Vehicle window glass

Abstract

To provide a window glass for a vehicle capable of acquiring satisfactory antenna sensitivity.SOLUTION: A window glass for a vehicle includes an information transmission region for allowing a sensor to acquire information from the outside, a first defogging region, a second defogging region adjacent to the first defogging region, and a radio wave reception region adjacent to the first defogging region, a pair of bus bars and heater wires connecting the pair of bus bars are arranged in the first defogging region, the heater wires include a first heater wire provided close to the radio wave reception region, and a plurality of second heater wires arranged in substantially parallel with the first heater wire, a third heater wire including a circumferential wire arranged around the information transmission region and a connection wire extending from the circumferential wire to be connected to the first heater wire is arranged in the second defogging region, the radio wave reception region is adjacent to both the first defogging region and the second defogging region, and a power feeding part and an antenna element extending from the power feeding part to be adjacent to the first heater wire are arranged in the radio wave reception region.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to vehicle glazings. [Background technology]

[0002] Generally, drivers of automobiles use the rearview mirror to check the rear. In particular, electronic rearview mirrors are used in SUVs and wagons, where rear visibility is often blocked by people or luggage in the back seats (Patent Document 1). A camera is attached to the back window (rear glass) to capture the image displayed on the electronic rearview mirror.

[0003] For example, Patent Document 2 discloses a vehicle window glass that includes an on-board camera arranged inside the vehicle so as to face a back window attached to the rear of the vehicle, a heating means (heat ray) for heating the back window, and an antenna. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-135020 A [Patent Document 2] International Publication No. 2019 / 017246 Summary of the Invention [Problem to be solved by the invention]

[0005] In vehicles equipped with a rearview mirror, an antenna element can be placed in the entire area of ​​the upper margin of the rear windshield above the heating wire, but the rear window disclosed in Patent Document 2 has an information acquisition device such as an on-board camera attached to the upper margin of the rear windshield above the heating wire, and further, in order to prevent fogging in the camera's field of view, the uppermost line of the heating wire is positioned to surround the camera's field of view, limiting the area in which the antenna element can be placed.

[0006] In addition, the length of the antenna itself is often affected by the limited area in which the antenna wire is placed. For example, since antenna sensitivity depends on the length of the antenna, if the antenna area is small, the antenna length will also be short, and good antenna performance cannot be obtained. If an antenna longer than the width of the antenna area is folded back, the direction of the induced current in the antenna will be reversed, and the radiated electric fields will cancel each other out, making it impossible to obtain good antenna sensitivity.

[0007] The present disclosure has been made to solve the above problems, and has an object to provide a vehicle window glass that is equipped with a glass plate for a vehicle window to be attached to the rear of a vehicle, a defogger, and an antenna, and that is capable of obtaining good antenna sensitivity even when the area for arranging antenna wires is limited. [Means for solving the problem]

[0008] That is, the present invention provides a window glass for a vehicle, comprising: an information transmission region for a sensor to obtain information from the outside by transmitting through the window glass; a first anti-fogging region arranged to include a central portion of the window glass; a second anti-fogging region adjacent to the first anti-fogging region; and a radio wave receiving region adjacent to the first anti-fogging region, wherein the first anti-fogging region is provided with a pair of bus bars arranged on both side portions of the window glass and extending in the up-down direction, and heating wires extending in the left-right direction and connecting the pair of bus bars, the heating wires being provided adjacent to the radio wave receiving region and being arranged substantially parallel to the first heating wires. the second anti-fogging region includes a circumferential line disposed around the information transmitting region and a third heating stripe including a connecting stripe extending from the circumferential line and connected to the first heating stripe; the second anti-fogging region includes a power supply section to which a power supply line is connected and an antenna element extending from the power supply section; the radio wave receiving region is adjacent to both the first anti-fogging region and the second anti-fogging region; and the antenna element is disposed so that at least a portion of the antenna element is adjacent to the first heating stripe and also adjacent to the third heating stripe.

