JP2008067300A - Rear window glass for vehicles - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rear window glass for vehicles in which a broad defogging and deicing area is provided for a driver and on which an antenna having a preferable performance in a high frequency band of 170 MHz or more is provided. <P>SOLUTION: The rear window glass includes: two bus bars 24 and 26 each provided on both sides of a glass sheet 8; a first heating section 21 composed of a plurality of lateral heating lines 5 arranged between the bus bars 24 and 26; a second heating section 20 provided above the first heating section 21 and on a central portion in a lateral direction of the glass sheet 8, and composed of a plurality of lateral heating lines 4 and two vertical heating lines 2a and 2b each thereof connecting ends of the lateral heating lines 4, respectively; and meander-shaped heating lines 32 and 34 arranged between the bus bars 24 and 26 and the second heating section 20, respectively, for connecting the bus bars to the vertical heating lines 2a and 2b. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention provides an effective anti-fogging and de-icing performance for a driver even in a rear window glass for a vehicle, particularly in a narrow antenna setting area, and at the same time, a broadcast wave having a frequency of 170 MHz or higher can be satisfactorily received. The present invention relates to a vehicle rear window glass provided with an antenna.

  Conventionally, in a vehicle such as a compact car, a minivan, or a wagon, the rear window glass is upright, and thus the vertical dimension of the window glass is reduced. In such a window glass, clearing performance and de-icing performance by a defogger are required on almost the entire surface of the glass, so that heat rays are widely distributed and an effective area for antenna setting cannot be secured. The antenna provided on such a window glass is limited to an antenna in a low frequency band (76 MHz to 108 MHz) such as a radio FM band. In general, it is provided at other sites.

  This is because the heat wire of the defogger functions as an antenna that receives a low frequency band of 76 to 108 MHz used for FM radio broadcasting and the like, and the antenna installed in the vicinity of the heat wire is capacitively coupled with the heat wire, This is because the antenna is suitable for reception at a low frequency and is not suitable for reception at a high frequency (170 MHz or higher).

As an example of solving the above problems, Patent Document 1 discloses an example in which an antenna that receives a high frequency band is provided on a rear window glass. FIG. 1 shows a rear window glass 6 described in Patent Document 1. The left and right portions of the heat ray in the upper region of the defogger 10 provided on the glass plate 8 are removed to secure the regions 12 and 14, and the monopole antennas 16 and 18 having a band of 170 MHz or more are provided in these regions. Reference numerals 17 and 19 denote antenna feeding points. Hereinafter, a normal heat ray portion in the lower region of the defogger 10 is referred to as a first heat generating portion 21, and a convex heat ray portion in the upper region is referred to as a second heat generating portion 20.
The second heat generating portion 20 is composed of two vertical heat wires 2a and 2b connected to the lower heat wire 22 and a plurality of horizontal heat wires 4 arranged therebetween. In the figure, reference numerals 24 and 26 denote bus bars of the defogger 10.
It is also known from Patent Document 2 that the influence of the heat rays on the antenna is reduced by making the heat rays of the defogger close to the antenna into a menanda shape.
JP2005-101809 International Publication WO2006 / 001486

In the rear window glass 6 of FIG. 1, in order to set an antenna that can receive a high frequency of 170 MHz or higher satisfactorily, it is necessary to secure a certain distance from the window frame of the vehicle body and the heat rays extending in the lateral direction. However, since there is no heat ray for anti-fogging / de-icing on the glass surface, the anti-fogging / de-icing performance of the portion cannot be obtained, and there is a problem that an effective fluoroscopic region cannot be obtained.
Therefore, the conventional heat ray pattern is not suitable for application to an upright window glass.

  The object of the present invention is to provide a driver with a wide anti-fogging and de-icing region and good in a high frequency band of 170 MHz or higher even for a rear window glass having a small vertical dimension (height). An object of the present invention is to provide a rear window glass for a vehicle provided with an antenna having excellent antenna performance.

