Conductive member, touch panel, and display device

This application is a Continuation of PCT International Application No. PCT/JP2018/040106 filed on Oct. 29, 2018, which was published under PCT Article 21(2) in Japanese, and which claims priority under 35 U.S.C. § 119(a) to Japanese Patent Application No. 2017-238573 filed on Dec. 13, 2017. The above applications are hereby expressly incorporated by reference, in their entirety, into the present application.

1. Field of the Invention

The present invention relates to a conductive member arranged on a display panel in which a plurality of pixels are arrayed in a mosaic array or a delta array, a touch panel including the conductive member, and a display device.

2. Description of the Related Art

In recent years, touch panels which are used by being combined with a display device such as a liquid crystal display device in various kinds of electronic devices including portable information devices such as tablet computers and smartphones, and perform an input operation into the electronic devices by causing a finger, a stylus pen, or the like to be contact with or be close to a screen have become popular.

A touch panel typically has a conductive member on which a plurality of detection electrodes and the like for detecting a touch operation with a finger, a stylus pen, or the like are formed. The detection electrode is often formed of a transparent conductive oxide such as indium tin oxide (ITO) but is also formed of a metal other than the transparent conductive oxide. The metal has advantages such as easier patterning, superior bendability, and a lower resistance value as compared with the transparent conductive oxide. Since a resistance value and a parasitic capacitance value can be reduced in a touch panel having a conductive member constituted using thin metal wires compared with a conventional touch panel constituted using a transparent conductive oxide, the detection sensitivity to a touch operation can be improved and attraction has been drawn.

In a case where a conductive member constituted using thin metal wires is arranged on a display panel of a liquid crystal display device or the like, generally, moire generated due to interference between the thin metal wire and a pixel pattern of the display panel is remarkably visually recognized and thus various measures have been taken to reduce the moire. For example, JP2012-164648A discloses a conductive member in which a rhombic mesh pattern constituted by a plurality of thin metal wires is formed on a transparent insulating substrate, and the inner angle of the rhombus is set to 60 degrees to 120 degrees.

However, in a display panel of a liquid crystal display device or the like which has been widely used in the related art, by arranging three sub-pixels in parallel inside each of a plurality of pixels arrayed, a plurality of pixels are arrayed in a so-called stripe array in which the same sub-pixels are aligned in a stripe shape in many cases. The conductive member disclosed in JP2012-164648A is used for a display panel in which a plurality of pixels are arrayed in a stripe array to reduce moire. However, in an organic electroluminescence (EL) display panel that has become popular in recent years, by arranging three sub-pixels to be located at the vertices of the triangle inside each of a plurality of pixels arrayed, the plurality of pixels are arrayed in a so-called mosaic array or a delta array in which sub-pixels of the same color are aligned in an oblique direction in many cases. In a case where the conductive member disclosed in JP2012-164648A is used for such a display panel, there is a problem that moire is remarkably visually recognized.

The present invention has been made in order to solve such a problem in the related art, and an object thereof is to provide a conductive member capable of reducing moire in a display panel in which a plurality of pixels are arrayed in a mosaic array and a delta array, a touch panel, and a display device.

A conductive member according to the present invention is a conductive member includes: a transparent insulating substrate; and at least one conductive layer which has a plurality of thin metal wires and is arranged on the transparent insulating substrate, in which in a case of being viewed from a direction perpendicular to the transparent insulating substrate, a mesh pattern is formed by the plurality of thin metal wires, the mesh pattern is constituted by a plurality of quadrangular mesh cells having two acute angles of less than 90 degrees and two obtuse angles of more than 90 degrees, and a degree of the acute angles is 44 degrees or more and 54 degrees or less.

Further, it is preferable that the degree of the acute angles of the conductive member is 46 degrees or more and 50 degrees or less. In addition, it is preferable that the quadrangular mesh cell in the conductive member has a shape of rhombus.

It is preferable that a length of one side of the rhombus is 168 μm or more and 248 μm or less. It is more preferable that the length of one side of the rhombus is 168 μm or more and 192 μm or less. In addition, it is preferable that a line width of the thin metal wire in the conductive member is 1 μm or more and 4 μm or less.

Two layers of the conductive layers may be arranged on the transparent insulating substrate, and the plurality of thin metal wires of the two conductive layers may be combined with each other to form the mesh pattern. Further, the two conductive layers may be respectively arranged on both surfaces of the transparent insulating substrate to face each other. Alternatively, the two conductive layers may be arranged on one surface of the transparent insulating substrate so as to overlap each other. Further, an interlayer transparent insulating layer may be provided between the two conductive layers.

A touch panel according to the present invention is a touch panel using the above conductive member.

Further, a display device according to the present invention includes a display panel in which a plurality of pixels are arrayed in a mosaic array or a delta array; and a conductive member including a transparent insulating substrate, and at least one conductive layer which has a plurality of thin metal wires and is arranged on the transparent insulating substrate, in which in a case of being viewed from a direction perpendicular to the transparent insulating substrate, a mesh pattern is formed by the plurality of thin metal wires, the mesh pattern is constituted by a plurality of quadrangular mesh cells having two acute angles of less than 90 degrees and two obtuse angles of more than 90 degrees, and a degree of the acute angles is 44 degrees or more and 54 degrees or less.

Further, it is preferable that the plurality of pixels have an array direction in which a plurality of sub-pixels are arrayed so as to repeat an order of a red pixel R, a green pixel G, and a blue pixel B, the quadrangular mesh cells are rhombic mesh cells, and the array direction and a direction along the bisector of the acute angles of the rhombic mesh cells match with each other. It is preferable that the degree of the acute angles in the display device is 46 degrees or more and 50 degrees or less.

It is preferable that a length of one side of the rhombus is 168 μm or more and 248 μm or less. It is more preferable that the length of one side of the rhombus is 168 μm or more and 192 μm or less. In addition, it is preferable that a line width of the thin metal wire in the display device is 1 μm or more and 4 μm or less. It is preferable that two layers of the conductive layers are arranged on the transparent insulating substrate, and the plurality of thin metal wires of the two conductive layers are combined with each other to form the mesh pattern.

