JP6127666B2 - Conductive mesh, conductive mesh sheet, touch panel device and image display device - Google Patents

Description

  The present invention relates to a conductive mesh that defines a large number of open regions, and more particularly to a conductive mesh that can make moiré and glare inconspicuous. The present invention also relates to a conductive mesh sheet having the conductive mesh, a touch panel device, and an image display device.

  Conventionally, a conductive mesh having visible light translucency has been widely used in various fields, for example, as an electromagnetic shielding material (electromagnetic shielding sheet) disclosed in Patent Documents 1 and 2 and a touch panel sensor. However, it is known that such a conductive mesh causes problems such as moire and glare. Various studies have been conducted to eliminate such problems.

  As the shape of the conductive mesh, as disclosed in Patent Document 1, a periodic lattice in which polygonal unit lattices such as squares and hexagons are arranged at regular intervals vertically and horizontally has been most commonly used. . However, such a periodic grating may interfere with the period of the conductive mesh and the period of the pixels to generate moire (striped pattern), which may hinder image visibility.

  Therefore, in order to eliminate the occurrence of moire, as disclosed in Patent Document 2, a random lattice without an array period in which unit lattices of various ununiform shapes are arrayed aperiodically has been proposed. However, although such a random lattice is free from moiré, it is recognized that the density of the unit lattice is glaring, and this in turn reduces the image visibility.

  Furthermore, in order to eliminate the glare of the random grating, as disclosed in Patent Document 3, a conductive mesh in which the periodicity of the periodic grating is partially broken and left partially is proposed. This is based on a square lattice having a repetition period in two directions of the X-axis direction and the Y-axis direction, and the conductive mesh in one direction (for example, the X-axis direction) makes the unit cell arrangement non-periodic, and the other (for example, The arrangement period in the (Y-axis direction) remains. However, when actually prototyped and evaluated, it was found that both the moire eliminating effect and the glare prevention effect were halfway.

Japanese Patent No. 4084055 JP-A-11-121974 WO2007 / 114076

  Moire is a phenomenon in which bright and dark streaks become visible, and the regularity (periodicity) of the pattern of the conductive mesh and the regularity of the pattern of other members overlaid on the conductive mesh (for example, a display device) This is caused by interference with the regularity of the pixel arrangement. For this reason, it has been generally considered that making the pattern of the conductive mesh irregular is effective for making the moire invisible.

  On the other hand, the glare is a phenomenon in which the amount of reflection of external light from the conductive mesh becomes non-uniform in the surface, and a brightly observed part locally exists. The occurrence of glare is believed to be due to local non-uniformity of the conductive mesh pattern.

  That is, making the conductive mesh pattern irregular is effective for making the moire invisible, and making the conductive mesh pattern regular is effective for making the glare invisible. For this reason, in the prior art, there is no conductive mesh that can cope with all of moire and glare. The present invention has been made in consideration of the above points, and a conductive mesh capable of making all of moire and glare inconspicuous, a conductive mesh sheet having the conductive mesh, a touch panel device, and an image display device The purpose is to provide.

The conductive mesh according to the present invention is:
A conductive mesh defining a number of open areas,
A plurality of conductive connecting elements extending between two branch points to define the open area;
The branch point is located on a corner of the rhombus in a reference pattern formed by laying two types of rhombus with sides having the same length and different inner angles.

  In the conductive mesh according to the present invention, the connecting element may extend between two branch points respectively corresponding to two corners forming both ends of the side of the rhombus in the reference pattern. In the conductive mesh according to the present invention, the connecting element may extend only between two branch points respectively corresponding to two corners forming both ends of the side of the rhombus in the reference pattern. Alternatively, in the conductive mesh according to the present invention, the connecting element is formed between two branch points respectively corresponding to two corners forming both ends of the side of the rhombus in the reference pattern, and a diagonal line of the rhombus in the reference pattern. May extend between two branch points respectively corresponding to the two corners forming the two ends.

  In the conductive mesh according to the present invention, one opening region may be defined corresponding to one rhombus in the reference pattern.

The conductive mesh sheet according to the present invention is:
Any of the conductive meshes according to the invention described above;
A transparent base material that supports the conductive mesh.

  The touch panel device according to the present invention includes either the conductive mesh or the conductive mesh sheet according to the present invention described above.

