JP2003170739A - Automotive window glass with conductive film and radio wave transmission / reception structure for automobile - Google Patents

Abstract

(57) An object is to provide a window glass for an automobile with a conductive film that has sufficient radio wave permeability and can prevent abnormal heat generation during energization. A glass plate A, a conductive film 5 provided on the surface of the glass plate A, upper bus bars 1 and 2 and a lower bus bar 3 provided along upper and lower sides of the conductive film 5, and an upper bus bar and The conductive film 5 is conducted through the lower bus bar. In the conductive film 5, a plurality of slits 11 are linearly arranged at intervals of 0.5 to 5 mm in the longitudinal direction and spaced in the slit width direction. A radio wave transmission region 10 formed in a double row with a gap is provided, and the longitudinal direction of the slit 11 is within a range of ± 45 ° with respect to the vertical direction of the glass plate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile window glass with a conductive film such as a heat ray reflective glass or an electrically heated glass and an electric wave transmitting / receiving structure for an automobile using the same.

[0002]

2. Description of the Related Art Conventionally, there has been a demand to reduce the feeling of intense heat during the summer and to reduce the cooling load. Under such circumstances, it has been proposed and practiced to use a heat ray reflective glass for the window glass.

For example, in the case of automobile window glass, the conventional heat-reflecting glass is generally two trapezoidal glass plates corresponding to a window frame, and polyvinyl butyral sandwiched between the two glass plates. And a heat ray reflective film provided on the glass plate surface between the two glass plates or on the film enclosed in the intermediate film. . As the heat ray reflective film, for example, a thin film of gold, silver or the like is used.

Further, conventionally, in severe winters and cold regions, snow, icing, frosting or clouding on windshields and rear windshields of vehicles such as trains, trains, trucks and passenger cars, or on windowpanes of buildings. However, it is difficult to quickly remove such haze. Under such circumstances, it has been proposed to use electrically heated glass for the window glass.

If the conventional electrically heated glass is, for example, a window glass of an automobile, it is generally two trapezoidal glass plates corresponding to a window frame and an intermediate film sandwiched between the two glass plates. And a pair of bus bars (current-carrying electrodes) provided above and below or to the left and right of the glass plate surface between the two glass plates, and a transparent conductive film provided so as to be connected to these bus bars. Has been done. By applying a predetermined voltage between the pair of bus bars, the transparent conductive film is energized to generate heat.

As the transparent conductive film, for example, IT
A thin film of O (composite oxide of indium and tin), gold, silver, etc. is used, and electricity is applied to the transparent conductive film from the battery via the bus bar to heat the window glass etc., and this heat causes snow melting. , Melting ice, anti-fog, etc. are done quickly. In recent years, transparent conductive films used for electrically heated glass have also been
Various materials have been developed, and a zinc oxide-based film (for example, a zinc oxide film containing gallium, hereinafter referred to as “gallium-containing zinc oxide film”, which can heat a glass plate more rapidly, is applied and heated at a high voltage of 280 V or more. "GZO film"), the film resistance is 6
There is known a silver-based thin film or the like that is heated by applying a low voltage of Ω / □ or more and 100 V or less.

Generally, window glass for automobiles is produced by bending a flat glass plate into a predetermined shape by heating it to a temperature of 600 to 700 ° C. or higher in the glass softening point in an air atmosphere.
It is manufactured by subjecting it to physical quenching treatment if necessary. However, in recent years, a transparent conductive film that withstands heating and bending during heating and bending of a glass plate (specifically, a predetermined conductivity or heat conductivity is obtained even after heat treatment at 500 to 680 ° C. for 1 to 10 minutes in an air atmosphere. A film exhibiting optical characteristics; hereinafter simply referred to as "heat-processable transparent conductive film" was developed,
By using the transparent conductive film, a large plate size transparent conductive film that can be heat-treated is uniformly coated on the surface of the glass plate in advance using a coating device dedicated to flat glass, and the uniformly coated glass plate is appropriately sized. Now, it becomes possible to cut into a shape and form a window glass for an automobile.

[0008] A coating device exclusively for flat glass can coat a transparent conductive film at a low cost, and it has become possible to provide an electrically heated glass for an automobile at a low cost. In particular, by using a heat-processable silver-based transparent conductive film having a film resistance of 2 to 10 Ω / □, energization and heating at a relatively low voltage can be performed. The SnO ₂ -based transparent conductive film is also a transparent conductive film that can be heat-treated, and has a resistance of 50Ω / □ due to the establishment of the CVD method.
The following membranes have become possible to manufacture inexpensively.

By the way, in recent years, ITS (Intelligent Tr
Practical application of a new transportation system for solving road traffic problems such as traffic accidents, traffic congestion, etc. by networking people, roads and vehicles with information using the latest information and communication technology Is progressing. VICS (Vehicle Informationa)
nd Communication System) for advanced navigation, AHS (Advanced Cruise-assist Highway Sys
tems) support safe driving, ETC (Electronic Tol)
l Collection System) uses a radio wave to transmit and receive information between a vehicle-mounted information transmission / reception device provided in a running vehicle and an external device.

In microwave communication, it is common to use circularly polarized waves as communication radio waves, which are unlikely to cause communication failures due to radio wave interference.

