double-glazed glass

Abstract

To appropriately increase the transmittance of radio waves of a desired frequency through double glazing. [Solution] A double-glazed glass (10) in which multiple glass panes (12) are stacked with gaps between them, comprising a first glass pane (12) that is the first glass on which a Low-E film (22) is formed, a second glass pane (12) that is the second glass on which a Low-E film (22) is formed, and a dielectric portion (16) formed of a dielectric having a dielectric constant different from that of air, the dielectric portion (16) being located between the Low-E film (22) on the first glass pane (12) and the Low-E film (22) on the second glass pane (12).

Description

[Technical Field]

[0001] The present invention relates to insulating glass. [Background technology]

[0002] Conventionally, double-glazing using Low-E glass, which is glass (plate glass) on which a Low-E film (Low-E metal film) is formed, has been widely used (see, for example, Patent Document 1). In recent years, due to factors such as the increasing quality required of window glass, double-glazing containing multiple pieces of Low-E glass has also become increasingly popular. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-175704 Summary of the Invention [Problem to be solved by the invention]

[0004] Window glass used in homes and offices is typically desired to have a certain degree of transmittance to radio waves, such as those used in mobile communication systems, so that mobile phones and other devices can be used indoors. However, when double-glazed glass using Low-E glass is used, the presence of the metallic Low-E film reduces the transmittance of radio waves. In particular, when a double-glazed glass contains multiple pieces of Low-E glass, it is expected that the transmittance of radio waves corresponding to frequencies used in mobile communication systems such as fifth-generation mobile communication systems (5G mobile communication systems) will be significantly reduced. In this case, it is also expected that the transmittance of radio waves corresponding to frequencies used in mobile communication systems beyond fifth generation mobile communication systems will be significantly reduced. Therefore, an object of the present invention is to provide double-glazed glass that can solve the above problems. [Means for solving the problem]

[0005] The inventors of the present application conducted extensive research into the effect of Low-E glass on radio wave transmittance. Through various experiments and simulations, they discovered that for double-glazed glass containing multiple Low-E glass panes, a transmittance peak occurs that selectively transmits radio waves of specific frequencies, for example, in a range that includes frequencies used by radio waves for mobile communication systems. They also discovered that the position of this peak changes depending on the distance between the multiple Low-E glass panes. In this case, for example, by adjusting the distance between the multiple Low-E glass panes in accordance with the frequency of radio waves for mobile communication systems, the transmittance of the required radio waves can be increased.

[0006] However, in double glazing, the distance between the glass panes (panes) is usually determined by construction standards, etc. Therefore, it is usually difficult to freely adjust the distance between the panes of double glazing. In response to this, the inventors of the present application, through further intensive research, came up with the idea of ​​adding a dielectric layer between multiple Low-E glass panes to change the frequency corresponding to the peak transmittance without changing the distance between the Low-E glass panes. Then, through actual experiments and simulations, they confirmed that this method can actually change the frequency corresponding to the peak transmittance.

[0007] Furthermore, the inventors of the present application have further intensively researched and discovered the features necessary to achieve such effects, and have arrived at the present invention. In order to solve the above problems, the present invention provides a double-glazing unit in which a plurality of glass sheets are overlapped with gaps therebetween, the double-glazing unit comprising a first glass sheet having a Low-E film formed thereon, a second glass sheet having a Low-E film formed thereon, and a dielectric portion formed of a dielectric material having a dielectric constant different from that of air, the dielectric portion being located between the Low-E film on the first glass sheet and the Low-E film on the second glass sheet.

[0008] In this configuration, the presence of the first and second glass panes on which the Low-E film is formed in the double-glazed glass can, for example, produce a transmittance peak at a predetermined frequency in the relationship between the frequency of radio waves and the transmittance of the radio waves through the double-glazed glass. In this case, for example, when measuring the relationship between the transmittance of radio waves through the double-glazed glass and the frequency of the radio waves, it can be assumed that a transmittance peak will occur at some frequency within at least a partial frequency range. Furthermore, in this case, the presence of the dielectric portion between the first and second glass panes can appropriately change the frequency corresponding to the transmittance peak, compared to, for example, when the dielectric portion is not present. Therefore, with this configuration, it is possible to appropriately increase the transmittance of radio waves of a desired frequency through the double-glazed glass.

[0009] In this case, it is also conceivable to set the thickness of at least a portion of the dielectric portion so that the frequency corresponding to the transmittance peak matches the frequency used in the mobile communication system. This configuration can appropriately increase the transmittance of the double-glazing glass for radio waves at frequencies used in the mobile communication system. In this case, the radio waves at frequencies used in the mobile communication system can be considered to be, for example, any of the frequencies used in the mobile communication system. In this case, it is also conceivable that the double-glazing glass has a blocking effect against radio waves at frequencies other than the transmittance peak. In this case, it is also conceivable to configure the double-glazing glass so that it transmits radio waves at frequencies used in the mobile communication system while blocking radio waves for Wi-Fi (wireless LAN) used indoors.

[0010] Furthermore, with this configuration, it can be considered that the transmittance of radio waves at frequencies for which the transmittance is increased is dramatically improved, for example, compared to when the dielectric portion is not present. More specifically, in this case, the presence of the dielectric portion can improve the radio wave transmittance by, for example, 25 dB or more for at least some frequencies used in mobile communication systems, compared to when the dielectric portion is not present. Therefore, in this case, it can be considered that a configuration can be realized in which a mobile communication system can be practically used indoors, for example, with double glazing including multiple Low-E films.

[0011] Furthermore, in this configuration, the transmittance peak can be considered to be, for example, the effect of resonance occurring in response to the distance between the Low-E films. In this case, if the distance between the Low-E film on the first glass and the Low-E film on the second glass is defined as the inter-membrane distance, and the frequency at which resonance occurs with respect to the inter-membrane distance is defined as the inter-membrane distance-corresponding frequency, the inter-membrane distance-corresponding frequency can be considered to be, for example, a frequency determined by the thickness of the dielectric portion. Furthermore, when the relationship between the transmittance of radio waves through double-glazed glass and the frequency of the radio waves is measured, it can be considered that the transmittance peak occurs, for example, at a frequency corresponding to the inter-membrane distance-corresponding frequency. With this configuration, it is possible to appropriately increase the transmittance through double-glazed glass for radio waves of a desired frequency, for example.

[0012] In this configuration, the dielectric portion may have multiple regions with different thicknesses or dielectric constants. In this case, for example, it can be assumed that the frequencies of the corresponding peaks differ for each region in the dielectric portion. Furthermore, when measuring the relationship between the transmittance of radio waves through double-glazing and the frequency of the radio waves, it can be assumed that transmittance peaks occur at multiple frequencies corresponding to the multiple regions in the dielectric portion. With this configuration, it is possible to appropriately increase the transmittance of double-glazing for radio waves in multiple frequency bands, for example.

[0013] In this configuration, the double-glazed glass may further include glass other than the first and second glass panes. In this case, the double-glazed glass may further include a third glass pane, which may be, for example, a sheet of glass without a Low-E film. In this case, the third glass pane may be, for example, located between the first and second glass panes. The dielectric portion may be, for example, on at least one surface of the third glass pane. With this configuration, the dielectric portion may be appropriately positioned, for example, between multiple Low-E films. The position of the dielectric portion may also be set to a different position. For example, the dielectric portion may be positioned on the inner surface of the first or second glass pane. The position on the inner surface of the first or second glass pane may also be considered to be, for example, on the Low-E film. With this configuration, the dielectric portion may also be appropriately positioned, for example, between multiple Low-E films.