The conductive member in the display device may constitute a touch panel. The plurality of pixels in the display device may be constituted by organic EL elements. In addition, it is preferable that a pixel pitch of the plurality of pixels in the display device is 40 μm or more and 110 μm or less.

According to the present invention, since a mesh pattern is formed by the plurality of thin metal wires in a case of being viewed from a direction perpendicular to the transparent insulating substrate, the mesh pattern is constituted by the plurality of quadrangular mesh cells having two acute angles of less than 90 degrees and two obtuse angles of more than 90 degrees, and the degree of the acute angles is 44 degrees or more and 54 degrees or less, it is possible to reduce moire in a display panel in which a plurality of pixels are arrayed in a mosaic array and a delta array.

FIG. 1 is a partial cross-sectional view of a touch panel according to an embodiment of the present invention.

FIG. 2 is a plan view of the touch panel according to the embodiment of the present invention.

FIG. 3 is a partially enlarged plan view of a first conductive layer in the embodiment of the present invention.

FIG. 4 is a partially enlarged plan view of a second conductive layer according to the embodiment of the present invention.

FIG. 5 is a partially enlarged plan view of a conductive member according to the embodiment of the present invention.

FIG. 6 is a partial cross-sectional view schematically showing a display device according to an embodiment of the present invention.

FIG. 7 is a view showing an example of an array of sub-pixels of the display panel according to the embodiment of the present invention.

FIG. 8 is a diagram illustrating an example of an array of pixels of the display panel according to the embodiment of the present invention.

FIG. 9 is a partial cross-sectional view of a touch panel according to a modification example of the embodiment of the present invention.

FIG. 10 is a partial cross-sectional view of a touch panel according to another modification example of the embodiment of the present invention.

Hereinafter, a conductive member according to an embodiment of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings. Hereinafter, the expression “to” indicating a numerical range includes numerical values described on both sides. For example, the expression “s is a numerical value t1 to a numerical value t2” means that the range of s includes the numerical value t1 and the numerical value t2, and t1≤s≤t2 in mathematical symbols. Unless otherwise specified, angles including “orthogonal” and “parallel” include error ranges generally accepted in the technical field. The term “transparent” means that the light transmittance is at least 40% or more, preferably 75% or more, more preferably 80% or more, and still more preferably 90% or more in a visible light wavelength range of 400 to 800 nm. The light transmittance is measured using, for example, “Plastics-A Method of Obtaining Total Light Transmittance and Total Light Reflectance” defined by JIS K7375: 2008.

FIG. 1 shows a configuration of a touch panel 1 according to an embodiment of the present invention. The touch panel 1 has a front surface 1 A and a back surface 1 B, and a display panel described later is arranged on the back surface 1 B side to constitute a display device. The front surface 1 A of the touch panel 1 is a touch surface for detecting a touch operation, and is a viewing side where an operator of the touch panel 1 observes an image displayed on the display device through the touch panel 1 . The touch panel 1 has a transparent insulating cover panel 2 arranged on the front surface 1 A side, and a conductive member 4 is bonded onto a surface of the cover panel 2 opposite to the front surface 1 A via a transparent adhesive layer 3 .

The conductive member 4 has a transparent insulating substrate 5 , and the transparent insulating substrate 5 has a first surface 5 A facing the front surface 1 A side of the touch panel 1 and a second surface 5 B facing a side opposite to the first surface 5 A. A first conductive layer 6 A is formed on the first surface 5 A, and a second conductive layer 6 B is formed on the second surface 5 B of the transparent insulating substrate 5 . As shown in FIG. 1 , a transparent protective layer 7 A covering the first conductive layer 6 A and a transparent protective layer 7 B covering the second conductive layer 6 B may be formed.

FIG. 2 is a plan view of the touch panel 1 when viewed from the viewing side in plan view. FIG. 1 is a cross-sectional view taken along line A-A in FIG. 2 . In addition, in FIG. 2 , the cover panel 2 , the adhesive layer 3 , the protective layer 7 A, and the protective layer 7 B are omitted for the sake of explanation. As shown in FIG. 2 , the conductive member 4 of the touch panel 1 is partitioned into an input region S 1 for detecting a touch operation by a finger and a stylus pen, and an outer region S 2 located outside the input region S 1 .

The first conductive layer 6 A formed on the first surface 5 A of the transparent insulating substrate 5 has a plurality of first detection electrodes SE 1 which are arranged to be parallel in a first direction D 1 at intervals and extend in a second direction D 2 orthogonal to the first direction D 1 . In addition, the first conductive layer 6 A further has a plurality of first electrode pads 11 respectively connected to one end of each of the plurality of first detection electrodes SE 1 , a plurality of first peripheral wirings 12 connected to each of the plurality of first electrode pads 11 , and a plurality of first external connection terminals 13 connected to each of the plurality of first peripheral wirings 12 and formed to be arrayed at the edge portion of the first surface 5 A of the transparent insulating substrate 5 . As the shape of the first electrode pad 11 , for example, the shape of the electrode terminal disclosed in JP2013-127657A can be used.

Here, the first detection electrode SE 1 may include the same electrode pad as the first electrode pad 11 even at the end portion to which the first peripheral wiring 12 is not electrically connected via the first electrode pad 11 . This electrode pad can also be used as a terminal for connecting the first peripheral wiring 12 , and can also be used as a terminal for conduction inspection of the first detection electrode SE 1 .

The second conductive layer 6 B formed on the second surface 5 B of the transparent insulating substrate 5 has a plurality of second detection electrodes SE 2 that are arranged to be parallel at intervals in the second direction D 2 and extend in the first direction D 1 . As shown in FIG. 2 , the plurality of second detection electrodes SE 2 are arranged so as to intersect and overlap with the plurality of first detection electrodes SE 1 in the input region S 1 when viewed from the viewing side.