  The image display device according to the present invention includes any one of the above-described conductive mesh and conductive mesh sheet according to the present invention.

  According to the present invention, moire and glare caused by the conductive mesh can be effectively made inconspicuous.

FIG. 1 is a plan view showing a conductive mesh for explaining an embodiment of the present invention. FIG. 2 is a partially enlarged plan view of FIG. FIG. 3 is a plan view for explaining a modified example of the conductive mesh. FIG. 4 is a cross-sectional view along the normal direction of a conductive mesh sheet having a conductive mesh. FIG. 5 is a diagram showing a display device including an electromagnetic wave shielding sheet made of a conductive mesh sheet. FIG. 6 is a schematic diagram showing a touch panel device including a touch panel sensor made of a conductive mesh sheet.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings attached to the present specification, for the sake of illustration and ease of understanding, the scale, the vertical / horizontal dimension ratio, and the like are appropriately changed and exaggerated from those of the actual product.

  In the present specification, the terms “plate”, “sheet”, and “film” are not distinguished from each other only based on the difference in names. For example, “sheet” is a concept that includes a member that can be called a plate or a film. Therefore, “conductive mesh sheet” is called a member called “conductive mesh plate” or “conductive mesh film”. It cannot be distinguished only by the difference.

  Furthermore, as used in this specification, the shape and geometric conditions and the degree thereof are specified. For example, terms such as “parallel”, “orthogonal”, “identical”, length and angle values, etc. Without being bound by meaning, it should be interpreted including the extent to which similar functions can be expected.

<< Conductive mesh and conductive mesh sheet >>
The conductive mesh 10 is a mesh-like material that defines a large number of open regions 15. As shown in FIGS. 1 and 2, the conductive mesh 10 includes a number of conductive connecting elements 20 that extend between two branch points 25 and define an open region 15. In particular, in the illustrated example, the conductive mesh 10 is configured as a collection of a number of connecting elements 20 that form branch points 25 at both ends. That is, the conductive mesh 10 is configured as a collection of a large number of connection elements 20 extending between the two branch points 25. An opening region 15 is defined by connecting the connecting element 20 at the branch point 25. In other words, one opening region 15 is defined by being surrounded and divided by the connecting element 20.

  The conductive mesh 10 has electrical conductivity, exhibits some function related to electrical conductivity, and has visible light transparency through the opening region 15. As an example of such a conductive mesh 10, an electromagnetic shielding material that is grounded and shields electromagnetic waves, an electrode for a touch panel sensor incorporated in a touch panel device, an antenna having visible light permeability, a collector electrode of a solar cell, dew condensation An exothermic electrode for prevention can be mentioned. As shown in FIG. 4, the conductive mesh 10 is often formed on the transparent base material 35 and forms the conductive mesh sheet 30 together with the transparent base material 35.

  Although depending on the specific application of the conductive mesh sheet 30, the transparent substrate 35 is appropriately configured so as to have appropriate strength and appropriate transparency. As an example, the thickness of the transparent substrate 35 can be 20 μm to 150 μm, and the light transmittance of the transparent substrate 35 may be 80% or more. As such a transparent substrate 35, for example, a resin film such as biaxially stretched polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polypropylene (PP), cyclic polyolefin, acrylic resin, or polycarbonate resin can be used. The biaxially stretched polyethylene terephthalate film is suitable for application as the transparent substrate 35 in that it has moderate transparency and durability against ultraviolet irradiation treatment, heat treatment, and the like. As another example, the thickness of the transparent substrate 35 can be 500 μm to 10000 μm (1 cm). As such a transparent material, for example, glass such as soda glass and potash glass, transparent ceramics such as PLZT, and a quartz plate can be used.

  It is preferable that the conductive mesh 10 having visible light transparency is difficult to visually recognize the connecting element 20. On the other hand, it is preferable that the surface resistance of the conductive mesh 10 is sufficiently low so that the function due to the conductivity expected of the conductive mesh 10 can be sufficiently exhibited. In the case where the conductive mesh 10 is used as described above, the conductive mesh 10 is expressed as follows from the viewpoint of effectively expressing the expected function and ensuring that the conductive mesh 10 has sufficient transparency. Can be designed to First, the line width of the connecting element 20 can be 50 μm or less, preferably 30 μm or less, more preferably 15 μm or less, and even more preferably 10 μm or less. The lower limit of the line width can be, for example, 1 μm or more, preferably 3 μm or more in order to avoid disconnection. Further, the size of one opening region 15 defined by the conductive mesh 10 formed using an opaque material can be set to 50 to 2000 μm. Here, the size of one opening region 15 is the average of the maximum width and the minimum width of the opening region 15 in plan view.