[0014] In this configuration, the double-glazing glass may further include a dielectric element located outside the area between the Low-E films. In this case, the double-glazing glass may further include an outer dielectric element located outside the area between the Low-E film on the first pane and the Low-E film on the second pane. The outer dielectric element may be located on the surface of the first pane opposite the surface facing the second pane. The use of such an outer dielectric element can appropriately reduce the reflection of radio waves incident on the double-glazing glass. In this case, the outer dielectric element may be, for example, a dielectric layer having a thickness that reduces the reflectance of radio waves at the frequency of the peak transmittance. The thickness of such an outer dielectric element may be considered to be the thickness of the outer dielectric element that reduces the reflectance of radio waves in an admittance control diagram showing the transmittance of radio waves at this frequency. More specifically, when such an outer dielectric element is used, measuring the relationship between the transmittance of radio waves and the frequency of the double-glazing glass, it may be considered that a transmittance peak occurs at some frequency, for example, in at least a partial frequency range. In this case, the outer dielectric portion can be considered to reduce the reflectance of radio waves from the double-glazing glass, for example, at least at one of the frequencies corresponding to the transmittance peak. This configuration can further increase the transmittance of radio waves from the double-glazing glass, for example, at least at some frequencies. The double-glazing glass may also be provided with outer dielectric portions on the outer surfaces of both the first and second panes.

[0015] As explained above, the phenomenon of the transmittance peak can be considered to have a blocking effect on radio waves of frequencies other than the transmittance peak. In this case, the present invention can be considered to feature, for example, a radio wave transmittance adjustment device that selectively transmits radio waves of a predetermined frequency through the glass. In this case, the present invention can be characterized as a radio wave transmittance adjustment device that is attached to double-glazed glass containing glass with a Low-E film, thereby selectively transmitting radio waves of a predetermined frequency through the double-glazed glass. The device includes: a metal film that is spaced from the Low-E film when the radio wave transmittance adjustment device is attached to the double-glazed glass; and a dielectric portion that is formed of a dielectric material and is located between the Low-E film and the metal film when the radio wave transmittance adjustment device is attached to the double-glazed glass. The radio wave transmittance adjustment device resonates with radio waves of a corresponding frequency, which is a frequency corresponding to the distance between the Low-E film and the metal film when the radio wave transmittance adjustment device is attached to the double-glazed glass, thereby selectively transmitting radio waves of the corresponding frequency through the double-glazed glass. With this configuration, for example, it is possible to maintain the permeability of the double-glazed glass for radio waves of a predetermined frequency while appropriately blocking radio waves of other frequencies. In this case, a configuration with only one layer of Low-E film can be preferably used as the double-glazed glass. For example, a two-layer glass (pair glass) having one glass layer with a Low-E film and one glass layer without a Low-E film can be preferably used as such a double-glazed glass.

[0016] Furthermore, the above-described structure for transmitting radio waves of a specific frequency may be used in various construction materials, not limited to glass. In this case, the present invention may be applied to, for example, a construction material used in construction, which is made up of a plurality of metal films overlapping each other with gaps therebetween and a dielectric portion in an area between the plurality of metal films. The metal film is characterized by the fact that it selectively transmits radio waves of a corresponding frequency, which is a frequency corresponding to the distance between the plurality of metal films, by causing resonance with the radio waves of the corresponding frequency. With this configuration, for example, in a construction member, it is possible to maintain the transmittance of radio waves of a predetermined frequency while appropriately blocking radio waves of other frequencies. [Effects of the Invention]

[0017] According to the present invention, for example, it is possible to appropriately increase the transmittance of radio waves of a desired frequency through double glazing. [Brief explanation of the drawings]

[0018] [Figure 1] 1A and 1B are diagrams illustrating a double-glazing unit 10 according to an embodiment of the present invention. Fig. 1A shows an example of the configuration of the main parts of the double-glazing unit 10. Fig. 1B shows an example of the configuration of a known double-glazing unit. [Figure 2] 2(a) and 2(b) show examples of simulation results for the radio wave transmittance of double glazing that does not use the dielectric portion 16. Fig. 2(a) shows the simulation results for double glazing when the width (L2, L3) of the hollow layer is set to 18 mm. Fig. 2(b) shows the simulation results for double glazing in which the distance between the Low-E films 22 is different from that shown in Fig. 2(a). [Figure 3] 10 is a diagram showing an example of the results of a simulation of the transmittance of radio waves through the double glazing 10 of this example that includes the dielectric portion 16. FIG. [Figure 4] FIG. 10 is a diagram showing the results of further simulations performed by the inventors of the present application. [Figure 5] 5A and 5B are diagrams illustrating modified examples of the configuration of the double glazing 10. Fig. 5(a) shows a modified example of the configuration of the dielectric portion 16 in the double glazing 10. Fig. 5(b) shows a modified example of the configuration of the double glazing 10. Fig. 5(c) shows a modified example of the configuration of the dielectric portion 20. [Figure 6]6(a) and 6(b) are diagrams illustrating modified examples related to a configuration that selectively transmits radio waves of a specific frequency. Fig. 6(a) is a diagram illustrating a modified example related to a double glazing 10 configured with only one glass sheet 12 on which a Low-E film 22 is formed. Fig. 6(b) shows a modified example of the configuration of the radio wave transmittance adjustment member 30. [Figure 7] 7(a) and 7(b) are diagrams further explaining matters related to the transmission of radio waves through double glazing, etc. Fig. 7(a) shows a modified example of the use of a dielectric part 20 for double glazing 10. Fig. 7(b) is a diagram explaining the configuration of a construction member 40 that selectively transmits radio waves of a specific frequency. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram illustrating a double-glazing unit 10 according to one embodiment of the present invention. FIG. 1(a) shows an example of the configuration of the main components of the double-glazing unit 10. In this example, the double-glazing unit 10 is a triple-glazing unit used in windows for homes, offices, etc., and comprises multiple glass panes 12, 14 and multiple dielectric sections 16. In this case, the double-glazing unit 10 comprises multiple types of glass panes, as distinguished by the reference numerals 12, 14 in the drawing. In addition to the components shown in the drawings, the double-glazing unit 10 may further comprise components that are the same as or similar to known double-glazing units. For example, the double-glazing unit 10 may further comprise a sealant, spacers, etc. in addition to the components shown in the drawings.

[0020] Furthermore, in the double-glazing glass 10, the multiple glass panes 12, 14 are overlapped with gaps between them, as shown in the figure, for example. In this case, the gaps between the glass panes 12, 14 can be considered, for example, as hollow layers (hollow portions) in the double-glazing glass 10. The multiple glass panes 12, 14 can also be considered, for example, to be overlapping and arranged opposite each other with the hollow layer sandwiched between them. In this example, the hollow layer in the double-glazing glass 10 is filled with an inert gas such as argon gas. This configuration can, for example, appropriately prevent oxidation and other degradation of the Low-E film described below.