In addition, the second conductive layer 6 B further has a plurality of second electrode pads 21 respectively connected to one end of each of the plurality of second detection electrodes SE 2 respectively, a plurality of second peripheral wirings 22 connected to each of the plurality of second electrode pads 21 , and a plurality of second external connection terminals 23 connected to each of the plurality of second peripheral wirings 22 and formed to be arrayed at the edge portion of the second surface 5 B of the transparent insulating substrate 5 . Here, the second detection electrode SE 2 may include the same electrode pad as the second electrode pad 21 even at the end portion to which the second peripheral wiring 22 is not electrically connected via the second electrode pad 21 . This electrode pad can also be used as a terminal for connecting the second peripheral wiring 22 , and can also be used as a terminal for conduction inspection of the second detection electrode SE 2 . As the shape of the second electrode pad 21 , similar to the first electrode pad 11 , for example, the shape of the electrode terminal disclosed in JP2013-127657A can be used.

FIG. 3 is a partial plan view when only the first conductive layer 6 A is viewed from the viewing side in plan view in a region R 0 where the first detection electrode SE 1 and the second detection electrode SE 2 overlap each other. As shown in FIG. 3 , the first detection electrode SE 1 is constituted by a plurality of thin metal wires MW 1 , and a first mesh pattern MP 1 is formed by the plurality of thin metal wires MW 1 . The first mesh pattern MP 1 has a rhombic first mesh cell C 1 having two acute angles A 1 and two obtuse angles B 1 as repeating units.

In addition, the line width of the thin metal wire MW 1 is 0.5 μm or more and 10 μm or less, and preferably 1 μm or more and 4 μm or less. By setting the line width of the thin metal wire MW 1 within this range, it is possible to prevent the thin metal wire MW 1 from being remarkably visually recognized in a case where the conductive member 4 is viewed from the viewing side.

FIG. 4 is a partial plan view when only the second conductive layer 6 B is viewed from the viewing side in plan view in the region R 0 . As shown in FIG. 4 , the second detection electrode SE 2 is constituted by a plurality of thin metal wires MW 2 , and a second mesh pattern MP 2 is formed by the plurality of thin metal wires MW 2 . The second mesh pattern MP 2 has a rhombic second mesh cell C 2 having two acute angles A 2 and two obtuse angles B 2 as repeating units. Here, the degree of the two acute angles A 2 of the second mesh cell C 2 is the same as the degree of the two acute angles A 1 of the first mesh cell C 1 , and the degree of the two obtuse angles B 2 of the second mesh cell C 2 is the same as the degree of the two obtuse angles B 1 of the first mesh cell C 1 . Further, the line width of the thin metal wire MW 2 is 0.5 μm or more and 10 μm or less, preferably 1 μm or more and 4 μm or less, similar to the line width of the thin metal wire MW 1 . In addition, for the sake of explanation, in FIG. 4 , the thin metal wire MW 2 constituting the second detection electrode SE 2 is drawn by a broken line, but is actually a continuous thin metal wire.

FIG. 5 shows a partial plan view when the conductive member 4 of the embodiment is viewed from the viewing side in plan view in the region R 0 , that is, when the conductive member is viewed from a direction perpendicular to the transparent insulating substrate 5 . As shown in FIG. 5 , in the conductive member 4 , the first detection electrode SE 1 and the second detection electrode SE 2 are combined with each other, that is, the first mesh pattern MP 1 and the second mesh pattern MP 2 are combined with each other to form a third mesh pattern MP 3 . The third mesh pattern MP 3 is constituted by a rhombic third mesh cell C 3 having two acute angles A 3 and two obtuse angles B 3 .

Here, in FIG. 5 , the first mesh pattern MP 1 and the second mesh pattern MP 2 are arranged to be shifted from each other in the first direction D 1 such that the vertex of the rhombic first mesh cell C 1 matches with the center of the rhombic second mesh cell C 2 , that is, the midpoint of the side of the first mesh cell C 1 matches with the midpoint of the second mesh cell C 2 . Therefore, the third mesh cell C 3 has one side with half the length of one side of the first mesh cell C 1 and half the length of one side of the second mesh cell C 2 , and the first mesh cell C 1 and the second mesh cell C 2 have shapes similar to each other.

Therefore, the degree of the two acute angles A 3 of the third mesh cell C 3 in the embodiment shown in FIG. 5 is the same as the degree of the acute angles A 1 of the first mesh cell C 1 , and the degree of the two obtuse angles B 3 of the third mesh cell C 3 is the same as the degree of the obtuse angles B 1 of the first mesh cell C 1 . In the present invention, by setting the degree of the acute angles A 3 of the third mesh cell C 3 to 44 degrees or more and 54 degrees or less, and more preferably 46 degrees or more and 50 degrees or less, moire can be reduced in a display panel in which a plurality of pixels are arrayed in a mosaic array or a delta array. The present inventors have conducted experiments showing such results, and the experiment results will be described later in detail.

In the present invention, the mosaic array or the delta array refers an array in which sub-pixels of the same color are aligned in an oblique direction by arranging three sub-pixels to be located at the vertices of the triangle inside each of the plurality of pixels arrayed. This mosaic array or delta array will be described later in detail.

The length of one side of the third mesh cell C 3 is preferably 168 μm or more and 248 μm or less, and more preferably 168 μm or more and 192 μm or less. By setting the length of one side of the third mesh cell C 3 within this range, as shown in the experimental results described later, moire can be reduced in a display panel in which a plurality of pixels are arrayed in a mosaic array or a delta array.

Next, a display panel in which the touch panel 1 and the conductive member 4 according to the embodiment are arranged will be described with reference to examples shown in FIGS. 6 to 8 . As schematically shown in FIG. 6 , a display device 31 according to an embodiment of the present invention is constituted by arranging the touch panel 1 on a display panel 32 . At this case, the touch panel 1 is arranged on the display panel 32 such that the back surface 1 B of the touch panel 1 faces the display panel 32 . The display panel 32 on which the touch panel 1 according to the embodiment of the present invention is arranged has a plurality of red pixels R, green pixels G, and blue pixels B as sub-pixels as shown in FIG. 7 .