[0009] The present invention also relates to a window glass characterized in that the antenna element has a first horizontal stripe extending from the power supply portion approximately parallel to the top edge of the window glass, a first vertical stripe extending from the first horizontal stripe approximately parallel to the vertical edge of the window glass, and a second horizontal stripe extending from the first vertical stripe approximately parallel to the first horizontal stripe.

[0010] The present invention also relates to a window glass characterized in that the receiving frequency of the antenna element includes 76 MHz to 108 MHz, the wavelength of the receiving frequency is λ, and the wavelength shortening rate of the glass is α, where λ is the wavelength of the receiving frequency, and α is the wavelength shortening rate of the glass, the length of the first horizontal stripe is 0.036αλ to 0.106αλ.

[0011] The present invention also relates to a window glass characterized in that the receiving frequency of the antenna element includes 76 MHz to 108 MHz, the wavelength of the receiving frequency is λ, and the wavelength shortening rate of the glass is α, where λ is the wavelength of the receiving frequency, and α is the wavelength shortening rate of the glass, the length of the first vertical stripe is 0.006αλ to 0.036αλ.

[0012] The present invention also relates to a window glass characterized in that the receiving frequency of the antenna element includes 76 MHz to 108 MHz, the wavelength of the receiving frequency is λ, and the wavelength shortening rate of the glass is α, where λ is the wavelength of the receiving frequency, and α is the wavelength shortening rate of the glass, the length of the second horizontal stripe is 0.078αλ to 0.168αλ.

[0013] The present invention also provides a window glass, wherein the distance between the first heating stripes and the second horizontal stripes is 5 mm to 15 mm.

[0014] The present invention also relates to a window glass, wherein a tip of the second horizontal strip is folded back.

[0015] The present invention also relates to a window glass, characterized in that the first antifogging region is provided with lines that intersect with the first heating lines and the plurality of second heating lines.

[0016] The present invention also relates to a window glass, wherein the connecting strip is disposed along the left end or the right end of the circumferential strip.

[0017] The present invention also relates to a window glass, wherein the third heating wire is arranged at a position farther from the antenna element than a vertical center line of the window glass. Effect of the Invention

[0018] According to the present disclosure, in a vehicle window glass equipped with a defogger and an antenna, good antenna sensitivity can be obtained even when the area in which the antenna wire is disposed is limited. [Brief description of the drawings]

[0019] [Figure 1] 1 is a front view showing a vehicle window glass according to a first embodiment of the present invention. [Diagram 2] FIG. 4 is a front view showing a vehicle window glass according to a second embodiment of the present invention. [Diagram 3] FIG. 11 is a front view showing a vehicle window glass according to a third embodiment of the present invention. [Figure 4] FIG. 11 is a front view showing a vehicle window glass according to a third embodiment of the present invention. [Diagram 5] FIG. 11 is a front view showing a vehicle window glass according to a fourth embodiment of the present invention. [Figure 6] FIG. 11 is a front view showing a vehicle window glass according to a fourth embodiment of the present invention. [Figure 7] FIG. 11 is a front view showing a vehicle window glass according to a fifth embodiment of the present invention. [Figure 8] FIG. 11 is a front view showing a vehicle window glass according to a fifth embodiment of the present invention. [Figure 9] FIG. 11 is a characteristic diagram of the antenna of the vehicle window glass according to the second embodiment. [Figure 10] FIG. 13 is a characteristic diagram of the antenna of the vehicle window glass according to the fifth embodiment. [Figure 11] 11 is a front view showing a vehicle window glass of a comparative example shown in the characteristic diagram of FIG. 10. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] 1 is a front view of a vehicle window glass according to a first embodiment of the present invention, as viewed from inside the vehicle. Each figure shows a window glass provided on the rear windshield of an automobile.

[0021] The window glass 1 of the first embodiment is provided with an antenna 2 and a defogger 3. In addition, the window glass 1 is provided with a black coating layer 4 on its peripheral edge.

