JP5682464B2 - Transparent antenna and image display device - Google Patents

Description

  The present invention relates to a transparent antenna having transparency and an image display device in which the transparent antenna is arranged on a screen. In particular, the present invention relates to a transparent antenna capable of achieving both transparency and conductivity of an antenna pattern, and preventing both occurrence of shading unevenness and moiré due to interference between pixel arrangements of a display panel, and an image display apparatus using the same.

  Currently, automobiles are used as transparent antennas for receiving various radio waves such as TV radio waves and FM radio waves, or for receiving radio waves of position coordinate information such as GPS (global positioning system) satellites with the spread of car navigation systems. A film antenna to be attached to a windshield is known. A film antenna is an antenna in which an antenna pattern is usually formed on a transparent polyester film or the like with a metal foil or a conductive paste so as not to obstruct the field of view. However, conductors such as a metal foil and a conductive paste constituting the antenna pattern are opaque per se and do not significantly disturb the field of view, but the antenna pattern itself can be seen. On the other hand, a transparent antenna using an ITO (indium tin oxide) film whose conductor is transparent as an antenna pattern has also been proposed (Patent Documents 1 and 2).

  However, a transparent antenna with an opaque conductor pattern such as metal or conductive paste has good conductivity, but the antenna pattern can be seen. For this reason, application to a use in the vicinity, for example, a use on a display panel screen such as a display window of a mobile phone, has become an obstacle to visually confirming the display and cannot be applied. In this respect, if an ITO film is used for the antenna pattern, the conductor itself is transparent, so that display is not hindered. However, the ITO film is inferior in conductivity, and the performance as an antenna cannot be sufficiently obtained. Further, the transparency of the ITO film decreases when the conductivity is increased. Therefore, the ITO film as a conductor of a transparent antenna that can be applied to such a use cannot satisfy both sufficient conductivity and sufficient transparency.

  Therefore, the present applicant has proposed a transparent antenna in which both transparency and conductivity of the antenna pattern are compatible (Patent Document 3). In this transparent antenna, the antenna pattern of a transparent antenna formed on a transparent substrate is a mesh-like conductor mesh having a conductor portion as an opaque conductor layer forming portion and a large number of openings as non-forming portions. It is formed by layers.

JP-A 63-198401 Japanese Patent Laid-Open No. 02/082701 Japanese Patent Application Laid-Open No. 2011-066610

However, in applications where the transparent antenna is placed on the screen of a display panel, such as when applied to a display window of a mobile phone, the repetition period of the pixels constituting the display panel and the mesh of the conductor mesh layer constituting the transparent antenna Moire may occur due to interference with the repetition cycle of the pattern.
Therefore, the present inventors aim to make the mesh pattern of the conductor mesh layer completely random in order to prevent moiré from occurring, and have been proposed in the field related to image display devices. Various random patterns were sought.

For example, as a mesh pattern of a conductor mesh layer for electromagnetic wave shielding, a pamphlet of International Publication No. 2007/114076 proposes a mesh pattern formed by chemical treatment combining organic solvent treatment and acid treatment. This mesh pattern is completely randomized. However, although the moire is eliminated in this mesh pattern, the pattern itself has a density, and there is a shading appearance unevenness due to the density, and when applied to a display panel, a shading unevenness of brightness occurs. Moreover, a part of line | wire has disconnected, and there exists a part which does not contribute to electroconductivity only by reducing transparency.
On the other hand, in Japanese Patent Application Laid-Open No. 11-121974, in order to prevent moiré, this is also a mesh pattern of a conductor mesh layer for electromagnetic wave shielding. Some have proposed randomized mesh patterns. However, with this partially randomized mesh pattern, shading unevenness is reduced and electrical conductivity can be secured, but moire remains.
As described above, in the known pattern proposed in the field related to the image display device, it is impossible to achieve both the elimination of moire and the elimination of uneven density.

  Accordingly, an object of the present invention is to provide a transparent antenna that achieves both sufficient conductivity and sufficient transparency by the mesh pattern, and also eliminates moire and density unevenness against moire and density unevenness caused by the mesh pattern. Is to provide. Another object of the present invention is to provide an image display device in which this transparent antenna is arranged on a screen.

Therefore, in the present invention, a transparent antenna and an image display device having the following configuration are provided.
(1) An antenna pattern is formed on at least one surface of the transparent substrate,
The antenna pattern is formed by a conductor mesh layer in which an opaque conductor layer is formed as a mesh pattern,
The mesh pattern is composed of a large number of boundary line segments extending between two branch points to define a large number of open areas, and the average value N of the number of boundary line segments extending from one branch point is 3.0 <N. <4.0 , and a transparent antenna including an area formed by a pattern in which the opening area does not have a direction having a repetition period.
(2) An image display device in which the transparent antenna of (1) above is disposed on a screen of a display panel.

(1) According to the transparent antenna of the present invention, a conductor mesh layer formed in a mesh pattern using a metal layer or a conductive composition layer, which is opaque in itself but excellent in conductivity, etc. Therefore, it is possible to achieve both sufficient conductivity and sufficient transparency. In addition, since there are no periodicities in any direction in the large number of opening regions defined by the mesh pattern of the conductor mesh layer, and there is no mesh pattern density, the pixels when applied to a display panel Both moire and dark and light unevenness do not occur, and both moire and dark and light unevenness are eliminated. Therefore, sufficient conductivity and sufficient transparency are compatible, and furthermore, moire cancellation and density unevenness cancellation are compatible.
(2) According to the image display device of the present invention, since the transparent antenna provided on the screen of the display panel has the above effect, sufficient conductivity as the antenna and sufficient transparency compatible with this can be obtained. Moreover, since both moire elimination and density unevenness elimination are compatible, a high-quality image can be displayed.

The perspective view which shows one Example of the transparent antenna by this invention. The top view which illustrates another shape of the antenna pattern of the transparent antenna by this invention. The top view which shows an example of the mesh pattern of the conductor mesh layer which comprises an antenna pattern. The top view explaining that a repeating period does not exist in a mesh pattern. The figure which shows the method of determining a generating point in the method of designing a mesh pattern. The figure which shows the method of determining a generating point in the method of designing a mesh pattern. The figure which shows the method of determining a generating point in the method of designing a mesh pattern. The figure explaining the degree of dispersion | distribution of the determined mother point group by an absolute coordinate system and a relative coordinate system. The figure which shows the method of creating a Voronoi diagram from the determined generating point and determining a mesh pattern. The top view which shows an example by which the mesh pattern was repeated as a unit pattern area | region of the magnitude | size of 1/3 or more of the dimension of the pattern area | region of an antenna pattern. The top view which shows the mesh pattern of the conductor mesh layer of the transparent antenna of this invention. The top view which shows the pixel arrangement | sequence of a display panel. The top view which shows the state which accumulated FIG. 11A and FIG. 11B. The top view which shows the conductor mesh layer (A) which has a regular pattern, the pixel arrangement | sequence (B) of a display panel, and the state (C) which accumulated these. Sectional drawing which shows the various examples of the main cut surface shape of the line part of a conductor mesh layer. Sectional drawing which illustrates another example (with a functional layer) of the transparent antenna by this invention. 1 is a cross-sectional view illustrating one embodiment of an image display device according to the present invention. Sectional drawing which illustrates one form of the conventional transparent antenna.

  Hereinafter, embodiments of the present invention will be described for each layer with reference to the drawings.

[A] Definition of terms:
Hereinafter, definitions of main terms used in the present invention will be described here.

