JP2620456B2 - Radio wave transmitting heat reflecting glass for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a window glass for automobiles provided with a heat insulating film and various antennas, and more particularly to a radio wave transmission for vehicles capable of efficiently transmitting radio waves and exhibiting sufficient heat insulating properties. Related to heat ray reflective glass.

[0002]

2. Description of the Related Art In recent years, especially in automobiles, not only reception of radio such as AM broadcast and FM broadcast, but also reception of television and the like, and various transmission and reception such as wireless telephones have been performed. Then, antennas of various shapes and various materials are arranged on the surface of the window glass for an automobile so that a sufficient gain can be obtained.

[0003] On the other hand, recently, as the window glass for automobiles has been increased in area and weight, the efficiency of cooling and heating in the automobile has been improved, human influence on optics has been reduced, or environmental friendliness has been improved. In order to respond to the demand for high occupancy, high safety, and high environmental performance, a film layer with various functions such as heat insulation is applied on the window glass of automobiles. It is getting.

However, usually, for example, the higher the heat insulation performance, the better the conductivity of the antenna itself and the better the shielding of the various transmission / reception waves. Therefore, various proposals have been made to solve this problem.

For example, Japanese Utility Model Publication No. Sho 63-49932 discloses a window glass for an automobile with an antenna. The window glass is fixed to a window frame and provided with a receiving or transmitting antenna element wire. On the glass surface,
A conductive film for heat ray reflection is provided leaving at least a portion of a predetermined width along the inside of the window frame, and without increasing the capacitance between the feeding point of the antenna and the vehicle body, heat ray reflection is prevented. It has a function.

For example, Japanese Utility Model Laid-Open Publication No. 61-121010 discloses a window glass for an automobile. The window glass is a window glass for an automobile having a heat ray reflective film or a conductive film and an antenna wire. The heat ray reflective film or the conductive film is provided on a portion where the antenna wire is not provided.

Further, for example, Japanese Unexamined Patent Publication (Kokai) No. 2-177601 discloses a window glass for an automobile. The window glass is an automobile window glass provided with a heat ray reflective film and an antenna conductor. The reflection film has a sheet resistance value of 20 KΩ / port or more.

Further, for example, Japanese Patent Application Laid-Open No. 3-250797, which has already been filed by the present applicant, describes a laminated plate having low reflection characteristics with respect to radio waves. A laminated plate in which a film, a film, or a plate is laminated is disclosed in which the film, the film, or the plate is divided such that the length of one side is 0.4 times or less the wavelength λ of the radio wave.

[0009]

As described above, in the above-mentioned Japanese Utility Model Publication No. 63-49932 and Japanese Patent Application Laid-Open No. 2-177601, the heat ray reflective film has a surface resistivity of 20 KΩ.
If the film is smaller than the aperture, the direction of the incoming radio wave is cut off, causing radio interference, and the original antenna performance cannot be exhibited. Also, those described in Japanese Utility Model Application Laid-open No. Sho 61-121010, it is necessary to pattern them depending on the glass antenna portion so that there is not a sufficient heat ray reflective film or conductive film. Sufficient heat insulation performance cannot be exhibited as a whole. Furthermore, the thing described in the above-mentioned JP-A-3-250797 prevents heat interference as a window glass of a building or the like and prevents a radio wave from being efficiently transmitted. It is hard to say that they have enough.

[0010]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above circumstances, and a vehicle window glass provided with a heat insulating film and an antenna wire has a requirement as a vehicle window glass. And AM broadcast wave or FM
It can be said that it does not cause radio interference by reducing the reflectance of various broadcast waves such as broadcast waves, and it is possible to make the radio wave transmittance as close as possible to the base glass that does not cover the film, and the original antenna performance is sufficient An object of the present invention is to provide a radio wave transmitting heat ray reflecting glass for a vehicle which can exert its performance and has sufficient heat insulating performance.