The rear window glass for a vehicle according to the present invention includes a glass plate, two first bus bars provided on both sides of the glass plate, and a plurality of first lateral directions arranged between the first bus bars. A first heat generating portion configured by heat rays; a first heat generating portion provided above the first heat generating portion and in a central portion in a lateral direction of the glass plate; a plurality of second lateral heat rays; A second heat generating part constituted by two vertical heat lines connecting the end portions of the horizontal heat lines and extending in the vertical direction, and disposed between each of the first bus bars and the second heat generating part. And a heat wire having a meander shape connecting the first bus bar and the longitudinal heat wire of the second heat generating portion, wherein the second heat generating portion is located above the heat wire having the meander shape. Extending above the hot wire having the meander shape, Characterized in that it comprises an antenna element on a glass plate surface of at least one region of the regions on both sides of the second heating portion which Zaisa the extension.
According to the present invention, in order to supply power to the second heat generating portion, two wires that connect between each of the two vertical heat rays of the second heat generating portion and the corresponding first bus bar. It is preferable to provide the second bus bar.

It is preferable to insert at least one coil in series into the second bus bar in the region where the antenna element is provided. In this case, the capacity of one coil is set to be high impedance at a frequency of 80 MHz or higher. Specifically, the inductance of one coil is 0.1 to 2.0 μH.
Moreover, it is preferable that the length that the second heat generating portion extends upward from the heat ray having the meander shape is 30 to 100 mm. By setting the distance to 30 mm or more, it is possible to secure a sufficient area above the meander-shaped heat ray and sufficient to provide an antenna in the area on the side of the second heat generating portion. Moreover, the area | region which does not provide a heat ray does not become large too much by setting it as 100 mm or less.

  When the window glass is attached to the vehicle body, the distance between the uppermost heat ray of the second heat generating portion and the upper side vehicle body can be about 20 mm. Therefore, the vertical width of the regions on both sides of the second heat generating portion is preferably 50 to 120 mm.

  In the rear window glass for a vehicle according to the present invention, the area where the heat ray does not exist for antenna setting is only a small area on the upper side of the window glass, and the heat ray is arranged in all other areas. It is a window glass having a clouded and defrosted region, and by providing the shape of the heat ray directly under the antenna as a meander shape, it is possible to provide good antenna performance at the same time.

  In addition, the rear window glass of the present invention can set an antenna having good reception performance in a band of 170 MHz or higher, so that it is difficult to set in the past, such as light vehicles, etc. It is possible to set the antenna for the media.

  Hereinafter, the Example of the rear window glass for vehicles of this invention is described.

FIG. 2 shows a vehicle rear window glass 30 according to the first embodiment. The same components as those in FIG. 1 are denoted by the same reference numerals.
The vehicle rear window glass 30 of the present embodiment includes a first heat bar 5 formed on both sides of the glass plate 8 and a plurality of lateral heat wires 5 arranged between the bus bars 24 and 26. The heat generating part 21 is disposed above the first heat generating part 21 and in the central part in the horizontal direction of the glass plate 8, and extends in the vertical direction by connecting the ends of the plurality of horizontal heat lines 4 and the horizontal heat lines 4. It arrange | positions between the 2nd heat generating part 20 comprised by the two vertical heat wires 2a and 2b, the bus bars 24 and 26, and the 2nd heat generating part 20, and each bus bar and the vertical heat wires 2a and 2b. Are provided with heat wires 32 and 34 having meander shapes.
The second heat generating portion 20 is arranged to extend above the heat wires 32 and 34 having a meander shape, and on the glass plate surfaces of the regions 12 and 14 on both sides of the second heat generating portion 20. Antennas 16 and 18 are provided.

The monopole antennas 16 and 18 are configured to have a pattern optimized for 200 MMz. Specifically, the length of the line from the feeding points 17 and 19 to the tip of the antenna element is 1 / 4λ · κ = 225 mm (the wavelength λ at 200 MHz is 150 mm, and κ is the wavelength reduction rate. It was 0.6 for glass).
Further, the height A of the area where the monopole antennas 16 and 18 are provided (the distance between the vehicle body on the upper side and the upper part of the meander heat wire) was 50 mm.
The second heat generating portion 20 extends upward by one interval (about 35 mm) of the transverse heat wire 4 from the upper part of the meander-shaped heat wires 32 and 34.
The distance between the monopole antennas 16 and 18 on the side of the monopole antennas 16 and 18 of the meander-shaped heat wires 32 and 34 and the monopole antennas 16 and 18 is about 3 mm in this embodiment. It is not limited to.
The line width of the horizontal heat wire 5 of the first heat generating part 21 and the horizontal heat wire 4 of the second heat generating part 20 is about 2 mm. The line width of each meander-shaped hot wire 32, 34 is about 5-6 mm. Since the current that can be supplied to the second heat generating unit 20 can be increased by increasing the line width of the meander-shaped heat wire in this way, the second heat generating unit 20 can have sufficient heat generation performance.