Although there is no distinction between the “one surface 1p” and the “other surface 1q”, the surface where the antenna pattern 2 always exists is treated as “one surface 1p”.
The “sheet surface” means a surface that coincides with the planar direction of the transparent antenna 10 when the transparent antenna 10 in a sheet form is viewed as a whole and globally. In this case, the “sheet surface” is also a surface parallel to “one surface 1p” and “other surface 1q” of the transparent substrate 1.
The “main cut surface shape” is a surface on which a target portion is formed with respect to the cross-sectional shape of the conductor mesh layer 3 (the conductor mesh layer 3 corresponding to the line portion Lt in the mesh pattern 3P). It means a shape at a “main cut surface” defined as a cross section perpendicular to the extending direction of a portion of the cross section parallel to the normal line n, which is focused on the cross section of the conductor mesh layer 3.
The “planar shape” means a shape on a surface on which an object of interest (antenna pattern 2 or conductor mesh layer 3) is formed. The “planar shape” refers to a target object (antenna pattern 2 or conductor mesh layer 3) of a shape of the sheet-like transparent antenna 10 viewed from the direction of the normal line n standing on the sheet surface. It is also a shape.

  The terms “sheet”, “film” and “plate” are not distinguished from each other based solely on the difference in designation. Therefore, for example, a “sheet” is a concept including a member that can also be called a film or a plate.

[B] Transparent antenna:
The transparent antenna of the present invention will be described with reference to an embodiment shown in the perspective view of FIG. FIG. 1A is an overall view of the transparent antenna 10, and FIG. 1B is a partially enlarged view of the transparent antenna 10 where the antenna pattern 2 is formed.

1A and 1B, the transparent antenna 10 of the present invention exemplified by the present invention has an antenna pattern 2 formed on one surface 1p of a transparent substrate 1, and this antenna pattern 2 is opaque. The conductive mesh layer 3 is formed by forming the conductive mesh layer 3 with the mesh pattern 3P unique to the present invention into the shape of the antenna pattern 2. The mesh pattern 3P is composed of a large number of boundary line segments L that define a large number of opening areas A, and the boundary line segment L has an average value N of the number of boundary line segments L extending from one branch point B of 3. 0 <N <4.0 , and the opening region A is a random pattern having a region where there is no direction having a repetition period.
By adopting such a configuration for the transparent antenna 10, it is possible to achieve both sufficient conductivity and sufficient transparency, and to achieve both moire elimination and density unevenness elimination.

  In the embodiment shown in FIG. 1, the antenna pattern 2 is formed only on one surface 1p of the transparent substrate, but the antenna pattern 2 is also formed on the other surface 1q of the transparent substrate 1. May be. In this case, the antenna pattern 2 may be the same or different between the pattern formed on the one surface 1p and the pattern formed on the other surface 1q.

  Hereinafter, the transparent antenna 10 according to the present invention will be described in detail for each component.

<Transparent substrate>
As illustrated in FIG. 1, the transparent substrate 1 is a layer that supports the conductor mesh layer 3 to be the antenna pattern 2 and has a function of preventing the deformation and the like.
A known transparent material may be used for the transparent substrate 1, and a resin film (or sheet) is representative in view of transparency in the visible light region, heat resistance, mechanical strength, and the like. Examples of the resin of the resin film (or sheet) include polyester resins such as polyethylene terephthalate, acrylic resins such as pomethyl methacrylate, polyolefin resins such as cycloolefin polymers, cellulose resins such as triacetyl cellulose, and polycarbonate resins. And polyimide resins. Among these, a biaxially stretched polyethylene terephthalate film is a suitable material in terms of mechanical strength, transparency, cost, and the like. The thickness of the sheet-like transparent substrate is usually 20 to 500 μm, preferably 25 to 200 μm, from the viewpoint of handleability and cost, but is not particularly limited.
The transparent substrate 1 is preferably a resin film from which a flexible (flexible) material can be selected in terms of easy attachment of the transparent antenna to the adherend. Also, rigid plates and molded products made of ceramics, resins, etc. can be used. In the case of a plate material, the thickness is usually 0.5 to 10 mm, but is not particularly limited.

The one surface 1p and the other surface 1q of the transparent substrate 1 usually correspond to the sheet surface and are parallel to each other because the transparent substrate 1 has a sheet shape.
The transparent substrate 1 is normally “sheet-like”, but this “sheet” is a concept including a film and a plate, and is not distinguished by thickness or rigidity.

《Antenna pattern》
The antenna pattern 2 is formed by forming an electrically conductive layer that is opaque as a conductive mesh layer 3 formed on the surface of the transparent base material 1 with a mesh pattern 3P. It is a pattern having an antenna function that looks transparent.
The antenna pattern 2 is formed on at least one surface 1p of the transparent substrate 1 and may be formed on another surface. For example, the sheet-like transparent substrate 1 may be formed on both surfaces of the sheet surface. Moreover, it is good also as a structure which pinches | interposes the antenna pattern 2 with the transparent base material 1 from the both surfaces.
The pattern shape itself of the antenna pattern 2 (the contour shape of the conductor mesh layer 3) may be determined according to the application such as a dipole antenna. For example, in addition to the pattern shape illustrated in FIG. 1A, the pattern shape illustrated in the plan view of FIG. 2 and the like, the appropriate pattern shape according to the frequency, electric field strength, desired gain, application, etc. of radio waves to be transmitted and received What should I do?

[Conductor mesh layer]
As illustrated in FIG. 1, in the present invention, the conductor layer forming the antenna pattern 2 is not constituted by a solid surface layer (continuous layer) in the antenna pattern 2 as in the prior art. The mesh pattern 3P having a large number of opening regions A is formed. As an expression focusing on the pattern shape, the conductor layer formed by the mesh pattern 3P is referred to as a conductor mesh layer 3. The conductor mesh layer 3 is opaque in the portion of the conductor layer that is the formation portion, but is secured by a large number of opening areas A that are the non-formation portions.
On the other hand, the conventional antenna pattern 2 using an ITO film like the conventional transparent antenna 20 illustrated in the cross-sectional view of FIG. 16 is a continuous layer conductive layer in which the opening area A does not exist in the entire area of the antenna pattern 2. It is the body continuous layer 5.

  The conductor mesh layer 3 has a mesh pattern 3P having a large number of opening areas A in a plan view, and the mesh pattern 3P has a specific shape having a large number of opening areas A. The opening area A has a repetition period. There is no direction with a random pattern.

[Mesh pattern and opening area defined by it]
As shown in FIG. 3, the mesh pattern 3 </ b> P includes a large number of boundary line segments L that extend between two branch points B and define a large number of opening areas A, and the boundary line segments that extend from one branch point B The average value N of the number of L is 3.0 <N <4.0 , that is, more than 3.0 and less than 4.0, and is repeated in the opening region A defined by the boundary line segment L. The shape has no direction with a return period.

  Further, regarding the mesh pattern 3P of the conductor mesh layer 3, the plane when the mesh pattern 3P is observed from the normal direction to the sheet surface of the sheet-like transparent antenna 10 with reference mainly to FIG. 3 and FIG. This will be described in terms of visual shape.

  As shown in FIGS. 3 and 9, the line portion Lt of the mesh pattern 3P includes a large number of branch points B. The line portion Lt of the mesh pattern 3P is composed of a number of boundary line segments L that form branch points B at both ends. That is, the line portion Lt of the mesh pattern 3P is composed of a number of boundary line segments L extending between the two branch points B. Then, at the branch point B, the boundary line segment L is connected, so that the opening region A is defined. In other words, an opening area A as a closed area is defined by being surrounded by a boundary line segment L and partitioned.

