JP2006287729A - Transparent antenna for window of building, and translucent member for window of building with antenna - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transparent antenna for a window of a building and glass for the window of the building with antenna without spoilng design of a windowpane, having transparency by which the outside (or the inside) of the window is visually recognized and low resistance is achieved. <P>SOLUTION: In the transparent antenna for the window of the building, it has a sheet-like transparent substrate 1a having insulation and an antenna pattern to be formed like a plane on the surface of the transparent substrate 1a, a conductive part 1b of the antenna pattern consists of conductive thin film of mesh structure, contours of each mesh are constituted of extrafine bands with approximately equal width, band width of the extrafine bands is 30μm or less and light transmission of an antenna pattern formation part is 50% or more. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is used by being attached to a window glass (including a case where a transparent synthetic resin plate is used as a window glass) in various buildings, houses and partitions, for receiving terrestrial waves and satellite broadcasting, or The present invention relates to a transparent antenna for a building window for transmitting and receiving radio waves, and also relates to a translucent member for a building window with such an antenna.

  Recently, various broadcasts including terrestrial digital broadcasts are provided, and indoor transmission / reception such as a wireless LAN is performed, and various antennas have been proposed. In particular, a film-like antenna to be attached to a window surface of a building is preferable because the antenna does not occupy a space, unlike a conventional rod-like antenna.

Such a film-like antenna for a building window has an antenna pattern formed on a transparent film, which can be attached to a window glass by an adhesive film layer on the back surface. 1]: those formed by arranging metal wires so as to correspond to the peripheral part of the window glass, [2]: those using a transparent conductive film such as ITO (indium tin oxide), etc. have been proposed (For example, refer to Patent Document 1). According to these, the antenna pattern is relatively inconspicuous.
JP 2001-196826 A (for example, FIGS. 1 and 4, paragraphs [0013] to [0017], [0019] to [0023])

  However, the building window antenna described in [1] uses a metal foil or forms a metal wire by means of print printing, so it is at most about 0.3 mm although it is thin. Although a metal wire is formed relatively inconspicuously in the peripheral part of the window glass, a metal wire that is inconspicuous and does not impair the design of the window is required.

  In addition, in the building window antenna of [2], the transparent conductive film used as the antenna pattern has a higher surface resistance as a measure of conductivity as the film thickness is reduced and the transparency is increased. In order to obtain the low resistance required for the antenna, it becomes a frosted glass wind. Incidentally, the resistance of the transparent conductive film in which the transparency is ensured is several tens to several hundreds Ω, whereas the resistance value required for the antenna is as small as 3Ω or less.

  Therefore, the present invention has been made in consideration of the problems in the conventional film-like antenna for a building window as described above, and its purpose is to maintain the outside (or inside) of the window without impairing the design of the window glass. An object of the present invention is to provide a transparent antenna for a building window that has visible transparency and can realize low resistance, and a glass for a building window with an antenna.

  A transparent antenna for a building window according to the present invention has an insulating sheet-like transparent substrate and an antenna pattern formed in a planar shape on the surface of the transparent substrate, and the conductive portion of the antenna pattern is a mesh. It is made of a conductive thin film having a structure, and the outline of each mesh is constituted by a very narrow band, the band width of which is 30 μm or less, and the light transmittance of the antenna pattern forming portion is 50% or more. It is characterized by being.

  According to the transparent antenna for a building window of the present invention, the conductive part of the antenna pattern is formed in a mesh structure having a large number of openings, and the outline of each mesh is composed of a very narrow band having a band width of 30 μm or less. The presence of the ultra-thin band is difficult to recognize, and when mounted on a window crow, the antenna pattern is recognized only as a slight change in gradation (gradation) even when viewed from the outside of the window or from the outside. The network structure, which is a collection of extra-fine bands, can realize the low resistance required for the antenna.

  For example, if the extra fine band is about 80 μm, the antenna pattern is conspicuous, so the visibility when looking at the outside (or inside) of the window is inferior. However, as in the present invention, the extra fine band has a width of 30 μm or less. If it is very thin, it will show good visibility.

  The light transmittance is preferably 60% or more, more preferably 70% or more.