The plurality of red pixels R, green pixels G, and blue pixels B are arrayed so as to repeat the order of the red pixel R, the green pixel G, and the blue pixel B in the second direction D 2 , and the arrays of the sub-pixels arrayed in this manner are arranged at every array interval L 1 in the first direction D 1 . Further, in the arrays in which the plurality of red pixels R, green pixels G, and blue pixels B are adjacent to each other in the first direction D 1 , the pixels are arranged at positions shifted from each other in the second direction D 2 . Thus, the plurality of sub-pixels of the same color, that is, the plurality of red pixels R, the plurality of green pixels G, and the plurality of blue pixels B are respectively arrayed in a direction parallel to an array axis E inclined with respect to the first direction D 1 and the second direction D 2 . In the present invention, the arrays of the plurality of sub-pixels are referred to as a mosaic array or a delta array. In a so-called organic EL display panel in which a plurality of pixels are constituted by organic EL elements, a plurality of pixels are arrayed in a mosaic array or a delta array in many cases.

In addition, as shown in FIG. 8 , such a mosaic array or delta array is constituted by two kinds of pixels PE 1 and PE 2 . The pixels PE 1 and PE 2 have the same size and shape as each other, and have directions rotated by 180 degrees from each other. In the first direction D 1 , the same pixels PE 1 or PE 2 are arrayed in parallel so as to be adjacent to each other, and in the second direction D 2 , the pixels PE 1 and PE 2 are alternately arrayed in parallel.

These pixels PE 1 and PE 2 each have three sub-pixels of a red pixel R, a green pixel G, and a blue pixel B, as shown in FIG. 8 . Specifically, the pixels PE 1 and PE 2 each have a red pixel R and a green pixel G adjacent to each other in the second direction D 2 , and a blue pixel B adjacent to the red pixel R and the green pixel G in the first direction D 1 .

Here, as the pixel pitches of the pixels PE 1 and PE 2 , a first direction pixel pitch P 1 in the first direction D 1 and a second direction pixel pitch P 2 in the second direction D 2 are determined. In the example shown in FIG. 8 , the first direction pixel pitch P 1 is an arrangement pitch of the same sub-pixels in the first direction D 1 , and the second direction pixel pitch P 2 is an arrangement pitch of the same sub-pixels in the second direction D 2 . The first direction pixel pitch P 1 is twice the array interval L 1 of the sub-pixels adjacent to each other.

In addition, it is preferable that the first direction pixel pitch P 1 and the second direction pixel pitch P 2 are 40 μm or more and 110 μm or less. In a case where the first direction pixel pitch P 1 and the second direction pixel pitch P 2 are set to values within this range, moire generated by interference between the third mesh pattern MP 3 formed on the touch panel 1 and the conductive member 4 according to the embodiment of the present invention and the pattern of the pixels included in the display panel 32 can be further reduced.

In the example shown in FIG. 8 , the red pixel R has a horizontal width LR 1 in the first direction D 1 and a vertical width LR 2 in the second direction D 2 , the green pixel G has a horizontal width LG 1 in the first direction D 1 and a vertical width LG 2 in the second direction D 2 , and the blue pixel B has a horizontal width LB 1 in the first direction D 1 and a vertical width LB 2 in the second direction D 2 .

As described above, according to the touch panel 1 and the conductive member 4 of the embodiment, it is possible to reduce moire in a display panel in which a plurality of pixels are arrayed in a mosaic array or a delta array. Particularly, as shown in FIGS. 5 and 7 , it is preferable to arrange the conductive member 4 on the display panel 32 such that the direction of the acute angles A 3 of the third mesh cell C 3 (the direction along the bisector of the acute angles A 3 ; the second direction D 2 in FIG. 5 ), and the direction in which the plurality of sub-pixels are arrayed in the display panel 32 so as to repeat the order of the red pixel R, the green pixel G, and the blue pixel B (the second direction D 2 in FIG. 7 ) match with each other since moire can be more effectively reduced.

In the embodiment of the present invention, the third mesh pattern MP 3 formed by overlapping the first conductive layer 6 A and the second conductive layer 6 B each other is constituted by the plurality of rhombic third mesh cells C 3 , but the shape of the third mesh cell C 3 is not limited to a shape of rhombus as long as the shape is a quadrangular shape which has two acute angles A 3 of less than 90 degrees and two obtuse angles B 3 of more than 90 degrees and in which the degree of the two acute angles A 3 is 44 degrees or more and 54 degrees or less. Even in a case where the third mesh cell C 3 has such a quadrangular shape, it is possible to reduce moire in a display panel in which a plurality of pixels are arrayed in a mosaic array or a delta array. However, it is preferable that the third mesh cell C 3 has a shape of rhombus since moire can be more effectively reduced. Particularly, it is more preferable that the third mesh cell C 3 has a shape of rhombus, and as shown in FIGS. 5 and 7 , the conductive member 4 is arranged on the display panel 32 such that the direction of the acute angles A 3 of the third mesh cell C 3 (the second direction D 2 in FIG. 5 ), and the direction in which the plurality of sub-pixels are arrayed in the display panel 32 so as to repeat the order of the red pixel R, the green pixel G, and the blue pixel B (the second direction D 2 in FIG. 7 ) match with each other since moire can be most effectively reduced.

In the embodiment of the present invention, the degree of the two acute angles A 1 of the first mesh cell C 1 constituting the first mesh pattern MP 1 and the degree of the two acute angles A 2 of the second mesh cell C 2 constituting the second mesh pattern MP 2 are the same as each other, but as long as the degree of the two acute angles A 3 of the third mesh cell C 3 constituting the third mesh pattern MP 3 is 44 degrees or more and 54 degrees or less, the degree of the two acute angles A 1 of the first mesh cell C 1 may be different from the degree of the two acute angles A 2 of the second mesh cell C 2 .

In addition, as long as the third mesh cell C 3 has a quadrangular shape which has two acute angles of less than 90 degrees and two obtuse angles of more than 90 degrees and in which the degree of the two acute angles is 44 degrees or more and 54 degrees or less, the pattern formed by the thin metal wire MW 1 on the first detection electrode SE 1 and the pattern formed by the thin metal wire MW 2 on the second detection electrode SE 2 are not limited to the rhombic mesh pattern. In this case, for example, although not shown, the pattern formed by the thin metal wire MW 1 on the first detection electrode SE 1 and the pattern formed by the thin metal wire MW 2 on the second detection electrode SE 2 can be designed to form a mesh pattern constituted by quadrangular mesh cells other than the plurality of rhombuses.

