TW201523381A - Conductive film, touch panel and display device provided with the same, and method for evaluating visibility of wiring - Google Patents

Abstract

A conductive film obtaining a quantitative value, less than a predeterminded threthold value, of vibility of a wiring according to following vlauses is provided. The vlause includes a sum of all peak intensities, an area ratio of a wiring region and an intensity difference of the wiring and a background. The all peak intensities are obtained from peak intensities of a plurality of spectrals in a two-dimensional Fourier spectrum of pixel values of a photographic image of the wiring in the conductive film in which a person's visual response characteristic is affected. The area ratio of the wiring region is provided by dividing the pixel values of the photographic image of the wiring into the wiring region and a background region. The intensity difference of the wiring and the background is provided by a difference of an average value between the two regions.

Description

Conductive film, touch panel provided therewith, display device, and method for evaluating visibility of wiring

The present invention relates to a method for evaluating the visibility of a conductive film, a touch panel and a display device including the same, and a wiring of a conductive film.

As a conductive film provided on a display unit of a display device (hereinafter also referred to as a display), there is a conductive film in which a fine conductive pattern (wiring) is provided on a transparent film, and a touch panel feeling is exemplified. Uses such as a touch panel sensor or an electromagnetic wave shield (for example, refer to Patent Document 1).

In the case where the conductive film is used for the touch panel sensor, a wiring conductive pattern (wiring pattern) formed by wiring of a metal thin wire or the like is present on the conductive film, so that the wiring itself can be seen. In particular, when the display unit is not lit, the wiring is visible, and the visibility of the wiring which becomes granular noise is a problem for the user, and depending on the degree, the image quality may be hindered.

Therefore, Patent Document 1 proposes a method in which two conductive micropatterns each including a linear trace of an open mesh in which a cell shape is repeatedly defined and electrically insulated from each other are provided. In a touch screen sensor in which the overlap is formed, a part in which the linear tracks are not parallel to each other, a part in which the honeycomb shapes of the two are different from each other, and a honeycomb size of the two are different from each other. At least one of the portions, and a threshold corresponding to the observation distance is set for the spatial contrast of the wiring, thereby obtaining low visibility of the conductive pattern of the touch screen sensor.

[Prior Art Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2012-519329 (WO 2010/099132 A2)

However, although Patent Document 1 discloses a condition for obtaining a low-visibility conductive pattern when used as a touch screen sensor, Patent Document 1 is used in addition to the use for a touch screen sensor. The use of a conductive film, such as an antenna, an electromagnetic interference (EMI) shield, and a pattern substrate, is merely a combination of two conductive micropatterns that are superimposed on the conductive film. In the combination of the regularity reduction, there is a problem that the visibility of the wiring of the physical sample of the touch panel display device in which the touch screen sensor is provided on the display unit of the display device cannot be evaluated as a quantitative value.

Moreover, the model disclosed in Patent Document 1 takes into consideration the wiring pattern. A quantitative model of the overall reflection intensity and the human visual sensitivity. However, when various samples having a change in the reflection intensity in the wiring pattern are mixed, Patent Document 1 which takes into consideration the reflection intensity of the entire wiring pattern and the human visual sensitivity is disclosed. In the quantitative model, there is a problem that all samples cannot be expressed.

Further, in the capacitance type conductive film, there are a top (Top) wiring and a bottom (Bottom) wiring, and the characteristics of the wiring also vary depending on the prescription (manufacturing method of the wiring), and thus, for example, by changing the transparent substrate (Thickness or material of polyethylene terephthalate (PET)), a process of fixing a metal such as silver as a wiring on a transparent substrate, and the like, thereby changing the reflection characteristics of the wiring, thereby causing background and wiring. A phenomenon of poor reflection intensity occurs between the top or bottom-bottom wiring.

Therefore, in the samples of the same prescription, the reflection intensity of the wiring pattern between the samples does not locally differ. Therefore, even if the quantitative model disclosed in Patent Document 1 is used, the quantitative evaluation can be performed, that is, the visual correspondence can be achieved. However, there is a problem that if the samples of different prescriptions are also included, the reflection intensity of the wiring pattern between the samples is locally different, and the visual correspondence cannot be obtained in the existing model, so that the wiring visibility cannot be evaluated as a quantitative value. .

The present invention solves the problems of the prior art, and an object thereof is to provide a conductive film, a touch panel and a display device therewith, and a conductive film, for example, a conductive film disposed on a display unit Visibility of the wiring The evaluation method of the visibility of the wiring which can be quantitatively evaluated even when the display unit is not lit, and the conductive pattern (wiring pattern) of the conductive film For example, in the case where the conductive film provided on the display unit is used for a touch panel sensor or the like, even the final product form provided on the display unit, for example, as a touch panel on the display unit, is sensed. The shape of the actual sample used in the device does not see the wiring itself, especially when the display unit is not lit, the wiring can be prevented, and the image quality can be prevented or reduced, so that the visibility of the wiring can be improved or improved. As a result, even when it is placed on the display screen of the display unit, the visibility can be greatly improved.

In order to achieve the above-mentioned object, the present inventors have proposed a technique of photographing a wiring pattern of a conductive film from the sum of peaks in the frequency space of the wiring and utilizing the technique of Japanese Patent Application No. 2013-181123. A quantitative value is calculated by weighting a visual transfer function (VTF) (human visual sensitivity function), and the visibility of the wiring of the conductive film is quantitatively evaluated, and a conductive film having excellent visibility is provided, and the conductive film is provided. Touch panel and display device.

However, it has been found that this technique is also a quantitative model in consideration of the reflection intensity of the entire wiring pattern and the human visual sensitivity, and therefore the problem of the prior art disclosed in Patent Document 1 cannot be solved by this technique, that is, There are various problems that arise from samples having varying reflection intensities in the wiring pattern.

Therefore, the inventors of the present invention have repeatedly conducted active research to solve the problems of the prior art, and found that the reflection intensity and the person's view are reflected on the entire wiring pattern. The feature amount of the sense sensitivity (the feature amount in the frequency space) plus the feature amount (the feature amount in the real space) reflecting the difference in the reflection intensity in the pattern, and the visibility of the wiring is quantified, whereby the conductive film can be applied The visibility of the wiring is quantitatively evaluated, so that a conductive film capable of improving the visibility of the wiring can be provided, thereby completing the present invention.

That is, the conductive film according to the first aspect of the present invention includes: a transparent substrate; and a conductive portion formed on at least one surface of the transparent substrate and including a plurality of metal thin wires; and the conductive film is characterized in that the conductive portion includes a wiring pattern The wiring pattern is formed in a mesh shape by a plurality of metal thin wires and includes wirings in which a plurality of openings are arranged, and the quantitative value of visibility of the wiring obtained based on the following values is a predetermined threshold or less, and the numerical value is The sum of the second peak intensities (in the second peak frequency) is obtained by applying a human visual response characteristic to the first peak intensity, which is an incident angle 45 in a darkroom environment. ° The signal value of the light per unit time obtained by dividing the signal value of the black light as the reference from the front side by the exposure time is set to a predetermined specification value, and the light is irradiated to the conductive film at an incident angle of 45° in a dark room environment. a plurality of spectral peaks in the two-dimensional Fourier spectrum of the pixel value of the captured image of the wiring pattern obtained as the specification value obtained by the front side (the first peak frequency) The peak intensity; the area ratio of the wiring area to the entire image of the wiring pattern, the wiring area including the pixel value of the captured image of the wiring pattern wiring, and the pixel value and background of the wiring The pixel value of the wiring at the pixel value; and the difference in the intensity of the wiring from the background, which is the average of all the pixel values in the wiring area and all the pixels in the remaining background area including the background The difference between the average values of the values is obtained.

In order to achieve the above object, a touch panel according to a second aspect of the present invention includes: a conductive film according to a first aspect; and a detection control unit that detects a contact position or a proximity position on a surface side of the conductive film; The conductive film and the detection control unit function as a touch panel sensor.

In addition, the display device according to the third aspect of the present invention includes the display unit and the conductive film of the first aspect, which is provided on the display unit.

Here, in the third aspect, it is preferable to further include a detection control unit that detects a contact position or a proximity position from the surface side of the conductive film, and the conductive film and the detection control unit function as a touch panel sensor. Features.

In order to achieve the above object, the method for evaluating the visibility of the conductive wiring according to the fourth aspect of the present invention is a method for evaluating the visibility of the wiring of the conductive film having the wiring pattern of the wiring, wherein the wiring pattern of the wiring is made of a plurality of metals The fine line is formed in a mesh shape and has a plurality of openings arranged therein, and the method for evaluating the visibility of the conductive wiring includes a black light that is irradiated with an incident angle of 45° in a dark room environment and is photographed from the front as a reference. The signal value is divided by the exposure time, and the signal value per unit exposure time obtained by the exposure time is a predetermined specification value. The conductive film is irradiated with light at an incident angle of 45° in a dark room environment, and the wiring pattern is obtained from the front side to obtain a wiring pattern. The pixel value of the captured image of the wiring is used as the specification value; the two-dimensional Fourier transform is performed on the pixel value of the captured image of the wiring of the obtained wiring pattern, and the two-dimensional Fourier of the pixel value of the captured image of the wiring is calculated. The first peak intensity of the plurality of spectral peaks in the spectrum (in the first peak frequency); the visual response characteristic of the human being acts on the observation distance The second peak intensity (of the second peak frequency) is calculated from the first peak intensity of the calculated wiring pattern (at the first peak frequency), and the obtained second peak (of the second peak frequency) is obtained. The sum of the intensities; the pixel value of the image of the wiring pattern is binarized and separated into the pixel value of the wiring and the pixel value of the background, and the wiring area including the pixel value of the separated wiring is obtained with respect to The area ratio of the entire image of the wiring pattern; the average value of all the pixel values in the wiring area and the average value of all the pixel values in the remaining background area including the background, and the obtained two average values The difference is the difference between the strength of the wiring and the background; the total of the obtained second peak intensity, the area ratio of the wiring area to the entire image of the wiring pattern, and the difference in the intensity between the wiring and the background to determine the visibility of the wiring. The value is a linear sum; the quantitative value of the visibility of the obtained wiring is evaluated by the visibility of the wiring of the conductive film having a predetermined threshold or less.

