JP2014026510A - Electrode substrate for touch panel, touch panel, and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode substrate for a touch panel that suppresses visible recognition of moire caused by interference with pixels of a display panel, a touch panel, and an image display device.SOLUTION: An electrode substrate 10 for a touch panel has a conductor mesh 2 that defines a plurality of opening areas A on a transparent substrate 1; and mesh patterns 2P thereof are formed of a plurality of boundary segments L that extend between two branch points B to define the opening areas, and have mesh patterns that satisfy the following three conditions: (a) the average value N of the number of the boundary segments extending from one branch point is 3.0≤N<4.0; (b) at least two opening areas are included from among an opening area surrounded by five boundary segments, an opening area surrounded by six boundary segments, and an opening area surrounded by seven boundary segments; and (c) opening areas surrounded by six boundary segments are included the most. A touch panel uses the electrode substrate for a touch panel, and an image display device includes the touch panel on a display surface side of a display panel.

Description

  The present invention relates to an electrode base material for a touch panel, a touch panel using the same, and an image display apparatus using the touch panel. In particular, the present invention relates to an electrode substrate for a touch panel, a touch panel, and an image display device in which moire due to interference with a periodic arrangement of pixels of a display panel is difficult to be visually recognized.

  In recent years, touch panels have become widespread as input devices for various electronic devices. Various types of touch panels, such as a resistive film type, have been put into practical use. Among them, a capacitive type touch panel capable of multi-touch (multi-point simultaneous input) is recently attracting attention.

In general, as shown in the cross-sectional view of FIG. 17, the touch panel is made of ITO (indium tin) on one surface of a transparent substrate 41 made of a glass plate, a polyethylene terephthalate film or the like as an electrode substrate 40 for a touch panel. An oxide is used in which a transparent conductive film 42a made of a thin film is formed (Patent Document 1).
However, the transparent conductive film 42a made of an ITO thin film is expensive because a rare metal (rare earth element) called indium is used, and the resistance (surface resistivity) is high in order to increase the area of the touch panel. Therefore, it is difficult to meet the demands for cost reduction and large screen.

  Therefore, instead of the transparent conductive film 42a of the ITO thin film, the transparent base material 41 is made of a metal, as in the touch panel electrode base material 40 shown in the cross-sectional view of FIG. 18A and the plan view of FIG. The thing which formed the metal mesh 42b which consists of a thin line pattern is proposed (patent document 2). According to the metal mesh 42b, the cost and resistance can be reduced compared to the ITO thin film.

JP 2008-310551 A JP 2011-134311 A

  However, the metal mesh 42b is invisible because it is composed of thin fine lines, but has a square lattice-like periodic pattern as shown in FIG. Moire (striped pattern) is visually recognized and it is generally difficult to avoid this.

  That is, an object of the present invention is to provide an electrode substrate for a touch panel in which moire due to interference with a periodic arrangement of pixels of a display panel is difficult to see while using a conductive mesh represented by metal, and a touch panel using the same Is to provide.

Therefore, in the present invention, an electrode substrate for a touch panel, a touch panel, and an image display device having the following configurations are provided.
(1) An electrode substrate for a touch panel having a transparent substrate and a conductor mesh that is formed on at least one surface of the transparent substrate and defines a large number of opening regions,
A mesh pattern that is a planar view shape of the conductor mesh is formed from a plurality of boundary line segments that extend between two branch points to define the opening region,
The mesh pattern is about the branch point, the boundary line segment, and the opening region.
(Condition a) The average value N of the number of boundary line segments extending from one branch point is 3.0 ≦ N <4.0.
(Condition b) An opening area surrounded by five boundary lines, an opening area surrounded by six boundary lines, and an opening area surrounded by seven boundary lines Among these, at least two types of opening regions are included.
(Condition c) The largest number of open areas surrounded by six boundary lines are included.
Including a mesh pattern that satisfies the following three conditions:
Electrode substrate for touch panel.
(2) The mesh pattern satisfying the three conditions further includes:
(Condition d) The shape of the opening region having the same number of border lines surrounding the periphery is not constant.
The electrode substrate for a touch panel as described in (1) above, which is a mesh pattern satisfying 4 and satisfying 4 conditions.
(3) A touch panel comprising the touch panel electrode substrate according to (1) or (2).
(4) An image display apparatus in which the touch panel of (3) is arranged on the display surface side of the display panel.

  According to the present invention, the conductive mesh functions as a transparent conductive film to ensure the transparency and conductivity necessary for the touch panel, and the mesh pattern of the conductive mesh and the periodic arrangement of pixels of the display panel It is possible to make it difficult for the moire due to interference to be visually recognized.

Sectional drawing (A) and top view (B) explaining one Embodiment of the electrode base material for touchscreens by this invention. Sectional drawing explaining another embodiment (double-sided formation) of the electrode base material for touchscreens by this invention. The top view which shows an example of the mesh pattern by this invention. The top view explaining that the direction which has periodicity does not exist in arrangement | positioning of the opening area | region defined by 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 the mesh pattern by 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. 10A and FIG. 10B. The top view which shows the conventional periodic mesh pattern. 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 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 electrode base material for touchscreens. The top view which illustrates typically one Embodiment (surface type capacitive system) of the touchscreen by this invention. The top view which illustrates typically another embodiment (projection capacitive system) of the touchscreen by this invention. The top view explaining the shape (A) of a 1st electrode pattern in FIG. 14, and the shape (B) of a 2nd electrode pattern. Sectional drawing which shows one Embodiment of the image display apparatus by this invention which combined the touch panel by this invention with the display panel. Sectional drawing which shows an example of the conventional electrode base material for touchscreens. Sectional drawing (A) and a top view (B) which show another example of the conventional electrode base material for touch panels.

    Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the drawings are conceptual diagrams, and the scale relations, aspect ratios, and the like of components may be exaggerated as appropriate for convenience of explanation.

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

The “sheet surface” means a surface that coincides with the planar direction when the sheet-like electrode substrate 10 for a touch panel is viewed as a whole and globally.
The “planar shape” means a shape in a plane parallel to the “sheet surface”. In other words, the “planar shape” means a shape viewed from the direction of the normal line set on the “sheet surface”.
The “sheet surface” is usually a surface parallel to the front surface or the back surface of the transparent substrate 1, and in FIG. 1, it is an XY plane or a surface parallel to the XY plane.
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] Touch panel electrode substrate:
First, an electrode substrate for a touch panel according to the present invention will be described with reference to an embodiment shown in FIG. 1A is a cross-sectional view, and FIG. 1B is a plan view.

An electrode substrate 10 for a touch panel according to the embodiment shown in FIG. 1 has a conductor mesh 2 on one side of a transparent substrate 1, and this conductor mesh 2 defines a large number of opening areas A, thereby forming a touch panel. Necessary transparency and conductivity are ensured. Furthermore, the mesh pattern 2P which is the planar view shape of the conductor mesh 2 is a pattern peculiar to the present invention.
That is, the mesh pattern 2P is formed from a large number of boundary line segments L that extend between the two branch points B and define the opening region A. For the branch points B, the boundary line segment L, and the opening region A,
(Condition a) The average value N of the number of boundary line segments extending from one branch point is 3.0 ≦ N <4.0.
(Condition b) An opening area surrounded by five boundary lines, an opening area surrounded by six boundary lines, and an opening area surrounded by seven boundary lines Among these, at least two types of opening regions are included.
(Condition c) The largest number of open areas surrounded by six boundary lines are included.
The pattern includes a mesh pattern satisfying the three conditions.

  For this reason, in the present embodiment, it is possible to make it difficult for the conductor mesh 2 and the mesh pattern 2P to be visually recognized due to interference with the periodic arrangement of pixels of the display panel.

Furthermore, in the present embodiment, the mesh pattern that satisfies the three conditions satisfies
(Condition d) The shape of the opening region having the same number of border lines surrounding the periphery is not constant.
And the mesh pattern satisfies the four conditions of (Condition a), (Condition b) (Condition c), and (Condition d).

  For this reason, in this embodiment, it is possible to make it difficult to visually recognize moire more stably.

  Hereinafter, the present invention will be described in detail for each component.

<Transparent substrate>
The transparent substrate 1 is not particularly limited as long as it is a transparent and electrically insulating substrate. Polyester resin such as polyethylene terephthalate and polyethylene naphthalate, acrylic resin such as polymethyl methacrylate, polyolefin resin such as polypropylene, triacetyl cellulose Cellulose resins such as (cellulose triacetate), resin sheets made of polycarbonate resin, and the like, inorganic plates made of glass, ceramics, and the like can be used.
In general, when an electrode substrate for a touch panel or a touch panel using the same is disposed on the display surface of a liquid crystal display panel, the sheet has a normal biaxially stretched polyethylene terephthalate sheet as the transparent substrate. The rotation effect of the polarization plane of the light emitted from the liquid crystal display panel due to optical anisotropy and the polarization filter effect of the sheet (by increasing the P-polarized component in the transmitted light and the S-polarized component in the reflected light) It is known that interference fringes or iridescent unevenness are visually recognized by the combined effect of the above and image visibility is hindered (see Japanese Patent No. 3947950, Japanese Patent No. 4888853, etc.). Such a problem may also occur in the electrode substrate 10 for a touch panel of the present invention or a touch panel using the same. In order to eliminate such interference fringes or iridescent unevenness, it is effective to use one of the following as the transparent substrate 1.
(1) A material having a small refractive index anisotropy such as a triacetylcellulose sheet.
(2) As disclosed in Japanese Patent No. 3947950, Japanese Patent No. 4888853 and the like, the in-plane retardation value Re is sufficiently larger than that of a normal biaxially stretched polyethylene terephthalate sheet, specifically, Re A polyester resin sheet such as a polyethylene terephthalate sheet stretched at a high stretch ratio (about 3 to 7 times) of ≧ 3000 nm, more preferably Re ≧ 8000 nm. Here, the in-plane retardation value Re is defined as Re = (nx−ny) × d from the phase axis direction refractive index nx, phase advance axis direction refractive index ny, and thickness d in the sheet surface of the resin sheet. Is done.

《Conductor mesh》
The conductor mesh 2 is formed by forming a conductor material with a predetermined mesh pattern 2P. As the conductor material, a highly conductive metal (including these alloys) such as copper, gold, silver, platinum, tin, aluminum, and nickel can be used. In particular, these highly conductive metals have an advantage that the surface resistivity of the surface on which the conductor mesh 2 is formed can be lowered as compared with a metal oxide thin film such as an ITO thin film. The conductive mesh 2 using a highly conductive metal is a known method such as patterning by etching a metal layer such as a metal foil or a metal vapor deposition layer, or a printing method using a conductive paste containing metal powder and a binder resin. It can be formed by a forming method.
As the binder resin, a thermosetting resin, an ionizing radiation curable resin, a thermoplastic resin, or the like can be used. Among them, the acrylate ionizing radiation curable resin is a kind of preferred resin because it cures quickly and is excellent in the strength of the conductor mesh 2.