When the above-mentioned heat ray-reflecting glass or electrically heated glass is attached to an automobile, there arises a problem that radio waves are blocked by a heat ray-reflecting film or a conductive film such as a transparent conductive film (for electrically heating). . Therefore, conventionally,
It has been proposed to partially hollow out the conductive film in order to impart radio wave transparency to the heat ray reflective glass and the electrically heated glass.

Further, Japanese Patent Application Laid-Open No. 8-250915 discloses a technique in which a slit having a predetermined length and a predetermined width is provided in a conductive film. The publication describes that slits are provided so as to intersect each other at an angle of 90 ° in order to transmit circularly polarized waves.

[0013]

However, when the conductive film is partially hollowed out, the hollowed-out portion becomes conspicuous, and the appearance and the appearance from the inside of the vehicle deteriorate. Further, the radio wave transmission cannot be sufficiently improved only by providing the slit as described in JP-A-8-250915. Further, as described in the publication, when slits are provided so as to intersect each other at an angle of 90 °, in the electrically heated glass, the conductive film is formed at the slits extending in the direction intersecting the direction of the current flowing through the conductive film. The flow of the current flowing through the membrane is disturbed, causing abnormal heat generation. The object of the present invention is to have an excellent appearance and sufficient radio wave transparency,
An object of the present invention is to provide a window glass for an automobile with a conductive film capable of preventing abnormal heat generation even when it is electrically heated and an electric wave transmitting / receiving structure for an automobile using the same.

[0014]

The present invention comprises a glass plate and
A conductive film provided on one surface thereof, and an upper bus bar and a lower bus bar provided on the glass plate along upper and lower sides of the conductive film, and the conductive film is provided through the upper bus bar and the lower bus bar. A window glass for an automobile with a conductive film through which the film is electrically connected, wherein a plurality of elongated slits are linearly arranged at intervals of 0.5 to 5 mm in the longitudinal direction of the conductive film. A plurality of rows of radio wave transmission regions are formed at intervals in the width direction, and the longitudinal direction of the slit is within ± 45 ° with respect to the vertical direction of the glass plate. There is provided a window glass for an automobile with a conductive film. Further, the present invention is a radio wave transmitting / receiving structure for an automobile, comprising the window glass for an automobile with the conductive film, and a transmitting / receiving device having a radio wave transmitting / receiving antenna arranged inside the vehicle, wherein the transmitting / receiving antenna is Virtually inclined to the outer peripheral side by 45 ° with respect to the normal line of the glass surface drawn from the outer peripheral edge portion of the radio wave transmission region within a range in which the shortest distance from the inside surface of the window glass for automobiles with the conductive film is within 40 cm Provided is a radio wave transmitting / receiving structure for an automobile, which is arranged in a range surrounded by an inclined surface. It is preferable that the radio wave transmission regions are provided in a concentric shape. It is preferable that the radio wave transmission regions are band-shaped and are provided in multiple rows at intervals in the width direction of the band.

In the present specification, the terms "upper" and "lower" used to represent directions and positions mean "upper" and "lower" when the glass with a conductive film is attached to the body of an automobile.

In order to maximize the radio wave radiation characteristics into the air, it is desirable that the slits have a length of ½ of the wavelength λ of the radio wave and are arranged in a straight line. Impedance of 188Ω, and
The radiation characteristics are the highest. In the present invention, at least two slits are provided linearly at intervals of 0.5 to 5 mm, more preferably at intervals of 1 to 2.5 mm, and the slits are also spaced in the width direction. A double row is provided to form a radio wave transmission area.

The lengthwise dimension of the slit is preferably 0.3 to 0.6 times the target radio wave wavelength.
The optimum value is 4 to 0.5 times. 5.8 GHz E
TC communication (transmission frequency is 5.795 GHz or 5.8
05 GHz, the reception frequency is 5.835 GHz or 5.
845 GHz), the longitudinal dimension of the slit is about 15 to 30 mm, more preferably 20 to 2
It can be about 5 mm. If the conductive film is sandwiched between two glass plates (dielectric constant 7.0), the slit length is smaller than the actual length because the electromagnetic effective length is longer. The length of the slit in the longitudinal direction as described above (0.3 to the target radio wave wavelength
0.6 times). In the case of ETC communication, the longitudinal dimension of the slit can be set to about 9 to 21 mm, more preferably about 12 to 17.5 mm.

The width (widthwise dimension) of the slit is 0.1.
It can be set to about 2 mm, more preferably about 0.2 mm to 0.5 mm. The row spacing of the slits is preferably 0.2 to 0.6 times the target radio wave wavelength,
The optimum value is 0.3 to 0.5 times. When the conductive film is sandwiched between two glass plates, the slit row spacing is set to the above value (0.2 to 0.6 of the target radio wave wavelength).
It should be set to 0.6 to 0.7 times.

According to the present invention, it is possible to make a window glass for an automobile with a conductive film have a sufficient radio wave transmission property without deteriorating the appearance and the appearance from the inside of the vehicle, and without attenuating the circularly polarized wave. Can be transmitted. Further, according to the present invention, abnormal heat generation does not occur even when the conductive film is electrically heated. In JP-A-8-250915, there is no description or suggestion about forming slits at intervals of 0.5 to 5 mm in the longitudinal direction and providing the slits in multiple rows to form a radio wave transmission region. Absent. As in the present invention, the radio wave transparency could be significantly improved by keeping the slits in the longitudinal direction within a predetermined range.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in more detail with reference to an example of a laminated vitrified electrically heated glass as a preferred embodiment. The heat-reflecting glass has a configuration in which the power feeding portion and the bus bar in the electrically heated glass are not provided. As the heat ray reflective film in the heat ray reflective glass, the same one as the transparent conductive film in the electrically heated glass can be used.