Although not shown, in this case, the third mesh cell C 3 can be constituted by the first mesh cell C 1 , the second mesh cell C 2 , and electrode-internal dummy pattern portions that are constituted by a thin metal wire and respectively provided inside the first mesh cell C 1 and the second mesh cell C 2 by providing the electrode-internal dummy pattern portions inside each of the first mesh cell C 1 and the second mesh cell C 2 .

For example, although not shown, a first electrode-internal dummy pattern portion provided inside the first mesh cell C 1 can be constituted by a thin metal wire that is arranged at an interval from the thin metal wire MW 1 constituting the first mesh cell C 1 to be insulated from the thin metal wire MW 1 and to be parallel to the side of the first mesh cell C 1 . In addition, for example, although not shown, a second electrode-internal dummy pattern portion provided inside the second mesh cell C 2 can be constituted by a thin metal wire that is arranged at an interval from the thin metal wire MW 2 constituting the second mesh cell C 2 to be insulated from the thin metal wire MW 2 and to be parallel to the side of the second mesh cell C 2 . Thus, the first electrode-internal dummy pattern portion and the second electrode-internal dummy pattern portion can be constituted such that the third mesh pattern cell C 3 having a quadrangular shape which has two acute angles of less than 90 degrees and two obtuse angles of more than 90 degrees and in which the degree of the two acute angles is 44 degrees or more and 54 degrees or less is formed by the first mesh cell C 1 , the first electrode-internal dummy pattern portion, the second mesh cell C 2 , and the second electrode-internal dummy pattern portion.

In addition, as long as the third mesh cell C 3 has a quadrangular shape which has two acute angles of less than 90 degrees and two obtuse angles of more than 90 degrees and in which the degree of the two acute angles is 44 degrees or more and 54 degrees or less, a mesh pattern may not be formed in each of the first detection electrode SE 1 and the second detection electrode SE 2 . In this case, for example, the thin metal wire MW 1 and the thin metal wire MW 2 can be designed to have a plurality of wavy patterns or a plurality of bending line patterns extending substantially in the first direction D 1 and the second direction D 2 , respectively. Examples of such patterns are disclosed in JP2016-126731A.

Although not shown, dummy electrodes insulated from the plurality of first detection electrodes SE 1 and the plurality of second detection electrodes SE 2 can be arranged between the plurality of first detection electrodes SE 1 arranged to be parallel in the first direction D 1 , and between the plurality of second detection electrodes SE 2 arranged to be parallel in the second direction D 2 , respectively.

In this case, the dummy electrode arranged on the first conductive layer 6 A is insulated from the first detection electrode SE 1 by being arranged at an interval from the first detection electrode SE 1 . In addition, similar to the first detection electrode SE 1 , it is preferable that the dummy electrode arranged on the first conductive layer 6 A is constituted by the thin metal wire MW 1 and has the same pattern as the pattern formed by the thin metal wire MW 1 on the first detection electrode SE 1 . In addition, the dummy electrode arranged on the second conductive layer 6 B is insulated from the second detection electrode SE 2 by being arranged at an interval from the second detection electrode SE 2 . In addition, similar to the second detection electrode SE 2 , it is preferable that the dummy electrode arranged on the second conductive layer 6 B is constituted by the thin metal wire MW 2 and has the same pattern as the pattern formed by the thin metal wire MW 2 in the second detection electrode SE 2 . Thus, in a case where the conductive member 4 is arranged on the display panel 32 , the gap between the plurality of first detection electrodes SE 1 and the gap between the plurality of second detection electrodes SE 2 can be prevented from being remarkably visually recognized. In addition, a disconnection portion may be provided in the thin metal wire arranged in the dummy electrode. It is preferable that the interval between the dummy electrode and the first detection electrode SE 1 , the interval between the dummy electrode and the second detection electrode SE 2 , and the length of the disconnection portion provided in the dummy electrodes are 5 μm or more and 20 μm or less, respectively.

Further, in the embodiment, the conductive member 4 has the first conductive layer 6 A and the second conductive layer 6 B, and the third mesh pattern MP 3 is formed by overlapping the first conductive layer 6 A and the second conductive layer 6 B each other. However, as long as a mesh pattern constituted by, as mesh cells, quadrangles, each of which has two acute angles of less than 90 degrees and two obtuse angles of more than 90 degrees and in which the angle of the two acute angles is 44 degrees or more and 54 degrees or less, in a case where the transparent insulating substrate 5 is viewed from the viewing side is formed, the conductive member 4 is not limited to having two conductive layers. For example, in a case where the first mesh pattern MP 1 in the first conductive layer 6 A is constituted by a quadrangular mesh cell which has two acute angles of less than 90 degrees and two obtuse angles of more than 90 degrees, and in which the degree of the two acute angles is 44 degrees or more and 54 degrees or less, the conductive member 4 may have only the first conductive layer 6 A as a conductive layer. A touch panel constituted by only the first conductive layer 6 A is disclosed in, for example, JP2015-106240A.

In the embodiment of the present invention, although the first conductive layer 6 A is formed on the first surface 5 A of the transparent insulating substrate 5 , and the second conductive layer 6 B is formed on the second surface 5 B of the transparent insulating substrate 5 , that is, the two conductive layers 6 A and 6 B are respectively arranged on both surfaces of the transparent insulating substrate 5 so as to face each other, as long as the first conductive layer 6 A and the second conductive layer 6 B are insulated from each other, the present invention is not limited to this embodiment.

FIG. 9 shows a partial cross-sectional view of a touch panel 41 according to a modification example of the embodiment of the present invention. In the example shown in FIG. 9 , a first conductive layer 6 A is formed on a transparent insulating substrate 42 formed of tempered glass, and an interlayer transparent insulating layer 8 is formed so as to cover the first conductive layer 6 A. Further, a second conductive layer 6 B is formed on the interlayer transparent insulating layer 8 , and a protective layer 7 B is formed so as to cover the second conductive layer 6 B. That is, the two conductive layers 6 A and 6 B are arranged on one surface of the transparent insulating substrate 42 so as to overlap each other. In this case, the interlayer transparent insulating layer 8 covering the first conductive layer 6 A is interposed between the first conductive layer 6 A and the second conductive layer 6 B, and the first conductive layer 6 A and the second conductive layer 6 B are insulated from each other by the presence of the interlayer transparent insulating layer 8 . In addition, in the modification example shown in FIG. 9 , the transparent insulating substrate 42 can be used as the cover panel 2 shown in FIG. 1 . Although not shown, a transparent insulating layer may be provided between the transparent insulating substrate 42 and the first conductive layer 6 A.