  If the conductor mesh 2 is allowed, the surface resistivity is higher than that of a metal. However, if the conductor mesh 2 is not completely transparent, such as an ITO thin film or an IZO (indium zinc oxide) thin film, It may be formed of a transparent conductive film with a visible pattern.

  When the conductor mesh 2 is opaque made of metal, the line width of the conductor mesh 2 depends on the invisibility according to the viewing distance and the required area resistivity in the position detection region where transparency is required. Set as appropriate. For example, the line width may 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 is, for example, 1 μm or more, preferably 3 μm or more in order to avoid disconnection.

  In addition, in embodiment shown in FIG. 1, although the conductor mesh 2 is the form formed in the single side | surface of the transparent base material 1, the electrode base material 10 for touchscreens of this invention is embodiment shown by sectional drawing of FIG. As an example, there may be a form in which the conductive mesh 2 is formed on both surfaces of the transparent substrate 1.

  Hereinafter, the mesh pattern 2P characteristic of the present invention will be described.

[Mesh pattern 2P and opening area A defined thereby]
The mesh pattern 2P is a planar view shape of the conductor mesh 2 when the conductor mesh 2 is observed from the normal direction of the sheet surface (Z-axis direction in FIG. 1). Hereinafter, the mesh pattern 2P will be described with reference mainly to FIGS.

As shown in FIGS. 3 and 9, the mesh pattern 2 </ b> P is formed from a number of boundary line segments L that extend between the two branch points B and define the opening region A.
The line portion Lt of the mesh pattern 2P includes a large number of branch points B. The line portion Lt of the mesh pattern 2P 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 2P 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, the perimeter is surrounded by the boundary line segment L and is partitioned to define an open area A as one closed area.

  In the mesh pattern 2P according to the present embodiment, as shown in FIGS. 3 and 9, the line portion Lt is composed only of the boundary line segment L, and therefore, all the boundary line segments L constituting the line portion Lt are mutual. As a result of forming a closed circuit electrically connected to the line region Lt, there is no line portion Lt that does not contribute to the sheet resistivity that extends into the opening region A and becomes a dead end, and does not reduce transparency. According to such an embodiment, it is possible to effectively realize simultaneously imparting sufficient low resistance and high transparency to the conductor mesh 2.

The mesh pattern 2P is about the branch point B, the boundary line segment L, and the opening region A.
(Condition a) The average value N of the number of boundary line segments extending from one branch point is 3.0 ≦ N <4.0.
(Condition b) An opening area surrounded by five boundary lines, an opening area surrounded by six boundary lines, and an opening area surrounded by seven boundary lines Among these, at least two types of opening regions are included.
(Condition c) The largest number of open areas surrounded by six boundary lines are included.
The pattern includes a mesh pattern satisfying the three conditions.

[(Condition a): Number of boundary line segments L extending from one branch point B]
The mesh pattern 2P includes a mesh pattern in which the average value N of the number of boundary line segments L extending from one branch point B is 3.0 ≦ N <4.0. 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 2P is shown in FIG. 11A. It is possible to make the pattern greatly different from the square lattice pattern (N = 4.0). 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 greatly different from the honeycomb arrangement (N = 3.0). It can be a pattern.

  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 branch points B included in the mesh pattern 2P. The average value will be calculated. However, in practice, the overall tendency of the number of boundary line segments L extending from one branch point B in consideration of the size of the opening area A per line defined by the line portion Lt, etc. Boundary extending about a branch point B included in one section having an area expected to reflect (for example, in the mesh pattern 2P in which the opening area A is formed in a dimension example described later, a portion of 10 mm × 10 mm) The number of line segments L is checked and an average value thereof is calculated, and the calculated value may be handled as an average value N of the number of boundary line segments L extending from one branch point B for the mesh pattern 2P. .

  Actually, in the mesh pattern 2P of the conductor mesh 2 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 2P 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.

[(Condition b) and (Condition c): Number of boundary line segments L surrounding the opening area A]
(Condition b) An opening region A surrounded by five boundary line segments L, an opening region A surrounded by six boundary line segments L, and seven boundary line segments L Of the enclosed opening area A, at least two kinds of opening areas A are included. as well as,
(Condition c) The opening region A surrounded by the six boundary line segments L is most often included.
In the above two conditions, the number of boundary line segments L that surround the periphery coincides with the number of corners (or the number of sides) of the polygon when the opening region A is a polygon.
That is, when the boundary line segments L constituting each opening area A are all composed only of straight lines, the opening area A surrounded by the five boundary line segments L is a pentagon, and the six boundary line segments are formed. The opening area A surrounded by L is a hexagon, and the opening area A surrounded by seven boundary line segments L is a hexagon.
Note that the boundary line segment L may be any as long as it does not contact other boundary line segment L such as a straight line, a broken line, or a curved line, as will be described later.