[0021] Furthermore, among the multiple glass panes in the double glazing 10, the multiple glass panes 12 are glass (Low-E glass) on which a Low-E film 22 is formed, and are arranged so that a glass pane 14 is sandwiched between them and a hollow layer is formed between the glass panes 14. More specifically, in this example, the distance between the multiple (two) glass panes 12 is a predetermined distance L1. One of the multiple glass panes 12 is spaced from the glass pane 14 by a predetermined distance L2. The other of the multiple glass panes 12 is spaced from the glass pane 14 by a predetermined distance L3. In this case, the distance L3 may be the same as the distance L2.

[0022] As the glass sheet 12, for example, a known Low-E glass can be suitably used. The multiple glass sheets 12 can be considered, for example, as the outer glass sheets of a three-layer glass. In this example, one of the multiple glass sheets 12 is an example of a first glass sheet on which a Low-E film 22 is formed. The other of the multiple glass sheets 12 is an example of a second glass sheet on which a Low-E film 22 is formed. In the glass sheet 12, the Low-E film 22 is formed on the surface of the glass sheet 12 facing the glass sheet 14, as shown in the figure, for example. The Low-E film 22 can also be considered to be formed on the surface of the hollow layer side of the double-glazing unit 10. The Low-E film 22 can also be considered to be formed on the surface of the glass sheet 12 facing the Low-E film 22 of another glass sheet 12, for example. In this example, the Low-E film 22 is a metal film (a thin metal film) formed on the glass surface of the glass sheet 12. As the Low-E film 22, for example, a metal thin film that is the same as or similar to a known Low-E film used in known Low-E glass can be used.

[0023] Furthermore, among the multiple glass panes in the double glazing 10, the glass pane 14 is a glass pane without a Low-E film formed thereon and is disposed between the multiple glass panes 12. In this case, the glass pane 14 can be considered to be located, for example, between the multiple Low-E films 22 on the multiple glass panes 12. In this example, the glass pane 14 is an example of a third glass pane, which is a glass pane other than the first and second glass panes. Furthermore, in the double glazing 10, the multiple dielectric portions 16 are layered bodies (film-like bodies) formed of a dielectric having a dielectric constant different from that of air. The dielectric portions 16 can be positioned, for example, on either side of the glass pane 14. With this configuration, the dielectric portions 16 can be appropriately disposed, for example, between the multiple Low-E films 22 on the double glazing 10. More specifically, in this example, the dielectric portions 16 are located on both sides of the glass pane 14. For example, a film-like member attached to the glass pane 14 can be suitably used as the dielectric portions 16. In this case, the dielectric portion 16 can be considered to be located between the plurality of Low-E films 22 on the plurality of glass sheets 12, similar to the glass sheets 14, for example.

[0024] In a modified configuration of the double-glazing glass 10, the dielectric portion 16 may be located at a position other than that shown in FIG. 1( a). In this case, too, the dielectric portion 16 may be located between the multiple Low-E films 22 on the multiple glass sheets 12. More specifically, the dielectric portion 16 may be located, for example, on only one surface of the glass sheets 14. The dielectric portion 16 may also be located, for example, on the inner surface of one of the glass sheets 12. In this case, the dielectric portion 16 may be located, for example, on the Low-E film 22 on one or both of the glass sheets 12. The reasons for using the dielectric portion 16 in the double-glazing glass 10 will be explained in more detail later. The double-glazing glass 10 of this example, excluding the multiple dielectric portions 16, may have the same or similar configuration as, for example, a known double-glazing glass. In this case, the known double-glazing glass may have the configuration shown in FIG. 1( b). FIG. 1( b) shows an example of the configuration of a known double-glazing glass.

[0025] Next, the reasons for using the dielectric portion 16 in the double-glazing unit 10 of this embodiment will be explained in more detail. For ease of explanation, an example of radio wave transmittance for a double-glazing unit having the configuration shown in FIG. 1(b), which does not use the dielectric portion 16, will be described first. FIG. 2 shows an example of the results of a simulation of radio wave transmittance for a double-glazing unit without the dielectric portion 16. FIG. 2(a) shows the results of a simulation for a double-glazing unit having the configuration shown in FIG. 1(b), in which glass sheets 12 and 14 of predetermined thicknesses are used and the width (L2, L3) of the air gap between the glass sheets 12 and 14 is set to 18 mm. In this case, the distance (actual distance) L1 between the Low-E films 22 in the double-glazing unit can be considered to be the sum of two air gap widths and the thickness of the glass sheets 14. The air gap width can be considered to correspond to the air gap width commonly used in known double-glazing units.

[0026] Regarding the distance between the Low-E films 22, in relation to radio waves, the effective distance, which is the effective distance taking into account the dielectric constant, is usually important, rather than the actual physical distance. In this case, the effective distance between the Low-E films 22 can be considered to be, for example, the sum of two widths of the hollow layer and the effective thickness of the glass sheet 14. The effective thickness of the glass sheet 14 can be considered, for example, as an effective thickness calculated based on the physical thickness of the glass sheet 14 and the dielectric constant of the glass sheet 14. Furthermore, when a dielectric portion 16 is used, as in the double-glazing unit 10 of this example described above with reference to FIG. 1(a), the effective thickness of the dielectric portion 16 can be considered to affect the transmittance of radio waves through the double-glazing unit 10. The effective thickness of the dielectric portion 16 can be considered, for example, as an effective thickness calculated based on the physical thickness of the dielectric portion 16 and the dielectric constant of the dielectric portion 16.

[0027] As explained above, the Low-E coating 22 on the glass sheet 12 is a thin metal film. Therefore, in known double-glazing systems and glass containing multiple Low-E coatings, such as the double-glazing system 10 of this example, the presence of the Low-E coatings typically results in extremely low radio wave transmittance. Furthermore, the simulation results shown in FIG. 2(a) also show extremely low radio wave transmittance across many frequency ranges. More specifically, the results shown in FIG. 2(a) show an extremely low transmittance of approximately -71 dB for radio waves at 3.6 GHz, which corresponds to the radio wave band used in fifth-generation mobile communication systems. Furthermore, although not shown, similar simulation results also show an extremely low transmittance of approximately -80 dB for radio waves at 5.2 GHz, which corresponds to another radio wave band used in fifth-generation mobile communication systems. In fact, it is difficult for known double-glazing systems, such as triple-glazing systems, to achieve practical levels of transmittance for radio waves in the 3.6 GHz and 5.2 GHz bands used in mobile communication systems.

[0028] In response to this, the present inventors have discovered that the transmittance of radio waves through known double-glazing glass exhibits a peak at a specific frequency, as shown in FIG. 2(a), for example. Furthermore, through various experiments and simulations in addition to the simulation shown in FIG. 2, the present inventors have discovered that the frequency corresponding to the peak transmittance varies depending on the distance between the Low-E films 22 in the double-glazing glass, as shown in FIG. 2(b), for example. FIG. 2(b) shows the results of a simulation of double-glazing glass in which the distance between the Low-E films 22 is different from that shown in FIG. 2(a). More specifically, in the simulation shown in FIG. 2(b), the width (L2, L3) of the air gap between the glass panes 12 and 14 in the configuration shown in FIG. 1(b) is changed to 11.7 mm. In this case, as shown in the figure, it can be confirmed that the transmittance for radio waves at 3.6 GHz, which corresponds to the radio wave band used in fifth-generation mobile communication systems, is significantly improved to approximately -37 dB. This level of transmittance can be considered to be a practical transmittance for radio waves in the 3.6 GHz band used in mobile communication systems.

