JP5443244B2 - Transparent conductive film - Google Patents

Description

  The present invention relates to a transparent conductive film having a mesh pattern including a plurality of polygonal meshes.

  Recently, a transparent conductive film in which a pattern made of a wire is provided on a transparent substrate has been developed. This transparent conductive film can be used as an electrode or a heat generating sheet. For example, you may apply not only to the electrode for touchscreens, an inorganic EL element, an organic EL element, or the electrode of a solar cell but to some parts, such as a vehicle defroster (defroster) and a window glass.

  For the users of the various articles described above, the pattern pattern corresponds to granular noise that hinders the visibility of the observation object due to the nature of its application. Therefore, various techniques for suppressing granular noise and improving the visibility of an observation object by arranging the same or different mesh shapes regularly or irregularly have been proposed.

  For example, in Patent Document 1, as shown in FIG. 27A, arc-shaped conductive wires 2 in which a part of a circle is notched are repeatedly arranged in a lattice shape, and ends of the arc-shaped wires 2 are arranged. As for a part, the plane view shape of the window for passenger vehicles and the pattern PT1 with which the mesh layer 4 connected to the center part vicinity of the adjacent arc-shaped wire 2 and its pattern PT1 are disclosed. Thereby, it is described that not only the visibility but also the shielding property and damage resistance of electromagnetic waves can be improved.

  Further, as shown in FIG. 27B, Patent Document 2 discloses a solution that spontaneously forms a network structure on a substrate, that is, a metal fine particle that self-assembles when left on the substrate after being applied to the substrate. A transparent conductive substrate manufactured using a solution and a plan view shape of the pattern PT2 are disclosed. As a result, it is described that an irregular network structure in which moire phenomenon does not occur can be obtained.

  Furthermore, in Patent Document 3, as shown in FIG. 27C, the electromagnetic wave shielding layer 6 has a sea-island structure, and the shape of the island region 8 formed of the opening surrounded by the electromagnetic wave shielding layer 6 is mutually different. Are different from each other in light-transmitting electromagnetic wave shielding material and a plan view shape of the pattern PT3. Thus, it is described that there is no moiré and that light transmission and electromagnetic shielding properties are improved.

JP 2009-137455 A ([0029]) JP 2009-16700 A ([0022] to [0024]) JP 2009-302439 A ([0011] to [0015])

  However, the patterns PT1 and PT2 disclosed in Patent Documents 1 and 2 have a problem in the structure of the pattern in order to further reduce the granular noise and improve the visibility.

  For example, in the mesh pattern PT1 of Patent Document 1, since the arc-shaped wire 2 is repeatedly arranged in a lattice shape, the periodicity of the wire 2 is extremely high. That is, when the power spectrum of the pattern PT1 is calculated, it is predicted that the pattern has a sharp peak in the spatial frequency band corresponding to the reciprocal of the arrangement interval of the wires 2. Here, in order to further improve the visibility of the pattern PT1, the size (diameter) of the arc must be reduced.

  Further, the mesh pattern PT2 of Patent Document 2 is extremely irregular because the mesh shape and size are not uniform. That is, when the power spectrum of the pattern PT2 is calculated, it is predicted to be a substantially constant value (close to white noise characteristics) regardless of the spatial frequency band. Here, in order to further improve the visibility of the pattern PT2, the size of the self-assembly must be reduced.

  Then, in order to further improve the visibility of both the window for a passenger moving body disclosed in Patent Document 1 and the transparent conductive substrate disclosed in Patent Document 2, the light transmittance and productivity are reduced. There was an inconvenience.

  Furthermore, since the pattern PT3 disclosed in Patent Document 3 does not constitute a mesh shape, the wiring shape of the cut surface varies. As a result, when the pattern PT3 is used as an electrode, for example, there is a disadvantage that a stable energization performance cannot be obtained.

  The present invention has been made to solve the above-described problems, and can reduce the noise granularity caused by the pattern, can greatly improve the visibility of the observation object, and has a stable energization performance even after cutting. It aims at providing the transparent conductive film which has.

  The present invention relates to a transparent conductive film having a mesh pattern including a plurality of polygonal meshes.