Incidentally, for the mesh pattern 2P of FIG. 10A to be described later, for a total of 4631 open areas A, the number (number) of boundary line segments L that surround the periphery and the number of open areas A for each number of boundary line segments L are as follows. When measured,
3 0
4 79
5 1141
6 2382
7 927
8 94
9 8
10 or more and 0, and the number of boundary lines L surrounding the periphery includes all 5, 6, and 7 opening areas A, and the number of 6 opening areas A is the largest. .

[Effects under 3 conditions]
As a result of intensive research, the inventors of the present invention do not simply make the pattern of the mesh pattern irregular, but a mesh pattern that satisfies the above three conditions (condition a), (condition b), and (condition c). By using the mesh pattern 2P including the conventional touch panel electrode base material 40 having a structure in which the metal mesh 42b is a periodic pattern and a display panel having a periodic pixel arrangement, a moire that can occur is superimposed. It has been found that it can be made very difficult to be visually recognized.
In order to obtain such a moire preventing effect over the entire area of the conductor mesh 2, the entire area of the mesh pattern 2P is made up of the above three conditions (condition a), (condition b), and (condition c). It is preferable that it is comprised only from the mesh pattern which satisfy | fills. In the present embodiment, such a mesh pattern 2P is formed.

[(Condition d); Shape of opening area A]
In addition to the above three conditions (condition a), (condition b), and (condition c), the mesh pattern 2P is further
(Condition d) The shape of the opening region having the same number of border lines surrounding the periphery is not constant.
It is preferable to include a mesh pattern satisfying the above condition and satisfying a total of four conditions.
The meaning of this (condition d) is that all of the opening regions A having the same number of boundary line segments L surrounding the periphery do not have the same shape, and at least one includes a shape different from the remaining opening region A. That means. It is preferable that 50% or more of the opening regions A having the same number of boundary line segments L surrounding the periphery have different shapes.
Here, even when the two opening areas A are congruent figures and have different directions, the shapes of the two opening areas A are considered to be different from each other.

(Area of opening region A)
It is more preferable that the opening area A having the same number of boundary line segments L that surround the periphery has not the same shape but also the area is not constant. In other words, among the opening regions A included in the mesh pattern 2P, the shape and area of all the opening regions A are the same among the opening regions A in which the number of boundary line segments L that surround the periphery is the same. In other words, it means that at least some of the opening regions A are different from others. The mesh pattern 2P in the present embodiment includes such a mesh pattern.
By doing so, it is possible to make the moire more difficult to be visually recognized and to make the light and dark unevenness more difficult to be visually recognized.

[Effects under 4 conditions]
The mesh pattern 2P of the conductor mesh 2 includes a mesh pattern that satisfies the condition (condition d) in addition to the three conditions (condition a), (condition b), and (condition c). Therefore, the moire that can be generated when the conventional touch panel electrode base material 40 having a structure in which the metal mesh 42b is a periodic pattern and the display panel having the periodic pixel arrangement are overlapped is extremely effectively and stably performed. It can be made difficult to see.
In order to obtain such a moire prevention effect over the entire area of the conductor mesh 2, the entire area of the mesh pattern 2P is the above (condition a), (condition b), (condition c) and (condition). It is preferable that it is comprised only from the mesh pattern which satisfy | fills the 4 conditions of d). In the present embodiment, such a mesh pattern 2P is formed.

[No repeat cycle]
In the mesh pattern 2P in the present embodiment, there is no direction having periodicity in the arrangement of the opening regions A.
FIG. 4 is a plan view on a sheet surface parallel to the XY plane with respect to the mesh pattern 2P. In the same figure, the area and shape of the opening area A in which the number of boundary line segments L surrounding the many opening areas A defined by the mesh pattern 2P are the same. And there is no area | region arrange | positioned by the fixed period in the opening area | region A, and there is no repetition period, in other words, the direction which has periodicity does not exist in arrangement | positioning of the opening area | region A. In the figure, one virtual straight line di that faces an arbitrary direction at an arbitrary position is selected.
This one straight line di intersects with the boundary line segment L of the line portion Lt 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 having the dimension t1 on the straight line di. Then, with respect to a straight line di in an arbitrary direction at an arbitrary position, from the boundary line segment L intersecting with the straight line di, a large number of opening regions A that encounter the straight line di in an arbitrary direction at an arbitrary position 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 2P along with the straight line di at the bottom of the drawing for easy understanding.

When this straight line di is rotated at an arbitrary angle from the one shown in FIG. 4 to obtain the dimensions t1, t2,... Of each opening region A in another direction, the straight line is again the same as in FIG. There is no periodicity in the di direction.
That is, there is no direction having a repetition period in the opening area A defined by the boundary line segment L as in the sequence of numerical values of t1, t2, t3,.
In other words, in the arrangement of the opening area A, a number sequence of the arrangement of the dimensions ti of the opening area A on the virtual line segment di in an arbitrary direction passing through an arbitrary position becomes an aperiodic function. That is, there is no M that satisfies t (i) = t (i + M) (i and M are independent positive integers).
Thus, the fact that there is no direction having periodicity in the arrangement of the opening areas A is also expressed as the absence of the direction in which the opening areas A are arranged at a constant repetition period.
Thus, the absence of a direction having periodicity in the arrangement of the opening region A contributes to making it difficult to visually recognize moire.