That is, according to the present invention, in a window glass for a vehicle provided with a heat insulating film and various antennas, the heat insulating film is placed in a direction orthogonal to a main element of the antenna.
A radio wave transmitting heat ray reflecting glass for a vehicle, wherein the glass is at least divided so as to have a stripe width of not more than 00 mm and a dividing groove is formed to form a fixed shape.

The above-mentioned radio wave transmitting heat ray reflecting glass for a vehicle, wherein the heat insulating film is divided so that a stripe width of 100 mm or less becomes 1/20 or less of a wavelength λ of an incoming radio wave. The above-mentioned radio wave transmitting heat ray reflective glass for a vehicle, wherein the width of the division groove is 5 mm or less. Further, the present invention provides the above-described vehicular radio wave transmitting heat ray reflective glass, wherein the fixed divided shape is a stripe shape or a lattice shape.

Here, the heat insulation film is, for example, I
TO thin film, SnO ₂ (Sb) thin film, SnO ₂ (F) thin film or dielectric / Ag thin film / dielectric, etc., and the film thickness is, for example, about 500 nm or less, preferably about 3 nm.
Visible light transmittance is, for example, 50% or less.
The surface resistivity may be, for example, about 10 Ω / port, and is not particularly limited, and the solar transmittance is, for example, about 60%. The following is preferred, and those having various functions may be employed as, for example, laminated glass for automobiles as long as they have sufficient durability and the like. Further, as a film forming method, for example, a sputtering method is preferable, but it goes without saying that, as long as the film has the above-mentioned performance, for example, various film forming methods may be used, or a film-like material having such a film may be attached. No.

The various antennas include, for example, those obtained by printing silver paste or the like on the surface of a window glass for automobiles, those having thin metal wires or the like disposed on an interlayer film of laminated glass, or those having a glass surface. It may be an adhered one, or a film-like one appropriately coated with a transparent conductive film, and its shape and site are not particularly limited. Preferably, both the printed and thin metal wire antennas, more preferably a thin metal wire antenna.

It is needless to say that the heat insulating film and the antenna should not be disposed on the same surface of the glass plate. In particular, the heat insulating film has a surface resistivity of, for example, 20K.
Ω / port or less, especially in the case of a conductive film, it is necessary that they are not on the same plane. If the heat insulating film is about 20 KΩ / port or more, the heat insulating film may be disposed on the same surface of the glass plate, and is divided at least so as to have a stripe width of 100 mm or less as described above. Needless to say, the antenna performance can be more stably maintained and exhibited by adopting the shape.

Next, the heat insulating film is divided at least so as to have a stripe width of 100 mm or less in a direction orthogonal to the main element of the antenna.
First, the orthogonal to the main element of the antenna is that, generally, when a radio wave is incident on the scatterer, a magnetic field component of the radio wave induces a radio wave on the surface of the scatterer in a direction orthogonal to the magnetic field, and the induced radio wave is induced. Since the devices that detect and amplify radio waves are receivers such as radios and televisions, it is necessary to install the glass antenna in the window glass for automobiles in a direction orthogonal to the magnetic field component of the incoming radio waves.
This is because it has been found that the stripe shape for dividing the heat insulating film needs to be at least in a direction orthogonal to the glass antenna. For example, when receiving a VHF wave, a radio wave that can be efficiently received by the vertical glass antenna is a vertically polarized wave (the direction of the electric field component is vertical), and the VHF wave is transmitted by the heat insulating film in front of the glass antenna. In order to prevent reflection, the heat insulating film may be divided into a fixed shape by providing at least a dividing groove, that is, a gap in the horizontal direction in a strap shape.

The reason for dividing at least so as to have a stripe width of 100 mm or less is that not only the effect of restricting the flow of the induced current but also the effect of the interaction between the patches is large because the division of the patch by the stripe has a large effect. In order to improve the transmission of radio waves due to this effect, for example, it is necessary to arrange at least about five or more patches, that is, it is necessary to at least divide a windowpane for an automobile into a stripe width of 100 mm or less.