  The rear window glass 30 having the above configuration was attached to the vehicle, and the antenna sensitivity was measured in an anechoic chamber. The measurement results are shown in FIG. The horizontal axis represents frequency (MHz), and the vertical axis represents antenna sensitivity. The average sensitivity is shown in Table 1. Note that all antenna sensitivities are expressed as dipole ratios based on the dipole antenna.

  In the above embodiment, the monopole antennas 16 and 18 are provided on the glass plate surfaces of the regions 12 and 14 on both sides of the second heat generating portion 20, respectively, but the monopole antenna is provided only on one region. Also good.

In the first embodiment shown in FIG. 2, a second bus bar is further provided. FIG. 4 shows the configuration. The second bus bar includes a bus bar 36 that connects the first bus bar 24 and the upper end of the vertical heat line 2a of the second heat generating unit 20, and a vertical heat line of the first bus bar 26 and the second heat generating unit 20. It is comprised by the bus bar 38 which connects the upper end part of 2b.
These second bus bars serve to supply electric power for heat generation to the second heat generating portion 20 in the same manner as the meander-shaped heat ray. In order to supply most of the electric power to the second heat generating portion, it is preferable to increase the line width of the second bus bar. In this embodiment, the line width of these second bus bars 36 and 38 is 4 to 5 mm. Correspondingly, even if the line width of the meander-shaped heat wires 32 and 34 is reduced to 1 to 2 mm, the second heat generating part can have sufficient heat generation performance. In this case, since the line width of the meander-shaped heat ray is 1 to 2 mm, the rear view can be improved.

  The rear window glass 30 having the above configuration was attached to the vehicle, and the antenna sensitivity was measured in an anechoic chamber. The measurement results are shown in FIG. 3 for comparison. The average sensitivity is shown in Table 2.

It can be seen that by attaching the second bus bars 36 and 38 covering the upper side of the antenna, the sensitivity is lowered due to the influence of the bus bars on the antenna, and the frequency is shifted to a lower frequency. This is because the meander-shaped heat wires surrounding the antenna and the bus bars 36 and 38 form a loop, and this loop is capacitively coupled to the antennas 16 and 18 and functions as an antenna that receives a low band.
In this embodiment, the line width of the meander-shaped hot wire can be made narrower than that of the first embodiment, so that the rear view can be improved as described above.

In this embodiment, compared to the first embodiment of FIG. 2, the distance between the transverse heat rays of the second heat generating portion 20 is only two intervals (about 70 mm) rather than the uppermost portions of the meander-shaped heat wires 32 and 34. The second heat generating part 20 extends upward. In this embodiment, the height A of the regions 12 and 14 where the antennas 16 and 18 are provided is 80 mm.
FIG. 5 shows the rear window glass of this example. Table 3 shows the measured antenna sensitivity (average sensitivity) in this example.

  It can be seen that the antenna sensitivity is improved as compared with the first embodiment.

The present embodiment is an example in which a second bus bar is provided with respect to the third embodiment. FIG. 6 shows the configuration. Similar to the second embodiment, the second bus bars 36 and 38 have a line width of 4 to 5 mm, and the meander-shaped heat wires 32 and 34 have a line width of 1 to 2 mm.
FIG. 7 shows the measured antenna sensitivity of this example, and Table 4 shows the average sensitivity.

  As described in the second embodiment, it is understood that when the second heat generating unit 20 is provided with the second power supply bus bars 36 and 38, the sensitivity is shifted to a low frequency. This is because the antenna moves to a lower frequency due to the influence of the second bus bar and the meander-shaped hot wire.

  As described in the second and fourth embodiments, when the second bus bars 36 and 38 for supplying power to the second heat generating portion 20 are provided, the sensitivity is shifted to a low frequency.