[Making method of mesh pattern]
Here, an example of a method for creating the mesh pattern 2P unique to the present invention 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. A step of determining a path of L, and a step of determining a thickness of the determined path to define each boundary line segment L and determining a pattern of the mesh pattern 2P (line portion Lt). . Hereinafter, each step will be described in order. Note that the pattern 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, the absolute coordinate system OXY (this coordinate system OXY is an ordinary two-dimensional plane, but in order to distinguish it from the relative coordinate system described later, A first generating point (hereinafter referred to as “first generating point”) BP1 is arranged at an arbitrary position of “absolute”. 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 of radius r (hereinafter referred to as “first circumference”) located on the absolute coordinate system OXY with the first generating point BP1 as the center. The second 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 2P is to be formed. When the mother point cannot be arranged in the region where the mesh pattern 2P is to be formed, the step of creating the mother 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 2P 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.
In FIG. 8A, a Voronoi boundary (see FIG. 9) obtained from these generating point groups is shown by a broken line for reference. From this figure, for example, it can be seen that both generating points of BP3 and BP1 are adjacent to each other, but both generating points of BP3 and BP6 are not 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 this relative coordinate system is that the distance between any two adjacent mother points constituting the mother point group is not a uniform distribution from 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 the size of the opening region A obtained from this (or from The distribution of the area of the opening region A) is not a uniform distribution (completely random) but is distributed within a finite range.

As can be seen from FIG. 8D, the orientation (angle) distribution of another generating point BP viewed from an arbitrary generating point BP is isotropic (or substantially isotropic). This corresponds to the azimuth (angle) distribution of the opening area A in the mesh pattern 2P generated from such generating point (group) BP being isotropic (or substantially isotropic).
By configuring in this way, the surface distribution of the opening region A becomes more uniform, the density of the mesh pattern 2P becomes more uniform, and the brightness unevenness that occurs when the uniformity of transparency when the conductor mesh 2 is viewed is insufficient. Can be made more inconspicuous even more effectively.

In order to prevent moiré and make the light and dark unevenness less noticeable, the distribution of the size D of the opening area A is
D _AVG −3σ ≦ D ≦ D _AVG + 3σ
Where D _AVG is the average value of magnitude D and σ is the standard deviation of the distribution of magnitude D,
3σ = 0.1D _{AVG to} 0.5D _AVG
Is preferable.

Here, the size D of the opening area A is defined as follows for all the opening areas A.
(1) When a circle passing through all the branch points B (all vertices in the case of a polygon) belonging to a certain opening area A can be drawn, the size D is determined by the circumscribed circle diameter of the opening area A. And
(2) If a circle passing through all branch points B (all vertices in the case of a polygon) belonging to a certain opening area A cannot be drawn, the maximum distance between the two branch points B belonging to this opening area A The value D (longest diagonal length in the case of a polygon) is used as the size D.

  In the step of determining the generating point, the size D of the opening area A 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 D of the opening area A, and conversely, by increasing the size of the distance r, The size D 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 perpendicular bisectors by drawing a perpendicular bisector between two adjacent generating points BP and BP. FIG. Here, a line segment composed of vertical bisectors is called a Voronoi boundary XB, an intersection of Voronoi boundaries XB forming the ends of the Voronoi boundary XB is called a Voronoi point XP, and a region surrounded by the Voronoi boundary XB is called a Voronoi boundary XB. This is called area XA.

In the Voronoi diagram created as shown in FIG. 9, each Voronoi point XP forms a branch point B of the mesh pattern 2P. Then, one boundary line segment L is provided between two Voronoi points XP forming the end of one Voronoi boundary XB.
The boundary line segment L may be determined so as to extend linearly between the two Voronoi points XP as shown in the figure, or the two Voronoi points XP within a range not contacting the other boundary line segment L. Various paths (for example, circular (arc), ellipse (arc), fence, hyperbola, sine curve, hyperbolic sine curve, elliptical function curve, Bessel function curve, etc., curved line, etc.) You may do it.
When the boundary line segment L is determined so as to extend linearly between the two Voronoi points XP as shown in the figure, each Voronoi boundary XB defines the boundary line segment L.

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 in consideration of the surface resistivity and transparency obtained by the conductor mesh 2 exhibiting the created mesh pattern 2P. As described above, the pattern of the mesh pattern 2P can be determined.
As typical dimension parameters of the mesh pattern 2P, for example, the line width of the boundary line segment L can be set to 1 to 100 μm, and the average value D _AVG of the size D of the opening region A can be set to 50 to 1000 μm.

[Moire generation due to interference with the pixel arrangement of the display panel]
FIG. 10C shows a state in which the mesh pattern 2P shown in FIGS. 3 and 10A is superimposed on a typical pixel array in the display panel 30 shown in FIG. 10B. As can be understood from FIG. 10C, when the mesh pattern 2P shown in FIG. 3 and FIG. 10A is actually produced and arranged on the pixel array of the display panel 30, there is no moiré that can be visually recognized. .

  Here, the pixel array of the display panel 30 shown in FIG. 10B is a typical pixel array in the display panel 30. As shown in FIG. 10B, in the display panel 30, one pixel P includes a sub-pixel (sub-pixel) Pr that emits red light, a sub-pixel Pg that emits green light, and a sub-pixel Pb 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. 10B, the pixels P are formed as a so-called stripe arrangement. That is, the sub-pixel Pr that emits red light, the sub-pixel Pg that emits green light, and the sub-pixel Pb that emits blue light are sequentially arranged in one direction (vertical direction in FIG. 10B). On the other hand, the subpixel Pr that emits red light, the subpixel Pg that emits green light, and the subpixel Pb that emits blue light are arranged one by one in a direction orthogonal to the one direction (the horizontal direction in FIG. 10B). It has been. 10B shows a state in which the display panel 30 is observed from the normal direction to the image forming surface (light exit 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. 11A to FIG. 11C illustrate the generation of moire when the arrangement of the defined opening areas A is a periodic mesh pattern 42P having periodicity.