  In the present invention, the shape of the mesh opening may be a polygon.

  If the mesh opening is not a polygon made of ultra-thin bands, for example, a large number of circular openings are formed on the sheet surface, a thick band portion can be formed between the openings even if the openings are arranged as closely as possible. Therefore, the thick band portion becomes conspicuous, and the light transmittance is reduced. Therefore, the shape of the mesh opening in the present invention excludes a circular or elliptical shape.

  Furthermore, in the present invention, the transparent antenna preferably has a transparent protective film formed on the surface of the antenna pattern. This is because the transparent protective film can prevent the antenna pattern from being damaged.

  In the present invention, it is preferable that a part of the conductive part is provided with a power feeding electrode, and a transparent protective film corresponding to the electrode is provided with a through-hole part to expose the electrode.

  In addition, in the present invention, it is desirable that the transparent antenna is obtained by applying a low reflection treatment to the surface of the ultrathin band. This is because even if the material of the ultra-thin band emits a metallic luster, the luster is attenuated by the low reflection treatment and becomes inconspicuous.

  In the present invention, it is preferable that the transparent antenna has a transparent adhesive layer formed on the surface of the transparent substrate opposite to the conductive part forming side. Thereby, the operation | work which retrofits the transparent antenna of this invention on the surface of a window glass can be performed easily.

  In the translucent member for a building window with an antenna according to the present invention, the transparent antenna for a building window having the above configuration in which a feeding electrode is provided in a part of the conductive portion, the electrode is protruded. It is characterized by being embedded in the joining surface of two translucent plates in a state. In addition, as said 2 translucent board | plate material, a laminated glass is mentioned, for example, It replaces with this glass and the thing using the transparent synthetic resin board | plate material may be used.

  According to the translucent member for a building window with an antenna of the present invention, for example, in the process of manufacturing laminated glass, a transparent antenna can be embedded in the joining surface of two pieces of glass. There is no step on the glass surface for the thickness of the transparent antenna, and the design can be further improved.

  Moreover, stable antenna performance can be ensured by embedding.

  According to the transparent antenna for building windows and the translucent member for building windows with antennas according to the present invention, the outside of the window can be seen well without losing the design (or can be seen from the outside to the inside of the window). ) It has transparency and can achieve the low resistance required for the antenna.

  Hereinafter, the present invention will be described in detail based on the embodiments shown in the drawings.

  FIG. 1 is a schematic view showing a state in which a building window transparent antenna 1 according to an embodiment of the present invention is attached to a window glass 10 of a house 11.

  In the figure, a building window transparent antenna 1 is disposed on the upper right side of a window glass 10. An antenna cord (not shown) is connected to the transparent antenna 1, an output end of the antenna cord is connected to an amplifier unit, and an antenna output cord output from the amplifier unit is connected to a TV tuner or the like.

  In addition, as a window glass (including the case where the transparent synthetic resin board | plate material is used as a window glass) to which the transparent antenna for building windows which concerns on this invention is applied, it is the window glass toward the outdoors in buildings, such as a building and a house Other examples include indoor window glass that separates rooms from each other and the hallway, or window glass used for partitions (partitions), and the transparent antenna of the present invention can be applied to any of them.

  FIG. 2 is an enlarged view of the transparent antenna 1.

  In FIG. 2, a transparent antenna 1 is formed by forming an antenna pattern by a conductive portion 1b on a transparent plastic sheet 1a as a transparent substrate having electrical insulation, and a gap between antenna patterns formed in a horizontally long rectangular shape. A pair of electrode portions 1d are opposed to each other with the portion 1c interposed therebetween.

  As the transparent plastic sheet 1a, a transparent resin film or plate material such as polycarbonate, acrylic, polyethylene terephthalate, and triacetyl cellulose can be used. In addition, a sheet-like transparent glass can also be used as the transparent substrate.

  The conductive portion 1b is composed of a conductive thin film having a network structure, and is a metal thin film such as copper, nickel, aluminum, gold, silver, or the like, or a conductive resin paste film containing these metal fine particles, or a conductive resin paste film containing carbon fine particles. Can be used. A fine mesh pattern is formed by photo-etching of the conductive thin film formed on the transparent plastic sheet 1a or by an etching method using a printing resist, or by a method of printing a conductive resin paste.