  Note that the dimensions of the conductive mesh 10 such as the line width of the connection element 20 and the size of the opening region 15 do not need to be specified by examining the entire region of the conductive mesh 10 and calculating the average value. Specifically, in consideration of the size of the opening area 15 per one defined by the connection element 20, the object to be calculated (the line width of the connection element 20, the size of the opening area 15, etc.) In a section with an area that can be expected to reflect the overall trend, it is specified by examining the number considered appropriate in consideration of the degree of variation of the object to be calculated and calculating the average value. That's fine. For example, in the conductive mesh 10 manufactured by the manufacturing method described in the next paragraph with the design value described immediately before as a target, 30 points included in a 30 mm × 30 mm region are measured with an electron microscope and averaged. By calculating, the line width of the connection element 20 and the size of the opening region 15 can be specified.

  The conductive mesh 10 as described above is formed by applying a metal film containing copper, aluminum, silver, or an alloy thereof onto the transparent substrate 35 by, for example, vapor deposition, sputtering, foil transfer, coating, or the like. A method of forming and etching the metal film in a desired pattern, or a conductive ink (for example, conductive metal particles such as acrylic resin and polyester resin dispersed in conductive metal particles such as silver, copper and nickel) The ink can be formed on the transparent substrate 35 by a conventionally known method such as a method of printing a desired pattern on the transparent substrate 35.

  Next, the pattern of the conductive mesh 10 will be described in detail with reference mainly to FIGS. 1 to 3 are plan views showing the conductive mesh 10. As described above, the conductive mesh 10 that defines the plurality of opening regions 15 includes a number of conductive connecting elements 20 that extend between the two branch points 25 and define the opening regions 15.

  As shown in FIG. 1 to FIG. 3, the branch point 25 is a corner of the reference pattern 11 formed by laying two types of diamonds 15 </ b> A and 15 </ b> B having the same side length and different inner angles. Is placed on top. In the illustrated example, the connection element 20 extends between two branch points 25 corresponding respectively to two corners forming both ends of the sides of the rhombuses 15A and 15B in the reference pattern 11. In particular, each connecting element 20 is provided corresponding to one of the sides of the rhombuses 15A and 15B. Connection elements 20 are provided corresponding to all sides of the rhombuses 15A and 15B forming the reference pattern 11.

  As shown in FIGS. 1 to 3, the reference pattern 11 is formed by filling the first rhombus 15 </ b> A and the second rhombus 15 </ b> B on a virtual plane. The length of one side of the first rhombus 15A is the same as the length of one side of the second rhombus 15B. In the reference pattern 11, the two rhombuses arranged adjacent to each other overlap one side with each other, in other words, one side of the two rhombuses arranged adjacent to each other is common. However, the inner angle of the first rhombus 15A is different from the inner angle of the second rhombus 15B. Therefore, the first rhombus 15A has an area different from that of the second rhombus 15B.

  In the illustrated reference pattern 11, two types of rhombuses 15A and 15B are planarly filled by an arrangement called a so-called Penrose tile. The inner angles of the first rhombus 15A are 72 ° and 108 °, and the inner angles of the second rhombus 15B are 36 ° and 144 °. In this reference pattern 11, two types of rhombuses 15A and 15B are arranged aperiodically, that is, without regularity.

  And according to the electroconductive mesh 10 produced based on this reference pattern 11, when it overlaps with the member containing the element arranged periodically, for example, the electroconductivity which functions as an electromagnetic shielding material or a sensor for touch panels When the conductive mesh 10 is overlapped with a display panel (image forming apparatus) having a regular pixel arrangement, moire can be made inconspicuous. In addition, according to the conductive mesh 10 manufactured based on the reference pattern 11, glare can be made inconspicuous.