[0029] In this way, varying the distance between the Low-E films 22 in a double-glazing unit can increase the transmittance of radio waves of a specific frequency through the double-glazing unit. However, the distance between the glass panes in a double-glazing unit is typically determined by construction standards. Even if the spacing between the glass panes 12 is adjustable according to standards, varying the spacing between the glass panes 12 may result in changes in the required properties of the double-glazing unit, such as thermal insulation. Therefore, it is generally difficult to freely adjust the distance between the Low-E films 22 in a double-glazing unit. In response to this, the inventors of the present application conducted further research and discovered that by placing a dielectric portion 16 between multiple Low-E films 22 in a double-glazing unit 10, they could change the frequency corresponding to the peak transmittance without changing the spacing between the glass panes 12. Then, through various related experiments and simulations, they confirmed that this method actually changes the frequency corresponding to the peak. More specifically, in this case, as shown in Figure 3, varying the frequency at which the transmittance peaks can significantly increase the transmittance of radio waves in the 3.6 GHz band.

[0030] FIG. 3 shows an example of a simulation result regarding the radio wave transmittance of the double-glazed glass 10 of this example, which includes a dielectric portion 16. This simulation can be considered to be a simulation performed under the same conditions as those shown in FIG. 2(a), except that the dielectric portion 16 has a predetermined dielectric constant and thickness. More specifically, in this simulation, the width (L2, L3) of the air gap between the glass sheets 12 and 14 is set to 18 mm, as in FIG. 2(a). In this case, the distance between the low-E films 22 can also be considered to be the same as in FIG. 2(a). Furthermore, in this simulation, the dielectric portion 16 is placed on both sides of the glass sheet 14 between the multiple low-E films 22. In this case, the thickness or dielectric constant of the dielectric portion 16 can be changed, for example, depending on the frequency of the radio wave for which transmittance is desired to be increased. As can be seen from the results shown in the figure, the transmittance of radio waves in the 3.6 GHz band can be increased to the same level as that shown in FIG. 2(b). More specifically, in the results shown in FIG. 3 , the transmittance of radio waves in the 3.6 GHz band is approximately −36.9 dB. Although not shown, the inventors of the present application confirmed that the transmittance of radio waves in the 5.2 GHz band can also be appropriately increased in the double-glazing unit 10 of this example, which includes a dielectric portion 16, by appropriately adjusting the dielectric constant or thickness of the dielectric portion 16. Therefore, according to this example, the transmittance of radio waves in the 3.6 GHz and 5.2 GHz bands used in mobile communication systems can be appropriately increased to a practical level in the double-glazing unit 10. Furthermore, as can be understood from the above explanation, it is also possible to increase the transmittance at frequencies other than the 3.6 GHz and 5.2 GHz bands by, for example, changing the thickness or dielectric constant of the dielectric portion 16. In this case, it is also possible to increase the transmittance of radio waves in the radio wave bands used in sixth-generation and later mobile communication systems in the double-glazing unit 10. As described above, according to this example, the transmittance of radio waves of a desired frequency through the double-glazing unit 10 can be appropriately increased.

[0031] Next, supplementary explanations and modifications regarding the matters described above will be provided. As described above, the double-glazing unit 10 of this embodiment utilizes a phenomenon resulting from the presence of the Low-E film 22, which is necessary for the function of the double-glazing unit 10, to enhance the transmittance of radio waves at a desired frequency. In this case, the Low-E film 22 can be considered, for example, as a low-emissivity film coated on the surface of the glass. Suitable examples of the Low-E film 22 include metal films such as tin oxide and silver. The Low-E film 22 can also be considered, for example, as a special metal film for achieving low reflectance. Furthermore, by using a glass sheet 12 having such a Low-E film 22 in the double-glazing unit 10, the insulating and heat-blocking properties of the double-glazing unit 10 can be appropriately enhanced. Furthermore, the radio wave transmittance has been described above primarily based on simulation results. In this regard, the inventors of the present application have confirmed the validity of the simulation described above by conducting various experiments corresponding to the simulation. In addition, in this regard, when considering the transmittance of high frequency radio waves used in the fifth generation mobile communication system and subsequent mobile communication systems, it has been confirmed that the characteristics of the Low-E film 22, which is a metal film, can be appropriately approximated by the characteristics of a dielectric film having a high dielectric constant, for example.

[0032] As explained above, in the double glazing 10 of this example, the presence of multiple glass sheets 12 on which the Low-E film 22 is formed can be considered to cause a transmittance peak to appear at a predetermined frequency in the relationship between the frequency of radio waves and the transmittance of the radio waves through the double glazing 10. In this case, when the relationship between the transmittance of radio waves through the double glazing 10 and the frequency of the radio waves is measured, it can be considered that a transmittance peak will appear at some frequency, for example, within at least a part of the frequency range. In the double glazing 10 of this example, the presence of the dielectric portion 16 between the multiple glass sheets 12 can be considered to change the frequency corresponding to the transmittance peak, for example, compared to when the dielectric portion 16 is not present.

[0033] In this case, the frequency corresponding to the peak can be considered to vary depending on, for example, the dielectric constant and thickness of the dielectric portion 16. More specifically, in this case, it is possible to adjust the frequency corresponding to the peak by using a dielectric portion 16 with a predetermined dielectric constant and changing the thickness of the dielectric portion 16. In this case, it is also possible to adjust the thickness of at least a portion of the dielectric portion 16 so that the frequency corresponding to the transmittance peak matches the frequency used in a mobile communication system. This configuration can appropriately increase the transmittance of radio waves of frequencies used in a mobile communication system through the double-glazing unit 10. In this case, the radio waves of frequencies used in a mobile communication system can be considered to be, for example, any of the frequencies used in a mobile communication system. In this case, the frequencies used in a mobile communication system are, for example, radio waves in the 3.6 GHz or 5.2 GHz band used in a fifth-generation mobile communication system. With this configuration, it is possible to appropriately transmit, for example, radio waves for a fifth-generation mobile communication system through the double-glazing unit 10. The frequency used in a mobile communication system may be, for example, radio waves in the band used in a sixth-generation or later mobile communication system. In this case, too, by using a dielectric portion 16 configured to match the frequency of radio waves, it is possible to allow radio waves for mobile communication systems, for example, to be transmitted through the double glazing 10 appropriately.

[0034] Furthermore, in this case, it can be considered that the transmittance of radio waves at frequencies (target frequencies) that increase the transmittance of the double-glazing unit 10 is dramatically improved, for example, compared to when the dielectric portion 16 is not present. More specifically, in this case, assuming that at least some frequencies used in mobile communication systems are the target frequencies, the presence of the dielectric portion 16 can improve the transmittance of radio waves at these frequencies by, for example, 25 dB or more, compared to when the dielectric portion 16 is not present. Therefore, according to this example, a double-glazing unit 10 including multiple Low-E films 22 can be appropriately configured to enable practical use of a mobile communication system indoors, for example. Furthermore, the improvement in radio wave transmittance obtained by the presence of the dielectric portion 16 can be, for example, 30 dB or more.