  The electrode part 1d is for attaching a power supply part (not shown) of the antenna cord, and the electrode part 1d is formed of a square sheet electrically connected to the mesh pattern. .

  When the antenna pattern is formed by photoetching, a photoresist film is formed on the metal thin film or the conductive resin paste film (hereinafter sometimes referred to as a metal thin film for convenience of explanation), and a photomask is used. The resist pattern antenna pattern is formed by exposing to light and developing with a developer. This is etched with an etching solution, and the resist film is peeled and removed to form an antenna pattern made of an ultrafine metal wire (including an ultrafine conductive resin wire formed from a conductive resin paste film, hereinafter the same).

  When the printed resist is formed by etching, the antenna pattern of the resist film is printed on the metal thin film by a method such as screen printing, gravure printing, or ink jet, and the metal thin film is etched except for the resist coating portion. Thereafter, the resist film is peeled off to form a metal thin film antenna pattern.

  When the conductive resin paste is formed by printing, an antenna pattern is printed on the transparent substrate with a conductive resin paste containing metal fine particles, a carbon resin paste, or the like to form a conductive antenna pattern. As the printing method at this time, screen printing, gravure printing, ink jet, and the like can be cited as described above.

  Note that if the surface of the ultrathin strip formed in the mesh pattern is subjected to low reflection treatment, the reflection color of metal or the like is suppressed, and the presence of the transparent antenna 1 becomes inconspicuous. Thereby, the visibility when looking outside the window through the mesh pattern is increased.

  Specific examples of the low reflection treatment include surface treatment such as chemical conversion treatment and plating treatment. The chemical conversion treatment is to form a low reflection layer on the metal surface by oxidation treatment and sulfuration treatment.For example, if copper is used as the material of the ultrafine metal wire and an oxide film is formed on the surface by oxidation treatment, Without reducing the cross-sectional dimension of the ultrafine metal wire, the surface of the ultrafine metal wire can be processed into black having antireflection properties.

  In addition, if, for example, black chrome plating is applied to the ultrafine metal wire as a plating treatment, the surface of the ultrafine metal wire can be treated in black with antireflection properties. Moreover, if high current density copper plating is applied, it can be processed brown.

  FIG. 3 shows a cross section taken along the line AA in FIG.

  In FIG. 3, when sticking the transparent antenna 1 to the window glass 10, the lower surface of the transparent antenna 1 shown to a figure is attached with respect to a window glass.

  A conductive portion 1b is formed on a transparent plastic sheet (transparent substrate) 1a, and this conductive portion 1b is further covered with a transparent cover layer (transparent protective film) 1e. By protecting the conductive portion 1b with the transparent cover layer 1e in this manner, stable antenna performance can be maintained even if the indoor environment where the transparent antenna 1 is attached, such as temperature and humidity, changes. ing. Further, the cover layer 1e hardly damages the antenna pattern.

  As a method for forming the transparent cover layer 1e, for example, the transparent cover layer 1e can be formed by laminating a transparent film on the antenna pattern made of the conductive portion 1b using a transparent adhesive or pressure-sensitive adhesive. It can also be formed by applying a transparent resin to a predetermined thickness.

  A through hole portion 1f is provided in a part of the transparent cover layer 1e, and the electrode portion 1d is exposed through the through hole portion 1f. The power supply portion of the antenna cord is attached to the exposed electrode portion 1d.

  A transparent adhesive layer 1g is provided on the surface of the transparent plastic sheet 1a opposite to the conductive portion 1b, and a release sheet 1h is attached to the surface of the transparent adhesive layer 1g.

  The transparent adhesive layer 1g does not impair the transparency of the antenna, for example, an acrylic adhesive used as a paste material for a smoke-like film attached to a window glass for the purpose of reducing ultraviolet rays. Can be used.

  When the transparent antenna 1 is attached to the window glass as a retrofit, the release sheet 1h is peeled off to expose the transparent adhesive layer 1g, and the transparent antenna 1 is attached to the window glass through the transparent adhesive layer 1g.