  In this regard, the inventors of the present invention based on the reference pattern 11 formed by plane filling the first rhombus 15A and the second rhombus 15B each having a side of 300 μm so that the line width is 5 μm. Was manufactured by the manufacturing method described above. The produced conductive mesh 10 is placed on a plasma display panel having a pixel pitch of 84 μm (sub-pixel pitch is 28 μm), and the presence or absence of moire and glare is confirmed. None of the glare was found. In addition, confirmation of moire and glare was performed in a state in which the plasma display panel is displaying white on the entire surface, that is, under conditions where the target defect is more easily visible.

  Although details of the reason why both the moire and the glare can be effectively prevented by the conductive mesh 10 are unknown, it is assumed that the following is one of the factors. That is, since the pattern of the conductive mesh 10 is determined based on the reference pattern 11 described above, the arrangement of the opening regions 15 defined by the conductive mesh 10, and in addition, the connection elements forming the conductive mesh 10. The 20 arrays become non-periodic and have no regularity. For this reason, it is thought that generation | occurrence | production of the moire resulting from the electroconductive mesh 10 can be prevented very effectively. On the other hand, since the reference pattern 11 described above is formed by plane-filling only two types of rhombuses 15A and 15B, the branch points 25 that strongly influence the arrangement of the connection elements 20 of the conductive mesh 10 are provided. Evenly distributed. Further, the direction connecting the two branch points 25 that define one connecting element 20 also varies without deviation. As a result, it is considered that the occurrence of glare caused by the conductive mesh 10 can be extremely effectively prevented.

  The exact arrangement of Penrose tiles is symmetrical five times. On the other hand, in a strict Penrose tile, one area including ten rhombuses surrounded by the ten sides shown in FIG. 2 is an area having the same shape as the one area and the one area. By exchanging with other regions in which ten rhombuses are arranged in a different manner, the reference pattern 11 having no 5-fold symmetry can be formed while maintaining the non-periodic planar filling property of the rhombuses. Then, in the same manner as the experiment described above, the inventor actually manufactured the conductive mesh 10 based on the reference pattern 11 that is not a strict Penrose tile arrangement, and combined with the plasma display panel. When the presence or absence of glare was confirmed, it was confirmed that the same effect as the conductive mesh 10 based on the reference pattern 11 of a strict Penrose tile arrangement was exhibited.

  By the way, as described above, the connection element 20 extends between the two branch points 25 respectively corresponding to the two corners forming both ends of the sides of the rhombuses 15A and 15B in the reference pattern 11. In the example shown in FIGS. 1 and 2, the connecting element 20 is linear between the two branch points 25 respectively corresponding to the two corners forming both ends of the sides of the rhombus 15A, 15B in the reference pattern 11. It extends. That is, the connection elements 20 are arranged in the same pattern as the sides of the rhombuses 15A and 15B formed in the reference pattern 11.

  However, as shown in FIG. 3, each connection element 20 does not need to extend linearly between the branch points 25 located at both ends thereof. In the conductive mesh 10 shown in FIG. 3, the connecting element 20 is connected between the two branch points 25 respectively corresponding to the two corners forming both ends of the sides of the rhombus 15A, 15B in the reference pattern 11. It extends along a different route from the side connecting the corners. That is, at least one connecting element 20 included in the conductive mesh 10 may extend in a curved line or a broken line between two branch points 25 located at both ends of the connecting element 20. By forming the connecting element 20 in a non-linear shape, the regularity or periodicity of the connecting element 20 forming the conductive mesh 10 is further weakened. Thereby, it becomes possible to make the moire that may be generated when the conductive mesh 10 is overlapped with a member including an element having other periodicity more effectively inconspicuous.

  When the connection element 20 is formed in a non-linear shape, it is preferable that the connection element 20 does not contact or intersect with the other connection elements 20. That is, it is preferable that only one opening region 15 is formed corresponding to one rhombus 15A, 15B that defines the reference pattern 11. In this case, the connecting element 20 is arranged more evenly, and thereby it is possible to effectively prevent the glare from being visually recognized. In addition, when the connecting element 20 is formed in a non-linear shape, the connecting element 20 has a reference pattern 11 extending linearly between two branch points 25 located at both ends of the connecting element 20, that is, It preferably crosses the side of the diamond that defines the reference pattern 11. In this case, it is possible to prevent the distribution of the connection elements 20 from greatly deviating from the distribution of the sides of the two types of rhombuses 15A and 15B that define the reference pattern 11. As a result, moire can be effectively invisible and glare can be made more inconspicuous.