[0035] Furthermore, the inventors of the present application believe that the transmittance peaks described above are due to the effects of resonance occurring in response to the distance between the Low-E films 22, and therefore conducted further simulations to confirm the relationship between the distance between the Low-E films 22 and the frequency corresponding to the transmittance peaks. Figure 4 shows the results of further simulations conducted by the inventors of the present application. In this simulation, for simplicity's sake, the transmittance of radio waves through a two-layer multi-pane glass (two-layer Low-E glass) consisting of two opposing Low-E glass panes with the Low-E films on the inside (two-layer Low-E glass pane) was calculated. This type of multi-pane glass can be considered, for example, to correspond to the configuration shown in Figure 1(b) with the middle glass pane 14 removed. Furthermore, in this simulation, the change in transmittance with frequency was confirmed under multiple conditions, with different thicknesses of the glass panes and different distances between the glass panes (thickness of the air layer), as shown in the figure.

[0036] More specifically, of the four graphs shown in Figure 4, the upper left graph shows the simulation results for a 3 mm thick plate glass and an 18 mm thick air layer. In this case, the transmittance for radio waves in the 3.6 GHz and 5.2 GHz bands used in fifth-generation mobile communication systems was below -70 dB. The radio wave transmittance peaked at 8.33 GHz, and the transmittance at this frequency was -32 dB. In this case, the peak wavelength (36 mm), which corresponds to the frequency at which the transmittance peaks (8.33 GHz), can be said to be twice the thickness of the air layer (18 mm). The upper right graph shows the simulation results for a 5 mm thick plate glass with the same air layer thickness as the upper left graph. In this case, the radio wave transmittance also peaked at 8.33 GHz. The transmittance at this frequency was -40 dB. These results show that, for example, the frequency at which the transmittance reaches its peak is not affected by the thickness of the glass sheet outside the Low-E film 22.

[0037] The graph on the bottom left shows the simulation results for a 5 mm thick plate glass and a 41.6 mm thick air layer. In this case, the air layer thickness can be considered to be half the wavelength (83.275 mm) corresponding to 3.6 GHz. As shown in the figure, the transmittance peak occurs at the frequency of 3.6 GHz. In contrast, the graph on the bottom right shows the simulation results for a 5 mm thick plate glass and a 27.758 mm thick air layer. In this case, the air layer thickness can be considered to be one-third the wavelength corresponding to 3.6 GHz. Since the frequency at which the transmittance peaks is shifted from 3.6 GHz, the transmittance at 3.6 GHz is significantly lower than in the graph on the bottom left. In this case, the conditions corresponding to the graph on the bottom right can be considered to be, for example, the conditions under which a blocking effect against 3.6 GHz can be obtained.

[0038] These results suggest that the increased transmittance of radio waves at a specific frequency in double-glazed glass having multiple Low-E films can be explained by, for example, resonance at a specific frequency between the multiple Low-E films, which increases the transmittance of radio waves. Furthermore, if a dielectric portion 16 is present between the multiple Low-E films, the resonant frequency may change depending on the dielectric constant and thickness of the dielectric portion 16. Therefore, in the configuration of the double-glazed glass 10 of this example, if the distance between the Low-E films 22 in the multiple glass sheets 12 corresponding to the first and second glass panes is defined as the inter-membrane distance, and the frequency that resonates with the inter-membrane distance is defined as the inter-membrane distance-related frequency, the inter-membrane distance-related frequency can be considered to be, for example, a frequency determined by the thickness of the dielectric portion 16. In this case, the fact that a frequency resonates with the inter-membrane distance can be explained by, for example, a correspondence between the resonant frequency and the inter-membrane distance. The fact that the inter-membrane distance corresponding frequency is determined depending on the thickness of the dielectric portion 16 can be considered to be, for example, that when a dielectric portion 16 with a predetermined dielectric constant is used, the inter-membrane distance corresponding frequency changes depending on the thickness of the dielectric portion 16. In this case, the inter-membrane distance corresponding frequency can also be considered to be determined depending on the dielectric constant and thickness of the dielectric portion 16, for example.

[0039] Furthermore, in this case, when measuring the relationship between the transmittance of radio waves through the double glazing 10 and the frequency of the radio waves, it can be considered that a transmittance peak occurs, for example, at a frequency corresponding to the inter-membrane distance frequency. More specifically, it can be considered that a transmittance peak occurs, for example, at the inter-membrane distance frequency. Furthermore, as can be understood from the above explanation, for example, by using a dielectric portion 16 with a dielectric constant and thickness that matches the desired frequency at which transmittance is to be increased, it is possible to change the inter-membrane distance frequency to match the desired frequency. Therefore, according to this example, it is possible to appropriately increase the transmittance of radio waves of a desired frequency through the double glazing 10. Furthermore, as described above, it can be considered that the inter-membrane distance frequency is determined, for example, by the inter-membrane distance, the dielectric constant and thickness of the dielectric portion 16, etc. In this case, if we consider strictly the phenomenon that a transmittance peak occurs at the frequency position corresponding to the intermembrane distance corresponding frequency, for example, it can be considered that the resonance does not simply occur in correspondence with the intermembrane distance alone, but that the peak frequency is determined by the involvement of reflected waves generated at various material boundaries in the radio wave path (for example, reflected waves generated by reflection at material boundaries with different dielectric constants).However, even in this case, the frequency at which the transmittance peaks is, for example, the frequency of resonance determined according to the intermembrane distance, and can be considered to correspond to the intermembrane distance.

[0040] As explained above, in this example, the dielectric portion 16 is a layered body made of a dielectric material having a dielectric constant different from that of air. In this case, the dielectric constant of the dielectric portion 16 being different from that of air can be considered to be, for example, a difference between the dielectric constant of the dielectric portion 16 and that of the gas filling the hollow layer in the insulating glass 10. The dielectric constant of the dielectric portion 16 can be set to be higher than that of air. This configuration can, for example, use the dielectric portion 16 to appropriately change the inter-film distance-dependent frequency. The dielectric constant of the dielectric portion 16 can also be set to be different from that of the glass used in the glass sheet 14, for example. This configuration can, for example, allow the appropriate use of dielectric portions 16 with a variety of dielectric constants. The dielectric constant of the dielectric portion 16 can be the same as that of the glass used in the glass sheet 14, for example.

[0041] The dielectric constant of the dielectric portion 16 may affect, for example, the broadening of the transmittance peak (e.g., half-width, etc.). In this case, for example, using a dielectric portion 16 with a higher dielectric constant may result in a narrower, sharper transmittance peak. Therefore, it is preferable to determine the dielectric constant of the dielectric portion 16 in accordance with, for example, the frequency range (bandwidth) desired to be transmitted through the double-glazing unit 10. In this case, by appropriately selecting the dielectric constant of the dielectric portion 16, it is possible to transmit only radio waves in a specific band within the frequency band used in mobile communication systems, or to transmit radio waves in multiple bands within a predetermined frequency range. Furthermore, when using a dielectric portion 16 tuned to a desired frequency, it is generally considered that the higher the dielectric constant of the dielectric portion 16, the smaller the thickness of the dielectric portion 16. Therefore, it is preferable to determine the dielectric constant of the dielectric portion 16, taking into account, for example, the various conditions described above.