[0022] The defogger 3 is provided in a first antifogging region 30 provided in the center of the window glass 1, and has a pair of bus bars 31 provided on the left and right sides of the window glass 1, a plurality of heating wires 32A, 32B, 33 connecting the two bus bars 31 and extending in a substantially horizontal direction, and a vertical wire 34 connecting the plurality of heating wires 32A, 32B, 33. The vertical wire 34 is preferably provided on the vertical center line of the window glass 1, and may connect all of the heating wires 33 to the heating wires 32A or 32B, or may connect some of the heating wires 32A, 32B, 33.

[0023] Each of the heating stripes 32A, 32B, 33, 42 is formed by printing a conductive ceramic paste on the surface of the window glass 1 or on the black coating layer 4, drying it, and then baking it in a heating furnace.

[0024] The black coating layer 4 is a colored (usually black) layer formed by printing an insulating ceramic paste made by mixing low-melting point glass powder and pigment into a paste on the window glass 1 and then baking it.

[0025] The black coating layer 4 extends downward in the upper central part of the window glass 1, where there is no black coating layer 4 and an information transparent area 41 is provided that can transmit through the window glass 1 to obtain information such as images. A sensor is attached to the information transparent area 41 for monitoring the rear of the vehicle through the window glass 1. For example, the sensor is an imaging element (CCD camera, CMOS camera, etc.) that captures images behind the vehicle. The sensor may be a rear monitoring radar, a near-infrared laser transceiver, an ultrasonic transceiver, or a millimeter wave transceiver. When the detection range of the sensor is rectangular, the information transparent area 41 is generally trapezoidal with a wider bottom because the window glass 1 is installed at an angle.

[0026] The information transmission region 41 is included in the second antifogging region 40 shown by the dashed line in the figure, and the third heating wire 42 is provided near or inside the information transmission region 41. For example, the third heating wire 42 is provided around the information transmission region 41, and heats the second antifogging region 40 to remove water droplets attached to the second antifogging region 40, thereby ensuring transparency. The third heating wire 42 has a circumferential line 42A and a connecting wire 42B provided around the information transmission region 41, and is connected between the uppermost heating wires 32A and 32B of the defogger 3. Specifically, a current flows in the order of the heating wire 32A, one connecting wire 42B, the circumferential line 42A, the other connecting wire 42B, and the heating wire 32B (or in the reverse order). Among the heating wires of the defogger 3, the path from the heating wire 32A to the heating wire 32B has a long line length, so it is preferable to make the cross-sectional area (width or thickness) of the wire large and make it have the same resistance as the other heating wires 33, thereby making the current flowing through each heating wire equal. The circumferential wire 42A is symmetrical with a wide bottom to match the shape of the information transmitting area 41, and preferably is symmetrical so as not to impair the appearance.

[0027] The antenna 2 is provided in the radio wave receiving region 20 on the left side of the upper portion of the defogger 3. The radio wave receiving region 20 is provided in a position adjacent to both the first antifogging region 30 and the second antifogging region 40. The antenna 2 has a power supply portion 21 provided in the black coating layer 4, and an element 22 composed of a conductor extending laterally from the power supply portion 21. The power supply portion 21 is connected to a power supply line. For example, as shown in FIG. 1, the element 22 has a first horizontal wire 22A extending substantially horizontally from the power supply portion 21, a first vertical wire 22B extending substantially vertically from the tip of the first horizontal wire 22A, and a second horizontal wire 22C extending substantially parallel to the first horizontal wire 22A from the lower end of the first vertical wire 22B. At least a part of the element 22 (for example, the second horizontal strip 22C on the tip side) is disposed in close proximity to the uppermost heating strip 32A of the defogger 3 (at a distance of 5 to 15 mm), and the antenna 2 and the heating strip 32A are capacitively coupled. For this reason, the heating strips 32A, 32B, and 33 of the defogger 3 function as antennas. In addition, at least a part of the element 22 (for example, the tip of the second horizontal strip 22C) is disposed in close proximity to the connecting strip 42B of the third heating strip 42 (at a distance of 5 to 10 mm), and the antenna 2 and the third heating strip 32A are capacitively coupled. The length of the element 22 is adjusted to resonate with the receiving frequency. When receiving a VHF band (for example, radio waves with a frequency of 76 to 108 MHz and a wavelength of λ), the length of the first horizontal stripe 22A is preferably 100 to 400 mm (0.036αλ to 0.106αλ), the length of the first vertical stripe 22B is preferably 15 to 100 mm (0.006αλ to 0.036αλ), and the length of the second horizontal stripe 22C is preferably 100 to 400 mm (0.078αλ to 0.168αλ), where α is the wavelength shortening rate of glass.