Here, in each aspect, it is preferable to set the total of the second peak intensity to x ₁ , the area ratio of the wiring region to x ₂ , the difference in the intensity between the wiring and the background to x ₃ , and the wiring. When the quantitative value of the visibility is E, the quantitative value E is obtained as a linear sum expressed by the following formula (1): E = c ₁ × x ₁ + c ₂ × x ₂ + c ₃ × x ₃ + C ......(1)

Where c ₁ , c ₂ , and c ₃ are coefficients, and C is a constant.

Further, the black as a reference is black in which the visual reflectance Y of the XYZ color system is 3.1%, and the predetermined specification value is 4/3 [I/ms], and the pixel value of the wiring is divided by the signal value of the wiring. When the exposure time is 64/45 [I/ms], the standardizer is 1.0, and in the formula (1), when c ₁ =259, c ₂ =73.0, c ₃ =-140, C=-13.0 Preferably, the predetermined threshold value is 6.0, the quantitative value E of the visibility of the wiring is 6.0 or less, more preferably the predetermined threshold value is 4.2, and the quantitative value of the visibility of the wiring is 4.2 or less.

Moreover, it is preferable that the conductive film is provided on the display unit of the display device, and the wiring pattern is superposed on the display unit.

Further, it is preferable that the second peak intensity is obtained by weighting the visual transfer function by convolution integral as a visual response characteristic.

Also, preferably, the visual transfer function is for Dolly. The Dooley-Shaw function introduces an evaluation function for the correction function of the luminance component.

Further, preferably, the visual transfer function is represented by a function VTF shown by the following formula (2).

VTF=5.05e ^-0.138u (1-e ^0.1u )‧‧‧(2)

Here, u is the spatial frequency (cycle/deg).

As described above, according to the present invention, the feature amount (the feature amount in the frequency space) reflecting the reflection intensity of the entire wiring pattern and the human visual sensitivity is added to the feature amount (real space) reflecting the difference in the reflection intensity in the pattern. The characteristic amount in the), and the visibility of the wiring is quantified, whereby even the conductive pattern of the conductive film (with a line pattern), for example, when a conductive film provided on a display unit is used for a touch panel sensor or the like, even in a final product form provided on the display unit, for example, as a touch on a display unit The form of the actual sample used for the panel sensor does not see the wiring itself. Especially when the display unit is not lit, the wiring will not be seen, which can prevent or reduce image quality obstacles and improve the visibility of the wiring. Alternatively, as a result, when it is placed on the display screen of the display unit, the visibility can be greatly improved.

Moreover, according to the present invention, the visibility of the conductive film, for example, the wiring of the conductive film provided on the display unit can be quantitatively evaluated, and in particular, the evaluation can be quantitatively performed even when the display unit is not lit.

10, 10a, 10b‧‧‧ conductive film

12‧‧‧Transparent support (transparent substrate)

12a‧‧‧1st transparent substrate

12b‧‧‧2nd transparent substrate

14‧‧‧Metal thin wires (metal thin wires)

16‧‧‧Electrical Department

16a‧‧‧1st Conductive Department

16b‧‧‧2nd Conductive Department

16c‧‧‧3rd Conductive Department

18‧‧‧ adhesive layer

18a‧‧‧1st bonding layer

18b‧‧‧2nd adhesive layer

20‧‧‧Protective layer

20a‧‧‧1st protective layer

20b‧‧‧2nd protective layer

22‧‧‧ Openings

24, 24c‧‧‧ wiring pattern

24a‧‧‧1st wiring pattern

24b‧‧‧2nd wiring pattern

28‧‧‧Wiring layer

28a‧‧‧1st wiring layer

28b‧‧‧2nd wiring layer

28c‧‧‧3rd wiring layer

30‧‧‧Display unit

32‧‧‧ pixels

32r, 32g, 32b‧‧‧ sub-pixels

34‧‧‧Black Matrix (BM)

36‧‧‧Area

38‧‧‧BM pattern

40‧‧‧ display device

42‧‧‧ Input surface

44‧‧‧ touch panel

46‧‧‧ frame

48‧‧‧ Cover member

50‧‧‧ cable

52‧‧‧Flexible substrate

54‧‧‧Detection Control Department

56‧‧‧Adhesive layer

58‧‧‧Contact body

60‧‧‧Photographic optical system

62‧‧‧Photographic samples

64‧‧‧ camera

E‧‧‧Quantitative value

Ph‧‧‧ horizontal pixel spacing

PI‧‧‧ camera image

Pv‧‧‧ vertical pixel spacing

S10~S30‧‧‧Steps

x ₁ ‧‧‧Intensity in frequency space

x ₂ ‧‧‧Proportion of wiring area (area ratio)

x ₃ ‧‧‧Distance of background and wiring

Z1, Z2‧‧‧ arrows

Θ‧‧‧ angle

FIG. 1 is a plan view schematically showing an example of a conductive film according to a first embodiment of the present invention.

Fig. 2 is a schematic partial cross-sectional view showing the conductive film shown in Fig. 1;

3 is a schematic partial cross-sectional view showing a main part of an example of a conductive film according to another embodiment of the present invention.

4 is a schematic partial cross-sectional view showing an example of a conductive film according to another embodiment of the present invention.

FIG. 5 is a schematic explanatory view showing an example of a pixel arrangement pattern of a part of a display unit to which the conductive film of the present invention is applied.

Fig. 6 is a schematic cross-sectional view showing an embodiment of a display device in which the conductive film shown in Fig. 3 is incorporated.

FIG. 7 is a flowchart showing an example of a method of evaluating the visibility of the wiring pattern of the conductive film of the present invention.

FIG. 8 is a flowchart showing details of the procedure of the method for evaluating the visibility of the wiring pattern of the conductive film shown in FIG. 7 .

Fig. 9 is an explanatory view for explaining a photographing optical system used in the present invention.

10(A) and 10(B) are schematic explanatory views showing an example of a rhombic and hexagonal wiring pattern used in the embodiment of the present invention, and FIG. 10(C) is a view showing the use of the present invention. A schematic explanatory diagram of an example of a lattice wiring pattern, and FIGS. 10(D), 10(E), and 10(F) are used for FIG. 10(A), FIG. 10(B), and FIG. 10(C), respectively. A partially enlarged view of the illustrated wiring pattern will be described.

Fig. 11 is a graph showing the relationship between the quantitative value of the wiring sample used in the examples and the sensory evaluation, and the regression equation thereof.

Hereinafter, a method of evaluating the visibility of the conductive film, the touch panel, the display device, and the wiring of the conductive film of the present invention will be described in detail with reference to preferred embodiments shown in the accompanying drawings.

Hereinafter, the conductive film of the present invention and the touch panel and the display device including the same are provided with a conductive film and a conductive film for use in a touch panel sensor provided on a display unit of a display device. Touch panel display on the display unit Although the present invention is not limited thereto, the conductive film may be integrally provided on the display unit, or may be provided on a liquid crystal display (LCD) or Conductive film on a display unit of a display device such as a plasma display panel (PDP) or an organic electroluminescence display (OELD: Organic ElectroLuminescence Display) or an inorganic electroluminescence (EL) display, and the conductive film The display device provided on the display unit may, for example, be a conductive film for electromagnetic wave shielding and a display device or the like in which the conductive film is integrally provided on the display unit. Further, the conductive film of the present invention is not limited to being provided on a display unit of a display device, and may be used alone.

1 and 2 are a plan view and a schematic partial cross-sectional view showing an example of a conductive film according to a first embodiment of the present invention.

As shown in the drawings, the conductive film 10 of the present embodiment is, for example, a conductive film provided on a display unit of a display device and having a wiring pattern integrally provided on the conductive film. In the state of the unit, when observing the display surface of the display unit, it is needless to say that when the display unit is lit, especially when the display unit is not lit, the reflection caused by the wiring is not recognized, and the visibility of the wiring is excellent. The wiring itself is not observed or the wiring is visually recognized as granular noise, and the visibility of the wiring is optimized.

The conductive film 10 of the present embodiment includes a transparent substrate 12, a first conductive portion 16a and a second conductive portion 16b (collectively referred to as a conductive portion 16), and a plurality of thin wires (hereinafter referred to as metal thin wires) 14 made of metal, respectively Two tables formed on the transparent substrate 12 The surface (the upper surface and the lower surface in FIG. 2) and the first protective layer 20a and the second protective layer 20b (collectively referred to as the protective layer 20) are respectively covered by the first bonding layer so as to cover the thin metal wires 14. The layer 18a and the second adhesive layer 18b (collectively referred to as the adhesive layer 18) are bonded to substantially the entire surface of the conductive portion 16a and the conductive portion 16b.