[0042] The specific configuration of the double-glazing glass 10 is not limited to the configuration described above and can be modified in various ways, as shown in FIG. 5, for example. FIG. 5 illustrates a modified configuration of the double-glazing glass 10. FIG. 5(a) illustrates a modified configuration of the dielectric portion 16 of the double-glazing glass 10. As described above, the double-glazing glass 10 uses a dielectric portion 16 with a dielectric constant and thickness that matches the desired frequency, thereby increasing the transmittance of radio waves at the desired frequency. In this regard, it may be desirable to increase the transmittance of radio waves at multiple different frequencies in the double-glazing glass 10. More specifically, when attempting to increase the transmittance of radio waves through the double-glazing glass 10 for frequencies used in mobile communication systems, it may be desirable to increase the transmittance for multiple different frequency bands. In this case, for example, for a fifth-generation mobile communication system, it is desirable to increase the transmittance of radio waves at both the 3.6 GHz band and the 5.2 GHz band. It may also be desirable to increase the transmittance of radio waves at frequencies used in multiple different generations of mobile communication systems in the double-glazing glass 10.

[0043] In this case, it is possible to use a dielectric portion 16 having multiple regions 102a-d with different corresponding peak frequencies, as shown in FIG. 5(a). In this case, the multiple regions 102a-d are, for example, multiple regions with different thicknesses or dielectric constants. This configuration allows, for example, the frequencies at which the transmittance peaks at each region to be appropriately varied. It is also possible to consider, for example, that the corresponding peak frequencies differ between regions in the dielectric portion 16. In this case, measuring the relationship between the transmittance of radio waves through the double-glazing unit 10 and the frequency of the radio waves reveals that transmittance peaks occur at multiple frequencies corresponding to the multiple regions 102. Therefore, this configuration allows the double-glazing unit 10 to appropriately increase the transmittance of radio waves in multiple frequency bands, for example.

[0044] As can be understood from the above explanation, the dielectric portion 16 in the double-glazing glass 10 can be considered to be a component for shifting the frequency of the transmittance peak that occurs in relation to resonance. However, a modified configuration of the double-glazing glass 10 may further include a dielectric portion 20 that serves a purpose different from that of the dielectric portion 16. In this case, the double-glazing glass 10 may have the configuration shown in FIG. 5(b), for example. FIG. 5(b) shows a modified configuration of the double-glazing glass 10. Except as described below, components in FIG. 5(b) that are designated by the same reference numerals as those in FIG. 1(a) may have the same or similar features as those in FIG. 1(a). In this modified configuration, the double-glazing glass 10 further includes a plurality of dielectric portions 20 in addition to the components shown in FIG. 1(a). In this case, the plurality of dielectric portions 20 are an example of outer dielectric portions and are disposed outside the regions of the glass sheets 12 that are sandwiched between the Low-E films 22. More specifically, in this modification, the dielectric portion 20 is a film-like body that is attached to the outside of the glass sheet 12, and is attached to the surface of the glass sheet 12 opposite the Low-E film 22, as shown in the figure, for example. In this case, if the multiple glass sheets 12 in the double glazing 10 are distinguished as first and second glass sheets, one of the multiple dielectric portions 20 can be considered to be located on the surface of the first glass sheet opposite to the surface facing the second glass sheet. Similarly, the other dielectric portion 20 can be considered to be located on the surface of the second glass sheet opposite to the surface facing the first glass sheet.

[0045] In this case, the plurality of dielectric sections 20, for example, located outside the region sandwiched between the low-E films 22, can be considered not to affect the frequency at which the transmittance of the double glazing 10 reaches its peak. In this respect, the dielectric sections 20 can be considered to be used for a purpose different from that of the dielectric section 16. More specifically, in this modification, the dielectric sections 20 are placed in the path of radio waves passing through the double glazing 10, thereby affecting the admittance control diagram (admittance chart) that indicates the transmittance of radio waves. In this case, for example, by using dielectric sections 20 with a dielectric constant and thickness selected according to the radio waves of a frequency at which the transmittance of the double glazing 10 is to be increased, the reflection of radio waves of that frequency can be reduced. More specifically, in this case, it is possible to use dielectric sections 20 configured to reduce the reflection of radio waves in the admittance control diagram for the frequency at which the transmittance of the double glazing 10 is to be increased. Even when such a dielectric portion 20 is used, measuring the relationship between the transmittance of radio waves through the double-glazing unit 10 and the frequency of the radio waves can be considered to reveal a transmittance peak at some frequency, for example, within at least a portion of the frequency range. In this case, for example, a dielectric portion 20 with a predetermined dielectric constant can be used, and multiple dielectric layers with a thickness that reduces the reflectance of radio waves at the frequency of the peak transmittance can be used as the dielectric portion 20. The thickness of such a dielectric portion 20 can be considered to be, for example, a thickness that reduces the reflectance of radio waves in an admittance control diagram showing the transmittance of radio waves at that frequency. In this case, for example, with respect to the configuration of FIG. 5(b), the dielectric constant and thickness of the dielectric portion 20 are determined so that the use of multiple dielectric portions 20 reduces the reflectance of radio waves. In a further variation of the configuration of the double-glazing unit 10, the number of dielectric portions 20 in the double-glazing unit 10 may be other than two (e.g., one). In this case, the dielectric constant and thickness of the dielectric portion 20 are determined so that the use of that number of dielectric portions 20 reduces the reflectance of radio waves.

[0046] Furthermore, it is conceivable that transmittance peaks occur at a plurality of frequencies in the double-glazing glass 10. Therefore, it is also conceivable that the dielectric portion 20 reduces the reflectance of radio waves from the double-glazing glass 10 at at least one of the frequencies corresponding to the transmittance peaks occurring in the double-glazing glass 10. In this case, by reducing the reflectance of radio waves at a specific frequency, it is possible to further increase the transmittance of radio waves at that frequency. Therefore, according to this modification, it is possible to further increase the transmittance of radio waves from the double-glazing glass 10 for at least some frequencies. It is also conceivable that the dielectric portion 20 increases the transmittance of radio waves from the double-glazing glass 10 by achieving admittance matching (impedance matching) for radio waves at a specific frequency.

[0047] In a further modified example of the configuration of the double-glazing unit 10, a dielectric unit 20 having multiple regions 202a-d may be used, as shown in FIG. 5(c), based on the same concept as the dielectric unit 16 shown in FIG. 5(a). FIG. 5(c) shows a modified configuration of the dielectric unit 20. In this case, the multiple regions 202a-d are, for example, regions with different thicknesses or dielectric constants. In this case, the multiple regions 202a-d can be considered to have different frequencies at which they reduce reflectivity. Such a dielectric unit 20 can be used together with the dielectric unit 16 shown in FIG. 5(a). In this case, the multiple regions 202a-d in the dielectric unit 20 can be considered to reduce reflection of radio waves at the frequencies of the transmittance peaks corresponding to the multiple regions 202a-d in the dielectric unit 16. This configuration allows the double-glazing unit 10 to more appropriately increase the transmittance of radio waves in multiple frequency bands, for example.