  Then, regarding the power spectrum of the center-of-gravity position distribution of each mesh, the average intensity on the spatial frequency band side higher than the predetermined spatial frequency is larger than the average intensity on the spatial frequency band side lower than the predetermined spatial frequency. The mesh pattern is formed.

  Thus, since the average intensity on the spatial frequency band side higher than the predetermined spatial frequency is larger than the average intensity on the spatial frequency band side lower than the predetermined spatial frequency, compared with the low spatial frequency band side Therefore, the amount of noise on the high spatial frequency band side is relatively large. Human vision has a high response characteristic in the low spatial frequency band, but has a property that the response characteristic sharply decreases in the medium to high spatial frequency band, so that a sense of noise visually felt by humans is reduced. Thereby, the noise granularity resulting from the pattern which a transparent conductive film has can be reduced, and the visibility of an observation target object can be improved significantly. In addition, since a plurality of polygonal meshes are provided, the cross-sectional shape of each wiring after cutting is also substantially constant and has stable energization performance.

  The predetermined spatial frequency is preferably a spatial frequency corresponding to 5% of the maximum response of human visual response characteristics.

  Furthermore, it is preferable that the human visual response characteristic is a visual response characteristic obtained based on a Dooley-Shaw function with a clear vision distance of 300 mm, and the predetermined spatial frequency is 6 cycles / mm.

  According to the transparent conductive film of the present invention, with respect to the power spectrum of the center-of-gravity position distribution of each mesh, the average intensity on the spatial frequency band side higher than the predetermined spatial frequency is lower than the predetermined spatial frequency side. Since the mesh pattern is formed so as to be larger than the average intensity at, the amount of noise on the high spatial frequency band side is relatively larger than that on the low spatial frequency band side. Human vision has a high response characteristic in the low spatial frequency band, but has a property that the response characteristic sharply decreases in the medium to high spatial frequency band, so that a sense of noise visually felt by humans is reduced. Thereby, the noise granularity resulting from the pattern which a transparent conductive film has can be reduced, and the visibility of an observation target object can be improved significantly. In addition, since a plurality of polygonal meshes are provided, the cross-sectional shape of each wiring after cutting is also substantially constant and has stable energization performance.

It is a schematic block diagram of the manufacturing apparatus for manufacturing the transparent conductive film which concerns on this Embodiment. 2A is a partially enlarged plan view of the conductive film of FIG. FIG. 2B is a schematic exploded perspective view showing an example of the configuration when the conductive film of FIG. 1 is applied to a touch panel. It is a schematic sectional drawing of the electroconductive film of FIG. 2A. It is a functional block diagram of the mesh pattern evaluation part and data update instruction | indication part of FIG. It is a figure which shows an example of the setting screen of image data creation conditions. It is a flowchart about operation | movement of the manufacturing apparatus of FIG. FIG. 7A is a schematic explanatory diagram visualizing image data representing the pattern of the mesh pattern according to the present embodiment. FIG. 7B is a distribution diagram of a two-dimensional power spectrum obtained by performing FFT on the image data of FIG. 7A. FIG. 7C is a cross-sectional view taken along the VIIC-VIIC line of the two-dimensional power spectrum distribution shown in FIG. 7B. It is a graph of a Dooley-Shaw function (observation distance 300mm). It is a flowchart explaining the production method of the image data for output. It is a graph showing an example of the relationship between the arrangement | positioning density of a seed point, and the whole transmittance | permeability. FIG. 11A and FIG. 11B are explanatory diagrams showing the result of defining eight regions each surrounding eight points using Voronoi diagrams. FIG. 12A and FIG. 12B are explanatory diagrams of the result of defining eight triangular regions each having eight points as vertices using the Delaunay triangulation method. FIG. 13A is an explanatory diagram illustrating the definition of a pixel address in image data. FIG. 13B is an explanatory diagram illustrating the definition of pixel values in image data. FIG. 14A is a schematic diagram of an initial position of a seed point. FIG. 14B is a Voronoi diagram based on the seed point of FIG. 14A. It is a detailed flowchart of step S26 shown in FIG. FIG. 16A is an explanatory diagram showing the positional relationship between the first seed point, the second seed point, and the candidate point in the image region. FIG. 16B is an explanatory diagram of the result of updating the position of the seed point by exchanging the second seed point and the candidate point. It is sectional drawing along the X-axis of the two-dimensional power spectrum obtained by performing FFT with respect to the image data of the mesh pattern which concerns on this Embodiment, and the various patterns which concern on a prior art example, respectively. It is explanatory drawing showing the gravity center position of each area | region shown to FIG. 11B. It is a schematic explanatory drawing which shows the relationship between a some mesh and the gravity center position of each mesh regarding the mesh pattern which concerns on this Embodiment. FIG. 20A is a schematic explanatory diagram in which image data representing the gravity center position distribution of each mesh included in the mesh pattern of FIG. 19 is visualized. 20B is a distribution diagram of a two-dimensional power spectrum obtained by performing FFT on the image data in FIG. 20A. 20C is a cross-sectional view taken along line XXC-XXC of the two-dimensional power spectrum distribution shown in FIG. 20B. It is a comparison figure of the graph of FIG. 7C and FIG. 20C. It is a schematic explanatory drawing showing the characteristic of the two-dimensional spectrum of FIG. 20C. FIG. 23A to FIG. 23E are process diagrams showing a first manufacturing method of the conductive film according to the present embodiment. 24A and 24B are process diagrams showing a second method for producing a conductive film according to the present embodiment. 25A and 25B are process diagrams showing a third manufacturing method of the conductive film according to the present embodiment. It is process drawing which shows the 4th manufacturing method of the electroconductive film which concerns on this Embodiment. 27A to 27C are enlarged plan views of patterns according to a comparative example.