In this example, the configuration of the rear window glass without shifting to a low frequency in the fourth example will be described. FIG. 8 shows the configuration. FIG. 8 shows only the vicinity of the left antenna because the rear window glass has the same shape on the left and right. A coil 40 is inserted in series in the middle of the second bus bar 36. The place where the coil is inserted may be any place as long as it is in the middle of the bus bar 36. As an example, the insertion position of the coil is set to a position of a distance of 1 / 4λ · κ from the connection portion 41 of the bus bar 36 to the second heat generating portion 20 with respect to the wavelength λ of 200 MHz. Here, κ is a wavelength shortening rate.
The line width of the bus bar 36 is 4 to 5 mm, and the line width of the meander-shaped heat wire 32 is 1 to 2 mm.

  FIG. 9 shows a method for installing the coil 40. A part of the bus bar 36 is opened, and a pad 42 is provided at the end of the opened bus bar, and the coil 40 is provided by connecting the end to the pad. The coil 40 passes power to the second heat generating unit 20, but functions to cut high-frequency components received by the antenna. For this purpose, the coil 40 needs to have a high impedance with respect to a high-frequency component of 80 MHz or higher. For this purpose, it is desirable that the impedance of the coil is 0.1 to 2.0 μH.

  In order to confirm the effect of the coil 40, antenna sensitivity was measured. The measurement results are shown in FIG. 7 for comparison. The average sensitivity is shown in Table 5.

From the measurement results, it can be seen that by connecting the coil in series in the middle of the bus bar and cutting the bus bar at a high frequency, the same performance as that without the bus bar is obtained.
When the coil is not inserted into the bus bar, the bus bar functions as an extension of the heat generating portion that covers the window glass, so the bus bar is a part of the antenna that functions in a lower band. For this reason, the frequency received is also a low frequency under the influence of the busner.
On the other hand, when the coil is inserted into the second bus bar, a part of the second bus bar is cut at a high frequency, and the function of the antenna working at a low frequency is taken away from the second bus bar. It becomes possible to return the reception performance to the original one.

  In the above embodiment, the monopole antennas 16 and 18 are provided on the glass plate surfaces of the regions 12 and 14 on both sides of the second heat generating portion 20, respectively, but the monopole antenna is provided only on one region. Also good. In this case, a coil is inserted into the second bus bar 36 in the region where the monopole antenna is provided.

(Comparative Example 1)
In order to confirm the effect of the window glass of the present invention, as shown in FIG. 10, the antenna sensitivity of the window glass when the monopole antenna 16 is provided on the upper part of the defogger not provided with the second heat generating part and the meander-shaped heat ray. Table 6 shows the measurement results of (average sensitivity).

As is apparent from comparison with the average sensitivity of each example, it can be seen that the sensitivity is not good as compared with the window glass of the present invention.
(Comparative Example 2)

In order to confirm the effects of the meander-shaped hot wires 32 and 34, the rear window glass of FIG. 11 having the meander-shaped hot wire as a linear hot wire with the configuration shown in FIG. 6 was prepared, and the antenna sensitivity was measured. The separation distance between the monopole antenna and the heat ray at this time is about 108 mm.
The measurement results are shown in FIG. The average sensitivity is shown in Table 7.

  From the above measurement results, those with meander-shaped hot wires have the same or better performance than those without them, and those with meander-shaped hot wires because the meander-shaped hot wires generate heat and have excellent sunny performance. It can be seen that is superior in terms of performance.

  In each of the first to fifth embodiments described above, the meander shape is a square wave type, but is not limited thereto. FIG. 13 shows a modification. FIG. 13A shows a triangular wave type meander-shaped hot wire 44, and FIG. 13B shows a sawtooth type meander-shaped hot wire 46. Also in these meander-shaped hot wires, the same effect as the square wave meander-shaped hot wires can be obtained.

  In each of the above embodiments, the antenna pattern has been described for the monopole type in which the feeding point is on the upper side of the glass plate, but is not limited thereto. In addition to monopole type antennas consisting of a single wire or multiple elements, many types of antennas can be designed, such as those with a rectangular loop shape or a ground point on the glass surface. is there. Various modifications are shown in FIGS.