  As shown in FIGS. 3 and 9, since the line portion Lt is composed only of the boundary line segment L, the line portion does not contribute to the conductivity that extends into the opening region A and becomes a dead end in the middle. Lt does not exist. According to such an aspect, it is possible to effectively realize simultaneously imparting sufficient transparency and high conductivity to the conductor mesh layer 3 constituting the antenna pattern 2.

  On the other hand, in order to prevent the occurrence of moire, in the mesh pattern 3P of the conductor mesh layer 3 according to the present embodiment, there is no direction in which the opening region A has a repeating cycle. In order to eliminate moiré with certainty, it is preferable that the entire region of the mesh pattern 3P has a configuration in which there is no direction having a repeating cycle in the opening region A in any part. As a result of intensive research, the inventors of the present invention do not simply irregularize the pattern of the mesh pattern 3P, but the opening areas A of the mesh pattern 3P are arranged at a repeating cycle having a certain regularity. By defining the pattern of the mesh pattern 3P so that there is no other direction, it can occur when the transparent antenna 10 having the mesh pattern 3P in the conductive mesh layer 3 and the display panel 30 having the pixel arrangement are overlapped. It has been found that moire can be made very inconspicuous.

(No repeat cycle)
FIG. 4 is a plan view on a sheet surface parallel to the XY plane for explaining that there are no repetition periods in a large number of opening regions A defined by the mesh pattern 3P. One virtual straight line di is selected at an arbitrary position in the sheet surface at an arbitrary direction.
This one straight line di intersects the boundary line segment L to form an intersection. The intersections are shown as intersections c1, c2, c3,..., C9 in order from the lower left in the drawing. The distance between adjacent intersections, for example, the intersection c1 and the intersection c2, is a dimension t1 on the straight line di of the certain opening region A. Next, the dimension t2 on the straight line di is similarly determined for another open area A adjacent to the open area A on the straight line di. Then, with respect to a straight line di at an arbitrary position in an arbitrary direction and a boundary line segment L intersecting with the straight line di, a number of opening regions A that encounter the straight line di at an arbitrary position in an arbitrary direction are as dimensions on the straight line di. t1, t2, t3,..., t8 are determined. And the sequence of numerical values of t1, t2, t3,..., T8 has no periodicity.
In FIG. 4, these t1, t2, t3,..., T8 are drawn separately from the mesh pattern 3P along with the straight line di in the lower part of the drawing for easy understanding.
When the straight line di is rotated by an arbitrary angle from the one shown in FIG. 4 and the dimensions t1, t2,... Thus, no periodicity is observed. That is, there is no direction having a repeating cycle in the opening area A defined by the boundary line segment L as in the sequence of numerical values of t1, t2, t3,.

  Furthermore, in the mesh pattern 3P of the conductor mesh layer 3 according to the present embodiment, the average value N of the number of boundary line segments L extending from one branch point B is 3.0 ≦ N <4.0. Thus, when the average value N of the number of boundary line segments L extending from one branch point B is 3.0 ≦ N <4.0, the arrangement pattern of the mesh pattern 3P is shown in FIG. The square lattice pattern (N = 4.0) shown in FIG. In addition, when the average value N of the number of boundary line segments L extending from one branch point B is 3.0 <N <4.0, it is also large from the honeycomb arrangement (N = 3.0). Different patterns can be used. When the average value N of the number of boundary line segments L extending from one branch point B is 3.0 ≦ N <4.0, the arrangement of the opening regions A is made irregular so that the opening region A repeats. It has been confirmed that it is possible to prevent the directions arranged with the return period from being stably present, and as a result, it is possible to make the moire extremely inconspicuous.

  The average value N of the number of boundary line segments L extending from one branch point B is strictly determined by examining the number of boundary line segments L extending for all the branch points B included in the mesh pattern 3P. The average value is calculated. In practice, however, the total number of boundary line segments L extending from one branch point B is considered in consideration of the size of the opening area A per line defined by the line portion Lt. It extends about a branch point B included in a section having an area that can be expected to reflect a tendency (for example, a portion of 10 mm × 10 mm in the mesh pattern 3P in which an opening area A is formed in a dimension example described later). The number of boundary line segments L to be output is checked and an average value thereof is calculated, and the calculated value is handled as an average value N of the number of boundary line segments L extending from one branch point B for the mesh pattern 3P. May be.

  Actually, in the mesh pattern 3P constituting the conductor mesh layer 3 of the transparent antenna 10 shown in FIG. 3, the average value N of the number of boundary line segments L extending from one branch point B is 3.0 <N. <4.0. For example, in the case of the mesh pattern 3P of FIG. 3, when a total of 387 branch points B are measured, the boundary line segment L has three branch points B and the boundary line segment L has four branches. The number of point B is 14 (the number of branch points where the number of boundary line segments L to branch is 5 or more is 0), and the average number of boundary line segments L coming from the branch point B (average branch number) is 3.04 Met.

(Moire status)
FIG. 11C shows a state in which the mesh pattern 3P of the conductive mesh layer 3 shown in FIGS. 3 and 11A is superimposed on a typical pixel array in the display panel 30 shown in FIG. 11B. It is shown. As can be understood from FIG. 11C, when the mesh pattern 3P shown in FIGS. 3 and 11A is actually produced and arranged on the pixel array of the display panel 30, a striped pattern that can be visually recognized, That is, moire (interference fringes) did not occur.

  Here, the pixel array of the display panel 30 shown in FIG. 11B is a typical pixel array in the display panel 30. As shown in FIG. 11B, in the display panel 30, one pixel P includes a sub-pixel (sub-pixel) RP that emits red light, a sub-pixel GP that emits green light, and a sub-pixel BP that emits blue light. It is composed of That is, the display panel 30 can form an image in color. In the example shown in FIG. 11B, the pixels P are formed as a so-called stripe arrangement. That is, the sub-pixel RP that emits red light, the sub-pixel GP that emits green light, and the sub-pixel BP that emits blue light are sequentially arranged in one direction (vertical direction in FIG. 11B). On the other hand, the sub-pixel RP that emits red light, the sub-pixel GP that emits green light, and the sub-pixel BP that emits blue light are arranged one by one in a direction perpendicular to the one direction (the horizontal direction in FIG. 11B). It has been. 11B shows a state in which the display panel 30 is observed from the normal direction to the image forming surface (light-emitting surface, that is, the screen) of the display panel 30, in other words, from the normal direction to the panel surface of the display panel 30. The arrangement of the pixels P is shown.

  On the other hand, FIG. 12 exemplifies the occurrence of moire when a certain repetition period exists in the opening area A defined by the mesh pattern 53P. Here, the mesh pattern 53P is also referred to as a repeating cycle pattern 53P in the sense of explicitly indicating that it has a certain repeating cycle.

What is illustrated in FIG. 12A is a conductive mesh layer 53 formed of a repeating periodic pattern 53P formed in a square lattice pattern and having a certain repeating period in the vertical and horizontal directions. This is different from the conductor mesh layer 3 of the antenna 10.
12C, the conductive mesh layer 53 of the repeating period pattern 53P having the repeating period shown in FIG. 12A is displayed on the display panel 30 (FIG. 11B) shown in FIG. The same as shown in FIG. 4A) is shown in a state where the image is overlaid on a typical pixel array. As can be understood from FIGS. 12A, 12B, and 12C, when the conductive mesh layer 53 including the repeating periodic pattern 53P is arranged on the pixel array of the display panel 30. FIG. Due to the interference between the regular pattern of the repeating periodic pattern 53P constituting the conductor mesh layer 53 and the regular pattern of the pixels, light and dark lines (in the example shown in FIG. 12C, from the upper left to the lower right) The extending light and dark stripes are visible.