Usually, the electrically heated glass is composed of two glass plates, an intermediate film sandwiched between the two glass plates, at least a pair of bus bars provided on the surface of one of the glass plates, and a pair of these. Of the transparent conductive film provided so as to connect between the bus bars, and the transparent conductive film is laminated so as to be on the intermediate film side. However, such a configuration is the same in the electrically heated glass of the present invention. is there.

The feature of the electrically heated glass of the present invention is that the transparent conductive film has a plurality of elongated slits in the longitudinal direction of 0.5.
They are arranged in a straight line with an interval of ~ 5 mm,
This is because the radio wave transmission region is formed in a double row at intervals in the slit width direction. Although the radio wave transmission area may be formed over almost the entire area of the transparent conductive film, it is preferable to provide the radio wave transmission area only in the vicinity of the transmitting / receiving device provided in the vehicle. In this case, the transmission / reception antenna is a virtual inclination that is inclined to the outer peripheral side by 45 ° with respect to the perpendicular of the glass surface drawn from the outer peripheral edge of the radio wave transmission area within a range of 40 cm from the inside surface of the glass with a conductive film. It is arranged in a range surrounded by a surface.

The glass plate used in the present invention is not particularly limited, and examples thereof include ordinary glass plate, tempered glass plate and partially tempered glass plate. These glass plates may be colored so that the transparency is not impaired. Further, the shape of these glass plates may be a curved shape processed into various shapes and curvatures, for example, a substantially trapezoidal shape having a curved surface as used in a windshield of an automobile. May be. Also,
The thickness of the glass plate used is not particularly limited, but is usually about 1.5 to 5 mm.

The interlayer film used in the present invention means, when a laminated glass is used, two glass plates disposed on both surfaces thereof are firmly adhered to each other, and even when the laminated glass is broken, the glass is In general, a polyvinyl butyral resin film having an effect of preventing the fragments from scattering is usually used, and various physical properties such as adhesion, weather resistance and heat resistance are improved. The thickness of this intermediate film is not particularly limited, but is usually about 0.2 to 0.9 mm.

The method for producing the laminated glass itself is not particularly limited and may be a conventionally known method. For example, two glass plates are stuck together with an interlayer film sandwiched between them, and pre-bonded,
A desired laminated glass is manufactured by a process such as an autoclave process.

As the transparent conductive film used in the present invention,
Any of various conventionally known transparent conductive films made of a conductive material can be used, and an optimum film is selected according to the purpose of use of the electrically heated glass. Further, since the applied voltage varies depending on the type of the transparent conductive film, the bus bar connected to the transparent conductive film is formed so as to be compatible with these.

As a method for forming the transparent conductive film on the glass plate, any conventionally known method can be used and is not particularly limited. For example, vacuum vapor deposition method, sputtering method, electron beam type heat vapor deposition method, spraying. Method, CVD method and the like. Of these, a sputtering method (especially magnetron DC sputtering method) is preferable because it can form a film with a uniform thickness on a large-area substrate with high productivity. The transparent conductive film is formed on one side of the glass plate, and its film thickness is usually 2
It is about 0 to 300 nm. In order to provide a non-film-forming portion on the periphery of the glass, a masking frame is superposed on the glass during film formation before film formation.

As the bus bar forming material used in the present invention, any conventionally known bus bar forming material can be used and is not particularly limited, but a material suitable for the voltage applied to the transparent conductive film is selected and used. preferable.

In the present invention, a colored concealing layer is provided on the surface of the glass plate on the outer side of the vehicle on the side of the interlayer film and / or on the surface of the inner side of the glass plate on the inner side of the vehicle so that the bus bar and / or the outside of the vehicle can be protected. It is preferable to make the insulating colored ceramics layer and the like invisible. This will further improve the product appeal in terms of safe driving and appearance quality.

An example of using the window glass for an automobile with a conductive film of the present invention as a windshield for an automobile will be described below.
A schematic plan view of an example of an automobile windshield is shown in FIG.
It shows in (A). In the following, for example, in a substantially trapezoidal glass plate as shown in FIG. 1A, “the upper side of the glass plate” means the upper side part of the glass plate on the drawing, and “the lower side of the glass plate” means the glass on the drawing. The lower side part of the plate and the "right side and left side of the glass plate" mean the right side part and the left side part of the glass plate in the drawing, respectively.

In FIG. 1A, 1 and 2 are upper side bus bars, 3 is a lower side bus bar, 5 is a transparent conductive film formed by heat treatment of a heat conductive transparent conductive film, 6 is a power feeding portion, and 21 is conductive. A line, A is a substantially trapezoidal glass plate inside the car, B
Is a conducting portion of the bus bar, and C is a wiring portion of the bus bar. Note that, in FIG. 1A, an intermediate film and a glass plate outside the vehicle, which are arranged on the vehicle outside (the front side with respect to the paper surface) of the glass plate A inside the vehicle, are omitted.