The transparent substrate 12 has insulating properties and contains a material having high light transmittance, and examples thereof include materials such as resin, glass, and enamel. Examples of the resin include polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), polypropylene (PP), and polystyrene (PS). )Wait.

The conductive portion 16 (16a, 16b) is formed with a wiring layer 28 (a first wiring layer 28a and a second wiring layer 28b) having a mesh formed by the metal thin wires 14 and the openings 22 between the adjacent metal thin wires 14. The hole-shaped wiring pattern 24 (the first wiring pattern 24a and the second wiring pattern 24b).

Specifically, in the conductive film 10, the first conductive portion 16a is formed on the side of the transparent substrate 12 (the upper side of FIG. 2) as the wiring layer 28a having the wiring pattern 24a including the wiring of the plurality of metal thin wires 14. In the same manner, the second conductive portion 16b is formed on the other side (the lower side in FIG. 2) of the transparent substrate 12 as the wiring layer 28b having the wiring pattern 24b including the wiring of the plurality of metal thin wires 14.

The fine metal wire 14 is not particularly limited as long as it is a fine metal wire having high conductivity, and examples thereof include a thin wire including a wire of gold (Au), silver (Ag), or copper (Cu). The line width of the fine metal wires 14 is preferably fine in terms of visibility, and may be, for example, 30 μm or less. Moreover, in the touch panel application, the line width of the metal thin wires 14 is preferably It is 0.1 μm or more and 15 μm or less, more preferably 1 μm or more and 9 μm or less, and still more preferably 2 μm or more and 7 μm or less.

Here, the wiring pattern 24a of the upper first conductive portion 16a and the wiring pattern 24b of the lower second conductive portion 16b are the same or the same wiring pattern, and the upper wiring pattern 24a is phase-biased with respect to the lower wiring pattern 24b. Move to the configuration. For example, in the illustrated example, the upper wiring pattern 24a is disposed with a half (1/2) pitch offset from the wiring pattern 24b. Specifically, as shown in FIG. 2, the thin metal wires 14 of the second conductive portion 16b constituting the wiring pattern 24b of the lower layer are located between the adjacent two metal thin wires 14 of the first conductive portion 16a constituting the wiring pattern 24a of the upper layer. Preferably, it is located in the center of its configuration. In the present specification, the arrangement state of the metal thin wires 14 of the wiring pattern 24a and the wiring pattern 24b is referred to as a state in which the upper first conductive portion 16a is nested with respect to the lower second conductive portion 16b. In other words, the upper wiring pattern 24a is placed so as to be phase-shifted with respect to the lower wiring pattern 24b.

As described above, the conductive portion 16 includes the wiring pattern 24 including wirings in which a plurality of metal thin wires 14 are arranged in a mesh shape. In the example of the drawing, the mesh shape of the opening 22 is a rhombic shape (see FIG. 1 and FIG. 10 (A) below). However, the present invention is not limited thereto, and the display surface can be displayed with respect to the display unit as described below. The wiring pattern 24 that optimizes the visibility of the wiring may be any shape as long as it has a polygonal shape of at least three sides, and may have the same mesh shape or different mesh shapes, for example, Examples include an equilateral triangle, a triangle such as an isosceles triangle, or a square (square lattice: see FIG. 10(C) below), and a rectangular shape such as a rectangle (a moment) The same or different polygons, etc., such as a shape, a pentagon, or a hexagon (a regular hexagon: see FIG. 10(B) below) may be inclined at a predetermined angle. For example, the rhombic shape shown in FIG. 1 and FIG. 10(A) is not inclined, but a parallelogram may be formed by rotating the rhombic rotation angle θ shown in FIG. 10(A) (see FIG. 10(D)). In other words, the wiring pattern optimized for the visibility of the wiring with respect to the predetermined display unit may be a wiring pattern formed by the arrangement of the regular openings 22, or may be formed by different shapes. A wiring pattern in which the openings 22 are arranged in a random manner.

The first protective layer 20a is adhered to substantially the entire surface of the first conductive portion 16a (wiring layer 28a) by the first adhesive layer 18a so as to cover the wiring of the first conductive portion 16a including the metal thin wires 14.

Moreover, the second protective layer 20b is adhered to substantially the entire surface of the second conductive portion 16b (wiring layer 28b) by the second adhesive layer 18b so as to cover the thin metal wires 14 of the second conductive portion 16b.

Here, as a material of the first adhesive layer 18a and the second adhesive layer 18b, a wet laminate adhesive, a dry laminate adhesive, a hot melt adhesive, or the like is exemplified. Further, the materials of the first adhesive layer 18a and the second adhesive layer 18b may be the same or different.

Further, similarly to the transparent substrate 12, the first protective layer 20a and the second protective layer 20b include a material having high light transmittance including resin, glass, and ruthenium. Further, the material of the first protective layer 20a and the material of the second protective layer 20b may be the same or different.

The refractive index n1 of the first protective layer 20a and the refractive index n2 of the second protective layer 20b are preferably equal to or close to the refractive index n0 of the transparent substrate 12. In this case, the relative refractive index nr1 and the relative refractive index nr2 of the transparent substrate 12 with respect to the first protective layer 20a and the second protective layer 20b are all close to one.

Here, the refractive index in the present specification means a refractive index of light having a wavelength of 589.3 nm (D-ray of sodium), for example, in a resin, in accordance with an international standard specification, the International Standardization Organization (ISO) 14782:1999 ( It is defined corresponding to Japanese Industrial Standards (JIS) K 7105).

Therefore, the relative refractive index nr1 of the transparent substrate 12 with respect to the first protective layer 20a is defined by nr1=(n1/n0), and the relative refractive index nr2 of the transparent substrate 12 with respect to the second protective layer 20b is nr2=(n2/n0). ) to define. Here, the relative refractive index nr1 and the relative refractive index nr2 may be in the range of 0.86 or more and 1.15 or less, and more preferably 0.91 or more and 1.08 or less.

Further, by limiting the range of the relative refractive index nr1 and the relative refractive index nr2 within the range, the transmittance of light between the transparent substrate 12 and the members of the protective layer 20a and the protective layer 20b can be controlled, and the wiring can be further improved and improved. Visibility.

In the conductive film 10 of the first embodiment, as shown in FIG. 2, the thin metal wires 14 of the second conductive portion 16b constituting the lower wiring pattern 24b of the lower side of the transparent substrate 12 are located to constitute a transparent substrate. The two adjacent metal thin wires 14 of the first conductive portion 16a of the upper wiring pattern 24a on the upper side of the upper layer 12 are preferably disposed at the center thereof. However, the present invention is not limited thereto, and both surfaces of the transparent substrate 12 are provided. The metal thin wires 14 constituting the wiring pattern 24a and the wiring pattern 24b of the first conductive portion 16a and the second conductive portion 16b may be located at positions corresponding to each other. That is, the first The plurality of metal thin wires 14 of the wiring pattern 24b of the conductive portion 16b may be disposed at positions corresponding to the plurality of metal thin wires 14 of the wiring pattern 24a of the first conductive portion 16a.

Furthermore, in this case, the wiring pattern 24a of the wiring layer 28a can be made the same as the wiring pattern 24b of the wiring layer 28b, and the visibility of the electrode can be further improved.

In the example shown in FIG. 2, the wiring layer 28a and the wiring layer 28b have the same wiring pattern 24, and one wiring pattern 24 (24a, 24b) is formed to be overlapped without being offset, and each of the wiring layer 28a and the wiring layer 28b is formed. The wiring pattern may be overlapped at the offset position as long as the evaluation criteria of the present invention are satisfied, and the respective wiring patterns themselves may be different.

In addition, the conductive film 10 of the first embodiment has the first conductive portion 16a and the second conductive portion 16b similarly on both surfaces of the transparent substrate 12, and the first conductive portion 16a and the second conductive portion 16b form wiring. In the layer 28a and the wiring layer 28b, the wiring layer 28a and the wiring layer 28b each have the first wiring pattern 24a and the second wiring pattern 24b including the metal thin wires 14. However, the present invention is not limited thereto, and both surfaces of the transparent substrate 12 are The wiring layer 28a and the wiring layer 28b may be formed by a dummy electrode portion of at least one of the wiring layers, and the remaining portion may be formed by the first conductive portion 16a and the second conductive portion 16b. That is, the wiring layer 28a is formed of the first conductive portion 16a and the dummy electrode portion, or the wiring layer 28b is formed of either or both of the second conductive portion 16b and the dummy electrode portion.

Here, the dummy electrode portion is formed on at least one side (at least one of the upper side and the lower side of FIG. 2) of the transparent substrate 12, similarly to the first conductive portion 16a and the second conductive portion 16b illustrated in FIG. 2 . Surface, but the dummy electrode preferably has the first conductive portion 16a The first wiring pattern 24a has the same or the same wiring pattern, or has the same wiring pattern as the second wiring pattern 24b of the second conductive portion 16b.

When the dummy electrode portion is formed in a part of the wiring layer 28a on the upper side of the transparent substrate 12, the dummy electrode portion is disposed at a predetermined interval from the first conductive portion 16a formed in the remaining portion of the wiring layer 28a, and is placed at the first conductive portion. In the case where the portion 16a is electrically insulated, when the wiring layer 28b is formed on the lower side of the transparent substrate 12, the second conductive portion 16b formed on the remaining portion of the wiring layer 28b is spaced apart from each other by a predetermined interval. The arrangement is in a state of being electrically insulated from the second conductive portion 16b.