  In the example shown in FIGS. 12A and 12C, the arrangement direction of the square lattice formed by the repeating periodic pattern 53P is inclined several degrees with respect to the arrangement direction of the pixels P. Yes. This inclination angle is referred to as a bias angle (degree). Such an inclination is a technique that is widely used in general to make moire inconspicuous. However, as can be understood from the fact that the striped pattern is visually recognized in FIG. 12C, the degree of moire generation is not determined solely by the bias angle, but in addition, the pixel P and the repeating period pattern 53P. This also depends on factors such as the repetition period ratio and the line width of the repetition period pattern 53P. In order to eliminate moire only with the bias angle of the repeating periodic pattern 53P, it is necessary to prepare transparent antennas having different bias angles according to the design specifications of the display panel 30.

(Mesh pattern pattern creation method)
Here, the average value N of the number of boundary line segments L extending from one branch point B is 3.0 <N <4.0 , and the open areas A are arranged in a repeating cycle having a certain regularity. An example of a method for producing a pattern of the mesh pattern 3P that does not have a given direction will be described below.

  The method described here includes a step of determining a generating point, a step of creating a Voronoi diagram from the determined generating point, and a boundary line segment extending between two Voronoi points connected by one Voronoi boundary in the Voronoi diagram. Determining a path of L, and determining a thickness of the determined path to demarcate each boundary line segment L and determine a pattern of the mesh pattern 3P (line portion Lt). . Hereinafter, each step will be described in order. Note that the mesh pattern 3P shown in FIG. 3 described above is a pattern actually determined by the method described below.

  First, the process of determining a generating point will be described. First, as shown in FIG. 5, an absolute coordinate system O-X-Y (this coordinate system O-X-Y is a normal two-dimensional plane. The first generating point (hereinafter referred to as “first generating point”) BP1 is arranged at an arbitrary position of “. Next, as shown in FIG. 6, the second generating point BP2 is arranged at an arbitrary position separated from the first generating point BP1 by a distance r. In other words, at any position on the circumference of a circle with a radius r centered on the first generating point BP1 on the absolute coordinate system XY (hereinafter referred to as “first circumference”), the second A generating point BP2 is arranged. Next, as shown in FIG. 7, the third mother point BP3 is arranged at an arbitrary position away from the first mother point BP1 by the distance r and away from the second mother point BP2 by the distance r or more. Thereafter, the fourth generating point is arranged at an arbitrary position separated from the first generating point BP1 by the distance r and from the other generating points BP2 and BP3 by the distance r or more.

  In this way, the mother point is arranged at an arbitrary position away from the first mother point BP1 by the distance r and away from the other mother points until the next mother point cannot be arranged. Go. Thereafter, this operation is continued based on the second generating point BP2. That is, the next generating point is arranged at an arbitrary position separated from the second generating point BP2 by the distance r and from the other generating points by the distance r or more. Based on the second generating point BP2, until the next generating point cannot be arranged, it is at an arbitrary position away from the second generating point BP2 by the distance r and from the other generating points by the distance r or more. Place the mother point. Thereafter, the base point as a reference is sequentially changed, and the base point is formed in the same procedure.

  With the above procedure, the mother point is arranged until the mother point cannot be arranged in the region where the mesh pattern 3P is to be formed. When the generating point cannot be arranged in the region where the mesh pattern 3P is to be formed, the step of generating the generating point is completed. By the processing so far, the mother point group irregularly arranged in the two-dimensional plane (XY plane) is uniformly dispersed in the region where the mesh pattern 3P is to be formed.

With respect to the generating point groups BP1, BP2,..., BP6 (see FIG. 8A) distributed in the two-dimensional plane (XY plane) in such a process, the distances between the individual generating points are not constant. Have However, the distribution of the distance R between any two adjacent generating points is not a complete random distribution (uniform distribution), but a range ΔR between the upper limit value R _MAX and the lower limit value R _MIN with the average value R _AVG in mind. = R _MAX -R _MIN is distributed. Note that, here, if two Voronoi regions XA are adjacent to each other but two Voronoi regions XA are adjacent to each other after a Voronoi diagram is generated from the generating point groups BP1, BP2,... It is defined that the generating points of are adjacent to each other.

That is, the generating point group described here is referred to as a coordinate system having each generating point as an origin (referred to as a relative coordinate system oxy, while a coordinate system defining an actual two-dimensional plane is referred to as an absolute coordinate system O. 8 (B), FIG. 8 (C),..., In which all the generating points adjacent to the generating point placed on the origin are plotted are obtained for all generating points. Then, when the graph of the adjacent generating points on all the relative coordinate systems is displayed with the origin o of each relative coordinate system superimposed, a graph as shown in FIG. 8D is obtained. The distribution pattern of adjacent mother point groups on the relative coordinate form is not a uniform distribution in which the distance between any two adjacent mother points constituting the mother point group is 0 to infinity, but the distance from the origin o. Is distributed in a finite range from R _AVG −ΔR to R _AVG + ΔR (a donut-shaped region from radius R _MIN to R _MAX ).

As described above, by setting the distance between each generating point, the Voronoi region XA obtained from the generating point group by the method described below, and further, the circumscribed circle diameter (or the opening region A) obtained from this point The distribution of the area of the opening region A) is not uniform (completely random) but distributed within a finite range.
By configuring in this way, the shading (brightness / darkness) unevenness when the mesh pattern 3P is viewed is more effectively eliminated. In order to make the shading unevenness of the mesh pattern 3P visible when the mesh pattern 3P is visually invisible, and to make the mesh pattern 3P non-periodic moiré prevention compatible, the circumscribed circle diameter D of the opening area A (of the opening area A The distribution range ΔD = D _MAX −D _MIN of the circumscribed circle diameter D with respect to the average value D _AVG of the circumscribed circle diameter D when the maximum value of the size) is D _MAX and the minimum value is D _MIN .
0.1 ≦ ΔD / D _AVG ≦ 0.6
More preferably,
0.2 ≦ ΔD / D _AVG ≦ 0.4
And

  In addition, in the process of determining the above generating points, the size of the opening area A per one can be adjusted by changing the size of the distance r. Specifically, by reducing the size of the distance r, it is possible to reduce the size of the opening area A, and conversely, by increasing the size of the distance r, The size of the opening area A can be increased.

  Next, as shown in FIG. 9, a Voronoi diagram is created based on the arranged generating points. As shown in FIG. 9, the Voronoi diagram is composed of line segments that are drawn at the intersection of two bisectors by drawing a perpendicular bisector between two adjacent generating points BP and BP. FIG. Here, the line segment of the bisector is called Voronoi boundary XB, the intersection of Voronoi boundary XB forming the end of Voronoi boundary XB is called Voronoi point XP, and the area surrounded by Voronoi boundary XB is Voronoi area XA Call it.

  In the Voronoi diagram created as shown in FIG. 9, each Voronoi point XP forms a branch point B of the mesh pattern 3P. Then, one boundary line segment L is provided between two Voronoi points XP forming the end of one Voronoi boundary XB. At this time, the boundary line segment L may be determined so as to extend linearly between the two Voronoi points XP as in the example shown in FIG. Various paths (for example, circle (arc), ellipse (arc), fence line, hyperbola, sine curve, hyperbolic sine curve, elliptic function curve, Bessel function curve, etc.) between the two Voronoi points XP without It may be extended by a broken line or the like. When the boundary line segment L is determined to extend linearly between two Voronoi points XP as in the example shown in FIG. 3, each Voronoi boundary XB defines the boundary line segment L. It becomes like this.