  Hereinafter, preferred embodiments of the transparent conductive film according to the present embodiment will be described in relation to a manufacturing apparatus for manufacturing the transparent conductive film, and will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic block diagram of a manufacturing apparatus 10 for manufacturing a transparent conductive film according to the present embodiment.

  The manufacturing apparatus 10 creates image data Img (including output image data ImgOut) representing a pattern corresponding to the mesh pattern M, and the output image data created by the image processing apparatus 12. Based on ImgOut, an exposure unit 18 that exposes the conductive film 14 (transparent conductive film) under the manufacturing process by irradiating light 16 and various conditions for creating the image data Img (mesh pattern M and structure to be described later) Input section 20 for inputting the image processing apparatus 12 to the image processing apparatus 12, and a display section 22 for displaying the GUI image for assisting the input operation by the input section 20, the stored output image data ImgOut, and the like. Is basically provided.

  The image processing device 12 generates image data Img, output image data ImgOut, position data SPd of candidate points SP, and position data SDd of seed points SD, and generates random numbers by generating pseudo-random numbers. A random number generation unit 26 that performs the initial position selection unit 28 that selects an initial position of a seed point SD from a predetermined two-dimensional image region using the random number value generated by the random number generation unit 26, and An update candidate position determination unit 30 that determines the position of the candidate point SP (excluding the position of the seed point SD) from the two-dimensional image region using numerical values, and the output image data ImgOut as a control signal for the exposure unit 18 An exposure data conversion unit 32 that converts (exposure data) and a display control unit 34 that performs control to display various images on the display unit 22 are provided.

  Note that the seed point SD includes a first seed point SDN that is not an update target and a second seed point SDS that is an update target. In other words, the position data SDd of the seed point SD is composed of the position data SDNd of the first seed point SDN and the position data SDSd of the second seed point SDS.

  The image processing apparatus 12 includes an image information estimation unit 36 that estimates image information corresponding to the mesh pattern M and the structure pattern based on visual information (details will be described later) input from the input unit 20, and the image information estimation. An image data creation unit 38 for creating image data Img representing a pattern corresponding to the mesh pattern M or the structure pattern based on the image information supplied from the unit 36 and the position of the seed point SD supplied from the storage unit 24; A mesh pattern evaluation unit 40 for calculating an evaluation value EVP for evaluating a mesh pattern based on the image data Img created by the image data creation unit 38, and an evaluation value calculated by the mesh pattern evaluation unit 40 A data update instruction unit 42 that instructs to update / non-update data such as the seed point SD and the evaluation value EVP based on the EVP.