FIG. 10 shows a partial cross-sectional view of a touch panel 43 according to another modification example of the embodiment of the present invention. In the modification example shown in FIG. 10 , a first conductive layer 6 A is formed on a first transparent insulating substrate 44 A, and a protective layer 7 A is formed so as to cover the first conductive layer 6 A. In addition, a second conductive layer 6 B is formed on a second transparent insulating substrate 44 B, and a protective layer 7 B is formed so as to cover the second conductive layer 6 B. Further, the protective layer 7 A formed on the first transparent insulating substrate 44 A and the second transparent insulating substrate 44 B are bonded to each other via a transparent adhesive layer 45 . In this case, the protective layer 7 A covering the first conductive layer 6 A, the adhesive layer 45 , and the second transparent insulating substrate 44 B are interposed between the first conductive layer 6 A and the second conductive layer 6 B, and the first conductive layer 6 A and the second conductive layer 6 B are insulated from each other by the presence of the protective layer 7 A, the adhesive layer 45 , and the second transparent insulating substrate 44 B. In addition, in the modification example shown in FIG. 10 , the first transparent insulating substrate 44 can be used as the cover panel 2 shown in FIG. 1 . The conductive member according to the embodiment of the present invention is not limited to the embodiments shown in FIGS. 9 and 10 and may have a structure in which the first conductive layer 6 A and the second conductive layer 6 B are insulated from each other.

In addition, the third mesh pattern MP 3 is constituted by a mesh formed by a regular pattern, but is not limited thereto. The third mesh pattern may be constituted by a mesh formed by an irregular pattern. In this case, as the third mesh cell C 3 constituting the third mesh pattern MP 3 , a quadrangular mesh cell having an irregular side length of −10% to +10% with respect to an average value of the lengths of the sides of the third mesh cell C 3 can be used. As described above, by forming the third mesh cell C 3 to have a random shape, in a case where the touch panel 1 or the conductive member 4 is arranged on the display panel 32 , moire can be reduced and further color noise can be reduced.

Further, in this case, in a case of calculating the average value of the lengths of the sides of the plurality of third mesh cells C 3 , an average value of the lengths of the sides of the third mesh cells C 3 arranged in a region having the predetermined area can be calculated. For example, it is possible to calculate the average of the lengths of the sides of a plurality of mesh cells arranged in a region of 10 mm×10 mm. In addition to the above, as examples of the irregular pattern, mesh patterns disclosed in JP2013-214545A and JP2015-143978A can be used.

Hereinafter, each member constituting the conductive member 4 of the embodiment will be described.

<Transparent Insulating Substrate>

The material of the transparent insulating substrate 5 is not particularly limited as long as the material is transparent, has electric insulation, and can support the first conductive layer 6 A and the second conductive layer 6 B. For example, as the material constituting the transparent insulating substrate 5 , glass, tempered glass, non-alkali glass, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), cyclo-olefin polymer (COP), cyclic olefin copolymer (COC), polycarbonate (PC), acrylic resin, polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), cellulose triacetate (TAC) and the like can be used. The thickness of the transparent insulating substrate 5 is, for example, 20 μm to 1000 μm, and particularly preferably 30 μm to 100 μm. The total light transmittance of the transparent insulating substrate 5 is preferably 40% to 100%. The total light transmittance is measured using, for example, “Plastics-A Method of Obtaining Total Light Transmittance and Total Light Reflectance” defined by JIS K 7375: 2008.

<Thin Metal Wire>

The thin metal wire MW 1 forming the first detection electrode SE 1 and the thin metal wire MW 2 forming the second detection electrode SE 2 are thin metal wires having a line width of 0.5 μm or more and 10 μm or less. A more preferable line width of these thin metal wires is 1 μm or more and 4 μm or less. Preferable materials of the thin metal wires include silver, copper, aluminum, gold, molybdenum, chromium, and the like, and alloys and oxides thereof or laminates thereof can be used. Particularly, from the viewpoint of the resistance value, silver or copper is preferable, and for example, a thin metal wire having a laminated configuration such as molybdenum/aluminum/molybdenum, molybdenum/copper/molybdenum, or copper oxide/copper/copper oxide can be used. The film thickness of the thin metal wires MW 1 and MW 2 is 0.05 μm or more and 10 μm or less, and preferably 0.1 μm or more and 1 μm or less. For the purpose of improving the visibility of the thin metal wire, a blackening layer may be provided on the thin metal wire or between the thin metal wire and the transparent insulating substrate 5 and the thin metal wire. For the blackening layer, copper oxide, molybdenum oxide, or the like can be used.

<Protective Layer>

As the transparent protective layers 7 A and 7 B respectively covering the thin metal wires MW 1 and MW 2 , organic films of gelatin, acrylic resin, urethane resin and the like and inorganic films of silicon dioxide and the like can be used, and the film thickness is preferably 0.01 μm or more and 10 μm or less. As necessary, a transparent coat layer may be formed on the protective layer. As the transparent coat layer, an organic film of acrylic resin, urethane resin or the like is used, and the film thickness is preferably 1 μm or more and 100 μm or less.

In addition, as necessary, the following layers can be additionally provided to the conductive member 4 of the embodiment.

<Peripheral Wiring Insulating Film>

A peripheral wiring insulating film may be formed on the first peripheral wiring 12 and the second peripheral wiring 22 shown in FIG. 2 for the purpose of preventing a short circuit between the peripheral wirings and corrosion of the peripheral wirings. As the peripheral wiring insulating film, an organic film of acrylic resin, urethane resin or the like is used, and the film thickness is preferably 1 μm or more and 30 μm or less. The peripheral wiring insulating film may be formed on only one of the first peripheral wiring 12 and the second peripheral wiring 22 .