FIG. 11A shows a square mesh-like periodic mesh pattern 42P, which is different from the mesh pattern 2P of the present invention.
11C overlays the periodic mesh pattern 42P shown in FIG. 11A on a typical pixel array in the display panel 30 shown in FIG. 11B (same as shown in FIG. 10B). The state is shown. As can be understood from FIGS. 11A, 11B, and 11C, when the electrode substrate 40 for a touch panel having the periodic mesh pattern 42P is arranged on the pixel array of the display panel 30, the periodic mesh pattern 42P and the pixels Due to the interference with the regular pattern, light and dark streaks (light and dark streaks extending from the upper left to the lower right as moire in the example shown in FIG. 11C) are visually recognized.

In the example shown in FIGS. 11A and 11C, the arrangement direction of a large number of straight lines constituting the stripes of the periodic mesh pattern 42P is inclined by several degrees with respect to the arrangement direction of the pixels P. 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. 11C, the degree of moire generation is not determined solely by the bias angle, but in addition, the period ratio of the pixel P and the periodic mesh pattern 42P. This also depends on factors such as the line width of the periodic mesh pattern 42P. In order to eliminate moire only with the bias angle of the periodic mesh pattern 42P, it is necessary to prepare electrode substrates for touch panels having different bias angles according to the design specifications of the display panel 30.
On the other hand, in the mesh pattern 2P unique to the present invention, it is difficult to visually recognize moire on the display panel 30 having various pixel designs with only one type of pattern without considering the bias angle, and practically no moire is visible. The electrode substrate 10 for touch panels with high versatility can be provided.

  As described above, according to the electrode substrate 10 for a touch panel of the present embodiment, it is effectively prevented that moiré can be visually recognized when superimposed on the display panel 30 having the periodically arranged pixels P. can do.

<Deformation>
The electrode base material 10 for touch panels of this invention can take forms other than an above-described form. Some of these will be described below.

[Repetition of mesh pattern 2P as unit pattern area]
In the above-described embodiment, the example in which the direction having periodicity does not exist in the arrangement of the opening region A in the entire region of the mesh pattern 2P has been described.
However, in the present invention, as shown in FIG. 12, the mesh pattern 2P of the conductor mesh 2 in the interior is gathered by arranging the unit pattern areas S in a specific direction to form a mesh pattern. 2P is configured so that a plurality of opening areas A are arranged in a pattern having no predetermined repetition period in each unit pattern area S. Also good.
That is, in this embodiment, two or more unit pattern regions S in which opening region groups are arranged in the same pattern are included in the entire region of the mesh pattern 2P when viewed locally. 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, it is difficult for the moire to be visually recognized in the unit pattern region S. In this example, the pattern of the mesh pattern 2P 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 has recently been increased in size, and for such a large-screen display panel 30, the mesh pattern 2 </ b> P included in the conductive mesh 2 is composed of an array of a plurality of unit pattern regions S. The pattern of the mesh pattern 2P is more preferably configured to include a plurality of unit pattern areas S in which the opening areas A are arranged in the same pattern in each unit pattern area S. This is preferable in that the creation can be made much easier.

  In particular, in an example in which a single type of unit pattern region S is arranged in a plurality of vertical and horizontal directions as shown in FIG. 12, there is 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. 12, 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 this condition, when the dimension of the unit pattern area S in a specific direction is Ls, and the unit pattern area S has M 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 M on the straight line dj. Have. That is, regarding the dimension tj on the straight line dj of the opening region A, the kth dimension tj (k) counted in order on the straight line dj, and the Mth (k + M) th dimension tj (k + M) from there. Is the same, and the relationship of tj (k) = tj (k + M) is established (k and M are independent positive integers).

  However, this regularity is based on the repetition period (the dimension Ls corresponds to the repetition period as described above) as the unit pattern area S, and the repetition period (periodicity) as the opening area A. Instead, in each unit pattern region S, the opening region A does not have periodicity in the arrangement 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. 12, the electrode substrate 10 for touch panel is divided into six unit pattern regions S having the same shape, and each conductor mesh 2 has a mesh pattern in each unit pattern region S. 2P 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. 12 at a repetition cycle SP1, and two regions are arranged in the horizontal direction in FIG. 12 at a repetition cycle SP2. Are arranged as follows.

[Addition of coloring filter]
The electrode substrate 10 for a touch panel of the present invention substantially does not cause moiré due to interference with the periodic arrangement of pixels of the display panel, and does not cause uneven brightness. However, although the cause is currently unknown, when a touch panel using the electrode substrate 10 for a touch panel is installed on the display surface side of the display panel, a fine flicker may occur in an image depending on conditions. In order to make this flicker less conspicuous, the electrode substrate 10 for a touch panel of the present invention has an absorption spectrum in a specific wavelength region in visible light at an appropriate position on the front surface, the back surface, or the constituent layers. It is effective to stack colored filters. That is, the electrode substrate 10 for a touch panel of the present invention can include the colored filter as a constituent layer. The coloring filter may be an achromatic color (black to gray) or a chromatic color (blue, brown, green, etc.), but an achromatic color is preferred in that it has little influence on the color of the image.

