total length of the first to fourth portions of the first element of the first digital television antenna shown was studied. In Examples 1 to 5, the total lengths of the first to fourth portions were approximately 0.7κ·λ, 0.95κ·λ, 1.1κ·λ, 1.2κ·λ, and 1.25κ·λ, respectively. Figure 7 Example 3 (numerical values ​​are in mm) refers to Examples 1, 2, 4, and 5, which are based on the dimensions shown in Example 3, with the lengths of the first to fourth portions adjusted to achieve the total length described above. The wavelength shortening rate κ of the glass plate is 0.7, and the center frequency of the test wave (470–710 MHz) is 590 MHz, resulting in a wavelength λ (=509 mm). This is also true in the examples described later.

[0149] The first digital television antennas of Examples 1-5 were formed on glass plates. Then, each glass plate was assembled into a car window frame, and the pointing characteristics in the horizontal plane were measured while changing the illumination angle of the radio waves, and the average gain was calculated. The pointing characteristic measurements were performed in the 470-710 MHz frequency band. The results are as follows... Figure 8 As shown. Furthermore, Figure 8 This indicates the results in the low-frequency band (470–575 MHz).

[0150] according to Figure 8 It can be seen that the normalized gain as a reference is in the range of -3dB or more, and the total length from the first part to the fourth part is preferably 0.75κ·λ to 1.30κ·λ.

[0151] <3. Research on the Shape of the First Digital Television Antenna 2>

[0152] The following is about Figure 9 The total length of the first to fifth portions of the first element of the first digital television antenna shown was studied. In Examples 6 to 10, the total lengths of the first to fifth portions were approximately 0.9κ·λ, 1.0κ·λ, 1.1κ·λ, 1.25κ·λ, and 1.35κ·λ, respectively. Figure 9 Example 9 (the numerical value is in mm) refers to Examples 6 to 8 and Examples 10, which adjusted the lengths of the first to fifth parts based on the dimensions shown in Example 9, in a manner that constitutes the total length.

[0153] These first digital television antennas, as described in Examples 6-10, were formed on glass plates. Then, the glass plates were assembled into the window frame of a car, and the pointing characteristics in the horizontal plane were measured while changing the illumination angle of the radio waves, and the average gain was calculated. The pointing characteristic measurements were performed in the 470-710 MHz frequency band. The results are as follows... Figure 10 As shown. Furthermore, Figure 10 This indicates the results in the low-frequency band (470–575 MHz).

[0154] according to Figure 10 It can be seen that the normalized gain as a reference is in the range of -3dB or more, and the total length from the first part to the fifth part is preferably 0.95κ·λ to 1.33κ·λ.

[0155] <4. Research on the Shape of the First Digital Television Antenna 3>

[0156] The following section examines the number of unpowered components in the first element of the first digital television antenna. Here, as... Figures 11A to 11C As shown, Examples 11 to 13 (unit: mm) were prepared with 0 to 2 unpowered components respectively. Furthermore, Example 14 was prepared in which two identical power-supply components were arranged above the unpowered components of Example 13. That is, Example 14 has 4 unpowered components.

[0157] These first digital television antennas, as described in Examples 11-14, were formed on glass plates. Then, the glass plates were assembled into the window frame of a car, and the pointing characteristics in the horizontal plane were measured while changing the illumination angle of the radio waves, and the average gain was calculated. The pointing characteristic measurements were performed in the 470-710 MHz frequency band. The results are as follows... Figure 12As shown. Furthermore, Figure 12 The results in the low-frequency band (470–575 MHz) and the low-frequency band (575–710 MHz) are presented separately.

[0158] according to Figure 12 It is known that the more unpowered components there are, the lower the normalized gain in the low-frequency band, and the higher the normalized gain in the high-frequency band. Therefore, it is known that the gain of the antenna in the low-frequency and high-frequency bands can be adjusted by increasing or decreasing the number of unpowered components. In fact, the optimal number can be adjusted through vehicle body design and equipment configuration. Furthermore, Example 14... Figure 12 As shown, although the normalized gain in the low-frequency band is reduced, it is still at a usable level.

[0159] <5. Research on the Shape of DAB Antennas 1>

[0160] Next, the shape of the DAB antenna is studied. The following section discusses... Figure 13 The total length of the first to fourth portions of the first element of the DAB antenna shown was investigated. In Examples 15 to 21, the total lengths of the first to fourth portions were approximately 0.22κ·λ, 0.25κ·λ, 0.26κ·λ, 0.28κ·λ, 0.30κ·λ, 0.32κ·λ, and 0.35κ·λ, respectively. Figure 13 Referring to Example 19 (the numerical values ​​are in mm), Examples 15-18, 20, and 21 adjusted the lengths of the first to fourth portions based on the dimensions shown in Example 19, in a manner that resulted in the total length described above. The wavelength shortening rate κ of the glass plate was 0.7, and the center frequency of the test wave (175-240MHz) was 207MHz, resulting in a wavelength λ (=1450mm). This is also consistent in the examples described later.

[0161] The DAB antennas of Examples 15-21 were formed on glass plates. Then, each glass plate was assembled into a car window frame, and the pointing characteristics in the horizontal plane were measured while changing the illumination angle of the radio waves, and the average gain was calculated. The pointing characteristic measurements were performed in the 175-240 MHz frequency band. The results are as follows... Figure 14 As shown.