<Undercoat Layer>

An undercoat layer may be provided between the transparent insulating substrate 5 and the first conductive layer 6 A or between the transparent insulating substrate 5 and the second conductive layer 6 B to enhance adhesiveness. As the undercoat layer, organic films of gelatin, acrylic resin, urethane resin, polyester resin and the like, and inorganic films of silicon dioxide and the like can be used, and the film thickness is preferably 0.01 μm or more and 10 μm or less.

<Flattening Layer>

A flattening layer may be provided between the transparent insulating substrate 5 and the first conductive layer 6 A or between the transparent insulating substrate 5 and the second conductive layer 6 B to flatten the surface of the transparent insulating substrate 5 . As the flattening layer, organic films of acrylic resin, urethane resin, polyester resin and the like can be used, and the film thickness is preferably 0.01 μm or more and 10 μm or less. Particularly, in a case where a decorative layer (not shown) is provided on the transparent insulating substrate 5 , it is preferable to provide the flattening layer.

<Circularly Polarizing Plate or Polarizing Plate>

In the configuration of the touch panel 1 shown in FIG. 1 , a circularly polarizing plate or a polarizing plate may be provided between the cover panel 2 and the conductive member 4 .

The conductive member 4 according to the embodiment of the present invention preferably has a shape of a conductive sheet. This sheet shape may be a film shape. Further, the conductive member 4 according to the embodiment of the present invention is preferably used for a touch sensor, and the touch sensor is preferably used for a touch panel.

Hereinafter, the present invention will be described in more detail based on the following examples. The materials, amounts used, ratios, treatment contents, treatment orders, and the like shown in the following examples can be appropriately changed without departing from the gist of the present invention, and the scope of the present invention should not be interpreted in a limited manner by the examples described below.

First, a method of producing the conductive member 4 according to the embodiment of the present invention will be described in detail.

(Preparation of Silver Halide Emulsion)

To the following liquid 1 kept at a temperature of 38° C. and a pH (potential of hydrogen) of 4.5, each of the following liquids 2 and 3 was simultaneously added in an amount corresponding to 90% with stirring over 20 minutes, thereby forming nucleus particles of 0.16 μm. Subsequently, the following liquids 4 and 5 were added over 8 minutes, and the remaining liquids 2 and 3 were added in an amount of 10% over 2 minutes, thereby growing the particles to 0.21 μm. Further, 0.15 g of potassium iodide was added, the mixture was ripened for 5 minutes, and then the particle formation was completed.

Liquid 1:

Liquid 2:

Liquid 3:

Liquid 4:

Liquid 5:

Thereafter, the resultant was washed with water by a flocculation method according to a usual manner. Specifically, the temperature was lowered to 35° C., 3 liters of distilled water was added, and the pH was lowered by using sulfuric acid until the silver halide was precipitated (in a range of pH 3.6±0.2). Next, about 3 liters of the supernatant was removed (first water washing). Further, 3 liters of distilled water was added and then sulfuric acid was added until the silver halide was precipitated, 3 liters of the supernatant was removed again (second washing). The same operation as the second washing was repeated once or more (third washing), thereby completing a water washing and desalting step. The emulsion after the water washing and desalting was adjusted to a pH of 6.4 and a pAg of 7.5, 3.9 g of gelatin, 10 mg of sodium benzenethiosulfonate, 3 mg of sodium benzenethiosulfinate, 15 mg of sodium thiosulfate, and 10 mg of chloroauric acid were added, chemical sensitization was performed so as to obtain optimum sensitivity at 55° C., and 100 mg of 1,3,3a,7-tetraazaindene as a stabilizer and 100 mg of PROXEL (trade name, manufactured by ICI Co., Ltd.) as a preservative were added. The finally obtained emulsion was a silver iodochlorobromide cubic grain emulsion containing 0.08% by mole of silver iodide, having a proportion of silver chlorobromide of 70% by mole of silver chloride and 30% by mole of silver bromide, and having an average grain size of 0.22 μm and a coefficient of variation of 9%.

(Preparation of Composition for Forming Photosensitive Layer)

To the emulsion, 1.2×10 −4 moles/mole Ag of 1,3,3a,7-tetraazaindene, 1.2×10 −2 moles/mole Ag of hydroquinone, 3.0×10 −4 moles/mole Ag of citric acid, 0.90 g/mole Ag of 2,4-dichloro-6-hydroxy-1,3,5-triazine sodium salt, and a trace amount of a hardening agent were added, and the resulting coating liquid was adjusted to have a pH of 5.6 by using citric acid.

To the coating liquid, a polymer latex containing a polymer represented by (P-1) and a dispersant including dialkylphenyl PEO sulfuric acid ester (the mass ratio of dispersant/polymer was 2.0/100=0.02) was added such that a mass ratio of the polymer to the gelatin contained in the coating liquid was 0.5/1.

Further, as a crosslinking agent, EPOXY RESIN DY 022 (trade name: manufactured by Nagase ChemteX Corporation) was added thereto. The amount of the crosslinking agent added was adjusted such that the amount of the crosslinking agent in the photosensitive layer, which will be described later, became 0.09 g/m 2 .

In this manner, a composition for forming a photosensitive layer was prepared.

The polymer represented by (P-1) above was synthesized with reference to JP3305459B and JP3754745B.

(Photosensitive Layer Forming Step)

The polymer latex described above was applied to both surfaces of the transparent insulating substrate to provide an undercoat layer having a thickness of 0.05 μm. As the transparent insulating substrate, a 38 μm polyethylene terephthalate film (manufactured by Fujifilm Corporation) was used.

Next, on the undercoat layer, an antihalation layer formed of a mixture of the polymer latex, gelatin, and a dye decolored by alkali of a developer with an optical density of about 1.0 was provided. The mixing mass ratio of the polymer and gelatin (polymer/gelatin) was 2/1, and the content of the polymer was 0.65 g/m 2 .