[0028] The antenna 2 is formed by printing a conductive ceramic paste on the surface of the window glass 1 or on the black coating layer 4, drying it, and then baking it in a heating furnace, but the conductor may also be formed on a synthetic resin sheet that is to be attached to the window glass 1.

[0029] In the window glass 1 of Example 1, a peripheral wire 41A is provided around the information-transmitting area 41 at the top of the defogger 3, and a radio wave receiving area 20 for providing an antenna 2 is secured at the top of the defogger 3, and the antenna element 22 is disposed adjacent to the heating wire 32A. Therefore, the radio waves captured by the heating wires 32A, 32B, and 33 can be guided to the antenna 2, thereby improving the sensitivity of the antenna 2.

[0030] <Example 2> 2 is a front view of a vehicle interior of a vehicle window glass according to a second embodiment of the present invention. In the second embodiment, the same components as those in the first embodiment are given the same reference numerals, and the description thereof will be omitted.

[0031] The window glass 1 of the second embodiment is provided with a plurality of vertical stripes 34 of the defogger 3. For example, an odd number of the vertical stripes 34 (three stripes in the figure) may be provided evenly between the bus bars 31. Each vertical strip 34 may connect all the heating stripes 33 and the heating stripes 32A or 32B, or may connect some of the heating stripes 32A, 32B, and 33.

[0032] In the window glass 1 of the second embodiment, since a plurality of vertical lines 34 are provided inside the defogger 3, it is possible to improve the sensitivity of the antenna 2. In particular, it is possible to improve the sensitivity to vertically polarized waves.

[0033] <Example 3> 3 and 4 are front views of a vehicle window glass according to a third embodiment of the present invention, as viewed from inside the vehicle. In the third embodiment, the same components as those in the first and second embodiments are given the same reference numerals, and the description thereof will be omitted.

[0034] In the third embodiment, the information transmitting area 41 is provided at a position offset from the horizontal center of the window glass 1, i.e., on the left side in the example shown in Fig. 3 and on the right side in the example shown in Fig. 4. Due to the left-right offset of the information transmitting area 41, the downward projection from the upper center of the black coating layer 4 is provided at a position offset to the left or right, and the third heating strip 42 is also provided at a position offset to the left or right. In the illustrated embodiment, the connecting strip 42B is arranged along the rightmost or leftmost position of the circumferential strip 42A.

[0035] In the window glass 1 of Example 3, the connecting wire 42B is provided in the horizontal center of the defogger 3, while the information transmitting area 41 is provided in a position shifted from the center. This improves the freedom of sensor placement without destroying the horizontal balance of the defogger 3 when viewed from outside the vehicle, and does not impair the design of the vehicle.

[0036] <Example 4> 5 and 6 are front views, as seen from inside the vehicle, of a vehicle window glass according to Example 4 of the present invention. In Example 4, the same components as those in Examples 1 to 3 described above are given the same reference numerals, and the description thereof will be omitted.