  On the other hand, as a mode in which the transparent antenna 1 is embedded in the window glass, for example, when the window glass employs laminated glass or double glass, the transparent antenna 1 may be sandwiched between two glasses in the manufacturing process. . In addition, you may use transparent synthetic resin board | plate materials, such as a transparent acrylic board and a transparent polycarbonate board, as said laminated glass or glass for double glass. When embedded in this way, the transparent antenna 1 is integrated with two pieces of glass (transparent synthetic resin plate material), so the transparent adhesive layer 1g is not necessarily provided. The transparent cover layer 1e is formed as necessary.

  When a transparent synthetic resin plate material is used as the window glass as described above, the transparent antenna 1 is inserted between the pasty transparent synthetic resin plate materials in the manufacturing process of the transparent synthetic resin plate material, A method of curing may be employed, and the transparent antenna 1 is firmly fixed to the transparent synthetic resin plate material.

  4 to 6 are enlarged views of a part of the antenna pattern.

  In the antenna pattern shown in FIG. 4, linear conductive portions 1b extending in the X direction and the Y direction are formed in a lattice-like mesh, and the light transmittance in the transparent antenna 1 can be secured by 50% or more. .

  The light transmittance, which is a measure of transparency, means the total light transmittance for the total amount of light that has passed through the sample surface with light of any wavelength emitted from a light source having a specific color temperature. On the other hand, if the light transmittance is less than 50%, the difference between the light transmittance of the window glass and the light transmittance of the transparent antenna 1 becomes large, and the antenna pattern of the transparent antenna 1 looks dark. Therefore, its presence becomes an obstacle. On the other hand, if the transmittance is increased excessively, good antenna characteristics (surface resistance value, etc.) cannot be obtained.

  The light transmittance is measured using a spectrophotometer (model number NDH2000) manufactured by Nippon Denshoku Industries Co., Ltd. However, the light transmittance in the air layer is 100%.

  The light transmittance is measured when the transparent cover layer 1e is formed on the transparent antenna 1, and when the transparent cover layer 1e is provided, the light transmittance is measured when the transparent adhesive layer 1g is provided. It is measured in a state including 1 g of the transparent adhesive layer.

  Further, the line width w of the X-direction ultrafine metal wire (extrafine strip) 1i and the Y-direction ultrafine metal wire (extrafine strip) 1j that form a square outline is formed to be equal to 30 μm or less, respectively. If the line width w exceeds 30 μm, the mesh of the antenna pattern becomes conspicuous and the design is also deteriorated. If the line width w is 30 μm or less, it is difficult to recognize the presence of the antenna pattern. It should be noted that when the aspect ratio of the line width / film thickness t is 0.5 or more, the thickness of the ultrafine metal wire can be easily formed with a high precision antenna pattern.

  In the present embodiment, the light transmittance of the transparent antenna 1 is selected from a combination of the line width of the ultrafine metal wires 1i and 1j and the size of the opening B formed by being surrounded by the ultrafine metal wires 1i and 1j. By doing so, a light transmittance of 50% or more can be secured.

  The antenna pattern shown in FIG. 5 has a mesh shape by using a hexagon as a nucleus and continuing in the X direction, the Ya direction, and the Yb direction.

  The line width w of the ultrafine metal wire 1k having a hexagonal outline is 30 μm or less.

  The antenna pattern shown in FIG. 6 has a mesh shape by using a ladder shape as a nucleus and continuing in the X and Y directions. The line widths w of the ultrafine metal lines 1l and 1m that form the ladder-shaped outline are each 30 μm or less.

  As described above, the antenna pattern is continuous with a rectangle as a nucleus, continuous with a polygon as a nucleus, or continuous with a ladder shape as a nucleus.

  Among these, those having a square as a core are particularly preferable because the antenna pattern is less likely to be recognized as a streak compared to other polygonal shapes.