The composition for forming a photosensitive layer was applied onto the antihalation layer, and a composition obtained by mixing the polymer latex, gelatin, EPOCROSS K-2020E (trade name: manufactured by Nippon Shokubai Co., Ltd., oxazoline-based crosslinking reactive polymer latex (crosslinkable group: oxazoline group)), and SNOWTEX C (registered trademark, trade name: colloidal silica, manufactured by Nissan Chemical Industries. Ltd.) at a solid content mass ratio (polymer/gelatin/EPOCROSS K-2020E/SNOWTEX C (registered trademark)) of 1/1/0.3/2 was applied such that the amount of gelatin became 0.08 g/m 2 , thereby obtaining a support having photosensitive layers formed on both surfaces. The support having photosensitive layers formed on both surfaces is referred to as a film A. The formed photosensitive layer had a silver amount of 6.2 g/m 2 and a gelatin amount of 1.0 g/m 2 .

(Exposure and Development Step)

For example, a first photo mask for forming a first detection electrode having a pattern as shown in FIG. 3 and a second photo mask for forming a second detection electrode having a pattern as shown in FIG. 4 were respectively prepared, and then the first photo mask and the second photo mask were respectively arranged on both surfaces of the film A to simultaneously expose the both surfaces to parallel light using a high pressure mercury lamp as a light source.

After the exposure, the film was developed with the following developer, and further subjected to a development treatment using a fixing solution (trade name: N3X-R for CN16X, manufactured by Fujifilm Corporation). Further, the support was rinsed with pure water and dried, thereby obtaining a support having a thin metal wire formed of Ag (silver) and a gelatin layer formed on both surfaces. The gelatin layer was formed between the thin metal wires. The obtained film is referred to as a film B.

(Composition of Developer)

The following compounds were contained in 1 liter (L) of the developer.

(Gelatin Decomposition Treatment)

The film B was immersed in an aqueous solution (concentration of protease: 0.5% by mass, liquid temperature: 40° C.) of a proteinase (BIOSEPLASE AL-15FG, manufactured by Nagase ChemteX Corporation) for 120 seconds. The film B was taken out of the aqueous solution and washed by being immersed in hot water (liquid temperature: 50° C.) for 120 seconds. The film after the gelatin decomposition treatment is referred to as a film C.

<Resistance Lowering Treatment>

The film C was subjected to a calendering treatment at a pressure of 30 kN using a calendering device including metal rollers. At this time, two polyethylene terephthalate films having a rough surface shape with a line roughness Ra=0.2 μm and Sm=1.9 μm (measured with a shape analysis laser microscope VK-X110, manufactured by KEYENCE CORPORATION (JIS-B-0601-1994)) were handled together such that the rough surfaces thereof faced the front and back surfaces of the film C, and the rough surface shapes were transferred and formed on the front and back surfaces of the film C.

After the above calendering treatment, a heating treatment was performed by allowing the film to pass through a superheated vapor tank at a temperature of 150° C. for 120 seconds. The film after the heat treatment is referred to as a film D. This film D is a conductive member.

<Production of Touch Panel>

By the above method, a conductive member including the first detection electrode having the same shape as the first detection electrode SE 1 in the embodiment shown in FIG. 3 and the second detection electrode having the same shape as the second detection electrode SE 2 in the embodiment shown in FIG. 4 was produced. In this case, the first detection electrode and the second detection electrode had a rhombic mesh shape formed by the thin metal wires, and the line width of the thin metal wire was 4.0 μm. A dummy electrode having the same rhombic mesh shape as the detection electrode formed by a thin metal wire having a line width of 4.0 μm was arranged between the first detection electrodes and between the second detection electrodes. In addition, for the evaluation, a plurality of conductive members were produced by changing the degree of the acute angles of the rhombic mesh cell and the length of one side of the rhombic mesh cell in the mesh pattern formed by combining the first detection electrode and the second detection electrode with each other.

Further, a plurality of touch panels were produced by bonding each of the plurality of conductive members produced to a cover panel formed of tempered glass having a thickness of 1.1 mm using an optically transparent pressure adhesive sheet having a thickness of 75 μm and formed of #8146-4 (product number), manufactured by 3M Corporation.

Next, Examples 1 to 6 and Comparative Examples 1 to 5 will be described. Examples 1 to 6 and Comparative Examples 1 to 5 are touch panels having the same configuration as the touch panel 1 according to the embodiment of the present invention shown in FIGS. 1 to 5 , and the degrees of the acute angles A 3 of the rhombic third mesh cells C 3 of each touch panel are different from each other. Examples 1 to 6 and Comparative Examples 1 to 5 included a plurality of samples prepared by changing the length of one side of the third mesh cell C 3 , respectively and the length of one side of the third mesh cell C 3 of each sample was 160 μm, 168 μm, 176 μm, 184 μm, 192 μm, 200 μm, 208 μm, 216 μm, 220 μm, 228 μm, 232 μm, 240 μm, 248 μm and 252 μm.

1 , 41 , 43 : touch panel

1 A: front surface

1 B: back side

2 : cover panel

3 , 45 : adhesive layer

4 : conductive member

5 , 42 : transparent insulating substrate

6 A: first conductive layer

6 B: second conductive layer

7 A, 7 B: protective layer

8 : interlayer transparent insulating layer

12 : first peripheral wiring

13 : first external connection terminal

14 : first electrode pad

22 : second peripheral wiring

23 : second external connection terminal

24 : second electrode pad

31 : display device

32 : display panel

44 A: first transparent insulating substrate

44 B: second transparent insulating substrate

A 1 , A 2 , A 3 : acute angle

B: blue pixel

B 1 , B 2 , B 3 : obtuse angle

C 1 : first mesh cell

C 2 : second mesh cell

C 3 : third mesh cell

D 1 : first direction

D 2 : second direction

E: array axis

G: green pixel

L 1 : array interval

LB 1 , LG 1 , LR 1 : horizontal width

LB 2 , LG 2 , LR 2 : vertical width

MP 1 : first mesh pattern

MP 2 : second mesh pattern

MP 3 : third mesh pattern

MW 1 , MW 2 : thin metal wire

P 1 : first direction pixel pitch

P 2 : second direction pixel pitch

PE 1 , PE 2 : pixel

R: red pixel

R 0 : region

S 1 : input region

S 2 : outer region

SE 1 : first detection electrode

SE 2 : second detection electrode