[0037] In the fourth embodiment, the connecting wire 42B of the third heating wire 42 is provided at a position shifted to the right side from the horizontal center of the window glass 1, and the radio wave receiving area 20 is expanded. In particular, the lower area of ​​the radio wave receiving area 20 where the second horizontal wire 22C is arranged is expanded to the right. This allows the element 22 to be longer, and the sensitivity of the antenna 2 to be improved. In addition, the capacitive coupling between the second horizontal wire 22C and the heating wire 32A becomes stronger, and the power of the received radio wave induced from the defogger 3 to the antenna 2 increases, and the sensitivity of the antenna 2 can be improved.

[0038] By locating the connecting wire 42B of the third heating wire 42 at a position shifted toward the right side from the horizontal center of the window glass 1, the radio wave receiving area can be expanded, so that a sufficient radio wave receiving area can be secured even in light cars and compact cars with narrow window glass 1 widths.

[0039] Furthermore, by locating the connecting wire 42B of the third heating wire 42 to the right side of the horizontal center of the window glass 1, the radio wave receiving area can be expanded, the antenna 2 can be lengthened, and the antenna resonance frequency can be adjusted to a low range. This makes it possible to obtain good antenna sensitivity even in the domestic band (76 MHz to 95 MHz).

[0040] For example, in the window glass 1 shown in Figures 5 and 6, the information transparent area 41 is provided in a position shifted to the right from the horizontal center of the window glass 1, and due to the rightward shift of the information transparent area 41, the downward projection from the upper center of the black coating layer 4 is provided in a position shifted to the right, and the third heating strip 42 is also provided in a position shifted to the right. Here, in the window glass 1 shown in Figure 5, the connecting strip 42B is provided in the center of the circumferential strip 42A. Also, in the window glass 1 shown in Figure 6, the connecting strip 42B is provided along the rightmost position of the circumferential strip 42A.

[0041] <Example 5> 7 and 8 are front views of a vehicle window glass according to a fifth embodiment of the present invention, as viewed from inside the vehicle. In the fifth embodiment, the same components as those in the first to fourth embodiments are given the same reference numerals, and the description thereof will be omitted.

[0042] In the fifth embodiment, the tip of the second horizontal wire 22C of the antenna 2 is folded back at a position close to the third heating wire 42, and the element 22 and the third heating wire 42 are disposed in close proximity to each other so as to be capacitively coupled to each other. The tip of the second horizontal wire 22C may be folded back counterclockwise as shown in FIG. 7 or clockwise as shown in FIG. 8.

[0043] In the window glass 1 of Example 5, the second horizontal wires 22C are capacitively coupled to the heating wires 32A and the third heating wires 42, so that the defogger 3 functions as an antenna, and the sensitivity of the antenna 2 can be improved.

[0044] In the embodiment described above, the radio wave receiving area 20 is provided on the left side of the window glass 1 , but the radio wave receiving area 20 may be provided on the right side of the window glass 1 .

[0045] <Antenna characteristics> Here, the characteristics of the antenna of the above-mentioned embodiment will be described.

[0046] FIG. 9 shows the change in sensitivity in the reception band (76 to 108 MHz) depending on the distance between the second horizontal line 22C and the heating line 32A in the antenna 2 of the second embodiment. As can be seen from the figure, as the distance between the second horizontal line 22C and the heating line 32A decreases, the capacitive coupling between the two lines increases. As a result, the sensitivity improves in the low frequency band, does not change significantly in the mid frequency band, and decreases in the high frequency band. In this way, when the distance between the second horizontal line 22C and the heating line 32A is short, the sensitivity within the reception band can be flattened.