The glass plate A on the inside of the vehicle has a substantially straight upper side,
It has an arc line-shaped lower side and a left side and a right side of the same length. On the vehicle inner side glass plate A, on the vehicle outer surface, a transparent conductive film 5 (indicated by a broken line) having a substantially similar shape, and the upper side bus bars 1 and 2 and the lower side bus bar 3 (the lower side bus bar 3 corresponds to the upper side bus bars 1 and 2). It is a common counter electrode bus bar) and is formed. The upper side bus bar is not limited to the illustrated form,
It may consist of one bus bar. Transparent conductive film 5
Are formed so as to overlap with the upper side bus bars 1 and 2 at the upper side and so as to overlap with the lower side bus bar 3 at the lower side, and are connected to these bus bars. At the ends of the upper busbars 1 and 2,
Wiring portions C extending along the left and right sides and the lower side of the glass plate A are connected. The power feeding unit 6 is connected to the central portion of the lower bus bar 3 in the longitudinal direction. The wiring portion C and the power feeding portion 6 are both formed outside the transparent conductive film 5. A conductive wire 21 from a power source (not shown) is connected to the wiring portion C and the power feeding portion 6 near the center of the lower side of the glass plate A. The positions of the wiring portion C and the power feeding portion 6 are not limited to the vicinity of the central portion.

The current-carrying portion B is a portion which is disposed in the plane of the transparent conductive film 5 of the upper busbars 1, 2 and the lower busbar 3 and is used to heat the transparent conductive film 5 by heating. The upper bus bar 1 on one side enters the surface of the transparent conductive film 5 from the left side of the transparent conductive film 5, extends along the upper side of the transparent conductive film 5, and terminates before reaching the right side of the transparent conductive film 5. . The upper side bus bar 1 has a tapered shape in which the width becomes narrower from the left end to the right end. And the upper bus bar 2 on the other side
Enter the surface of the transparent conductive film 5 from the right side of the transparent conductive film 5, extend substantially parallel to the lower side of the upper side bus bar 1 with a minute interval, and terminate before reaching the left side of the transparent conductive film 5. ing. The upper bus bar 2 has a tapered shape in which the width becomes narrower from the right end toward the left end.

The lower side bus bar 3 has almost the entire area thereof as a current-carrying portion B, and the left and right ends thereof are terminated immediately before the left and right sides of the transparent conductive film 5, or cross the left and right sides of the transparent conductive film 5. Is being done. The left and right ends of the lower bus bar 3 are energized by the upper bus bars 1, 2.
It protrudes in the left-right direction (horizontal direction) from the left and right ends.

On the passenger side of the transparent conductive film 5 (right side in the figure)
A radio wave transmission area 10 is provided in the lower corner portion. The radio wave transmission region 10 has a vertical dimension of about ½ of the vertical dimension of the portion of the transparent conductive film 5 that is energized and heated, and is 1/1 of the horizontal dimension of the portion of the transparent conductive film 5 that is energized and heated.
It has a horizontal dimension of about 4.

In the radio wave transmission region 10, a plurality of elongated slits 11 are linearly arranged at a predetermined interval L (0.5 to 5 mm) in the longitudinal direction as shown in FIG. 1 (B), and The slits 11 are formed by providing double rows in the width direction. As shown in FIG. 1B, the slit 11 may be inclined at a predetermined inclination angle θ1 with respect to the vertical direction of the transparent conductive film. The inclination angle θ1 is within ± 45 ° with respect to the vertical direction of the glass plate. Of course, as shown in FIG. 1C, the slit 11 may be provided in parallel with the vertical direction of the transparent conductive film.

A positive electrode is connected to the conducting portion 6 of the lower bus bar 3 shown in FIG. 1A, a negative electrode is connected to the wiring portion C of the upper bus bars 1 and 2, and a current is passed through the transparent conductive film 5. The transparent conductive film 5 can be energized to generate heat. In this example, since the inclination angle θ1 of the slit 11 is within ± 45 °, the flow of current passing through the radio wave transmission region 10 from the lower side bus bar 3 to the upper side bus bars 1 and 2 is disturbed. There is no abnormal heat generation.

FIG. 2 is an exploded view of a section taken along the line aa in FIG. As shown in FIG. 2, a glass plate A on the inside of the vehicle
The vehicle outer side glass plate D is bonded to the vehicle outer side surface through the intermediate film 4. Preferably, the bus bar 1 provided on the inside glass plate A is provided around the inside surface of the outside glass plate D.
The colored concealing layer 7 is provided so as to conceal 3 to 3 so that these bus bars 1 to 3 cannot be seen from the outside of the vehicle. Further, preferably, in the peripheral portion of the inside surface of the glass plate A inside the vehicle,
The colored concealing layer 8 is provided so as to conceal the bus bars 1 to 3 provided on the glass plate A on the inside of the vehicle so that the bus bars 1 to 3 cannot be seen from the inside of the vehicle. As the material for forming the colored hiding layers 7 and 8, any of the materials conventionally used for forming the hiding portion can be used and is not particularly limited.
For example, black ceramic paste and the like can be mentioned.