Further, 1/20 of the wavelength λ of the incoming radio wave.
For example, the above-described VH
In the case of the F wave, although a current is induced in a direction orthogonal to the magnetic field component of the vertical polarization (horizontal direction), that is, in the vertical direction,
Since the conductor cannot be resonated because the length of the conductor is 1/20 or less of the wavelength λ, the radio wave cannot be reflected and passes through the heat insulating film, so that the radio wave reaches the glass antenna. Preferably it is 1/25 or less, more preferably 1/30 or less.

Further, the reason why the width of the dividing groove is 5 mm or less is that the dividing groove (also referred to as a gap or a slit) has a width and / or a width of a groove parallel to an electric field direction of an incoming radio wave. The width of the orthogonal groove is 5mm
The reason for the following is that the larger the width of the dividing groove is, the smaller the radio wave interference is. For example, in particular, in general high heat insulation products having relatively low resistance, the surface resistivity is about 10 Ω / port and the solar transmittance is about 50% or less. As the division width is increased, the radio wave reflection is slightly reduced even if it is far from ordinary filmless glass,
If the width of the groove becomes 5 mm or more, a feeling of discomfort to a driver such as a driver gradually appears, and it is hard to say that the design is also preferable. 5 mm or less, preferably about 3 mm or less, more preferably 1/1500 mm times or less the wavelength λ of the incoming radio wave (corresponding to about 1 mm or less at 200 MHz).

Further, the fixed divided shape is as follows:
As described above, the width of the horizontal groove may be zero in the case of horizontal polarization, and the width of the vertical groove may be zero in the case of vertical polarization. ,
Further, the width of the horizontal groove and the width of the vertical groove may have a simultaneous gap, and may correspond to the direction in the main element of the glass antenna, and may be a vertical or horizontal stripe shape or a lattice shape. It is.

With respect to the lower limit of the stripe width, for example, in the case of the above-described ordinary high heat insulation product, the solar radiation transmittance is about 60% or less and the radio wave frequency is 200% or less.
In the case of MHz, if the width of the groove is 0.5 mm, the heat insulating effect can be expected up to a stripe width of about 3 mm. For example, the range of the stripe division width is about 2/1000 to 1/30 of the wavelength λ. Becomes If the width of the groove is further reduced, the lower limit is further reduced. On the other hand, if the width of the groove is made too small, the TV broadcast band has a high frequency, and the current jumps over the gap of the groove by the displacement current defined by Maxwell, and the heat insulating film becomes a continuous body electrically. There is a phenomenon that will. However, with the groove width of about 0.05 mm that can be processed by a laser, for example, even when the incoming radio wave has a high frequency of 10 GHz,
It played the role of the groove and transmitted the incoming radio wave.

[0022]

The present inventors have conducted intensive studies to minimize radio interference caused by a plate-like body having a high reflectivity to radio waves such as heat insulating glass. The present invention has been made by paying attention to the unique division of an adiabatic film or the like.

As described above, by dividing the length (L) of the side parallel to the electric field direction of the arriving radio wave into 1/20 or less times the wavelength λ of the radio wave, the low radio wave reflection value closer to the base glass can be obtained. It can be seen that the glass becomes a rate glass and the amount of reflection is remarkably reduced. The same tendency is observed from a TV broadcast wave having a frequency of 90 MHz and a VHF band to a TV broadcast wave having a frequency of 770 MHz and the entire UHF band.

This is considered to be due to the following reasons. That is, when a plane wave is incident on an arbitrary scatterer, a conductive current or a polarization current flows through the scatterer, which serves as a secondary radiation source, generates an electromagnetic wave, and reflects the electromagnetic wave. In reality, the electrons do not move from one end of the scatterer to the other, but only oscillate at some point in synchronization with the frequency of the incident electromagnetic wave.

A portion having a high electron concentration caused by such electron vibration moves. This is a factor that reflects electromagnetic waves. By dividing the plate-like body or the like to reduce L / λ, the area where electrons can freely move becomes narrower, and as a result, the amount of reflection per unit area decreases. It is presumed that.