  In other words, when a regularly continuous pattern with a certain shape as a nucleus is viewed, it tends to look like a streak whose contour is continuous along the direction in which the nucleus (opening) continues. For example, in the case of a hexagonal core, the line of the ultrathin band along the continuous direction becomes zigzag, so it appears thicker by the amplitude of this zigzag, and as a result, the ultrathin band expands It looks like. In this respect, in the case where the square is continuous as a nucleus, the line of the ultrathin strip along the continuous direction is straight, so there is no concern that it will appear thicker than the original width, and the ultrathin strip is 30 μm as described above. Because it is very thin as below, its existence is difficult to recognize and the antenna pattern is not conspicuous.

  Also, in the case where the rectangle is continuous as a nucleus, the long side direction and the short side direction of this rectangle have different pitches, so when looking at the whole, the short side direction with a shorter pitch is darker than the long side direction. It appears and flickers and tends to appear flickering. However, when the square is continuous as a nucleus, such streaks do not appear and are not noticeable.

  The square is not limited to a completely square, but includes a chamfered square.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited by the following examples, but may be appropriately modified within a range that can meet the purpose described above and below. Of course, it is possible to implement them, and they are all included in the technical scope of the present invention.

  A metal thin film is formed by forming a transparent resin layer containing a plating catalyst on a transparent polyethylene terephthalate film (transparent substrate 1a) having a thickness of 75 μm, performing an electroless copper-nickel plating process, and subsequently performing an electrolytic copper plating process. Formed. Next, a chemical conversion treatment (low reflection treatment) was performed on this, and the surface of the metal thin film was made low reflection. Next, a mesh opening was formed in the metal thin film by a photo-etching method (a conductive thin film having a mesh structure) to form an antenna pattern. The conductive portion 1b of the antenna pattern is a square mesh pattern as shown in FIG. 4, and the extra fine band 1i has a line width (w) of 25 μm and a line-to-line pitch of 300 μm.

  Next, a transparent polyethylene terephthalate cover film (cover layer (transparent protective film) 1e) having a thickness of 50 μm was adhered onto the conductive portion 1b of the antenna pattern using an acrylic transparent adhesive. However, the electrode portion 1d is exposed from an opening (through hole portion 1f) formed by cutting a part of the cover film.

  A transparent acrylic double-sided adhesive film (transparent adhesive layer) with a release sheet 1h for attaching the transparent antenna 1 to a window glass on the surface (back surface) opposite to the conductive portion 1b of the transparent polyethylene terephthalate film (transparent substrate 1a) 1 g) was applied.

  In this way, a laminate is obtained in which an antenna pattern is formed on a transparent polyethylene terephthalate film, further covered with a cover film, and a transparent acrylic double-sided adhesive film with a release sheet is attached to the back surface of the transparent polyethylene terephthalate film. The laminated body was cut along the antenna pattern to produce the transparent antenna 1.

  The light transmittance of the transparent antenna 1 produced as described above was 60%.

  When the peeling sheet 1h of the transparent antenna 1 is peeled off and attached to the window glass of the building, the transparent antenna 1 almost recognizes the presence of the antenna pattern both when viewed from the inside and from the outside. I couldn't get out of my sight.

  Next, when an antenna cord was connected to the transparent antenna 1 and the antenna cord was connected to a TV tuner to receive a television broadcast, a good reception state was obtained.

  On a transparent acrylic film (transparent substrate 1a) having a thickness of 75 μm, a copper foil having a thickness of 12 μm, which has been subjected to low reflection by chemical conversion treatment, is adhered with a transparent adhesive, and then an antenna pattern of a resist film is printed. After etching other than the resist coating portion in the copper foil, the resist film was peeled off to form an antenna pattern. The conductive portion 1b of the antenna pattern has a mesh opening shape of an equilateral triangle, and the line width of the extra fine band is 20 μm.

  Next, the outside was cut along the produced antenna pattern, and the transparent antenna 1 was produced. The light transmittance of this transparent antenna (laminated body of transparent substrate 1a and antenna pattern) 1 was 60%.

  The transparent antenna 1 was mounted so as to be sandwiched between the respective glasses in a pair glass (double glass) to obtain a window glass with an antenna (a translucent member for a building window with an antenna). However, at this time, the electrode part 1d was made to protrude from the glass periphery.