[0162] according to Figure 14 It can be seen that the normalized gain as a reference is in the range of -4dB or higher, and the total length from the first part to the fourth part is preferably 0.22κ·λ to 0.32κ·λ.

[0163] <6. Research on the Shape of DAB Antennas 2>

[0164] The following is about Figure 15The total length of the first to fifth portions of the first element of the DAB antenna shown was investigated. In embodiments 22 to 25, the total lengths of the first to fifth portions were approximately 0.32κ·λ, 0.33κ·λ, 0.40κ·λ, and 0.43κ·λ, respectively. Figure 15 Example 24 (the numerical value is in mm), Examples 22, 23, and 25 are based on the dimensions shown in Example 24, and the lengths of the first to fifth parts are adjusted in a manner that becomes the total length.

[0165] These DAB antennas from Examples 22-25 were formed on glass plates. Then, the glass plates were assembled into the window frame of a car, and the pointing characteristics in the horizontal plane were measured while changing the illumination angle of the radio waves, and the average gain was calculated. The pointing characteristic measurements were performed in the 175-240 MHz frequency band. The results are as follows... Figure 16 As shown.

[0166] according to Figure 16 It can be seen that the normalized gain as a reference is in the range of -4dB or higher, and the total length from the first part to the fifth part is preferably 0.32κ·λ to 0.43κ·λ.

[0167] Explanation of reference numerals in the attached figures

[0168] 1: Glass plate

[0169] 2: Light-blocking layer

[0170] 3: Demister

[0171] 4: First digital television antenna (first antenna)

[0172] 41: Frontline Unit

[0173] 42: Grounding section

[0174] 43: First Component

[0175] 44: Second Component

[0176] 45: No power supply components

[0177] 5: Second digital TV antenna (second antenna)

[0178] 51: Frontline Unit

[0179] 52: Grounding section

[0180] 53: First Component

[0181] 54: Second element.

Claims

1. A type of window glass for vehicles, characterized in that, include: glass plate; A light-shielding layer is stacked on the periphery of the glass plate; A demister, at least a portion of which is disposed in the light-transmitting area of ​​the glass plate surrounded by the light-shielding layer; and The first antenna is positioned on the glass plate below the demister. In the light-shielding layer, the portion stacked at the upper end of the glass plate has a vertical width of 25~200mm. When the horizontal length at the center of the vertical direction of the light-transmitting area is defined as a1, the vertical length at the center of the horizontal direction of the glass plate is defined as b1, and the wavelength of the center frequency of the radio wave received by the first antenna is defined as λ, then a1 + b1 ≥ 0.5λ is satisfied. The first antenna includes: First connection point; Second connection point; The first element extending from the first connection point; and The second element extending from the second connection point The first element includes: a first portion extending downward from the first connection point; a second portion extending horizontally from the lower end of the first portion; a third portion extending upward from the end of the second portion; and a fourth portion extending from the upper end of the third portion toward the first connection point.

2. The vehicle window glass according to claim 1, characterized in that: The first element further includes a fifth portion, which is connected to the upper end of the third portion and extends horizontally away from the first connection point.

3. The vehicle window glass according to claim 1 or 2, characterized in that: The first antenna is a digital television antenna. When the wavelength shortening rate of the glass is κ, the total length from the first part to the fourth part is in the range of 0.75κ·λ to 1.30κ·λ.

4. The vehicle window glass according to claim 2, characterized in that: The first antenna is a digital television antenna. When the wavelength shortening rate of the glass is κ, the total length from the first part to the fifth part is in the range of 0.95κ·λ to 1.33κ·λ.

5. The vehicle window glass according to claim 1 or 2, characterized in that: At a position above the fourth portion of the first element, there is also at least one unpowered element extending in the horizontal direction.

6. The vehicle window glass according to claim 1 or 2, characterized in that: It also includes the second line, The first antenna and the second antenna are arranged with their horizontal centers separated by the glass plate. The first antenna and the second antenna have asymmetrical shapes about the center.

7. The vehicle window glass according to claim 6, characterized in that: The first antenna and the second antenna are configured to receive broadcast waves in the UHF band.

8. The vehicle window glass according to claim 6, characterized in that: The first antenna and the second antenna are configured to receive horizontally polarized waves.

9. The vehicle window glass according to claim 6, characterized in that: The demister includes a pair of busbars and a plurality of heating wires extending between the pair of busbars and arranged parallel to each other in the vertical direction. The first antenna is positioned below the lowest heating wire. The second antenna is positioned between the lowest heating wire and the second heating wire from the bottom.

10. The vehicle window glass according to claim 6, characterized in that: The second antenna includes: Third connection point; Fourth connection point; The third element extending from the third connection point; and The fourth element extending from the fourth connection point, The third element includes a sixth portion extending upward from the third connection point and a seventh portion extending horizontally from the upper end of the sixth portion.

11. The vehicle window glass according to claim 1 or 2, characterized in that: The first antenna is a DAB antenna. When the wavelength shortening rate of the glass is κ, the total length from the first part to the fourth part is in the range of 0.22κ·λ to 0.32κ·λ.

12. The vehicle window glass according to claim 2, characterized in that: The first antenna is a DAB antenna. When the wavelength shortening rate of the glass is κ, the total length from the first part to the fifth part is in the range of 0.32κ·λ to 0.43κ·λ.

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