An antenna 90 of a receiver, a transmitter, or a transceiver is arranged inside the electrically heated glass. The antenna 90 has a range in which the vertical distance Z from the vehicle interior side surface of the vehicle interior glass plate A is within 40 cm, and the radio wave transmission area 10
45 to the perpendicular of the glass surface drawn from the outer peripheral edge of
° It is arranged in a range surrounded by a virtual inclined surface S inclined to the outer peripheral side. With such a configuration, radio waves are smoothly transmitted and received between the antenna 90 and a communication device provided on a road or the like.

Next, a second example of the electrically heated glass according to the present invention will be described with reference to FIG. In the examples described below, members having the same configurations and functions as the members described in the first example will be denoted by the same reference numerals in the drawings to simplify the description. As shown in FIG.
In this example, the transparent conductive film 5 in which a heat-processible transparent conductive film is heat-treated is formed on the entire outer surface of the vehicle inner glass plate A. An insulating colored ceramics layer 18 is formed in a strip shape on the entire peripheral portion of the outer side surface of the transparent conductive film 5. That is, by the insulating colored ceramics layer 18,
It covers the portion of the transparent conductive film 5 which is not desired to be energized and heated. The wiring portion C is formed on the insulating colored ceramic layer 18. If the broken line in FIG. 1 (A) is regarded as a line showing the inner peripheral edge of the insulating colored ceramic layer 18 in this example, FIG. 1 (A) can also be regarded as a schematic plan view in this example.

A specific example of the transparent conductive film 5 that can be heat-treated is
As a transparent conductive film used at a relatively low voltage (high current), for example, a dielectric film (oxide or the like) and a noble metal film (Ag, Au, Pd, or the like) are alternately (2n +) from the substrate side.
1) A multilayer film (n ≧ 1) laminated, and a protective film (nitride film or the like) formed between the substrate and the dielectric film and / or on the uppermost dielectric film (a noble metal if necessary) A thin film that prevents oxidation of the noble metal film may be provided above and / or below the film). Further, as the transparent conductive film used at high voltage (low current), for example, 2
Examples thereof include an ITO film, a tin oxide film, and a GZO film which are used by applying a voltage of 88V. In the present invention, both a transparent conductive film to which a low voltage and a high voltage are applied can be used.

FIG. 4A is a schematic plan view showing a third example of the electrically heated glass according to the present invention. In this example,
A radio wave transmission region 20 is formed concentrically in the lower corner on the passenger seat side. Here, the radio wave transmission region 20 is composed of a circular region 20a and a ring region 20b that is arranged at a distance from the outer peripheral edge of the circular region 20a to the outer peripheral side. Circle area 2
0a and the ring region 20b, a plurality of slits are arranged linearly at intervals of 0.5 to 5 mm in the longitudinal direction,
In addition, it is formed by providing a plurality of rows at intervals in the slit width direction. As described in the first example, the longitudinal direction of the slit is ± 45 ° with respect to the vertical direction of the glass plate.
It may be inclined within the range.

FIG. 4B schematically shows the positional relationship among the circular region 20a and the ring region 20b formed on the transparent conductive film 5, the glass plate A on the inside of the vehicle, and the antenna 90 arranged inside the vehicle. FIG. As shown in FIG. 4B, the antenna 90 is arranged on the perpendicular line of the glass surface drawn from the center of the circular region 20a. The distance Z from the vehicle interior side surface of the vehicle interior glass plate A to the antenna 90 is set within 40 cm.

The radius R of the circular area 20a of the radio wave transmitting area, the radial distance W1 from the outer peripheral edge of the circular area 20a to the inner peripheral edge of the ring area 20b, and the radial dimension (ring width) W2 of the ring area 20b are as follows. It is set in consideration of this. The radio wave that reaches the transparent conductive film 5 from the outside of the vehicle passes through each slit in the radio wave transmission region of the transparent conductive film 5 and then diffracts to reach the antenna 90, but the phase of the wave coming from each slit is significantly large. If they are deviated from each other, the waves interfere with each other and cancel each other, and the intensity of the radio wave received by the antenna 90 is weakened. In order to avoid this, the positions of the slits are adjusted so that the waves coming from the respective slits have substantially the same phase at the position of the antenna 90 or have a phase shift of at least -π / 4 to + π / 4 or less. To place.

When the phase at the position of the antenna 90 of the wave transmitted through the slit at the center of the circular area 20a is set to 0,
The phase α of the wave transmitted through the slit at the distance r from the center at the position of the antenna 90 is α = cos
⁻¹ (2π (J−H) / λ). Where H
Is the distance from the center of the circular area 20a to the antenna 90, J
Is the antenna 90 from the slit at the position r from the center.
Is the distance, and λ is the wavelength of the radio wave. Such a phase α
In consideration of the above, the radius R of the circular region 20a and the radial distance W from the outer peripheral edge of the circular region 20a to the inner peripheral edge of the ring region 20b.
1 and the radial dimension W2 of the ring region 20b are set.

For example, the wavelength λ is 5.8 GHz and H is 10
0 mm, slit size 21 mm x 1 mm, slit longitudinal interval 1 mm, slit row interval 11.5 m
In the case of m, the radius R of the circular area 20a is 77 mm, the circular area 2
By setting the radial distance W1 from the outer peripheral edge of 0a to the inner peripheral edge of the ring region 20b to 29 mm and the radial dimension W2 of the ring region 20b to 31 mm, the receivability at the antenna 90 becomes extremely good. Further, it is possible to add another ring area to the outer peripheral side of the ring area 20b, but in the case of a wavelength of 5.8 GHz, the effect of adding another ring area is small.