  This window glass with an antenna was attached to a window of a house, an antenna cord was connected to the electrode portion 1d of the transparent antenna 1, and this antenna cord was connected to a TV tuner.

  Regarding the window glass with an antenna, the presence of the antenna pattern could hardly be recognized even when viewed from the inside or the outside of the house, and the field of view was hardly disturbed. Moreover, when a television broadcast was received, a good reception state was obtained.

  On a transparent polycarbonate film with a thickness of 100 μm (transparent substrate 1a), a copper foil with a thickness of 25 μm whose both surfaces have been made low-reflective by chemical conversion treatment is adhered with a transparent adhesive, and then an antenna pattern of a resist film is printed. After etching other than the resist coating portion in the copper foil, the resist film was peeled off to form an antenna pattern. The conductive portion 1b of the antenna pattern has a ladder shape in which the mesh opening has a rectangular shape (long side: 700 μm, short side: 400 μm), and the line widths of the ultrathin bands 1 m and 1 l are 25 μm.

  Next, the outside was cut along the produced antenna pattern, and the transparent antenna 1 was produced. The light transmittance of this transparent antenna (laminated body of transparent substrate 1a and antenna pattern) 1 was 75%.

  A polycarbonate plate was bonded onto the antenna pattern forming surface of the transparent antenna 1 using an acrylic acid-based transparent adhesive to obtain a window glass with an antenna (a translucent member for a building window with an antenna). However, in this bonding, the electrode portion 1d was in a state of protruding from the peripheral edge of the glass.

  This antenna-attached window glass was attached to a sunroom window, an antenna cord was connected to the electrode portion 1d of the transparent antenna 1, and this antenna cord was connected to a TV tuner.

  Regarding the window glass with an antenna, the presence of the antenna pattern could hardly be recognized even when viewed from the inside or outside of the solarium, and the field of view was hardly disturbed. Moreover, when a television broadcast was received, a good reception state was obtained.

It is the schematic which showed the state which affixed the transparent antenna for building windows which concerns on one Embodiment of this invention to the window glass of a house. It is an enlarged view of the transparent antenna for building windows shown in FIG. It is AA arrow sectional drawing shown in FIG. It is a principal part enlarged view which shows the basic pattern of the ultrafine metal wire which comprises the electroconductive part of FIG. FIG. 5 is a view corresponding to FIG. 4 showing a modified example of the antenna pattern. FIG. 5 is a view corresponding to FIG. 4 showing another modification of the antenna pattern.

Explanation of symbols

1 Transparent antenna 1a Transparent plastic sheet (transparent substrate)
1b Conductive part 1c Gap part 1d Electrode part 1e Cover layer 1f Perforated part 1g Transparent adhesive layer 1h Release sheet 1i, 1j, 1k, 1l, 1m Extra fine metal wire (extra fine band)

Claims (7)

A sheet-like transparent substrate having insulating properties, and an antenna pattern formed in a planar shape on the surface of the transparent substrate;
The conductive portion of the antenna pattern is formed of a conductive thin film having a mesh structure, and the outline of each mesh is configured by an ultra-thin band having a substantially equal width, and the band width of the ultra-thin band is 30 μm or less. A transparent antenna for a building window having a light transmittance of 50% or more.   The transparent antenna for building windows according to claim 1, wherein the mesh opening has a polygonal shape.   The said transparent antenna is a transparent antenna for building windows of Claim 1 or 2 by which the transparent protective film is formed in the surface of the said antenna pattern.   The building according to claim 3, wherein a power feeding electrode is provided in a part of the conductive part, and a through hole is provided in the transparent protective film corresponding to the electrode to expose the electrode. Transparent antenna for windows.   The said transparent antenna is a transparent antenna for building windows of any one of Claims 1-4 by which the low reflection process was given to the surface of the said ultrafine strip.   The transparent antenna for a building window according to any one of claims 1 to 5, wherein the transparent antenna has a transparent adhesive layer formed on a surface of the transparent base opposite to the conductive part forming side. . 6. A transparent antenna for a building window according to any one of claims 1 to 5, wherein a part of the conductive part is provided with a power feeding electrode. A translucent member for a building window with an antenna, which is embedded in the joint surface of the antenna.

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