  FIG. 14 shows a monopole antenna 52 in which the feeding point 50 is provided on the side of the glass window.

  FIG. 15 shows an inverted T-shaped antenna 54 in which a feeding point 50 is provided on the upper side of the glass window.

  FIG. 16 shows an example of an antenna pattern in which the feeding point 50 is provided on the upper side of the glass window and is composed of a plurality of antenna elements 56 and 58.

  FIG. 17 shows a rectangular antenna 60 in which the feeding point 50 is provided on the upper side of the glass window.

  FIG. 18 shows monopole antennas 62 and 64 in which two feeding points 50 and 51 are provided on the upper side of the glass window and extend from each feeding point.

  FIG. 19 is a diagram showing a coaxial ground connection type antenna in which feed points 50 and 51 are provided on the upper side of the glass window, and a hot element 66 and a ground element 68 extend from each feed point. In this case, the core wire of the coaxial ship 53 is connected to the feeding point 50 on the hot element 66 side, and the outer sheath wire of the coaxial line is connected to the feeding point 51 on the ground element 68 side.

  FIG. 20 is a diagram showing a loop antenna 70 in which feeding points 50 and 51 are provided on the upper side of the glass window and configured between the feeding points.

It is a figure which shows the structure of the conventional rear window glass. It is a figure which shows the structure of the rear window glass which is the 1st Example of this invention. It is a figure which shows the measurement result of antenna sensitivity. It is a figure which shows the structure of the rear window glass which is the 2nd Example of this invention. It is a figure which shows the structure of the rear window glass which is the 3rd Example of this invention. It is a figure which shows the structure of the rear window glass which is the 4th Example of this invention. It is a figure which shows the measurement result of antenna sensitivity. It is a figure which shows the example which inserted the coil in the bus-bar. It is a figure which shows the installation method of a coil. It is a figure which shows the structure of the conventional rear window glass without a 2nd heat generating part. It is a figure which shows the example of the heat ray without a meander shape. It is a figure which shows the measurement result of antenna sensitivity. It is a figure which shows the other example of an antenna pattern. It is a figure which shows the other example of an antenna pattern. It is a figure which shows the other example of an antenna pattern. It is a figure which shows the other example of an antenna pattern. It is a figure which shows the other example of an antenna pattern. It is a figure which shows the other example of an antenna pattern. It is a figure which shows the other example of an antenna pattern. It is a figure which shows the other example of an antenna pattern.

Explanation of symbols

10, 30 defogga
12, 14 areas
16, 18 antenna
20 Second heat generating part
21 First heat generating part
24,26 First bus bar
32, 34 meander-shaped hot wire
36,38 Second bus bar
40 coils

Claims (6)

In the rear window glass for vehicles,
A glass plate,
Two first bus bars provided on both sides of the glass plate;
A first heat generating portion configured by a plurality of first lateral heat wires arranged between the first bus bars;
It is located above the first heat generating part and in the central part in the lateral direction of the glass plate, and connects a plurality of second lateral heat rays and the end portions of the second transverse heat rays in the longitudinal direction. A second heat generating part constituted by two longitudinal heat rays extending;
A heat wire disposed between each of the first bus bars and the second heat generating portion and having a meander shape connecting the first bus bar and the vertical heat wire of the second heat generating portion; ,
The second heat generating part is arranged to extend upward from the heat ray having the meander shape,
An antenna element is provided on a glass plate surface of at least one of the regions on both sides of the extended second heat generating portion and above the heat ray having the meander shape. Rear window glass.   In order to supply power to the second heat generating part, two second bus bars connecting between each of the two vertical heat lines of the second heat generating part and the corresponding first bus bar are provided. The rear window glass for a vehicle according to claim 1, further comprising:   The vehicle rear window glass according to claim 2, wherein at least one coil is inserted in series into a second bus bar in a region where the antenna element is provided.   The vehicle rear window glass according to claim 3, wherein an inductance of the at least one coil is 0.1 to 2.0 μH.   5. The vehicle rear window glass according to claim 1, wherein a length of the second heat generating portion extending upward from the heat ray having the meander shape is 30 to 100 mm. .   The vehicle rear window glass according to any one of claims 1 to 4, wherein a width of the region in the vertical direction is 50 to 120 mm.

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