[0047] Fig. 10 shows the characteristics (sensitivity) of the antenna of the embodiment 5 shown in Fig. 7 compared with the antenna of the comparative example shown in Fig. 11. The total length of the element 22 of the antenna 2 is the same in the antenna of the embodiment 5 shown in Fig. 7 and the antenna of the comparative example shown in Fig. 11, but the second horizontal wire 22C is shorter in the antenna of the comparative example shown in Fig. 11. As can be seen from the figure, when the length of the second horizontal wire 22C adjacent to the heating wire 32A is increased, the capacitive coupling between the two wires becomes stronger, and the sensitivity within the reception band can be improved. [Explanation of symbols]

[0048] 1. Window Glass 2 Antennas 3 Defogger 4 Black coating layer 20 Radio reception area 21 Power supply unit 22 Elements 22A First horizontal stripe 22B 1st vertical line 22C Second horizontal stripe 30 1st anti-fog area 31 Bus Bar 32A, 32B, 33 Heating wire 34 Vertical striations 40 2nd anti-fog area 41 Information transparent area 42 Third heating wire 42A Circumferential stripe 42B Connecting wire

Claims

1. A window glass for a vehicle, an information transmission area for a sensor to acquire information from the outside through the window glass; A first anti-fogging area disposed to include a central portion of the window glass; a second antifogging region adjacent to the first antifogging region; The first antifogging area and a radio wave receiving area adjacent to each other are provided, In the first antifogging region, a pair of bus bars are arranged on both side surfaces of the window glass, extending in the vertical direction, and heating wires are arranged to extend in the horizontal direction and connect the pair of bus bars, The heating wire includes a first heating wire provided adjacent to the radio wave receiving region and a plurality of second heating wires arranged substantially parallel to the first heating wires, The second antifogging region is provided with a peripheral line arranged around the information transparent region, and a third heating line extending from the peripheral line and including a connecting line connected to the first heating line, The radio wave receiving region is adjacent to both the first anti-fogging region and the second anti-fogging region, a power supply unit to which a power supply line is connected and an antenna element extending from the power supply unit are disposed in the radio wave receiving area; The window glass, wherein the antenna element is arranged such that at least a portion of the antenna element is adjacent to the first heating wire and adjacent to the third heating wire.

2. 2. A glazing according to claim 1, The window glass characterized in that the antenna element has a first horizontal stripe extending from the power supply portion approximately parallel to the top edge of the window glass, a first vertical stripe extending from the first horizontal stripe approximately parallel to the vertical edge of the window glass, and a second horizontal stripe extending from the first vertical stripe approximately parallel to the first horizontal stripe.

3. 3. A glazing according to claim 2, A window glass characterized in that the receiving frequency of the antenna element includes 76 MHz to 108 MHz, the wavelength of the receiving frequency is λ, and the wavelength shortening rate of the glass is α, the length of the first horizontal stripe is 0.036αλ to 0.106αλ.

4. Window glass according to claim 2 or 3, The window glass is characterized in that the receiving frequency of the antenna element includes 76 MHz to 108 MHz, the wavelength of the receiving frequency is λ, and the wavelength shortening rate of the glass is α, the length of the first vertical stripe is 0.006αλ to 0.036αλ.

5. 5. A glazing according to any one of claims 2 to 4, The window glass is characterized in that the receiving frequency of the antenna element includes 76 MHz to 108 MHz, the wavelength of the receiving frequency is λ, and the wavelength shortening rate of the glass is α, the length of the second horizontal stripe is 0.078αλ to 0.168αλ.

6. 6. A glazing according to any one of claims 2 to 5, A window glass characterized in that the distance between the first heating stripe and the second horizontal stripe is 5 mm to 15 mm.

7. 7. A glazing according to any one of claims 2 to 6, A window glass characterized in that the second horizontal stripes have their tips folded back.

8. 8. A glazing according to any one of claims 1 to 7, A window glass, characterized in that the first anti-fogging region is provided with lines that intersect with the first heating lines and the plurality of second heating lines.

9. 9. A glazing according to any one of claims 1 to 8, The window glass is characterized in that the connecting strip is arranged along the left end or the right end of the circumferential strip.

10. 10. A glazing according to any one of claims 1 to 9, The window glass, wherein the third heating wire is disposed at a position farther from the antenna element than a vertical center line of the window glass.

Images