[0048] Furthermore, increasing the transmittance of radio waves of a specific frequency corresponding to the peak in the double glazing 10 can also be considered to have the effect of blocking radio waves of frequencies other than the transmittance peak. In this case, the double glazing 10 can be configured to transmit radio waves of frequencies used in mobile communication systems, while blocking radio waves for indoor Wi-Fi (wireless LAN). Furthermore, the characteristic of selectively transmitting radio waves of such specific frequencies can be applied to a double glazing 10 with only one layer of Low-E film 22, as shown in Figure 6.

[0049] FIG. 6 is a diagram illustrating a modified example of a configuration that selectively transmits radio waves of a specific frequency. Except as otherwise described below, components in FIG. 6 that are designated by the same reference numerals as those in FIGS. 1 to 5 may have the same or similar features as those in FIGS. 1 to 5. FIG. 6(a) is a diagram illustrating a modified example of a double-glazing unit 10 having only one glass sheet 12 on which a Low-E film 22 is formed. In this configuration, as shown on the left side of the figure, the double-glazing unit 10 is a two-layer multi-layer glass (paired glass) that includes a glass sheet 12 on which a Low-E film 22 is formed and a glass sheet 14 on which no Low-E film 22 is formed. The two glass sheets 12, 14 face each other with a hollow space between them, with the Low-E film 22 of the glass sheet 12 facing the glass sheet 14. This type of double-glazing unit 10 can be considered to have, for example, only one layer of Low-E film 22. Furthermore, the double glazing 10 can also be considered to have the same or similar structure as, for example, a known two-layer double glazing.

[0050] In this modification, as shown on the right side of the figure, a radio wave transmittance adjustment member 30 is attached to the double-glazing unit 10, allowing radio waves of a predetermined frequency to selectively pass through the double-glazing unit 10. More specifically, in this modification, the radio wave transmittance adjustment member 30 includes a metal film 32 and a dielectric portion 34. In this case, the metal film 32 is a member that is spaced apart from the Low-E film 22 on the double-glazing unit 10 when the radio wave transmittance adjustment member 30 is attached to the double-glazing unit 10, and faces the Low-E film 22 with a gap between them. The dielectric portion 34 is a portion made of a dielectric, and is located between the Low-E film 22 and the metal film 32 when the radio wave transmittance adjustment member 30 is attached to the double-glazing unit 10. In this case, the relationship between the Low-E film 22 in the double glazing 10 of this modified example and the metal film 32 in the radio wave transmittance adjustment member 30 can be considered to be similar to that between the multiple Low-E films 22 in the double glazing 10 configured as shown in Fig. 1 . Therefore, in this modified example, when the radio wave transmittance adjustment member 30 is attached to the double glazing 10, the radio wave transmittance adjustment member 30 resonates with radio waves of a corresponding frequency, which is a frequency corresponding to the distance between the Low-E film 22 and the metal film 32. This allows the radio wave transmittance adjustment member 30 to selectively transmit radio waves of a corresponding frequency through the double glazing 10.

[0051] More specifically, in this modification, the metal film 32 is preferably a film having radio wave characteristics similar to those of the Low-E film 22 in the double-glazing glass 10. The metal film 32 can be considered, for example, to be a film that resonates with the Low-E film 22 at a predetermined frequency. In this case, the radio wave transmittance adjusting member 30 can be considered, for example, to be a member that selectively transmits radio waves of a predetermined frequency through the double-glazing glass 10 by attaching it to the double-glazing glass 10 including the glass sheet 12 on which the Low-E film 22 is formed. In this modification, the dielectric portion 34 can be considered, for example, to be the same or similar member as the dielectric portion 16 in the configuration described with reference to Figures 1 to 5. In this case, the corresponding frequency can be appropriately changed by, for example, changing the thickness or dielectric constant of the dielectric portion 34. Therefore, this modification allows radio waves of a desired frequency to be appropriately transmitted through the double-glazing glass 10. In this case, the radio wave transmittance through the double-glazing glass 10 can be considered to maintain the transmittance of radio waves of the corresponding frequency while blocking other frequencies. Therefore, in this modified example, the double-glazing unit 10 can maintain the transmittance of radio waves of a predetermined frequency while appropriately blocking radio waves of other frequencies. In this case, the radio wave transmittance adjusting member 30 can be used to achieve a configuration that transmits radio waves of frequencies used in mobile communication systems while blocking radio waves for indoor Wi-Fi (wireless LAN). As described above, in this modified example, the dielectric portion 34 can be considered to correspond to the dielectric portion 16 in the configuration described with reference to Figures 1 to 5. Therefore, the dielectric portion 34 can also be configured to have multiple regions, similar to the configuration shown in Figure 5(a). With this configuration, for example, radio waves of multiple frequency bands can be selectively transmitted through the double-glazing unit 10.

[0052] The above-described resonance may be generated solely by the radio wave transmittance adjustment member 30, for example, by using a radio wave transmittance adjustment member 30 configured as shown in FIG. 6(b). FIG. 6(b) shows a modified configuration of the radio wave transmittance adjustment member 30. In this case, the radio wave transmittance adjustment member 30 includes multiple metal films 32 and a dielectric portion 34. The multiple metal films 32 are formed on both sides of the dielectric portion 34, for example, so that they face each other across the dielectric portion 34. With this configuration, it is possible to generate a resonance that increases the transmittance of specific frequencies with respect to the radio wave transmittance through the radio wave transmittance adjustment member 30, depending on, for example, the distance between the multiple metal films 32 and the dielectric constant and thickness of the dielectric portion 34. Therefore, by using such a radio wave transmittance adjustment member 30, it is possible to selectively transmit radio waves of specific frequencies through double-glazed glass, for example. In this case, the double-glazed glass to which the radio wave transmittance adjustment member 30 is attached may be, for example, a double-glazed glass having no Low-E film 22. It is also conceivable that the radio wave transmittance adjustment member 30 be attached to, for example, a single-layer glass on which the Low-E film 22 is not formed. Furthermore, it is also conceivable that the radio wave transmittance adjustment member 30 having such a configuration be attached to, for example, a construction material other than glass. In this case, for example, by attaching the radio wave transmittance adjustment member 30 to a construction material such as a wall material, it is conceivable to selectively transmit radio waves of a specific frequency through the construction material. In this case, too, it is conceivable that the radio wave transmittance adjustment member 30 can be configured to transmit, for example, radio waves of a frequency used in a mobile communication system while blocking radio waves for Wi-Fi (wireless LAN) used indoors.

[0053] Furthermore, when considering the transmittance of radio waves through double-glazed glass, it can be assumed that a double-glazed glass (e.g., double-pane glass) with only one layer of Low-E film 22 typically has a higher transmittance than a double-glazed glass (e.g., triple-pane glass) with two layers of Low-E film 22. In this case, appropriate transmittance for radio waves at frequencies used in mobile communication systems may be obtained without generating the resonance described above. In this case, for example, as shown in FIG. 7(a), a double-glazed glass 10 may be used that does not have a dielectric portion 16 for generating resonance, and a dielectric portion 20 with a dielectric constant and thickness selected to reduce radio wave reflection may be attached to one of the outer surfaces of the double-glazed glass 10. FIG. 7 further explains matters related to the transmittance of radio waves through double-glazed glass and the like. FIG. 7(a) shows a modified example of the use of the dielectric portion 20 in the double-glazed glass 10. Except as described below, components in FIG. 7 that are designated by the same reference numerals as those in FIGS. 1 to 6 may have the same or similar features as those in FIGS. 1 to 6.