FIG. 5A is a schematic plan view showing a fourth example of the electrically heated glass according to the present invention. In this example,
In the lower corner on the passenger seat side, the radio wave transmission regions 30 are formed in a strip shape substantially along the vertical direction of the glass plate, and are provided in multiple rows at intervals in the width direction of the strip. Here, the radio wave transmission region 30 includes a central band region 30a and a central band region 3
0a on both sides of the band regions 30b, 3 which are arranged at intervals.
It consists of 0b. Central band region 30a and band region 30
b and 30b may be slightly inclined with respect to the vertical direction of the transparent conductive film. The inclination angle θ2 shown in FIG.
It may be within 45 °. Of course, as shown in FIG. 5 (C), the central band region 30a and the band regions 30b and 30b.
However, it may be provided in parallel with the vertical direction of the transparent conductive film. As described in the first example, the longitudinal direction of the slit may be inclined within ± 45 ° with respect to the vertical direction of the glass plate.

Central band region 30a and band regions 30b, 3
The width dimension of 0b can be determined in consideration of the phase shift at the position of the antenna as described in the second example. For example, wavelength λ is 5.8 GHz, H is 100 m
m, the slit size is 21 mm × 1 mm, the slit longitudinal interval is 1 mm, and the slit row interval is 11.5 mm, the vertical projection position of the antenna (not shown) on the inside of the vehicle onto the transparent conductive film 5 is 0. , The width of the central band region 30a is -77 mm to 77 mm (= width 154 mm), and the width of the band region 30b on the left side of the drawing is -106 mm to -137.
mm (= width 31 mm), and the width dimension of the band region 30b on the right side in the drawing is 106 mm to 137 mm (= width 31 mm), the receivability of the antenna 90 becomes extremely good. The “width dimension” referred to here is the central band region 30.
The horizontal dimension (horizontal dimension) of a and the strip region 30b are both inclining at θ2 as shown in FIG. 5B and not inclined as in FIG. 5C. To do. In the case of FIG. 5B, the horizontal direction is not orthogonal to the longitudinal direction of the band, but in the case of FIG. 5C, the horizontal direction is orthogonal to the longitudinal direction of the band.

The central region 30a and the band regions 30b, 30
The length dimension of b is set in consideration of the following. Assuming an ETC on a highway, the transmission / reception device in the vehicle interior and the transmission / reception device in the tollgate are fixed, but their positional relationship changes as the vehicle moves. The angle of attack of the on-vehicle transmitter / receiver with respect to the transmitter / receiver at the toll booth increases linearly as it approaches the toll booth. Central band region 30a and band regions 30b, 30b
The length dimension of is appropriately long in order to cope with such a relative position change between the vehicle-mounted transceiver device and the vehicle-outside transceiver device. For example, the wavelength λ is 5.8 GHz and H is 100
mm, slit size 21 mm x 1 mm, slit longitudinal interval 1 mm, radio wave transmission line row interval 11.5 m
When m and θ2 are 30 °, it is preferable that the central region 30a and the band regions 30b and 30b have a length dimension of 150 to 250 mm. The "length" here means
It means the longitudinal dimension of the strip. In the case of FIG. 5B, the longitudinal direction of the strip and the vertical direction of the glass plate are not parallel,
In the case of FIG. 5C, the longitudinal direction of the strip is parallel to the vertical direction of the glass plate.

[0050]

EXAMPLES Next, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. Example 1 (1) Film formation of transparent conductive film A silver-based transparent conductive film heat-processable by sputtering on a clear float glass plate having a plate thickness of 2.3 mm, a length of 2 m, and a width of 3 m (hereinafter simply referred to as “silver-based conductive film”). "). The film structure of this silver-based conductive film is, in order from the glass plate side,
AlN film (8 nm) / ZnAlO film (23 nm) / Ag
Pd film (10 nm) / ZnAl film (2 nm) / ZnAl
O film (79 nm) / AgPd film (10 nm) / ZnAl
A film (2 nm) / ZnAlO film (23 nm) / AlN film (8 nm).

The AlN film was formed by reactive sputtering in an Ar / N ₂ sputtering gas atmosphere using an Al metal target. The ZnAlO film is formed by using a ZnAl metal target having an Al content of 5% in terms of a molar ratio, Ar / O.
_{2 The} film was formed by reactive sputtering in a sputtering gas atmosphere. The ZnAl film was formed in a 100% Ar sputtering gas atmosphere by using a ZnAl metal target having an Al content of 5% in molar ratio. The AgPd film was formed in a 100% Ar sputtering gas atmosphere using an AgPd metal target having a Pd content of 0.5% in molar ratio. The ratio of the metal component in each film was almost the same as that of the target. The ZnAl film is a thin film that prevents the AgPd film, which is a noble metal, from being oxidized. Immediately after the silver-based conductive film is formed, the surface resistance value is 5.5 Ω / □,
The visible light transmittance was 68%.

(2) Cutting Out A cut glass is cut into a predetermined glass plate shape with a diamond glass cutter on the coated surface of the above-mentioned whole glass plate,
Unnecessary ears were cut off to finish into a predetermined substantially trapezoidal glass plate shape. After the chamfered edges were chamfered with a diamond chamfering roller, they were washed with pure water and dried with an air knife to prepare an electrically heated glass substrate.