For example, in the case where the dummy electrode portion includes a plurality of metal thin wires 14 formed at positions corresponding to the plurality of metal thin wires 14 of the second conductive portion 16b formed on one surface of the transparent substrate 12, the transparent substrate 12 can be controlled. The scattering of a surface caused by thin metal wires can improve the visibility of the electrode wiring.

In the example of the conductive film 10 of the present invention shown in FIG. 2, in the wiring layer 28a and the wiring layer 28b, the metal thin wires constituting the wiring pattern 24a and the wiring pattern 24b are offset from each other by a half pitch. Although the present invention is not limited to this, the wiring layer 28a or the wiring layer 28b may not be formed with a conductive portion or a dummy electrode portion, that is, a blank region in which the metal thin wires 14 are not formed.

Further, in the conductive film 10 shown in FIG. 2, the first conductive portion 16a and the second conductive portion 16b are provided on both surfaces of the transparent substrate 12. However, the present invention is not limited thereto, and may be as shown in FIG. The conductive film 10a is generally provided with a multilayer wiring, that is, the first conductive portion 16a and the second conductive portion 16b are provided on both surfaces of the first transparent substrate 12a, and the second transparent substrate is disposed on the lower side of the second conductive portion 16b. 12b, that is, in the second transparent The second conductive portion 16b is formed on the upper surface of the base 12b, the second conductive portion 16b is formed on the upper surface of the second transparent substrate 12b, and the third conductive portion is formed on the lower surface of the second transparent substrate 12b. 16c.

In the conductive film 10a, as in the case of the conductive film 10 shown in FIG. 2, the first protective layer 20a is adhered to the upper side of the first conductive portion 16a via the first adhesive layer 18a, and the second The protective layer 20b is bonded to the lower side of the third conductive portion 16c via the second adhesive layer 18b.

Further, the first transparent substrate 12a and the second transparent substrate 12b can be the same as those of the transparent substrate 12 shown in Fig. 2 .

In the same manner as the first interconnect layer 28a of the first conductive portion 16a and the first interconnect layer 28b of the first conductive portion 16b, the third conductive portion 16c has the wiring pattern 24c including the wiring of the plurality of thin metal wires 14 The wiring layer 28c is formed on the side of the transparent substrate 12b (the lower side in FIG. 2). The wiring pattern 24c preferably has the same wiring pattern as the wiring pattern 24a and the wiring pattern 24b, but may have different wiring patterns.

The conductive film 10a shown in FIG. 3 includes three layers of wiring including the first wiring layer 28a, the second wiring layer 28b, and the third wiring layer 28c. However, the present invention is not limited thereto, and may include four or more layers. Multilayer wiring of the wiring layer.

Further, as shown in FIG. 4, as in the conductive film 10b shown in FIG. 3, the conductive portion 16 may be provided only on one surface of the transparent substrate 12, and the protective layer 20 may be adhered to each other via the adhesive layer 18. The upper side of the conductive portion 16. The conductive portion 16 forms the wiring layer 28 including the wiring pattern 24.

The conductive film 10 according to the first embodiment of the present invention and the conductive film 10, the conductive film 10a, and the conductive film 10b of the other embodiments are applied to, for example, a part of the display unit 30 schematically shown in FIG. The touch panel of the portion) has a wiring pattern that is optimized in terms of visibility of the wiring when the display unit 30 is turned on and when the display unit 30 is turned on with respect to the surface of the display unit 30 (in particular, reflection of the surface). Further, in the present invention, the wiring pattern optimized in terms of the visibility of the wiring with respect to the predetermined display unit means that the human visually does not recognize the wiring (metal thin line) alone or in a state of being disposed on the display unit. Or one or two or more one-group wiring patterns of the wiring pattern. Further, in the present invention, in the two or more one-group wiring patterns optimized for a predetermined display unit, it is possible to determine the order from the most unnoticeable wiring pattern to the hard-to-detect wiring pattern. It is needless to say that the predetermined display unit is turned on when the display unit 30 is turned on, and in particular, when one is not lit, one wiring pattern of the wiring is not noticed at all.

Furthermore, the evaluation and optimization of the visibility of the wiring of the wiring pattern will be described below.

The conductive film of the present invention is basically configured as described above.

FIG. 5 is a schematic explanatory view showing an example of a pixel arrangement pattern of a part of a display unit to which the conductive film of the present invention is applied.

As shown in FIG. 5, on the display unit 30, a plurality of pixels 32 are arranged in a matrix to form a predetermined pixel arrangement pattern. One pixel 32 is composed of three sub-pixels (red sub-pixel 32r, green sub-pixel 32g, and blue sub-pixel 32b) arranged in the horizontal direction. One sub-pixel is a rectangular shape that is vertically long in the vertical direction, and three sub-pixels 32r, sub-pixels 32g, and sub-pixels 32b are set to be the same or the same. Rectangular. The arrangement pitch (horizontal pixel pitch Ph) of the pixels 32 in the horizontal direction is substantially the same as the arrangement pitch (vertical pixel pitch Pv) of the pixels 32 in the vertical direction. In other words, the shape (the region 36 indicated by the hatching) composed of one pixel 32 and a black matrix (BM) 34 (pattern material) surrounding the one pixel 32 is square. Further, the aspect ratio of one pixel 32 is not 1, and the length in the horizontal direction (lateral direction) is the length in the vertical direction (longitudinal direction).

Further, in the illustrated example, the shape of one sub-pixel (32r, 32g, 32b) is a rectangular shape, but the present invention is not limited thereto, and may be, for example, a rectangular shape having a notch at the end, or An elongated strip shape bent or bent at a predetermined angle, or may be a curved elongated strip shape, or may have a notch at the end, and the shape of the notch may be any shape as long as it is well known. The pixel shape can also be any shape.

Further, the pixel pitch (horizontal pixel pitch Ph and vertical pixel pitch Pv) may be any pitch as long as it is a pitch corresponding to the resolution of the display unit 30, and may be, for example, a pitch in the range of 84 μm to 264 μm. .

As is apparent from FIG. 5, the pixel arrangement pattern composed of the respective sub-pixels 32r, sub-pixels 32g, and sub-pixels 32b of the plurality of pixels 32 surrounds the sub-pixels 32r and the sub-pixels, respectively. The BM pattern 38 of the BM 34 of 32g and the sub-pixel 32b defines that the BM pattern 38 is a reverse pattern of the pixel arrangement pattern, but is similarly shown as the same pattern.

When the conductive film 10 is disposed on, for example, the display panel of the display unit 30 having the BM pattern 38 composed of the BM 34, the wiring pattern 24 of the conductive film 10 has a BM (pixel arrangement) pattern 38 with respect to Display unit 30 Since the display panel is optimized in terms of visibility of the wiring, scattering of the thin metal wires 14 from the conductive film 10 and the like are hardly recognized, and generation of granular noise can be suppressed.

Further, the display unit 30 shown in FIG. 5 may be constituted by a display panel such as a liquid crystal panel, a plasma panel, an organic EL panel, or an inorganic EL panel.

Next, a display device in which the conductive film of the present invention is integrally incorporated will be described with reference to FIG. In the display device 40, a projection type capacitive touch panel incorporating the conductive film 10 of the second embodiment of the present invention is exemplified as a representative example. However, the present invention is not limited thereto. this.

As shown in FIG. 6, the display device 40 includes a display unit 30 (refer to FIG. 3) that can display a color image and/or a monochrome image, and a touch panel 44 that is detected from the input surface 42 (the side of the arrow Z1 direction). The contact position; and the frame 46 accommodates the display unit 30 and the touch panel 44. The user can access the touch panel 44 via a large opening provided on one surface (the side of the arrow Z1 direction) of the housing 46.

In addition to the conductive film 10 (see FIG. 2), the touch panel 44 further includes a cover member 48 laminated on one surface of the conductive film 10 (on the side of the arrow Z1 direction); and a flexible substrate 52 via a cable 50 is electrically connected to the conductive film 10; and the detection control unit 54 is disposed on the flexible substrate 52.

The conductive film 10 is adhered to one surface (the side in the arrow Z1 direction) of the display unit 30 via the adhesive layer 56. The conductive film 10 is disposed on the display screen with the other main surface side (the second conductive portion 16b side) facing the display unit 30.

The cover member 48 functions as the input surface 42 by covering one surface of the conductive film 10. Also, by preventing the contact body 58 (such as a finger or a stylus (stylus) The direct contact of pen)) can suppress the occurrence of scratches or the adhesion of dust, and the conductivity of the conductive film 10 can be stabilized.

The material of the cover member 48 may be, for example, glass or a resin film. The cover member 48 may be adhered to one surface (the side in the arrow Z1 direction) of the conductive film 10 in a state in which one surface (the side in the arrow Z2 direction) of the cover member 48 is applied by ruthenium oxide or the like. Moreover, in order to prevent damage by friction or the like, the conductive film 10 and the cover member 48 may be bonded together.

The flexible substrate 52 is a flexible electronic substrate. In the example of the figure, the inner wall of the side surface of the frame body 46 is fixed, but the arrangement position can be variously changed. The detection control unit 54 constitutes a circuit that detects a change in electrostatic capacitance between the contact body 58 and the conductive film 10 when the contact body 58 that is a conductor is brought into contact with (or close to) the input surface 42 to detect the contact position (or the proximity position). ).

The display device to which the conductive film of the present invention is applied is basically configured as described above.