When a radio wave having a frequency of f is vertically irradiated on a conductive film or film having a thickness of x (m), the radio wave transmittance E becomes E = exp (−αx). Here, α is an attenuation constant of the conductive film, and α = 4.82 · π ·
f ^1/2 [unit: 1 / m], for example, x is 5
Assuming that 0 nm and f are 100 MHz, the transmittance E is 0.98.
Since it is hardly absorbed and the amount of reflection is reduced by dividing, it can be seen that radio waves are transmitted efficiently.

With these, the radio wave reflectance of the arriving radio wave approximated to the base glass is obtained. On the other hand, the heat insulation performance uses a unique thin film with a specific surface resistivity, which has a relatively high radio wave reflectivity, to achieve the heat insulation effect as close as possible to the current high-performance heat-insulating glass. It is possible to obtain the same quality as that of the high-performance heat insulating glass.

That is, in the current high-performance insulating glass,
It solves the difficulties in solving radio interference and makes it possible to make the radio wave transmission as close as possible to the non-film base glass, exhibiting the performance of the original glass antenna, reducing the load in cooling and heating, and using the current high-performance insulating glass. An object of the present invention is to provide a radio wave transmitting heat ray reflecting glass for a vehicle which can use a thin film as it is, is environmentally friendly and has excellent livability.

[0029]

An embodiment of the present invention will be described below in detail with reference to the drawings. However, the present invention is not limited to such an embodiment.

FIG. 1 is a plan view showing an example of a radio wave transmitting heat ray reflecting glass for a vehicle embodying the present invention, and FIG. 2 is a sectional view taken along line XX in FIG. That is, a radio wave transmitting heat ray reflecting glass for a vehicle used for a rear window glass of an automobile.
First , a clear float glass having a thickness of about 2 mm was used, and a film having a heat insulating property was coated on the sheet glass by a DC magnetron sputtering method to a structure and a thickness shown in Table 1 to obtain a heat insulating film. Next, the heat insulating sputtered film is cut into gaps 4 which are division grooves by a YAG laser, and a laterally striped type heat insulating film 3 is applied to the outside glass 7 as in FIG. Printed, sintered and baked anti-fog line 9,
A type (vertical two pairs) glass antenna 2 made of a fine metal wire and provided with a feeding point 5 on the other surface of the inside glass 6 which is a 2.3 mm-thick bronze float glass as shown in FIG. By bonding the inner glass 6 temporarily bonded to the surface of the PVB film 8, which is an adhesive intermediate film, on which the heat insulating film surface and the PVB film surface are bonded, the outer glass 7 / heat insulating This is an automotive window glass made of laminated glass having a structure of membrane 3 / PVB membrane 8 / glass antenna 2 / inside glass 6 with anti-fog line 9.

Each of the following examples was carried out in various ways based on the same structure as the laminated glass having the above structure, and the three types of heat insulating films shown in Table 1 had the main element shapes shown in FIGS. Type (vertical 2 pairs), B type (vertical 1
Each) and C type (two horizontal) glass antennas,
6 to 8 are attached to the rear window of an automobile by changing the shape of the divided stripes by combining patches of a lattice type, a horizontal stripe type and a vertical stripe type heat insulating film, respectively. It shows a part of the items evaluated by the above.

Example 1 The structure was basically the same as that of the above-mentioned laminated glass. As shown in Table 1, the film structure was an ITO film having a thickness of about 300 nm. About 12Ω / mouth,
A heat insulating film having a visible light transmittance Tv of about 76% and a solar transmittance Ts of about 58% is provided with a stripe width of about 20 mm with a gap width of about 1 mm. The shape was combined using the A type (vertical two pairs) crow antenna of FIG.

Table 2 shows that the heat insulating film of the laminated glass was formed into a lattice type shown in FIG. 6, a horizontal stripe type shown in FIG. 7, a vertical stripe type shown in FIG. For the filmless type, the average reception gain in horizontal polarization was measured, and the gain difference when the reception gain of a standard dipole antenna was set to 0 dB was expressed as a dipole ratio (dB). The gain was measured and evaluated in the band and the VHF band.