[C] Touch panel:
The touch panel according to the present invention is an input device including the touch panel electrode substrate 10 described above.
The electrode base material 10 for a touch panel is incorporated into a touch panel in a form in which a necessary part of the conductor mesh 2 is left and an unnecessary part is removed to form a necessary electrode pattern. Or you may form the said electrode base material 10 for touchscreens by the electrode pattern required from the time of the formation of the conductor mesh 2. FIG. The electrode substrate 10 for a touch panel incorporated in the touch panel may be a pattern formed by other conductive layers such as wiring other than the electrode pattern, or a part or all of the pattern formed by the conductive mesh 2.

13 and 14 show an embodiment of the touch panel 20 of the present invention. FIG. 13 schematically shows a surface-type capacitive touch panel 20. FIG. 14 schematically shows a projected capacitive touch panel 20.
The projected electrostatic capacity method is also attracting attention because it allows multi-touch (multi-point simultaneous input), but a technique that enables multi-touch using other methods has also been proposed.

  A surface-type capacitive touch panel 20 shown in FIG. 13 has a rectangular electrode pattern 3 made of a conductive mesh 2 uniformly on one surface of a transparent substrate 1. A plurality of wirings 5 connected to the outer periphery of the electrode pattern 3 are connected to a control circuit 6 provided outside the transparent base material 1 through a flexible wiring board (not shown). Input position detection is performed.

The projected capacitive touch panel 20 in FIG. 14 includes a first electrode pattern 3a extending in the first direction as shown in FIG. 15A and a second direction as shown in FIG. And a second electrode pattern 3b extending in the direction. The first electrode pattern 3a and the second electrode pattern 3b are electrically insulated from each other.
The first direction and the second direction intersect each other, and are orthogonal to each other in this embodiment. Each of the plurality of first electrode patterns 3a is formed by connecting a plurality of rectangular or rhombic unit electrodes 4a at the corners. Similarly, each of the second electrode patterns 3b is formed by connecting a plurality of rectangular or rhomboidal unit electrodes 4b at the corners.

  As shown in the lower right of FIG. 14, the unit electrode 4a has a mesh pattern 2P unique to the present invention. The plurality of unit electrodes 4a may all be the same mesh pattern 2P. That is, the unit pattern region S described with reference to FIG. 12 corresponds to the unit electrode 4a. The plurality of unit electrodes 4b may be the same, and all the mesh patterns 2P in the plurality of unit electrodes 4a and the plurality of unit electrodes 4b may be the same pattern.

  The formation surface of the 1st electrode pattern 3a and the 2nd electrode pattern 3b has the aspect formed in the same surface of the transparent base material 1, and the aspect which forms each in a different surface. In the latter form formed on different surfaces, an aspect formed separately on both front and back surfaces of the same transparent base material 1 and an aspect formed separately on each one surface of two different transparent base materials 1 There is.

  In the case where the first electrode pattern 3a and the second electrode pattern 3b are formed on the same surface, although not shown, the first electrode pattern 3a and the second electrode pattern 3b The first electrode pattern 3a and the second electrode pattern 3b are provided by providing an insulating layer, a conductive layer, and the like at the crossing portions (the portions connecting the unit electrodes 4a or the unit electrodes 4b). Are electrically insulated from each other.

  The plurality of first electrode patterns 3a and the plurality of second electrode patterns 3b are formed by connecting a flexible wiring board (not shown) to the control circuit 6 provided outside the transparent base material 1 via the wiring 5a and the wiring 5b, respectively. The control circuit 6 performs driving and input position detection.

  As described above, the basic configuration of the capacitive touch panel 20 has been described with reference to FIGS. 13 and 14. In addition to the components described above, a connector, a protective glass, and a protective film provided according to product specifications. Etc., and may include known members.

Further, as the position detection method, the surface-type and projection-type capacitive touch panels have been described as examples, but the touch panel electrode substrate 10 of the present invention or the touch panel 20 using the touch panel has the position. The detection method is not limited to this.
Further, the electrode pattern may have various shapes other than those described above, for example, even in the same projected capacitive touch panel.

[Addition of coloring filter]
When the touch panel 20 according to the present invention is installed on the display surface side of the display panel when the touch panel 20 is installed on the display surface side of the touch panel electrode substrate 10 for the same reason as described above as a modified form of the electrode substrate 10 for touch panel, In order to make this flicker less noticeable, it is preferable to include the colored filter as a constituent layer.

[Addition of anti-reflection treatment]
An antireflection treatment may be applied to the image observer side surface of the touch panel 20 having the electrode member 10 for a touch panel according to the present invention as a constituent element, the display panel 30 side surface, or both the image observer side surface and the display panel 30 side surface. it can. When antireflection treatment is performed on the surface of the image observer, it is possible to prevent image whitening due to reflection of extraneous light such as sunlight and electric light, and deterioration of image visibility due to reflection of surrounding scenery. When the antireflection treatment is performed on the display panel 30 side surface, it is possible to prevent the occurrence of interference fringes (such as a Newton ring), a ghost image, and the like due to optical multiple reflection between the display panel 30 and the touch panel 20. As such an antireflection treatment, a conventionally known one can be appropriately employed. For example, the following (1) to (3) can be adopted.