Next, a procedure for evaluating and optimizing the visibility of the wiring of the wiring pattern of the conductive film provided on the predetermined display unit having the BM pattern of the display device in the present invention will be described. In other words, a procedure for evaluating and determining a wiring pattern in the conductive film of the present invention will be described. It is needless to say that the wiring pattern is not related to the predetermined display unit of the display device, and when the lighting is not lit, The vision is also unaware that the wiring itself or the wiring-based granular noise is optimized and overlapped on the display unit.

FIG. 7 is a flowchart showing an example of a method of evaluating the visibility of the wiring pattern of the conductive film provided on the display unit of the present invention. Figure 8 is a diagram of Figure 7 A flowchart of the details of the procedure of the method for evaluating the visibility of the wiring pattern of the conductive film shown.

The method for evaluating the visibility of the wiring of the present invention sets in advance the processing conditions (white balance, dynamic range of the image, and normalized condition of the imaging signal value) for the imaging signal value suitable for imaging. In the wiring pattern of the conductive film, it is preferable to capture an image of the wiring pattern of the conductive film provided on a predetermined display unit of the display device to obtain a reflection image of the wiring (representing a reflectance). The value is quantified as image data (normalized pixel value), that is, the image data of the captured image of the wiring is subjected to frequency analysis using Fast Fourier Transform (FFT) to obtain a frequency space. In the middle of the intensity (feature amount 1), the image data of the captured image of the wiring is binarized and divided into a wiring area and a background area, and the (area) ratio of the wiring area in the real space is obtained. 2) and the difference between the average value of the image data of each of the wiring area and the background area, that is, the difference between the background and the wiring strength in the real space (feature amount 3), and obtain the three feature amounts 1 The linear sum of the feature amount 2 and the feature amount 3 is used to calculate a quantitative value of the visibility of the wiring for evaluating the visibility of the wiring, and the wiring pattern that satisfies the predetermined condition (the predetermined threshold or less) is evaluated and determined as The wiring pattern optimized in such a manner that the wiring of the conductive film provided on the display unit is not recognized particularly when the display unit is not lit.

Furthermore, the intensity (feature amount 1) in the frequency space is obtained by calculating the first peak frequency of the obtained spectrum peak from the image data of the captured image of the wiring by frequency analysis using FFT. The first peak intensity in the The second peak intensity of the second peak frequency which is weighted by the first peak intensity of the calculated first peak frequency for each of the predetermined visual observation characteristics is obtained, and the obtained The sum of the second peak intensities of all the second peak frequencies.

In the method of the present invention, the FFT is generally used for the peak of the spectrum, but the frequency/intensity of the object greatly changes depending on the method of use. Therefore, the following procedure is defined.

In other words, in the present invention, not only the frequency characteristics in the frequency space of the wiring pattern of the conductive film but also the reflection intensity (reflectance) in the actual space of the wiring of the conductive film are reflected, and the wiring for taking the conductive film is input. The obtained image can be quantified even if it is a physical sample. Therefore, in the present invention, it is possible to quantify even if it is a single conductive film, or a touch panel module in which a conductive film and a peripheral member are combined, or a final product form in which a conductive film is provided on a display.

Specifically, the quantification is achieved by capturing an image of a wiring of a conductive film under predetermined conditions, and obtaining image data of a captured image of a wiring having a normalized pixel value. The frequency characteristic (peak frequency and intensity) obtained by using the FFT for the image data is obtained by using the human visual sensitivity function (VTF) to obtain the intensity in the frequency space (feature amount 1), and on the other hand, based on the image data. When it is divided into the wiring area and the background area, the area ratio (feature amount 2) of the wiring area and the feature quantity in the real space of the difference between the background and the wiring strength difference (feature amount 3) which is the difference between the average values of the two areas are obtained. In addition to using the feature amount 1 in the frequency space, the feature quantity 2 and the feature quantity 3 in the real space are used to calculate the quantification of the visibility of the wiring. value.

In the present invention, in addition to the feature amount 1 in the frequency space, the area ratio of the wiring area of the feature quantity 2 in the real space and the difference in the intensity of the wiring and the background of the feature quantity 3 in the actual space are caused by If the reflection intensity of the wiring pattern between the plurality of conductive film samples is not locally different as described in the prior art, even if there is a difference in reflection intensity between the top wiring and the bottom wiring, if the difference is substantially the same between the samples, The visual correspondence can be achieved, and the evaluation can be performed only by the feature amount 1 in the frequency space. However, if the reflection intensity of the wiring pattern between the samples is locally different, for example, if the reflection intensity of the background and the wiring is poor, the top wiring and the bottom are When the difference in the reflection intensity of the wiring changes between the samples, the visual correlation cannot be obtained. Therefore, accurate evaluation cannot be performed only by the feature amount 1 in the frequency space, and in the accurate evaluation of the visibility of the conductive film, in addition to the frequency space In addition to the feature amount 1, it is also necessary to reflect the feature amount of the difference in the reflection intensity in the wiring pattern, and it is necessary to add the feature amount 2 in the actual space and Feature amount 3.

Therefore, in the present invention, as the feature amount 2 in the real space, the area ratio of the wiring region indicating the region where the reflection intensity is high is used, and the background indicating the reflection intensity of the wiring is used as the feature amount 2 in the real space. The difference from the strength of the wiring (the difference between the average values of the two regions).

In the method of the present invention, first, as the program 1, the wiring pattern 24 of the conductive film 10 is prepared as shown in FIG. 7, and the image pickup image PI of the wiring of the wiring pattern 24 is obtained by shooting in step S10. Specifically, as shown in FIG. 8, in step S10, the conductive film 10 is placed in a dark room environment, and the wiring pattern of the conductive film 10 is taken. The image pickup signal value is obtained from the image of the wiring of 24, and the image pickup signal value is normalized to obtain a captured image (image data (normalized pixel value)) PI of the wiring. For example, the conductive film 10 on the display unit 30 of the display device 40 shown in FIG. 6 is superimposed (in the dark room environment), that is, the wiring (metal thin line 14) of the wiring pattern 24 of the conductive film 10 is photographed (refer to The captured image PI of the wiring is obtained from the image of FIG. 3). At this time, the display unit 30 provided with the conductive film 10 must be previously set to be unlit. Further, the wiring pattern 24 of the conductive film 10 provided on the display unit 30 is of course excellent in visibility of the wiring when the display unit 30 is turned on.

In the present invention, as shown in FIG. 9, when the conductive film 10 placed on the display unit 30 is placed on the conductive film 10 in the dark room environment, it is preferable to use the conductive film 10 as the imaging sample 62. The photographic sample 62 illuminates the light from the light source at an incident angle of 45°, and the photographic imaging system 60 that has the camera 64 disposed on the front side receives the light reflected from the photographic sample 62 from the front side using the camera 64, and photographs the photographic sample 62 from the front side using the camera 64. .

A light source (not shown) constituting the photographing optical system 60 used in the present invention, a camera 64, and a lens (not shown: built in the camera 64) are capable of capturing wiring necessary for calculating a quantitative value of the visibility of the wiring. The image may be any, and it is preferred to use the following.

As the camera used in the present invention, for example, a monochrome camera using a resolution of 1392×1040 is preferably used, and for example, Monochrome QICAM Cooled manufactured by Roper, Japan, or the like can be used.

As the lens used in the present invention, for example, it is preferable to use an actual field of view 35.2. Mm, depth of field ± 16 mm At the telecentric lens of F10, for example, a telecentric lens manufactured by Edmund, 0.18X or the like can be used.

As the light source used in the present invention, for example, a halogen light source or the like can be used, and a halogen light source having a feedback capable of maintaining a fixed amount of light is preferably used. For example, LA-150FBU manufactured by Lin Watch Industry Co., Ltd., or the like can be used.

In the photographic environment used in the present invention, since the visibility of the wiring (metal thin line 14) of the wiring pattern 24 of the conductive film 10 must be evaluated even when the display unit 30 provided with the conductive film 10 is not lit, it is preferable. In order to set the dark room environment, the light is irradiated from the light source at an incident angle of 45° in a dark room environment and photographed from the front.

Further, as the imaging conditions used in the present invention, it is preferable to adjust the aperture and the focus of the lens. For example, the aperture and the focus of the lens may be adjusted so that the depth of field is 10 mm using a depth gauge.

Furthermore, it is preferable to perform the adjustment of the white balance and the prior procedure of setting the dynamic range of the image to be photographed before the photographing of the wiring image in step S10.

In the pre-procedure, black, black, black, black, black, black, black, black, black, black, black, black, black, black, black, black, black, black, black, black, black, black, black, black, black, black, black The signal value Ib of the camera and the exposure time Exb are obtained by the visual reflectance Y = 3.1%). The value (the signal intensity (value) per unit exposure time) Ib/Exb obtained by dividing the signal value Ib of the camera at the time of black shooting, which is obtained as a reference, by the exposure time Exb at the time of black shooting as a reference is set in advance. Specify a specification value such as 4/3 [I/ms] (for example, when shooting black as a reference) The dynamic value of the captured image of the camera is set in such a manner that the signal value I when the light time is 180 ms is 240).

Further, the image pickup signal value of the wiring pattern obtained by the camera in which the dynamic range of the photographic image is set, that is, the pixel value of the captured image is obtained by dividing the signal value Ib by the exposure time Exb (per unit) The on-axis of the signal value of the exposure time is normalized so that the predetermined signal value (pixel value) is, for example, 64/45 [I/ms] is 1.0. In this way, image data (normalized pixel value) of the captured image of the wiring of the wiring pattern is obtained.