(3) Printing for forming the insulating colored ceramic layer Next, the insulating colored ceramic layer is formed on the periphery of the transparent conductive film (width: upper side, right and left sides 2.6 cm, lower side 11.0 cm) of the coated glass plate. Insulating colored ceramics paste was printed to form the film and dried at 120 ° C. for 5 minutes. For printing, a screen printing method using a 250 mesh (250 lines / inch) screen plate was used. As the insulating colored ceramic paste, an insulating black ceramic paste was used.

(4) In order to form a bus bar and a print bus bar for forming terminals, silver paste is collectively printed on the insulating colored ceramic layer of the glass plate by a screen printing method and dried at 120 ° C. for 5 minutes. did. Printing is 250
A screen printing method using a screen plate of mesh (250 lines / inch) was used. The silver paste contains silver particles and glass frit, and the weight ratio of silver and glass frit components is 99.5: 0.5, which is almost the same after firing.

(5) Preliminary firing A glass plate on which the above-mentioned colored ceramics paste and silver paste were printed was placed in a flat roller furnace at 55 in an air atmosphere.
It was calcined at 0 ° C. for 5 minutes.

(6) Preparation of Outer Glass Plate A glass plate was cut into a glass plate having a conductive film (inner glass plate) having substantially the same shape, the edges were chamfered, and the glass plate was washed to obtain an outer glass plate of laminated glass. However, the portion of the glass plate with a conductive film to be the terminal was made smaller than the glass plate with a conductive film so that the terminal could be taken out. Peripheral part of the above glass plate (width: upper side and right and left sides 2.8 cm, lower side 1
1.5 cm), glass plate with conductive film (inner glass plate)
The colored ceramics paste for forming the concealing colored layer was printed so as to slightly cover the bus bar and the insulating colored ceramics layer printed on, and dried at 120 ° C. for 5 minutes.
For printing, a screen printing method using a 250 mesh (250 lines / inch) screen plate was used. A black ceramic paste was used as the colored ceramic paste.

(7) A glass plate with a conductive film (inner glass plate) on which an insulating colored ceramics layer and a bus bar are formed by bending and pre-baking.
An outer glass plate having the same shape as the glass plate with a conductive film and having a colored concealing layer formed on one side by pre-baking, and a conductive film surface of the glass plate with a conductive film and an insulating colored ceramic layer of the outer glass plate. Were stacked so as to face each other, and fine particles of particles for preventing self-adhesion were sprinkled on the entire surface of the glass plate, then placed on a glass forming metal frame, put into a glass forming furnace, and subjected to self-weight bending, and then bent into a mold shape. The molding conditions are as follows:
The furnace temperature was 650 ° C. for 5 minutes.

(8) The two bent and bent glass plates were cooled and then separated, washed with a pure water brush washing machine to wash away dirt and dust, and then dried with an air knife. Next, a polyvinyl butyral (PVB) film (thickness 0.76 mm) was placed between the two glass plates.
Was sandwiched and temporary pressure bonding was performed. The condition of temporary pressure bonding was that glass was put in a rubber bag, the inside of the rubber bag was evacuated, and the rubber bag was heated while a static pressure of about 1 atm was applied to the glass surface. The heating was performed at the maximum temperature of 135 ° C. for 10 minutes, and the total heating time was 30 minutes including the temperature decrease. The temporarily press-bonded glass plate was put into an autoclave to obtain an electrically heated glass. The conditions of the autoclave were such that the maximum pressure was 13 atm and the maximum temperature was 135 ° C. for 20 minutes, and the total pressure was 60 minutes including step-up and step-down. When the characteristics of the electrically heated glass produced above were measured, the visible light transmittance was 75%, the visible light reflectance was 8%, the solar radiation transmittance was 45%, the film resistance was 4.0Ω / □, and the vertical The resistance between the bus bars was 2.7 Ω / □.

The obtained electrically heated glass has the same form as that of the second example (FIG. 3) of the above-mentioned embodiment, and the upper side length is 10
0 cm, left side length and right side length 75 cm, distance 80c in the longitudinal center portion of the upper side bus bar and the lower side bus bar
m, the curve length of the lower side bus bar is 160 cm. As the radio wave transmitting region, the one having the form shown in FIG. 1 was formed. The slits were formed by scanning and irradiating the film surface with a xenon laser beam after the molding to heat and evaporate the conductive film.

Example 2 An electrically heated glass was produced in the same manner as in Example 1 except that the form of the radio wave transmission region was changed to that of the third example (FIG. 4A) of the above-described embodiment. That is, the radio wave transmission area is a concentric window (20), and the radius is 65 m from the center.
A circle (20a) of m and a radius 105 from the center outside the circle (20a)
It consists of a ring (20b) of ~ 140 mm. The slits have a width of 1 mm and a length of 20 mm, and the slits are arranged at intervals of 1 mm in the vertical direction (length direction) and 20 in the horizontal direction (width direction).
mm. The orientation of the slit is almost vertical.