(1) An antireflection layer comprising a single layer of a low refractive index layer or 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 at the uppermost layer. Silicon oxide, magnesium fluoride, fluorine-containing resin or the like is used for the low refractive index layer, and titanium oxide, zinc sulfide, zirconium oxide, niobium oxide or the like is used for the high refractive index layer. Here, the high (low) refractive index layer means that the refractive index of the layer is relatively higher than the layer adjacent to the layer (for example, the transparent substrate 1 or the low (high) refractive index layer). It means high (low).
(2) A process of roughening the outermost surface on which light is incident in order to scatter or diffuse extraneous light. For this roughening treatment, a method of forming a rough surface directly on the surface of the substrate by sandblasting or embossing or the like; and roughening the surface of the substrate with a resin binder that is cured by radiation or heat, or a combination thereof, Examples include a method of providing a roughened layer with a coating film containing inorganic particles such as silica or organic particles such as resin particles as light diffusing particles; and a method of forming a porous film with a sea-island structure on the surface of the substrate. be able to. As the resin of the resin binder, a thermosetting or ionizing radiation curable acrylic resin, polyester resin, epoxy resin, urethane resin, or the like is preferably used because the surface strength is desired as the surface layer.
(3) A microprojection group in which the distance d between adjacent projections is arranged on the surface with the shortest wavelength λmin or less of the visible light wavelength band as disclosed in Japanese Patent No. 4406553, Japanese Patent No. 4265729, Japanese Patent No. 4632589, etc. The process which forms the micro uneven structure which consists of. The microprotrusions are shaped so that the cross-sectional area at a virtual cut surface perpendicular to the thickness direction decreases as it goes to the outside (adjacent air side). Such a fine concavo-convex structure continuously changes the refractive index of the surface portion with respect to incident light in the thickness direction from the refractive index of the material constituting the microprotrusions toward the refractive index of the external medium (usually air). To function. This can reduce light reflection caused by the refractive index discontinuity at the interface between the object and the external medium.

[D] Image display device:
The image display apparatus according to the present invention is an image display apparatus having a configuration in which the touch panel 20 described above is arranged on the display surface side of the display panel.
The cross-sectional view of FIG. 16 shows an embodiment of the image display device of the present invention. The image display device 100 of FIG. 16 is disposed on the display panel 30 and the light exit surface 30a (screen) of the display panel 30. It is an apparatus having a configuration including at least the touch panel 20 of the present invention.
The display panel 30 may be a liquid crystal display panel, a plasma display panel, an EL (electroluminescent) panel, various display panels such as electronic paper, or a cathode ray tube.

[Addition of coloring filter]
The image display device 100 according to the present invention has a touch panel 20 in order to make the flicker less noticeable when the image has a fine flicker due to the same reason as described as a modification of the electrode substrate 10 for the touch panel. However, it is preferable that the coloring filter is included at an appropriate position on the display surface 30a side of the display panel 30 even if the coloring filter is not included or included.

[E] Application:
The use of the electrode substrate 10 for a touch panel and the touch panel 20 according to the present invention is not particularly limited. However, the use combined with the thing which has a periodic pattern which can produce a moire especially is suitable. For example, the display panel or black and white or color prints represented by halftone dots.
The image display device 100 of the present invention includes a television receiver device, a computer device, a telephone, a measuring instrument, a medical device, an amusement device, an office device, an automatic teller machine, an electronic blackboard, an electronic book terminal, an electronic signboard, a vending machine, and the like. The present invention can be widely applied to an image display apparatus provided with an input unit in a display unit or the like.

DESCRIPTION OF SYMBOLS 1 Transparent base material 2 Conductor mesh 2P Mesh pattern 3, 3a, 3b Electrode pattern 4a, 4b Unit electrode 5, 5a, 5b Wiring 6 Control circuit 10 Electrode base material for touch panels 20 Touch panel 30 Display panel 30a Display surface 40 Conventional touch panel Electrode substrate 41 transparent substrate 42a transparent conductive film 42b metal mesh 42P periodic mesh pattern 100 image display device A opening area B branch point BP generating point L boundary line segment Lt line part (set of boundary line segment)
S Unit pattern area

Claims (4)

An electrode substrate for a touch panel having a transparent substrate and a conductor mesh that is formed on at least one side of the transparent substrate and defines a large number of opening regions,
A mesh pattern that is a planar view shape of the conductor mesh is formed from a plurality of boundary line segments that extend between two branch points to define the opening region,
The mesh pattern is about the branch point, the boundary line segment, and the opening region.
(Condition a) The average value N of the number of boundary line segments extending from one branch point is 3.0 ≦ N <4.0.
(Condition b) An opening area surrounded by five boundary lines, an opening area surrounded by six boundary lines, and an opening area surrounded by seven boundary lines Among these, at least two types of opening regions are included.
(Condition c) The largest number of open areas surrounded by six boundary lines are included.
Including a mesh pattern that satisfies the following three conditions:
Electrode substrate for touch panel. The mesh pattern satisfying the three conditions further includes:
(Condition d) The shape of the opening region having the same number of border lines surrounding the periphery is not constant.
The electrode substrate for a touch panel according to claim 1, wherein the electrode substrate is a mesh pattern satisfying 4 and satisfying 4 conditions.   A touch panel comprising the electrode substrate for a touch panel according to claim 1.   An image display device comprising the touch panel according to claim 3 disposed on a display surface side of a display panel.

Images