As shown in Table 2, among the various types of laminated glass described above, the difference from the non-film type is as follows.
In the FM band, the lattice type is +0.2 dB, the horizontal stripe type is -0.1 dB, and in the VHF band, the lattice type is +2 dB and the horizontal stripe type is -0.3 dB. The radio wave transmission is as close as possible to the above.

That is, the heat insulating film is divided at least so as to have a stripe width of 100 mm or less in a direction orthogonal to the main element of the glass antenna, and a dividing groove (gap) is formed to form a fixed shape. F
In the M-band and VHF-band, of course, it can sufficiently transmit various broadcast radio waves, exhibit its original antenna performance, reflect heat rays and have sufficient insulation performance, reduce the load in cooling and heating, etc. It is a useful radio wave transmitting heat ray reflecting glass for vehicles, for example, which is excellent in safety and comfort for passengers.

Example 2 In the same manner as in the above-described embodiment, the film had the film configuration shown in Table 1, and the characteristics of the film were surface resistivity Rs, visible light transmittance Tv, and solar radiation transmittance Ts shown in Table 1. A heat-insulating film having the same gap width and the same stripe width as in Example 1 was used, and the main element of the glass antenna was a B-type (one vertical) glass antenna shown in FIG. This was a combined laminated glass.

Table 2 shows that the heat-insulating film of the laminated glass was evaluated in the same manner as in Example 1 by measuring the gain in the respective divided shapes and the type without the film, particularly in the FM band and the VHF band. Things.

As shown in Table 2, the difference between the above-mentioned various types of laminated glass and the non-film type is as follows.
In the FM band, the lattice type is -0.2 dB, the horizontal stripe type is +0.1 dB, and in the VHF band, the lattice type is -0.1 dB and the horizontal stripe type is +0.2 dB.
B indicates that the radio wave transmission becomes as close as possible to the raw glass sheet that does not cover the film.

That is, similarly to the first embodiment, a heat insulating film is provided in a direction orthogonal to the main element of the glass antenna.
By dividing at least into a stripe width of 0 mm or less and forming a dividing groove (gap) so as to form a fixed shape, similar to the first embodiment, useful with various desired excellent characteristics. It was a radio wave transmitting heat ray reflective glass for vehicles.

Example 3 In the same manner as in the above-mentioned Example , the film had the film configuration shown in Table 1, and the characteristics of the film were as shown in Table 1 such as surface resistivity Rs, visible light transmittance Tv, and solar radiation transmittance Ts. A heat-insulating film having the same gap width and the same stripe width as in Example 1 was used, and the shape of the main element of the glass antenna was a C type (two horizontal) glass antenna shown in FIG. This was a combined laminated glass.

Table 2 shows that the heat insulating film of the laminated glass was evaluated in the same manner as in Example 1 by measuring the gain in each of the divided shapes and the type without the film, particularly in the FM band and the VHF band. Things.

As shown in Table 2, the difference between the above-mentioned various types of laminated glass and the non-film type is as follows.
In the FM band, the lattice type is -0.2 dB, the vertical stripe type is -0.3 dB, and in the VHF band, the lattice type is -0.1 dB and the vertical stripe type is +0.1 dB.
B indicates that the radio wave transmission becomes as close as possible to the raw glass sheet that does not cover the film.

That is, as in the first embodiment, a heat insulating film is formed in a direction orthogonal to the main element of the glass antenna.
By splitting at least so as to have a stripe width of 0 mm or less and forming a dividing groove (gap) to form a fixed shape, similar to Examples 1 and 2, provided with various desired excellent characteristics. It was a useful radio wave transmitting heat reflecting glass for vehicles.

The present invention is not limited to the above-mentioned preferred embodiments, and various applications are possible. Regarding automotive window glass, regardless of the interior and exterior glass, it may be colorless or colored, and in addition to flat, bent plate glass, and various processed glass such as strengthened or tempered glass, laminated glass as well as single glass or Double-layer glass may be used, as long as it has a lower radio wave reflectance than the film or film to be further divided,
Various materials such as organic and inorganic materials such as plastics can be adopted.