  After determining the path of each boundary line segment L, the line width (thickness) of each boundary line segment L is determined. The line width of the boundary line segment L is determined so as not to impair the conductivity and transparency of the antenna pattern 2. As described above, the pattern of the mesh pattern 3P can be determined.

According to the present embodiment as described above, the mesh pattern 3P of the conductor mesh layer 3 constituting the antenna pattern 2 has a large number of boundary line segments that extend between the two branch points B and define the opening region A. The average value N of the number of boundary line segments L extending from one branch point B is 3.0 <N <4.0 , and the opening region A has a repetition period. There is no direction.
As a result, even when the transparent antenna 10 is superimposed on the display panel 30 in which the pixels P are regularly (periodically) arranged, the striped pattern (moire, interference fringes) is generated to such a degree that it can be visually recognized. Can be effectively prevented.

(Repeat as unit pattern area)
In the above-described embodiment, there is no direction in which the opening region A defined by the mesh pattern 3P of the conductor mesh layer 3 has a repetition period in the entire region of the conductor mesh layer 3 constituting the antenna pattern 2. Explained the example. However, as shown in FIG. 10, the entire area of the mesh pattern 3P included in the conductor mesh layer 3 in the antenna pattern 2 is formed by collecting a plurality of unit pattern areas S to form the entire area of the mesh pattern 3P. Thus, in each unit pattern region S, the plurality of opening regions A may be formed of regions arranged in a pattern having no predetermined repetition period. That is, in this embodiment, the unit pattern area S in which the opening area groups are arranged in the same pattern when viewed locally in the entire area of the mesh pattern 3P corresponding to the entire area of the antenna pattern 2. 2 or more are included. In this case, the connection between the unit pattern regions S is substantially inconspicuous and can be ignored unless there are four or more repetitions in a certain period in a specific direction. Of course, neither moire nor shading unevenness occurs in the unit pattern region S. In this example, the pattern of the mesh pattern 3P in one unit pattern region S can be created in the same manner as the pattern creation method described with reference to FIGS.

  In particular, the display panel 30 has recently been increased in size, and the transparent antenna 10 is applied to the large-screen display panel 30 when the transparent antenna 10 is applied to the entire surface of the large screen. Sometimes, the mesh pattern 3P included in the conductor mesh layer 3 constituting the antenna pattern 2 is composed of an array of a plurality of unit pattern regions S, and each unit pattern region S is identical to each other. In the case of including a plurality of unit pattern areas S configured so that the opening areas A are arranged in a pattern, it is preferable in that the pattern creation of the mesh pattern 3P can be greatly facilitated.

  In particular, in the example in which one type of unit pattern region S is arranged in a plurality of vertical and horizontal directions as shown in FIG. 10, there is a repetition as the unit pattern region S in a specific direction (two directions in the drawing vertical direction and horizontal direction). . In the embodiment of FIG. 10, the unit pattern region S is repeated with a repetition period SP2 in the horizontal direction and a repetition period SP1 in the vertical direction. Under these conditions, when the dimension of the unit pattern area S in a specific direction is Ls, and the unit pattern area S has N opening areas A in the dimension Ls on an arbitrary straight line dj extending in the specific direction, When attention is paid to a certain opening area A on dj, there is a regularity that there is always an opening area A having exactly the same size tj and shape at a position where the number of the opening areas A is separated by N on the straight line dj. Have. However, this regularity is based on the repetition cycle as the unit pattern region S (the dimension Ls corresponds to the repetition cycle in the above description), and is not the repetition cycle as the opening region A. In the unit pattern area S, the opening area A does not have a repetition period in the specific direction. In addition, the repetition cycle as the unit pattern region S is not close to the dimensional relationship in which moire is generated because the size is different from the arrangement cycle of the pixel arrangement of the display panel by, for example, 1000 times or more.

  In the example shown in FIG. 10, the rectangular antenna pattern 2 is divided into six unit pattern regions S having the same shape, and the conductor mesh layer 3 is included in each unit pattern region S. The mesh pattern 3P is configured identically. In the six unit pattern regions S, three regions are arranged in the vertical direction (vertical direction in the drawing) in FIG. 10 at a repetition cycle SP1, and two regions are arranged in the horizontal direction in FIG. 10 at a repetition cycle SP2. Are arranged as follows.

[Main cut surface shape of conductor mesh layer]
The cross-sectional shape of the conductor mesh layer 3, that is, the main cut surface shape is not particularly limited. For example, in the cross-sectional view of FIG. 13, FIG. 13 (1) is a rectangle (including square), FIG. 13 (2) is a trapezoid with the bottom of the transparent substrate 1 as a wide bottom, and FIG. FIG. 13 (4) shows a triangle or a trapezoidal hypotenuse whose shape is modulated in a convex shape toward the outside (in the case of a triangle). The drawings are conceptual, and the corners of the cross-sectional shape may be rounded in consideration of manufacturing accuracy such as ink fluidity or shape durability.

[Dimensions of conductor mesh layer]
The dimensions of the conductor mesh layer 3 are “non-visibility” in that the line width of the boundary line segment L constituting the mesh pattern 3P is 1 to 100 μm and the boundary line segment L is difficult to see from the viewpoint of conductivity and transparency. Then, the line width should be as narrow as possible, preferably 50 μm or less, more preferably 30 μm or less. On the other hand, from the viewpoint of securing conductivity and shape durability, it is preferable to secure a line width of 3 μm or more, preferably 10 μm or more. Since the visibility (easy visibility) of the thin line depends on how far the transparent antenna 10 is viewed from, the line width of the thin line may be set according to the application. In addition, the line width of the boundary line segment L is generally uniform in the entire area of the mesh pattern 3P, but it is not necessary to be the same in the entire area of the mesh pattern 3P, for example, by changing the position.
The transparency in the region of the antenna pattern 2 composed of the conductor mesh layer 3 is 50% or more, more preferably 70% or more, in the visible light wavelength region of 380 to 780 nm. It depends on.

The size of the opening area A defined by the mesh pattern 3P is about 50 to 1000 μm in the diameter of a circumscribed circle inscribed in the opening area A. However, it goes without saying that it is within the range satisfying the conductivity (surface resistivity) as the required surface in consideration of the aperture ratio. In addition, the aperture ratio of the conductor mesh layer 3 ((defined by the total area of the opening area A that is a non-formation part of the conductor mesh layer 3 / the total covering area of the conductor mesh layer 3 including the opening area A) × 100) Is preferably 50% or more, preferably 70% or more, from the viewpoint of achieving both conductivity and transparency (visible light transparency). Moreover, the thickness of the conductor mesh layer 3 is about 1-100 micrometers from points, such as a viewpoint of electroconductivity (and transparency).
Here, as an example, the conductor mesh layer 3 has a thickness of 20 μm, a line width (also a line width at the portion of the line portion Lt of the mesh pattern 3P) of 20 μm, and an average dimension of the circumscribed circle of the opening region A of 300 μm. It is. The aperture ratio is 85%.

[Conductor mesh layer material]
As a conductor layer that can be used for the conductor mesh layer 3, a layer transparent to visible light itself such as an ITO film cannot be used because it cannot be expected to have sufficient conductivity. A layer which is obtained but becomes an opaque layer is employed. As the conductor layer that becomes a layer opaque to visible light itself, a known layer may be used as appropriate, and there is no particular limitation as long as the mesh pattern 3P having a line width of 100 μm or less can be formed. The material and the forming method can be appropriately selected from known materials. For example, a metal composition or a conductive composition layer in which conductive particles made of silver or the like are dispersed in a resin binder.