Example 3 An electrically heated glass was produced in the same manner as in Example 1 except that the form of the radio wave transmitting region was changed to that of the fourth example (FIG. 5A) of the above-described embodiment. That is, the radio wave transmission area is composed of three parallelogrammic windows (30).
Explaining the shape with (B), the inclination angle θ2 = 30 °, 30
a is a height of 300 mm, a width of 130 mm, and 30 at two places.
b is arranged 40 mm apart from 30a on the right side and the left side, and has a height of 300 mm and a width of 35 mm. The shape of the slits is 1 mm in width and 20 mm in length, and the intervals of the slit array are 1 mm in the vertical direction (length direction) and 20 mm in the horizontal direction (width direction). The orientation of the slit is almost vertical.

Comparative Example An electrically heated glass as in Example 1 was prepared without providing a transparent conductive film.

Radio wave transparency test While changing the distance Z (see FIG. 3) between the antenna disposed inside the vehicle and the side surface of the electrically heated glass inside the vehicle, a circularly polarized wave of 5.8 GHz for ETC communication was used in Example 1. .About.3 and Comparative Example, and the electric field strengths of the radio waves received by the antennas were compared. Results are shown in FIG. FIG. 6 is a graph in which the electric field strength in the comparative example is 0 dB. In Example 1, −6 to
It is -7 dB, which is a level with no practical problem. In Example 2, the influence of the distance Z is large, but Example 1
Better results are obtained, in particular, Z of 0.06 to 0.0
In the range of 8, it was +4 dB or more. Example 3
Also, although the influence of the distance Z is large (the influence of the distance Z is smaller than that of the second embodiment), a better result is obtained than that of the first embodiment. Particularly, in the range of Z of 0.1 to 0.16, The radio wave transmission was better than that of the comparative example. Although not shown, in the example in which the slit is not provided in the transparent conductive film, the
It was a decrease of 21 dB.

Electricity / Thawing Test The electric heating glass of Examples 1 to 3 was left in a low temperature chamber at -20 ° C., sprayed with water to spray frost and ice with a thickness of 2 mm, and left for 24 hours again. did. Then, when a direct current voltage of 42 V was applied to the terminals of the bus bars on the upper side and the lower side of the energization heating glass to generate heat, the current amount reached 16 A, the total heat generation amount was 690 W, and the heat generation power was 7 from the area calculation.
It became 30 W / m ² . The ice on the surface of the glass plate started to melt in 2 minutes and was completely melted in 10 minutes. In any of Examples 1 to 3, abnormal hot spots did not occur.

[0065]

As described in detail above, according to the present invention, a window glass for an automobile with a conductive film, which has an excellent appearance, has a sufficient radio wave transmission property, and can prevent abnormal heat generation even when electrically heated. It is also possible to provide a radio wave transmission / reception structure for automobiles using the same.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of an electrically heated glass according to the present invention.

FIG. 2 is an exploded view of the section aa in FIG.

FIG. 3 is a schematic plan view showing a modified example of the electrically heated glass according to the embodiment.

FIG. 4 is a schematic diagram showing another modification of the electrically heated glass according to the embodiment.

FIG. 5 is a schematic diagram showing another modification of the electrically heated glass according to the embodiment.

FIG. 6 is a graph illustrating effects of the example.

[Explanation of symbols]

1, 2 Upper bus bar 3, bottom bus bar 4 Intermediate film 5 Transparent conductive film 6 power supply 7, 8 Coloring hiding layer 10, 20, 30 Radio wave transmission area 11 slits 18 Insulating colored ceramics layer 21 Conductive wire 90 antenna A inner glass plate B energizing part C wiring section D outer glass plate

Continued front page    F-term (reference) 4G059 AA01 AB05 AB09 AC06 AC13                       AC30 DA01 DA05 DB02 EA07                       EA12 EB04 GA02 GA14

Claims (4)

[Claims] 1. A glass plate, a conductive film provided on one surface thereof, an upper bus bar and a lower bus bar provided on the glass plate along upper and lower sides of the conductive film, and the upper side. A window glass for a vehicle with a conductive film, wherein the conductive film is electrically connected through a bus bar and a lower bus bar, wherein a plurality of elongated slits are provided in the conductive film at intervals of 0.5 to 5 mm in a longitudinal direction thereof. A radio wave transmission region is provided which is linearly arranged and is formed in multiple rows at intervals in the slit width direction, and the longitudinal direction of the slit is ± 45 with respect to the vertical direction of the glass plate.
A window glass for an automobile with a conductive film, which is in the range of °. 2. The window glass for an automobile with a conductive film according to claim 1, wherein the radio wave transmission region is provided in a concentric shape. 3. The window glass for an automobile with a conductive film according to claim 1, wherein the radio wave transmission region is band-shaped, and is provided in multiple rows at intervals in the width direction of the band. 4. A radio wave transmission / reception structure for an automobile, comprising: the automobile window glass with a conductive film according to claim 1; and a transmission / reception device having a radio wave transmission / reception antenna disposed inside the vehicle. The transmitting / receiving antenna is within a range in which the shortest distance from the inner side surface of the window glass for an automobile with the conductive film is within 40 cm, and with respect to a perpendicular line of a glass surface drawn from an outer peripheral edge portion of the radio wave transmission region. , A radio wave transmitting / receiving structure for an automobile, which is arranged in a range surrounded by a virtual inclined surface inclined to the outer peripheral side of 45 °.