Here, as shown in FIG. 1 and FIG. 10(A), the wiring pattern 24 of the conductive film 10 can be a diamond pattern in which the metal thin wires 14 of the wiring are inclined at a predetermined angle with respect to the horizontal line, but as described above. The opening pattern of the wiring pattern may be any shape, and the diamond pattern itself may be inclined at a predetermined angle, and may be, for example, a regular hexagon or a square lattice as shown in FIG. 10(B) and FIG. 10(C) below. The square lattice may of course be a square lattice inclined at a predetermined angle.

Next, as shown in FIG. 7, the captured image PI obtained from the imaging step S10 is calculated in step S12 by the feature amount 1 in the frequency space, and in step S14, the feature amount 2 in the real space is calculated, and in step S16. Calculate the feature amount 3 in the actual space.

In other words, as shown in FIG. 8, as the program 2, the image data of the image of the wiring of the wiring pattern 24 obtained from the program 1 is used to calculate the frequency space for evaluating the visibility of the wiring and the feature amount in the real space. , feature quantity 2 and feature quantity 3. Here, the order in which steps S12, S14, and S16 are performed is not particularly limited, and may be Either one of them is performed first and the remaining one is subsequently performed, preferably set to be processed simultaneously.

Hereinafter, step S12, step S14, and step S16 will be described in order.

First, as shown in FIGS. 7 and 8, in step S12, the feature quantity 1 in the frequency space, that is, the intensity x ₁ in the frequency space is calculated.

In step S12, as shown in FIG. 8, in the sub-step S22, the image data of the image of the wiring of the wiring pattern 24 obtained in the program 1 (imaging step S10) is subjected to two-dimensional fast Fourier transform (2DFFT). . Specifically, in the sub-step S22, the image data of the image of the wiring of the wiring pattern 24 obtained in step S10 is subjected to 2D FFT processing, and the two-dimensional image data of the image of the wiring in the wiring pattern 24 is calculated. The first peak frequency and the first peak intensity of a plurality of spectral peaks in the Fourier spectrum. Here, the peak intensity is treated as an absolute value.

Here, in the two-dimensional Fourier spectrum of the image data of the image of the wiring in the wiring pattern 24, the position of the spectral peak indicating the intensity characteristic on the two-dimensional frequency coordinate, that is, the peak position indicates the peak frequency, and the two-dimensional position at the peak position The intensity of the Fourier spectrum becomes the peak intensity.

Here, the frequency and intensity of the peak of each spectral peak of the wiring pattern 24 are obtained as follows.

First, in the acquisition of the peak frequency, the frequency peak is obtained from the fundamental frequency of the wiring pattern 24 in order to calculate the peak value. The reason for this is that the image data of the image of the wiring subjected to the 2D FFT processing is a discrete value, and therefore the peak frequency depends on the reciprocal of the image size. The frequency peak position can be an independent two-dimensional fundamental vector component (for example, when the frequency coordinate is set to the fxfy coordinate, the two vector components in the fx direction and the fy direction) are The basis is to combine representations. Therefore, of course, the peak position obtained is in a lattice shape. In other words, the position at the frequency coordinate fxfy of the spectral peak of the wiring pattern 24, that is, the peak position, is given as the position of the lattice point on the frequency coordinate fxfy at which the reciprocal of the pattern pitch (1/p(pitch) is the lattice interval.

On the other hand, in the acquisition of the peak intensity, since the peak position is obtained in the acquisition of the peak frequency, the intensity (absolute value) of the two-dimensional Fourier spectrum which the peak position has is obtained. At this time, the FFT processing is performed on the digital data, so there is a case where the peak position straddles a plurality of pixels. Therefore, when obtaining the intensity at the peak position, it is preferable to increase the intensity of the spectral intensity of the plurality of pixels in the region including the plurality of pixels around the peak position from the upper position, for example, 7×7 pixels. The total value of the intensity (absolute value) of the spectral intensity of the pixel in the region from the upper position is set to the peak intensity.

Here, the peak intensity obtained is preferably normalized in image area (image size). In the above example, it is preferable to normalize in the form of 8192×8192 (Parseval's theorem).

Next, as shown in FIG. 8, in the sub-step S24, the human visual response characteristic is applied to the first peak intensity in the first peak frequency. Specifically, in the sub-step S24, the visual response characteristic of the human is applied to the first peak intensity in the first peak frequency of the two-dimensional Fourier spectrum of the wiring pattern 24 calculated in the sub-step S22 at a predetermined observation distance. That is, convolution integration is performed and weighting is performed, and the second peak intensity in the second peak frequency weighted by the observation distance is calculated. In other words, a visual transfer function showing an example of the visual response characteristics of a person represented by the following formula (2) (VTF; Visual Transfer Function) convolution at the 1st peak frequency. strength. Here, the first peak intensity and the second peak intensity are also treated as absolute values.

VTF=5.05e ^-0.138u (1-e ^0.1u )‧‧‧(2)

Here, u is the spatial frequency (cycle/deg).

In the formula (2), the spatial frequency u (cycle/deg) is defined by a solid angle, and thus when the spatial frequency fr (cycle/mm) defined by the length is converted Let L be the observation distance (mm), and transform by the following transformation formula (3).

Furthermore, the equation (3) is a conversion formula that converts the spatial frequency fr (cycle/mm) defined by the length into a spatial frequency u (cycle/deg) defined by a solid angle, and L is the observation distance (mm). ).

That is, in the present invention, the human visual transfer function (VTF) uses a VTF proposed by Dooley et al. Furthermore, the VTF type proposed by Dooley et al. is described in reference (1) (R.P. Dooley, R. Shaw: Noise Perception in Electrophotography, J. Appl. Photogr. Eng., 5, 4 (1979), pp. 190-196.).

Here, in particular, the formula (2) proposed by Dooley et al. can be referred to reference (2) (simulated image evaluation technique of color electrophotographic system, http://www.konicaminolta.jp/about /research/technology_report/2008/pdf/introduce_003.pdf)etc.

Further, in the present invention, when the visual transfer function is convoluted, the observation distance L is set to a predetermined distance to perform convolution integration. However, for example, when the observation distance L is quantified at 300 mm, the space is self-spaced. The equation (3) in which the frequency fr (cycle/mm) is converted to the spatial frequency u (cycle/deg) can be expressed by the following formula (4).

u=300. π. Fr/180...(4)

As described above, in the sub-step S24, the first peak frequency and the first peak intensity obtained by subsuming the human visual transfer function (VTF) shown in the above formula (2) can be calculated and performed. The weighted second peak frequency and the second peak intensity.

Then, as shown in FIG. 8, in the sub-step S26, the second peak intensities among all the second peak frequencies calculated in the sub-step S24 are added to obtain a total, and the wiring pattern 24 of the conductive film 10 is calculated. The feature quantity 1 in the frequency space is the intensity x ₁ in the frequency space.

This concludes step S12.

Next, as shown in FIGS. 7 and 8, in step S14, the feature amount 2 in the real space, that is, the ratio (area ratio) x _{2 of the} wiring region is calculated.

In step S14, as shown in FIG. 8, in the sub-step S28, the captured image of the wiring of the wiring pattern 24 obtained in the program 1 (imaging step S10) is binarized, that is, the captured image of the wiring The image data is binarized to separate the entire captured image into a wiring area and a background area.

The method of binarization performed in the sub-step S28 is not particularly limited, and a well-known binarization method can be applied. For example, a normal discriminant analysis method or the like can be used. As a general discriminant analysis method, for example, reference (3) (Otsu, N, "A Threshold Selection Method from Gray-Level Histograms," IEEE Transaction on Systems, Man, and Cybernetics ("A Grayscale Histogram" Threshold selection method "IEEE Journal System, Human and Cybernetics", Vol. 9, No. 1, 1979, pp. 62-66.) and the like.

When the binarization method using the discriminant analysis method described in this document is summarized, the histogram of the captured image is used, and it is dispersed in the class (the diffusion of the histogram in each level). The minimum and inter-level dispersion (diffusion between levels) becomes the maximum position determination threshold. Here, the histogram of each captured image sample is different, so the threshold of binarization changes every time.

For example, in the histogram of the captured image sample, the average value of all the pixels is set to μ ₀ , and the dispersion of level 1 and level 2 when the threshold value t is divided into level 1 and level 2 is set to σ _{1 .} ² and σ ₂ ² , the average value of level 1 and level 2 is set to μ ₁ and μ ₂ , the number of pixels of level 1 and level 2 is set to n ₁ and n ₂ , and the dispersion between levels is set to σ _B ² When the intra-level dispersion is σ _W ² and the inter-level dispersion σ _B ² and the intra-level dispersion σ _W ² are expressed by the following formula, the ratio of the inter-level dispersion σ _B ² /the intra-level dispersion σ _W ² can be maximized. The value of t is determined to be a threshold of binarization.

Intra-level dispersion σ _W ² =(n ₁ .σ ₁ ² +n ₂ .σ ₂ ² )/(n ₁ +n ₂ )

Inter-level dispersion σ _B ² =(n ₁ .(μ ₁ -μ ₀ ) ² +n ₂ .(μ ₂ -μ ₀ ) ² )/(n ₁ +n ₂ )

Next, as shown in FIG. 8, the ratio x _{2 of the} wiring area to the entire captured image is calculated in the sub-step S30. Specifically, in the sub-step S30, the area of the wiring area separated in the sub-step S28 is obtained, and the ratio x ₂ of the area of the wiring area to the area of the entire captured image is calculated.