[0045]

[Table 1]

[0046]

[Table 2]

[0047]

The radio wave transmitting heat ray reflective glass for a vehicle according to the present invention has a relatively high radio wave reflectance and a surface resistivity of 20 KΩ /.
By forming a heat insulating film having a relatively low surface resistivity of 500Ω / mouth or less, such as a mouth glass or less, into a window glass for an automobile, which is divided into fixed-form patches with specified stripes,
In the M-band and VHF-band, of course, it can sufficiently transmit various broadcast radio waves, exhibit its original antenna performance, reflect heat rays and have sufficient insulation performance, reduce the load in cooling and heating, etc. The present invention provides useful radio wave transmitting heat ray reflecting glass for vehicles, such as being excellent in safety and livability for passengers, etc., and environmentally friendly.

[Brief description of the drawings]

FIG. 1 is a plan view showing a radio wave transmitting heat ray reflecting glass for a vehicle according to an embodiment of the present invention, which is provided with a glass antenna whose main element shape is an A type (vertical two pairs) glass and a horizontal stripe type heat insulating film.

2 is a cross-sectional view of the vehicular radio wave transmitting heat ray reflective glass of FIG. 1 when viewed from XX.

FIG. 3 is a view illustrating a radio wave transmitting heat ray reflecting glass for a vehicle implemented in the present invention, in which an inner glass of a window glass for an automobile and PVB are used.
It is a top view which shows the A type (vertical two pairs) glass antenna arrange | positioned between films.

FIG. 4 is a view showing a radio wave transmitting heat ray reflecting glass for a vehicle implemented in the present invention, wherein an inner glass of a window glass for an automobile and PVB are used.
It is a top view which shows the B type (one vertical) glass antenna arrange | positioned between films.

FIG. 5 is a view illustrating a radio wave transmitting heat ray reflecting glass for a vehicle implemented in the present invention, in which an inner glass of a window glass for an automobile and PVB are used.
It is a top view which shows the C type (two horizontal) glass antenna arrange | positioned between films.

FIG. 6 is a plan view showing a case in which a heat insulating film applied to an outside glass of a window glass of an automobile has a lattice-shaped divisional shape in the vehicular radio wave transmitting heat ray reflecting glass implemented in the present invention.

FIG. 7 is a plan view showing a case in which a heat insulating film applied to an outside glass of a window glass for a vehicle has a horizontal stripe type in a vehicle radio wave transmitting heat reflecting glass implemented in the present invention.

FIG. 8 is a plan view showing a case in which the heat insulating film applied to the outside glass of the window glass for a vehicle has a vertical stripe type divisional shape in the vehicular radio wave transmitting heat ray reflecting glass implemented in the present invention.

[Description of Signs] 1 Radio wave transmitting heat ray reflecting glass for vehicle 2 A type (vertical 2 pairs) glass antenna 3 Horizontal stripe type heat insulating film 4 Gap 6 Interior glass 7 Vehicle side glass 8 PVB film 10 Grid type heat insulating film 11 Vertical stripe type heat insulating film 12 B type (one vertical) glass antenna 13 C type (two horizontal) glass antenna

Claims (4)

(57) [Claims] 1. A window glass for a vehicle provided with a heat insulating film and various antennas, the heat insulating film is divided at least in a direction orthogonal to a main element of the antenna so as to have a stripe width of 100 mm or less to form a dividing groove. A radio wave transmitting heat ray reflecting glass for a vehicle, wherein the glass is formed into a fixed shape. 2. A radio wave transmitting heat ray reflecting glass for a vehicle according to claim 1, wherein said heat insulating film is divided so that a stripe width of 100 mm or less becomes 1/20 or less of a wavelength λ of an incoming radio wave. . 3. The reflecting glass according to claim 1, wherein the width of the dividing groove is 5 mm or less. 4. A radio wave transmitting heat ray reflecting glass for a vehicle according to claim 1, wherein said fixed divided shape is a stripe shape or a lattice shape.