(Metal layer)
The metal of the metal layer is a highly conductive metal, for example, a metal (including alloy) such as gold, silver, copper, platinum, tin, aluminum, iron, or nickel. Among these, copper is generally used as a metal, but it is also preferable to use aluminum which is cheaper than copper.

In the case of a metal layer, the conductor mesh layer 3 can be roughly divided into two methods: a method of forming a pattern from a non-patterned metal layer and a method of forming a patterned metal layer from the beginning.
In the former method, a metal foil laminating method, a plating method, or a dry method such as vapor deposition or sputtering is used to form a non-patterned metal layer. A chemical etching method can be used to form a pattern on the metal layer, and a photolithography method or a printing method is used to form an etching resist pattern.
When forming a metal layer as a metal thin film by vapor deposition or sputtering, a negative pattern is formed in advance with a water-soluble resin on the surface of the metal thin film (forms the resin layer on the portion to be the opening region A), There is also a method of removing the metal thin film on the negative pattern together with the water-soluble resin by washing with water after forming the metal thin film.

On the other hand, as a method of forming the metal layer patterned from the beginning of the latter, a method of plating the metal layer only on the catalyst pattern patterned by printing of the plating catalyst ink, conversely, a conductive surface such as metal is used. There is a method of forming a conductive mesh layer 3 by patterning a plating resist on a portion to be an upper non-formed portion, and then electroplating the non-formed portion of the plating resist to peel from the conductive surface. In addition, peeling peels with the transparent base material 1 after laminating | stacking the transparent base material 1 further.
In addition, for the metal layer before pattern formation and after pattern formation, a method of changing the laminated surface of the metal layer by using a transfer method can also be used. For example, the conductor mesh layer 3 is laminated | stacked on the transparent base material 1 through the contact bonding layer from the transfer foil which formed the conductor mesh layer 3 as a transfer layer on a peelable base material. For the peelable substrate, use a resin film or the like listed on the transparent substrate (but may be opaque), and the adhesive layer is made of acrylic thermoplastic resin or the like on the transfer foil side, the transparent substrate side, or both. Apply.

  In general, the conductor mesh layer 3 is manufactured by a method of photoetching a metal layer formed on the transparent substrate 1 by adhesion of metal foil, plating, metal vapor deposition or the like when the metal layer is used. When the conductive mesh layer 3 is formed as the conductive composition layer, the conductive mesh layer 3 is formed by printing ink made of the conductive composition.

  When patterning a plating catalyst pattern, resist pattern, or the following conductive composition layer by printing, silk screen printing, flexographic printing, intaglio printing, inkjet printing, etc. may be selected as appropriate. In particular, the “pulling primer type intaglio printing method” described later is preferable in that it can be made fine and highly accurate.

When the metal layer as the conductor mesh layer 3 is an aluminum metal layer, the method of forming the mesh pattern 3P is not particularly limited, but preferably aluminum because a fine pattern can be easily formed. This can be done by etching the foil. However, the metal aluminum itself is highly active and has an oxide film on the surface. For this reason, it is difficult to perform uniform and stable chemical etching. Giza (the contour line in the plan view of the line portion becomes a ZigZag non-linear shape) etc. Pattern accuracy is poor. However, if the thickness of the oxide film is regulated to 0 to 13 mm or less, uniform and stable chemical etching can be performed, and the conductor mesh layer can be formed of aluminum which is cheaper than copper. The upper limit of the thickness is 13 mm, but is preferably 12 mm, more preferably 10 mm, and still more preferably 8 mm. The lower limit of the thickness is 0 mm from the point of not inhibiting chemical etching, but it is also possible to have an oxide film of about 2 to 3 mm from the viewpoint of preventing undesired oxidation and corrosion during processing and storage of the foil. . Note that 1Å = 0.1 nm.
The thickness regulation of the oxide film is the side where the etchant first comes into contact (usually, the foil is etched after being laminated on a transparent substrate, so the surface far from the transparent substrate may be referred to as the upper surface, and the other surface as the lower surface) However, the other surface (lower surface) can be defined as the same. In addition, the oxide film of a general aluminum foil has a thickness of 15 mm or more, usually about 20 to 100 mm.
In order to reduce the thickness of the oxide film, it is possible to adjust rolling conditions and annealing conditions at the time of manufacturing the aluminum foil. The thickness of the oxide film is measured by the Hunter Hall method or X-ray photoelectron spectroscopy (XPS) which is a kind of fluorescent X-ray analysis.
The aluminum foil preferably has a purity of 99.0% or more in terms of high conductivity, and uses a foil that conforms to the aluminum foil defined by JIS H4160 (aluminum and aluminum alloy foil) and JIS H4170 (high purity aluminum foil). can do.

(Conductive composition layer)
The conductive composition layer as the conductor mesh layer 3 is a layer in which conductive particles are dispersed in a resin binder. Examples of the conductive particles include gold, silver, platinum, copper, tin, aluminum, and nickel. Conductive metal (including alloy) particles may be used, or metal-coated particles in which the surfaces of resin particles or inorganic particles are coated with the above highly conductive metal such as gold or silver, or graphite particles may be used.

  As the resin of the resin binder, a thermoplastic resin, a thermosetting resin, an ionizing radiation curable resin, or the like is used alone or in combination. A thermoplastic polyester resin, a thermoplastic acrylic resin, or the like is used as the thermoplastic resin, and a melamine resin, a thermosetting polyester resin, a thermosetting acrylic resin, a thermosetting urethane resin, or the like is used as the thermosetting resin. In addition, as the ionizing radiation curable resin, a composition containing a monomer and / or a prepolymer that undergoes a crosslinking reaction with ionizing radiation and is cured. As the monomer or prepolymer, a radical polymerizable or cationic polymerizable compound is used. Among these, ionizing radiation curable resins using acrylate compounds are typical.

The conductive composition layer can be patterned from the beginning at the time of layer formation. When patterning by printing, silk screen printing, flexographic printing, intaglio printing, ink jet printing, etc. may be appropriately selected. The “pulling primer intaglio printing method” described later is preferable in that a fine pattern can be formed with high accuracy. The conductive composition is also referred to as conductive ink, conductive paste, or the like.
Or after forming the pattern groove | channel of the target mesh pattern 3P in the surface of the transparent base material 1, and apply | coating a conductive composition to the whole surface of this transparent base material 1, it is unnecessary other than this pattern groove | channel. The conductive mesh layer 3 can also be formed by scraping off a conductive composition with a blade or the like and leaving the conductive composition only inside the pattern groove (so-called wiping method). The substrate for forming the pattern groove may be laminated on the transparent substrate 1 by transfer after being formed on another substrate in addition to the transparent substrate 1.

The “pulling primer type intaglio printing method” is a printing method disclosed in Japanese Patent No. 4436441 (pamphlet of International Publication No. 2008/149969), and has a thin and fine pattern that was impossible in the past. It is a printing method that can be formed and has both excellent conductivity and excellent light transmittance. Further, in this printing method, the conductive mesh layer 3 is formed by intaglio printing a conductive composition (also referred to as ink or paste) made of metal particles such as silver and a resin binder to form a conductive composition layer. As a result, the conductor mesh layer 3 is formed.
The “pulling primer type intaglio printing method” is a method of intaglio printing an ink of a conductive composition on a primer layer (primer fluidized layer) in a fluid state applied on the transparent substrate 1, and in that case, While the transparent substrate 1 is present on the plate surface of the intaglio, the primer fluidized layer between the plate surface and the transparent substrate 1 is cured by ultraviolet irradiation or the like to solidify and form the primer layer, and then the transparent substrate 1 is formed. In this method, the patterned conductor mesh layer 3 is printed on the transparent substrate 1 through a primer layer by releasing from the intaglio. When the primer layer is in a fluid state, it promotes the transfer of ink from the printing plate to the printing material, in other words, draws out the ink filled in the concave portion of the intaglio plate surface and transfers it to the printing material (transparent substrate). Have. A major feature of printed matter by the “Pulling Primer Intaglio Printing Method” that is not seen in other printing methods is that the thickness of the primer layer is different from that of the conductive composition layer in terms of the thickness of the primer layer. It becomes a shape thicker than the thickness in the opening area | region A which is a formation part.