In this manner, the feature amount 2 in the actual space of the wiring pattern 24 of the conductive film 10, that is, the ratio x ₂ of the wiring region in the real space is calculated, and the step S14 is ended.

Next, as shown in FIG. 7 and FIG. 8, in step S16, the feature amount 3 in the real space, that is, the intensity difference x ₃ between the background and the wiring in the real space is calculated.

In step S16, as shown in FIG. 8, the average value of the image data (pixel value) is obtained in the wiring area and the background area divided in the sub-step S28 of step S14, and the difference between the average values is calculated as The difference in strength between the background and the wiring is x ₃ .

In the case where step S16 is performed earlier than step S14, sub-step S28 may be performed as a sub-step of step S16. When performing simultaneous processing, sub-step S28 is preferably used as a step. Sub-steps of S14 and S16 are performed.

In this manner, the feature amount 3 in the actual space of the wiring pattern 24 of the conductive film 10, that is, the intensity difference x ₃ between the background and the wiring in the real space is calculated, and the step S16 is ended.

Next, as shown in FIG. 7 and FIG. 8, in step S18, the quantitative value E of the visibility of the wiring is calculated from the feature amount 1, the feature amount 2, and the feature amount 3 calculated in steps S12, S14, and S16.

In other words, as shown in FIG. 8, in step S18, the intensity x ₁ in the frequency space calculated in step S12 of the program 2 and the actual space calculated in step S14 are calculated as the program 3 based on the following equation (1). The ratio x ₂ of the wiring area and the linear difference between the background and the intensity difference x ₃ of the wiring in the actual space calculated in step S16, and the calculated linear sum is the quantitative value E of the visibility of the wiring.

E=c ₁ ×x ₁ +c ₂ ×x ₂ +c ₃ ×x ₃ +C...(1)

In the formula (1), the coefficient c ₁ , the coefficient c ₂ , the coefficient c _{3 ,} and the constant C can be, for example, the following values. That is, it can be set as a coefficient c ₁ = 259 (259.46506), a coefficient c ₂ = 73.0 (73.04913), a coefficient c ₃ = -140 (-139.59975), and a constant C = -13.0 (-12.97544).

In this manner, in step S18, the quantitative value E of the visibility of the wiring of the wiring pattern 24 of the conductive film 10 can be calculated.

Next, as shown in FIG. 7 and FIG. 8, in step S20, the visibility of the wiring is evaluated using the quantitative value E of the visibility of the wiring calculated in step S18.

That is, as shown in FIG. 8, in step S20, as the program 4, the program 3 is The quantitative value E of the visibility of the wiring calculated in the step S18 is not less than the predetermined threshold value, preferably 6.0 or less, and more preferably 4.2 or less, and the visibility of the wiring of the conductive film 10 is appropriately evaluated. In other words, the wiring pattern 24 can be evaluated as the conductive film of the present invention. The optimized wiring pattern 24 of the 10, when the conductive film 10 is a separate conductive film 10 and the conductive film 10 is disposed on the display unit 30 of the display device and the display unit 30 is not lit, The wiring pattern 24 that can be optimized and can be set as the conductive film 10 of the present invention can be evaluated without considering the wiring itself.

Further, in the case where the numerical value of the quantitative value of the visibility of the wiring obtained in the present invention is the same as that of the conductive film 10, for example, in the case of the same conductive film 10 provided on the same display unit 30, In addition, the image signal value per unit time obtained by black based on the shooting is changed to the specification of the predetermined specification value (the dynamic range of the setting image) and the imaging signal value (pixel value). In the case where the setting and the normalization are performed in the same manner, if the numerical values of the quantitative values of the visibility of the wiring in the case of the same conductive film 10 are the same, the setting and the normalization may be performed without departing from the invention. The scope of the subject matter of the evaluation method is carried out in any manner.

As described in the embodiment of the evaluation method of the present invention, the predetermined specification value of the imaging signal value per unit time obtained by capturing black as a reference (visual reflectance 3.1%) is set to 4/3 [I/ms]. , the wiring of the conductive film to be set and photographed as such The imaging signal value (pixel value) of the pattern is normalized on the axis of the imaging signal value per unit exposure time, and the predetermined signal value (pixel value) when the normalized value is 1.0 is 64/45 [I/ms]. The quantitative value of the visibility of the wiring is preferably 6.0 or less, more preferably 4.2 or less.

Of course, it can be obtained according to the line width of the metal thin wires 14 of the wiring pattern 24 or the shape of the opening portion 22 or its size (pitch or angle) or the phase angle (rotation angle, offset angle) of the wiring patterns of the two wiring layers. Although the plurality of optimized wiring patterns 24 are used, the plurality of optimized wiring patterns 24 may be ordered by selecting the optimum wiring pattern 24 as the smaller the quantitative value of the visibility of the wiring.

By thus completing the wiring evaluation method of the conductive film of the present invention, it is possible to produce the conductive film of the present invention having an optimized wiring pattern which is a single conductive film and is superposed on the display device. When the BM pattern of the display unit and the display unit are not lit, the wiring can be prevented or suppressed, and the visibility of the wiring is excellent even for display devices of different resolutions.

Further, the conductive film of the present invention has a mesh-like wiring pattern including continuous metal thin wires. However, the present invention is not limited thereto, and may be any one that satisfies the evaluation criteria of the present invention as described above. A conductive film having a mesh-like wiring pattern of any pattern shape.

[Examples]

Hereinafter, the present invention will be specifically described based on examples.

A physical sample of the conductive film 10 having a pitch pattern and a wiring pattern 24 having a different prescription (wiring manufacturing method) is taken, and a quantitative value of the visibility of the wiring is obtained, and Five researchers conducted a sensory evaluation of the visibility of the wiring of the wiring pattern 24 of the conductive film 10 by visually using the five-stage deterioration scale.

In the present embodiment, LA-150FBU manufactured by Lin Watch Industry Co., Ltd. was used as a light source, Monochrome QICAM Cooled manufactured by Japan Roper Co., Ltd. was used as a camera, and a telecentric lens 0.18X manufactured by Edmund was used as a lens, and a depth gauge was used to have a depth of field of 10 mm. The aperture and focus of the lens are adjusted in a manner, and the physical sample is placed in a dark room environment and photographed by the photographing optical system 60 shown in FIG.

Furthermore, the camera has a signal value per unit exposure time of 4/3 [I/ms when shooting the macbeth chart (color checker of x-rite) (the visual reflectance Y = 3.1% of the XYZ color system). The setting method of shooting is performed under the conditions of . In addition, the signal value of the captured image is normalized so as to be equal to 64/45 [I/ms] on the axis of the signal value per unit exposure time, and is set as the image data (pixel value) of the captured image.

Using the image data of the captured image thus obtained, the intensity x ₁ in the frequency space, the ratio x _{2 of the} wiring region, and the intensity difference x _{3 between the} background and the wiring are obtained in accordance with the flow shown in FIGS. 7 and 8 . And the quantitative value E of the visibility of the wiring is obtained according to the above formula (1).

The results are shown in Table 1.

Furthermore, the range of physical samples is as follows.

. Spacing [μm]: 175~250

. Intensity in frequency space (x ₁ ): 0.026~0.106

. The proportion of the wiring area (x ₂ ): 0.225~0.366

. Background and wiring strength difference (x ₃ ): 0.055~0.174

Further, in Table 1, the difference in reflection intensity between the top (Top) wiring and the bottom (Bot) wiring of the physical sample of the conductive film was also determined. The difference in reflection intensity ranges from 0.00 to 0.09. In addition, the difference in reflection intensity is calculated by extracting the peaks of the top (top) wiring and the bottom (Bot) wiring from the pixel histogram of the wiring pattern of the physical sample of the conductive film, and taking the difference therebetween. Furthermore, the peak extraction can be done manually, setting the value to zero when there is no peak. In addition, the value of the reflection intensity of the wiring is a value standardized so as to be 64/45 [I/ms] as described above.

Here, the functional evaluation is that the light is irradiated at an incident angle of 45° in a dark room environment and viewed from the front, and is evaluated by visually observing the deterioration scale of the visibility of the wiring under the same conditions as the photographing, and the functional evaluation result is deteriorated by the scale 1 ~ 5 levels of degradation scale 5 are performed. The deterioration scale of the functional evaluation was taken as the average of 5 researchers. The degradation scale is as follows.

Deterioration scale 1: The wiring is not recognized.

Deterioration scale 2: If it is not pointed out, the wiring cannot be visually recognized, and even if it is judged that the wiring is not concerned.

Deterioration scale 3: Even if it is not pointed out, the wiring can be slightly visually recognized, and even if it is judged that the wiring is not hindered.

Deterioration scale 4: The wiring is visually recognized and becomes an obstacle.

Deterioration scale 5: Clearly visualizing the wiring and it is a hindrance.

[Table 1]

According to the above Table 1, it is understood that even if the wiring pattern is an arbitrary pattern, that is, the line width of the thin metal wires or the shape of the opening portion or the size (pitch) thereof is arbitrary, regardless of the top (Top) wiring and the bottom (Bot) wiring. The presence or absence of the difference in the reflection intensity, as long as the quantitative value E of the visibility of the wiring is 4.2 or less, in any of the examples of the present invention, the visual sensitization evaluation of the deterioration scale 3 which does not recognize the wiring or the granular noise is observed. When the quantitative value E is more than 4.2 and 6.0 or less, it is a visual sensory evaluation in which the deterioration scale of 3 or more and less than 3.6 is not hindered even if wiring or granular noise is recognized, and if the quantitative value E is When it exceeds 6.0, it is a visual evaluation function which visually recognizes wiring or granular noise, and is a hindrance scale of 3.6 or more.