[0054] In this case, for example, a radio wave transmittance adjusting member including a dielectric portion 20 may be used and attached to the double-glazed glass 10. Such a radio wave transmittance adjusting member can be considered, for example, to adjust the transmittance of radio waves by reducing the reflectance of specific radio waves. Furthermore, when using the dielectric portion 20 as shown in FIG. 7(a), the dielectric portion 20 can be considered, for example, as the dielectric portion 20 in the configuration shown in FIG. 5(b), to reduce the reflection of radio waves of specific frequencies by affecting the admittance control diagram. This configuration can also appropriately increase the transmittance of radio waves of specific frequencies through the double-glazed glass 10. Furthermore, the dielectric portion 20 may also be configured to have multiple regions with different thicknesses or dielectric constants, as shown in FIG. 5(c). This configuration can appropriately increase the transmittance of radio waves across multiple frequency bands through the double-glazed glass 10.

[0055] As explained above, selectively transmitting radio waves of a specific frequency using resonance can be realized not only in glass but also in various construction materials used in construction. In this case, instead of attaching a radio wave transmittance adjustment member 30 (see FIG. 6 ) afterward, a construction material 40 having the configuration shown in FIG. 7(b) may be used, for example, to generate resonance through the configuration of the construction material 40 itself. FIG. 7(b) illustrates the configuration of a construction material 40 that selectively transmits radio waves of a specific frequency. The left side of FIG. 7(b) shows an example of the configuration of the construction material 40. In this case, the construction material 40 has a substrate portion 42, multiple metal films 44, and a dielectric portion 46. The substrate portion 42 is the main portion of the construction material 40, which serves as the base material for the shape of the construction material 40. The multiple metal films 44 have the same or similar characteristics as the metal film 32 (see FIG. 6 ) in the radio wave transmittance adjustment member 30 shown in FIG. 6 , and face each other with the substrate portion 42 and the metal film 44 sandwiched between them. In this case, the plurality of metal films 44 can be considered to be overlapped with gaps between them, similar to the plurality of Low-E films in triple-layered double glazing. The dielectric portion 46 has the same or similar characteristics as the dielectric portion 34 (see FIG. 6) in the radio wave transmittance adjustment member 30 shown in FIG. 6. The dielectric portion 46 can be considered to be, for example, a portion made of a dielectric material, and located in the region between the plurality of metal films 44.

[0056] Even with this configuration, for example, by adjusting the thickness or dielectric constant of the dielectric portion 46, resonance can be generated at a specific frequency, thereby increasing the transmittance of radio waves of that frequency through the construction member 40. In this case, it can be considered that the construction member 40 selectively transmits radio waves of the corresponding frequency by resonating with the radio waves of the corresponding frequency, which is, for example, a frequency corresponding to the distance between the multiple metal films 44. It can also be considered that the construction member 40 has a blocking effect against radio waves other than the corresponding frequency. Therefore, with this configuration, the construction member 40 can, for example, maintain the transmittance of radio waves of a predetermined frequency while appropriately blocking radio waves of other frequencies. In this case, it is possible to realize a configuration in the construction member 40 that transmits radio waves of frequencies used in mobile communication systems while blocking radio waves for Wi-Fi (wireless LAN) used indoors.

[0057] The construction member 40 may also be configured as shown on the right side of FIG. 7(b). In this case, the position of one metal film 44 may be considered to be, for example, between the substrate 42 and the metal film 44. Furthermore, the multiple metal films 44 may be considered to sandwich the dielectric portion 46 on the outside of the substrate 42. Even with this configuration, the construction member 40 can maintain the transparency of radio waves of a predetermined frequency while appropriately blocking radio waves of other frequencies, as in the above case. Furthermore, even in these cases, the dielectric portion 46 may have multiple regions with different thicknesses or dielectric constants, similar to the dielectric portion 16 shown in FIG. 5(a). [Industrial Applicability]

[0058] The present invention can be suitably used in, for example, double glazing. [Explanation of symbols]

[0059] 10...double glazing, 102...area, 12...plate glass, 14...plate glass, 16...dielectric part, 20...dielectric part, 202...area, 22...Low-E film, 30...radio wave transmittance adjusting material, 32...metal film, 34...dielectric part, 40...construction material, 42...base material, 44...metal film, 46...dielectric part

Claims

1. It is a double-glazed glass in which multiple glass panes overlap with gaps between them, a first glass sheet on which a Low-E film is formed; a second glass sheet on which a Low-E film is formed; a third glass plate between the first glass plate and the second glass plate, the third glass plate being the glass plate on which no Low-E film is formed; A dielectric portion formed of a dielectric material with a dielectric constant different from that of air. Equipped with The double-glazing unit is characterized in that the dielectric portion is located between the Low-E film of the first glass and the Low-E film of the second glass.

2. When the relationship between the transmittance of radio waves and the frequency of radio waves through the double glazing is measured, a peak in transmittance occurs at any frequency within at least a part of the frequency range, 2. The double-glazed glass according to claim 1, wherein the thickness of at least a portion of the dielectric portion is such that the frequency corresponding to the transmittance peak is matched to the frequency used in a mobile communication system.

3. The double-glazed glass according to claim 2, characterized in that the presence of the dielectric portion improves the radio wave transmittance by 25 dB or more for at least some frequencies used in mobile communication systems, compared to when the dielectric portion is not present.

4. When the distance between the Low-E film in the first glass and the Low-E film in the second glass is defined as an inter-film distance, and a frequency that resonates with the inter-film distance is defined as an inter-film distance corresponding frequency, the inter-film distance corresponding frequency is a frequency determined depending on the thickness of the dielectric portion, When the relationship between the radio wave transmittance and the radio wave frequency of the double glazing glass is measured, a peak in the transmittance occurs at a frequency corresponding to the inter-film distance frequency, 2. The double glazing according to claim 1, wherein the thickness of at least a part of the dielectric portion is such that the frequency corresponding to the transmittance peak is matched to a frequency used in a mobile communication system.

5. the dielectric portion has a plurality of regions each having a different thickness or dielectric constant, the plurality of regions having different thicknesses or dielectric constants are regions located at different positions in an in-plane direction in one of the dielectric portions, The double-glazed glass according to claim 1, characterized in that when the relationship between the transmittance of radio waves and the frequency of the radio waves through the double-glazed glass is measured, transmittance peaks occur at multiple frequencies corresponding to the multiple regions in the dielectric portion.

6. A double-glazed glass panel as described in claim 1, characterized in that the dielectric portion is located on at least one surface of the third glass panel.

7. The optical fiber further includes an outer dielectric portion formed of a dielectric material and located outside a region sandwiched between the Low-E film of the first glass and the Low-E film of the second glass, The double glazing according to claim 1 , wherein the outer dielectric portion is located on a surface of the first glass panel opposite to a surface facing the second glass panel.

8. When the relationship between the transmittance of radio waves and the frequency of radio waves through the double glazing is measured, a peak in transmittance occurs at any frequency within at least a part of the frequency range, The double-glazing unit according to claim 7, wherein the outer dielectric portion reduces the reflectance of radio waves from the double-glazing unit at least at any frequency corresponding to the peak of transmittance.

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