  For the primer layer, a thermoplastic resin, a curable resin, or the like is used. As the curable resin, a thermosetting resin or an ionizing radiation curable resin can be used, but a rapid change from a fluidized state to a solidified state is possible. An ionizing radiation curable resin is preferably used because it can be controlled. As ionizing radiation, ultraviolet rays, electron beams and the like are usually used.

(Blackening treatment)
In order to make the conductive mesh layer 3 formed as a metal layer, a conductive composition layer, or the like a bright color such as a metal color or a silver color and make the mesh pattern 3P stand out, in order to make it inconspicuous The surface may have a blackening treatment layer. As the blackening treatment layer, in the case of a metal layer, a known treatment such as blackening nickel plating may be appropriately employed. Alternatively, in the case of the conductive composition, a black or dark color material such as carbon black may be added to the composition.

[Method of making conductor mesh layer pattern shape of antenna pattern]
In order to form the pattern shape of the antenna pattern 2 with the conductor mesh layer 3 of the mesh pattern 3P as described above, it may be performed simultaneously with the formation of the mesh pattern 3P of the conductor mesh layer 3. That is, the mesh pattern 3P of the conductor mesh layer 3 may be formed by setting the contour shape of the region of the conductor mesh layer 3 (or mesh pattern 3P) as the pattern shape of the antenna pattern 2.
Alternatively, the conductor mesh layer 3 may be formed in a pattern shape of the antenna pattern 2 from the one that is formed with a larger area than the antenna pattern 2 (general raw material). For example, a material obtained by forming the conductive mesh layer 3 on the transparent base material 1 is used as a general-purpose raw material, and this is cut into the shape of the antenna pattern 2 together with the transparent base material 1 according to the shape of the required antenna pattern 2. It can be formed by cutting out. Moreover, when the conductor mesh layer 2 is a metal layer, it can be formed by removing the conductor mesh layer 3 in an unnecessary region of the general-purpose raw fabric by etching.
Thus, the method of making the conductor mesh layer 3 the pattern shape of the antenna pattern 2 is not particularly limited.

<Functional layer>
A functional layer 4 may be further formed on the transparent antenna 10.
By providing the functional layer, various functions such as an antireflection function can be provided according to the type of the functional layer.
The transparent antenna 10 of the embodiment illustrated in FIG. 14A is an example in which the functional layer 4 is provided on the surface of the transparent substrate 1 side. The transparent substrate 1 side means a side opposite to the side where the antenna pattern 2 is formed with respect to the transparent substrate 1 in the transparent antenna 10.
The transparent antenna 10 of the embodiment illustrated in FIG. 14B is an example in which the functional layer 4 is provided on the surface on the antenna pattern 2 side.
Although not shown, the functional layer 4 may be provided between the transparent substrate 1 and the antenna pattern 2. In this embodiment, the antenna pattern 2 is laminated on the transparent substrate 1. It will be formed above. Thus, in the transparent antenna 10, the functional layer 4 is provided at any one or more positions among the surface on the transparent substrate 1 side, the surface on the antenna pattern 2 side, and between the transparent substrate 1 and the antenna pattern 2. May be. Therefore, the functional layer 4 may be provided at a plurality of positions, for example, at two locations including a surface on the transparent substrate 1 side and a surface on the antenna pattern 2 side.
As a specific example, an antireflection layer is further provided for the transparent substrate 1 that functions as a surface protective layer that protects the antenna pattern 2 from external force, and the functional layer provided on the surface on the antenna pattern 2 side, In this embodiment, an adhesive layer for attaching the transparent antenna 10 to an adherend and a release sheet for temporarily protecting the adhesive layer are employed.

  The functional layer 4 is provided in order to provide a function that cannot be realized only by the transparent substrate 1 and the antenna pattern 2 among the functions required for the transparent antenna 10. For example, in the above-mentioned example, it was an adhesive layer, a release sheet, a transparent protective layer, and an antireflection layer. As the functional layer 4, in the case where the transparent antenna 10 is applied on the screen of the display panel, a layer that realizes various known functions as a front filter of the display panel or the like can be appropriately employed. Such a functional layer 4 can be broadly classified into an optical functional layer responsible for optical functions and a non-optical functional layer responsible for functions other than optical functions. Examples of the optical functional layer include an antireflection layer (antiglare, antireflection, antiglare and antireflection), an ultraviolet absorbing layer that absorbs ultraviolet rays, and a color that corrects the display image to a desired color tone. There is a specific light transmission layer such as a correction function. Examples of non-optical functional layers include a surface protective layer, a hard coat layer, an antistatic layer, an antifouling layer, an adhesive layer (including an adhesive layer) that adheres the layers, and an adhesive layer temporarily. There is an exfoliation sheet etc. which protects automatically. In addition, each layer of the optical functional layer and the non-optical functional layer may be used as a single layer, or may be used between the optical functional layer and the non-optical functional layer.

  Hereinafter, the transparent protective layer, the antireflection layer, and the adhesive layer (including the pressure-sensitive adhesive layer) will be further described.

[Transparent protective layer]
The transparent protective layer is preferably formed on at least the antenna pattern 2, but may be formed on the entire surface of the transparent antenna 10 including the portion where the antenna pattern 2 is not formed. The transparent protective layer can be formed by laminating a transparent resin film via an adhesive or pressure-sensitive adhesive or applying a transparent resin paint. What was listed with the said transparent base material etc. can be used for a transparent resin film. As the resin of the transparent resin paint, a thermoplastic resin, a curable resin, or the like can be used. The thermoplastic resin is, for example, an acrylic resin, a polyester resin, a cellulose resin, a thermoplastic urethane resin, or the like, and is curable. The resin is, for example, a thermosetting resin such as a thermosetting urethane resin, a thermosetting acrylic resin, or an epoxy resin, or an ionizing radiation curable resin that is cured by ultraviolet rays or an electron beam. Examples of the ionizing radiation curable resin include resins containing a radical polymerizable compound typified by an acrylate type and a cationic polymerizable compound typified by an epoxy type.
A known transparent material such as a urethane resin can be used as the adhesive, and a known transparent material such as an acrylic resin described later can be used as the adhesive.

[Antireflection layer]
The antireflection layer is provided as a functional layer at a position that is the outermost layer of the transparent antenna 10. The antireflection layer can prevent a decrease in light transmittance due to surface reflection, and prevent a decrease in transparency of the transparent antenna 10 as a whole.
What is necessary is just to employ | adopt a well-known thing suitably as an antireflection layer. For example, the antireflection layer includes a multilayer structure in which a low refractive index layer and a high refractive index layer are alternately laminated so that the low refractive index layer is positioned on the outermost surface, or a single layer structure of only a low refractive index layer (part Each layer is formed by a wet method such as coating or a dry method such as vapor deposition or sputtering.
For example, the low refractive index layer uses silicon oxide, magnesium fluoride, lithium fluoride, calcium fluoride, fluorine-containing resin, etc. as the low refractive index material, and the high refractive index layer uses oxidized material as the high refractive index material. Titanium, zirconium oxide, niobium oxide, etc. are used. When the coating is formed, a curable resin such as a thermosetting resin or an ionizing radiation curable resin as listed in the transparent protective layer is preferably used as the binder resin. For example, a resin layer in which hollow silica is dispersed in an ionizing radiation curable resin as a low refractive index material is used for the low refractive index layer, and zirconium oxide is used as the high refractive index material in the ionizing radiation curable resin for the high refractive index layer. A resin layer dispersed therein is used, or the transparent base material 1 or the transparent protective layer itself is substituted.