Further, the deterioration scale of the functional evaluation shown in Table 1 was compared with the quantitative value, and the deterioration scale of the functional evaluation was taken on the x-axis and the quantitative value was taken on the y-axis on the two-dimensional coordinates. The result of the plot, as shown in Fig. 11, can be expressed by the regression equation y=2.9865x-4.7451, and the coefficient of determination R2 is 0.9402 (R2=0.9402) and close to 1.0, so that it is understood that there is a good correlation and can be quantified. .

According to the above, the conductive film of the present invention having the quantitative value of the visibility of the wiring satisfying the wiring pattern of the range can be prevented or suppressed when it is provided separately and on the surface of the display and the surface characteristics of the display are different. Visual recognition can be greatly improved by recognizing wiring or granular noise.

The effects of the present invention will become apparent from the above description.

In the present invention, a wiring pattern having various pattern shapes is prepared in advance as in the above-described embodiment, and a conductive film having an optimized wiring pattern can be determined by the evaluation method of the present invention, but in one wiring pattern When the quantitative value of the visibility of the wiring is equal to or greater than the predetermined value, the image data of the image of the wiring of the wiring pattern may be updated to the image data of the image of the wiring of the new wiring pattern, and the present invention may be applied. The evaluation method determines the quantitative value of the visibility of the wiring, and determines the conductive film having the optimized wiring pattern.

Here, the updated new wiring pattern can be either a pre-prepared person or a new producer. In the case of a new production, the rotation angle, the pitch, and the pattern width of the image data of the image of the wiring pattern may be changed, and the shape of the opening of the wiring pattern may be changed. Or size. Furthermore, these can also be made random.

In the above, the conductive film of the present invention, the display device including the same, and the method for evaluating the conductive film will be described with reference to various embodiments and examples. The present invention is not limited to the embodiments and examples, and various modifications and changes may be made without departing from the spirit and scope of the invention.

PI‧‧‧ camera image

S10, S12, S14, S16, S18, S20, S24‧‧

x ₁ ‧‧‧Intensity in frequency space

x ₂ ‧‧‧Proportion of wiring area

x ₃ ‧‧‧Distance of background and wiring

E‧‧‧Quantitative value

Claims (16)

A conductive film comprising: a transparent substrate; and a conductive portion formed on both surfaces of the transparent substrate and comprising a plurality of metal thin wires, the conductive film being characterized in that the conductive portion includes a wiring pattern, The wiring pattern is formed in a mesh shape by the plurality of thin metal wires, and includes a wiring in which a plurality of openings are arranged, and a quantitative value of the visibility of the wiring obtained based on the numerical value is a predetermined threshold or less. The numerical value includes a sum of the second peak intensities obtained by causing a human visual response characteristic to be applied to the first peak intensity, which is to be irradiated with an incident angle of 45° in a dark room environment and taken from the front as a reference. The signal value of the black time signal value divided by the exposure time is set to a predetermined specification value, and the conductive film is irradiated with light at an incident angle of 45° in the dark room environment and obtained from the front side. The peak intensity of a plurality of spectral peaks in the two-dimensional Fourier spectrum of the pixel value of the captured image of the wiring in the wiring pattern as the specification value; the wiring area In the area ratio of the entire image of the wiring pattern, the wiring region includes a pixel value of the captured image of the wiring of the wiring pattern, and is separated into a pixel value and a background of the wiring. a pixel value of the wiring at a pixel value; and a difference in intensity between the wiring and the background, the intensity difference being an average value of all pixel values in the wiring area and including the background Remaining background area The difference between the average values of all the pixel values in the interior is obtained. The conductive film according to claim 1, wherein the total of the second peak intensity is x ₁ and the area ratio of the wiring region is x ₂ , and the wiring is When the intensity difference of the background is x ₃ and the quantitative value of the visibility of the wiring is E, the quantitative value E is obtained as a linear sum represented by the following formula (1): E=c ₁ × x ₁ + c ₂ × x ₂ + c ₃ × x ₃ + C (1) wherein c ₁ , c ₂ , and c ₃ are coefficients, and C is a constant. The conductive film according to claim 2, wherein the black which is the reference is black in which the visual reflectance Y of the XYZ color system is 3.1%, and the predetermined specification value is 4/3 [I/ Ms], the pixel value of the wiring is standardized so that 64/45 [I/ms] becomes 1.0 when the signal value of the wiring is divided by the exposure time, in the equation (1), When c ₁ = 259, c ₂ = 73.0, c ₃ = -140, and C = -13.0, the predetermined threshold value is 6.0, and the quantitative value E of the visibility of the wiring is 6.0 or less. The conductive film according to claim 3, wherein the predetermined threshold value is 4.2, and the quantitative value of the visibility of the wiring is 4.2 or less. The conductive film according to any one of claims 1 to 4, wherein the conductive film is provided on a display unit of a display device, and The wiring pattern is overlapped with the display unit. The conductive film according to any one of claims 1 to 4, wherein the second peak intensity is weighted by convolution integration of a visual transfer function as the visual response characteristic Find out. The conductive film of claim 6, wherein the visual transfer function is for Dolly. The Dooley-Shaw function introduces an evaluation function for the correction function of the luminance component. The conductive film according to claim 7, wherein the visual transfer function is represented by a function VTF represented by the following formula (2): VTF = 5.05e - ^0.138u (1-e ^0.1u ) ‧ ‧(2) Here, u is the spatial frequency (cycle/deg). A touch panel, comprising: the conductive film according to any one of claims 1 to 8; and a detection control unit that detects a contact position from a surface side of the conductive film or The proximity position, wherein the conductive film and the detection control unit function as a touch panel sensor. A display device, comprising: a display unit; The conductive film according to any one of claims 1 to 8, wherein the conductive film is provided on the display unit. The display device according to claim 10, further comprising: a detection control unit that detects a contact position or a proximity position from a surface side of the conductive film, wherein the conductive film and the detection control unit serve as a touch The panel sensor functions. A method for evaluating the visibility of a wiring, which is a method for evaluating the visibility of a wiring of a conductive film having a wiring pattern in which a plurality of metal thin wires are formed in a mesh shape and a plurality of openings are arranged The method for evaluating the visibility of the wiring includes: a signal value obtained by illuminating light at an incident angle of 45° in a dark room environment and photographing black as a reference from the front side divided by an exposure time per unit exposure time. When the signal value is a predetermined standard value, the conductive film is irradiated with light at an incident angle of 45° in the dark room environment, and the captured image of the wiring of the wiring pattern is obtained from the front side. a pixel value is used as a specification value; and a pixel value of the captured image of the wiring of the obtained wiring pattern is subjected to two-dimensional Fourier transform to calculate a pixel value of the captured image of the wiring a first peak intensity of a plurality of spectral peaks in the two-dimensional Fourier spectrum; causing a human visual response characteristic to act on the calculated first peak of the wiring pattern according to an observation distance Calculating the second peak intensity by the value intensity; and obtaining the sum of the obtained second peak intensities; The pixel value of the image of the wiring of the wiring pattern is binarized and separated into a pixel value of the wiring and a pixel value of the background, and a pixel value including the separated wiring is obtained. An area ratio of the wiring area to the entire image of the wiring pattern; an average value of all pixel values in the wiring area and an average value of all pixel values in the remaining background area including the background And obtaining a difference between the obtained two average values as a difference in intensity between the wiring and the background; a sum of the obtained second peak intensities, and a wiring area with respect to the wiring pattern A quantitative value of the total area of the image and a difference between the wiring and the background, and a quantitative value of the visibility of the wiring is obtained as a linear sum; and a quantitative value of the visibility of the obtained wiring is an apparent threshold The visibility of the wiring of the conductive film described below was evaluated. The method for evaluating the visibility of a wiring according to claim 12, wherein the total of the second peak intensity is x ₁ and the area ratio of the wiring region is x ₂ , and the wiring is When the intensity difference from the background is x ₃ and the quantitative value of the visibility of the wiring is E, the quantitative value E is obtained as a linear sum represented by the following formula (1). :E=c ₁ ×x ₁ +c ₂ ×x ₂ +c ₃ ×x ₃ +C (1) wherein c ₁ , c ₂ , and c ₃ are coefficients, and C is a constant. The method for evaluating the visibility of the wiring according to the thirteenth aspect of the invention, wherein the black to be the reference is black in which the visual reflectance Y of the XYZ color system is 3.1%, and the photographing condition is the predetermined specification. The value is 4/3 [I/ms], and the pixel value of the wiring is normalized by dividing the signal value of the wiring by the exposure time by 64/45 [I/ms]. In the above formula (1), when c ₁ = 259, c ₂ = 73.0, c ₃ = -140, C = -13.0, the predetermined threshold value is 6.0, and the quantitative value E of the visibility of the wiring is Below 6.0. The method for evaluating the visibility of the wiring according to claim 14, wherein the predetermined threshold is 4.2, and the quantitative value of the visibility of the wiring is 4.2 or less. The method for evaluating the visibility of the wiring according to any one of the items 12 to 15, wherein the conductive film is provided on a display unit of the display device, and the wiring pattern is overlapped with the display unit.