  Furthermore, in the above-described embodiment, an example in which one connection element 20 is provided for all sides of the rhombuses 15A and 15B that define the reference pattern 11 is shown. One connecting element 20 may be provided for only a part of the rhombuses 15A and 15B that define the pattern 11. In the above-described embodiment, the connecting element 20 extends only between the two branch points 25 respectively corresponding to the two corners forming both ends of the sides of the rhombus 15A, 15B defining the reference pattern 11. However, the present invention is not limited to this. In addition to or instead of the two branch points 25 respectively corresponding to the two corners forming both ends of the sides of the rhombus 15A, 15B defining the reference pattern 11, the connecting element 20 is connected to the rhombus 15A, You may make it extend between the two branch points 25 respectively corresponding to the two corners which make the both ends of the diagonal of 15B. For example, from the viewpoint of effectively avoiding the occurrence of glare, the connecting elements 21 have rhombuses 15A and 15B whose inner angles are equal to or larger than a predetermined angle as shown by two-dot chain lines in FIGS. You may make it extend between the two branch points 25 respectively corresponding to the two corners which make the both ends of the diagonal line extended from this corner. As shown as a two-dot chain line in FIGS. 2 and 3 as a specific example, the connecting element 21 has two branch points 25 respectively corresponding to two corners forming both ends of the shorter diagonal line in each rhombus 15A, 15B. In other words, the inner angles of the rhombuses 15A and 15B in FIGS. 2 and 3 extend between the two branch points 25 respectively corresponding to the two obtuse angles forming the opposite ends of the diagonal line extending from the angle larger than 90 °. May be.

  In the example described above, an example in which all the branch points 25 are located on the corners of any of the rhombuses 15A and 15B in the reference pattern 11 is shown. Even if it is disposed at a position slightly deviated from the corner of 15B, it is possible to expect the effect of preventing both the above-described moire and glare.

<< Use of conductive mesh and conductive mesh sheet >>
Next, an example of the use of the conductive mesh 10 and the conductive mesh sheet 30 having the above configuration and characteristics will be described. As described above, the conductive mesh 10 is, for example, an electromagnetic shielding material that is grounded to shield electromagnetic waves, an electrode for a touch panel sensor of a touch panel device, an antenna having visible light permeability, and a solar cell current collector. It can be used as an electrode or a heating electrode for preventing condensation.

<Electromagnetic wave shielding material>
As shown in FIG. 5, the conductive mesh 10 is a display unit for a television receiver, various measuring devices and instruments, various office devices, various medical devices, computer devices, telephones, electric signs, various game machines, and the like. In an image display device such as a plasma display (PDP) device, a cathode ray tube display (CRT) device, a liquid crystal display device (LCD), or an electroluminescent display (EL) device used for the above-mentioned, it can be incorporated as an electromagnetic shielding material.

  In the example shown in FIG. 5, the image display device 40 includes an image forming device (display unit) 41 that can form an image, and a stacked body 45 that is disposed on the light output side of the image forming device 41. Yes. Therefore, the light emitting surface of the stacked body 45 forms the display surface (light emitting surface) 40 a of the image display device 40, and the observer observes the image formed by the image forming device 41 through the stacked body 45. Become. A conductive mesh sheet 30 as an electromagnetic wave shielding sheet is incorporated in the laminated body 45. The conductive mesh 10 of the conductive mesh sheet 30 extends and spreads in a region where an image of the image forming apparatus 41 is formed. As described above, the conductive mesh 10 can effectively prevent the generation of moire and glare while effectively shielding electromagnetic waves. In addition, although functional sheets, such as an antireflection sheet and a louver, are appropriately incorporated in the laminated body 45, generation of moire between the conductive mesh 10 and other functional sheets is effectively prevented. become.

  In addition, for electromagnetic shielding applications such as windows for buildings such as houses, schools, hospitals, offices, stores, etc., windows for vehicles such as vehicles, aircraft and ships, windows for various household appliances such as microwave oven windows, etc. It can be used. In this example, the window that supports the conductive mesh 10 as the electromagnetic wave shielding material may form the transparent base material 35 in the conductive mesh sheet 30. In this case, it is possible to effectively prevent the generation of moire between the screens and curtains arranged on the windows and the conductive mesh 10 and to receive discomfort due to glare. Effectively prevented.