As the adhesive layer, known adhesives and pressure-sensitive adhesives can be appropriately employed. For example, (1) a so-called heat seal (hot seal) type or hot melt (hot melt) type adhesive that uses a thermoplastic resin and is cooled and solidified after heat melting and bonded, and (2) a thermosetting resin. Use, so-called thermosetting adhesive that is cured by a polymerization or cross-linking reaction by heating, and (3) an ionizing radiation curable resin, and is cured by an ionizing radiation irradiation or cured by a cross-linking reaction and bonded. A so-called ionizing radiation curable adhesive, (4) using a resin having adhesiveness on the surface, and adhering only by contact and pressure (without applying energy such as heating, irradiation of ionizing radiation, or using a chemical reaction); Examples include so-called pressure-sensitive adhesives.
Among these, a pressure-sensitive adhesive is general-purpose and convenient in that a special treatment such as heating is unnecessary and re-peeling is possible as necessary. Examples of the adhesive layer using the adhesive as the adhesive, that is, the adhesive layer, are, for example, an acrylic adhesive, a silicone adhesive, a rubber adhesive, and the like, and a known coating method or an adhesive film with a separator, etc. It is formed by laminating. On the pressure-sensitive adhesive surface of the pressure-sensitive adhesive layer, a release sheet that is peeled off during use is usually laminated. As the release sheet, for example, a known sheet such as a polyester film or paper coated with a release material such as silicone can be used. In addition to the transparent release sheet, the release sheet may be not transparent because it is peeled off during use.
As the adhesive layer, in addition to the form consisting of the adhesive layer alone, a three-layer structure in which adhesive layers are laminated on both the front and back surfaces of a core material sheet such as a nonwoven fabric or a resin sheet (so-called double-sided adhesive tape) Can also be used.

<Deformation>
In the transparent antenna 10 according to the present invention, on the surface of the transparent substrate 1, in addition to the antenna pattern 2, wirings and electrodes that are electrically connected to the antenna pattern 2 may be formed. Wiring and electrodes are formed of the conductor mesh layer 3 in the same manner as the antenna pattern 2 portion, so that sufficient conductivity and sufficient transparency can be achieved at the wiring and electrode portions, and moire can be eliminated and density unevenness can be reduced. Elimination can be compatible. However, since the electrode portion is usually provided on the outer peripheral portion of the transparent antenna 10 that does not require transparency, such as a display panel, the electrode portion does not need to be transparent. In this case, the electrode portion may be a conductor continuous layer in which the opening region A does not exist. As the conductor continuous layer, the above-described conductive composition layer or metal layer can be used.

  As described above, in the transparent antenna 10, at least the antenna pattern 2 is formed of the conductor mesh layer 3, but when the transparent antenna 10 includes a conductor layer other than the antenna pattern 2, the conductor layer What is necessary is just to employ | adopt well-known conductors other than the performed conductor mesh layer 3. FIG.

In the above embodiment example with reference to FIG. 1, the entire area of the antenna pattern 2 of the transparent antenna 10 is composed of only the mesh pattern 3P in which the direction in which the opening area A has a repeating cycle does not exist.
However, if the moire with the pixels of the display panel 30 is within a substantially negligible range, a direction in which the opening area A has a repetition period exists in a part of the entire area of the antenna pattern 2. A mesh pattern 3P may be adopted. Of course, there is no direction in which the opening region A has a repeating cycle other than the specific direction. Such a form is also included in the mesh pattern 3P of the present invention.

[C] Image display device:
The image display apparatus according to the present invention is an image display apparatus 100 including the transparent antenna 10 as described above on the screen 20a of the display panel 30 like the image display apparatus 100 shown in the embodiment illustrated in FIG. is there. In addition to the display panel 30, the image display device 100 is a well-known device such as a cabinet, a input / output component, etc., and a tuner in the case of a television receiver, for example, depending on the use of the image display device. It is equipped with various parts. These other components are not particularly limited, and depend on the application.
The display panel 30 is a display panel capable of displaying a planar image, such as a plasma display panel, a liquid crystal panel, or an EL (electroluminescence) panel. The display panel 30 may be a cathode ray tube or the like whose display surface is flat or curved. The display panel 30 may include various circuits such as a display driving circuit, wiring between the driving circuit and the display panel body, a chassis, a frame, and the like for integrating them. Therefore, the display panel 30 can also be called a “display module” or a “panel module”.

  By using the image display device 100 having such a configuration, sufficient transparency compatible with sufficient conductivity as an antenna can be obtained, and furthermore, moire elimination and density unevenness elimination can be achieved at the same time, so a high-quality image can be displayed. it can.

The transparent antenna 10 is disposed on the screen 30a of the display panel 30, but there may be an air layer between the transparent antenna 10 and the screen 30a of the display panel 30, or it may be filled with a resin layer or the like. good.
Although not shown, the image display device 100 may include other optical members in addition to the transparent antenna 10 on the screen of the display panel 30. The other optical member is, for example, an optical member having the functional layer described above. For example, surface protective glass.

[D] Application:
The transparent antenna 10 according to the present invention can be used in various applications as a reception antenna or transmission or transmission / reception antenna for various radio waves such as televisions, radios, GPS (Global Positioning System) satellites, and FM radio waves.
In particular, a combination application with a periodic pattern, for example, an arrangement on a screen on the viewer side of a display panel is particularly suitable because moire and shading unevenness do not occur. Specifically, display of images such as portable television receivers, digital photo frames with reception functions, portable multi-function information terminals, cellular phones, portable GPS devices, portable information devices, amusement devices, electronic signs, etc. Windows.
Or, it is attached to the window of a vehicle such as an automobile, and is attached to a reception antenna or transmission / transmission / reception antenna of a car navigation system, a transparent window of a product display case, etc. This is used for transmission, reception, or a transmission / reception antenna of a breakage detection sensor installed on a window or door glass.
Similarly to the above, the image display apparatus 100 according to the present invention includes a portable television receiver, a portable multifunction information terminal, a portable information device such as a cellular phone and a portable GPS device, a digital photo frame with a reception function, and a game. It can be used for applications such as equipment and display modules for electronic signage.

DESCRIPTION OF SYMBOLS 1 Transparent base material 2 Antenna pattern 3 Conductor mesh layer 3P Mesh pattern 4 Functional layer 5 Conductor continuous layer 10 Transparent antenna 20 Conventional transparent antenna 30 Display panel 100 Image display apparatus A Opening area B Branch point BP Mother point L Boundary line Minute Lt Line part (set of boundary line segments)
S Unit pattern area V Observer

Claims (2)

An antenna pattern is formed on at least one surface of the transparent substrate,
The antenna pattern is formed by a conductor mesh layer in which an opaque conductor layer is formed as a mesh pattern,
The mesh pattern is composed of a large number of boundary line segments extending between two branch points to define a large number of open areas, and the average value N of the number of boundary line segments extending from one branch point is 3.0 <N. <4.0 , and a transparent antenna including an area formed by a pattern in which the opening area does not have a direction having a repetition period.   An image display device, wherein the transparent antenna according to claim 1 is arranged on a screen of a display panel.

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