<Touch pancell sensor>
FIG. 6 discloses a touch panel device 50 including touch panel sensors 51 and 52. The illustrated touch panel device 50 is configured as a projected capacitively coupled touch panel device, and includes a first touch panel sensor 51 and a second touch panel sensor 52 each having an electrode 55 formed on a transparent substrate 35. ing. have. The touch panel device 50 is arranged on the image forming apparatus. The first and second touch panel sensors 51 and 52 include an active area Aa1 facing an area where pixels of the image forming apparatus are arranged, and an active area. And an inactive area Aa2 around Aa1. The electrode 55 includes a detection electrode 60 that is located in the active area Aa1 and used for position detection, and an extraction electrode 70 that is connected to the detection electrode 60 and located in the inactive area Aa2.

  As shown in FIG. 5, each detection electrode 60 is connected to a large number of conductive meshes 10 arranged at intervals in the longitudinal direction, and connection conductors 61 connecting between two adjacent conductive meshes 10. And have. Each detection electrode 60 extends linearly in the active area Aa <b> 1 by the conductive mesh 10 and the connecting conductor 61. The width of the region where each detection electrode 60 is arranged is thicker in the portion where the conductive mesh 10 is provided. Each detection electrode 60 included in one touch panel sensor 51, 52 intersects with a large number of detection electrodes 60 included in the other touch panel sensor 52, 51. As shown in FIG. 5, the conductive mesh 10 of one touch panel sensor 51, 52 is on the detection electrode 60 between intersections of two adjacent detection electrodes 60 of the other touch panel sensor 52, 51. Has been placed.

  In the touch panel device 50, the conductive mesh 10 of the touch panel sensors 51 and 52 is disposed on a region where the pixels of the image forming apparatus 41 are arranged. The conductive mesh 10 functions as the detection electrode 60 due to its excellent conductivity, and can prevent the occurrence of moire and glare as described above.

  The shape of the electrode 55 shown in FIG. 6 is merely an example, and various changes can be made. Further, the conductive mesh 10 and the conductive mesh sheet 30 are not limited to the projected capacitive coupling type touch panel device, and can be applied to various types of touch panel devices.

<Others>
As another application, the conductive mesh 10 functions as an antenna supported by a window. In addition, the conductive mesh 10 functions as a heat generation electrode for preventing condensation supported by the window. In these examples, the window forms the transparent base material 35 of the conductive mesh sheet 30. In these examples, it is possible to effectively prevent the occurrence of moire between the screens and curtains arranged on the windows and the conductive mesh 10, and discomfort due to glare. Is effectively prevented.

DESCRIPTION OF SYMBOLS 10 Conductive mesh 11 Reference pattern 15 Opening area | region 15A 1st rhombus 15B 2nd rhombus 20 Connection element 25 Branch point 30 Conductive mesh sheet 35 Transparent base material 40 Image display apparatus 40a Display surface 41 Display part 45 Laminate body 50 Touch panel apparatus 51 First touch panel sensor 52 Second touch panel sensor 55 Electrode 60 Detection electrode 61 Connection lead 70 Extraction electrode

Claims (5)

A conductive mesh defining a plurality of open areas,
A plurality of conductive connecting elements extending between two branch points to define the open area;
The branch point is located on the corner of the rhombus in a reference pattern formed by laying two types of rhombus with sides having the same length and different inner angles .
The conductive mesh , wherein at least one connecting element extends non-linearly between two branch points respectively corresponding to two corners forming both ends of the side of the rhombus in the reference pattern . Corresponds to one rhombus in the reference pattern, the opening area is made one picture, the conductive mesh of claim 1. The conductive mesh according to claim 1 or 2 ,
A conductive mesh sheet comprising: a transparent base material that supports the conductive mesh. A touch panel device comprising the conductive mesh according to claim 1 or 2 , or the conductive mesh sheet according to claim 3 . An image display device comprising the conductive mesh according to claim 1 or 2 , or the conductive mesh sheet according to claim 3 .

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