  The conductive film 14 in FIG. 1 has a plurality of conductive portions 50 and a plurality of openings 52, as shown in FIG. 2A. The plurality of conductive portions 50 form a mesh pattern M (mesh-like wiring) in which a plurality of fine metal wires 54 intersect each other. That is, the combined shape of one opening 52 and at least two conductive portions 50 surrounding the one opening 52 is a mesh shape. This mesh shape is different for each opening 52, and is arranged irregularly (that is, aperiodically). Hereinafter, the material constituting the conductive portion 50 may be referred to as “wire”.

The line width of the fine metal wire 54 can be selected from 5 μm to 200 μm (0.2 mm). Of course, in order to improve translucency, you may select from 5 micrometers or more and 50 micrometers or less. Further, the area of the opening 52 is preferably 0.02 mm ² or more and 40 mm ² or less, and more preferably 0.1 mm ² or more and 1 mm ² or less.

  With this configuration, the entire light transmittance of the conductive film 14 is 70% or more and less than 99%, 80% or more and less than 99%, and further 85% or more and less than 99%. it can.

  This conductive film 14 is a conductive film that can be used as an electrode of a touch panel, an inorganic EL element, an organic EL element, or a solar cell. As shown in FIG. 3, the conductive film 14 includes a transparent film base 56 (transparent base), and the conductive portion 50 and the opening 52 formed on the transparent film base 56.

  A schematic exploded perspective view when this conductive film 14 is used as an electrode of a touch panel is shown in FIG. 2B. For example, a capacitive touch panel is configured by arranging a large number of electrodes in a mesh shape, and detects the fingertip position by detecting a change in capacitance between a human fingertip and a conductive film. .

  A filter member 57 having the same size as that of the conductive film 14 is disposed on the surface of the conductive film 14 so as to overlap therewith. The filter member 57 includes a plurality of red filters 58r, a plurality of green filters 58g, a plurality of blue filters 58b, and a black matrix 59.

  Red filters 58r (green filter 58g or blue filter 58b) are arranged in parallel in the vertical direction of the filter member 57. Further, a red filter 58r, a green filter 58g, a blue filter 58b, a red filter 58r,... Are periodically arranged in the left-right direction of the filter member 57. That is, a unit pixel in which a plane area in which one red filter 58r, one green filter 58g, and one blue filter 58b are arranged can display any color by a combination of red light, green light, or blue light. 60.

  The black matrix 59 has a function of a light shielding material for preventing the reflected light from the outside and the transmitted light from the backlight (not shown) from being mixed between the adjacent unit pixels 60. The black matrix 59 includes a light shielding material 61h extending in the left-right direction and a light shielding material 61v extending in the vertical direction. These light shielding members 61h and 61v form a rectangular lattice and surround a set of color filters (that is, a red filter 58r, a green filter 58g, and a blue filter 58b) constituting the unit pixel 60, respectively.

  The conductive film 14 also functions as a transparent heating element that generates heat when an electric current is applied. In this case, first and second electrodes (not shown) are formed at opposite ends of the conductive film 14, and a current flows from the first electrode to the second electrode. As a result, the transparent heating element generates heat, and a heating object (for example, a window glass of a building, a window glass for a vehicle, a front cover of a vehicle lamp, etc.) that is in contact with or incorporates the transparent heating element is heated. The As a result, snow or the like attached to the heating object is removed.

  FIG. 4 is a detailed functional block diagram of the mesh pattern evaluation unit 40 and the data update instruction unit 42 shown in FIG.

  The mesh pattern evaluation unit 40 performs fast Fourier transformation (hereinafter referred to as FFT) on the image data Img supplied from the image data generation unit 38 and performs two-dimensional spectrum data (hereinafter simply referred to as “spectrum Spc”). .) And an evaluation value calculation unit 102 that calculates an evaluation value EVP based on the spectrum Spc supplied from the FFT calculation unit 100.

  The data update instruction unit 42 includes a counter 108 that counts the number of evaluations by the mesh pattern evaluation unit 40, a pseudo temperature management unit 110 that manages a value of a pseudo temperature T used in a pseudo annealing method described later, and the mesh pattern evaluation unit 40. An update probability calculation unit 112 that calculates an update probability of the seed point SD based on the supplied evaluation value EVP and the pseudo temperature T supplied from the pseudo temperature management unit 110, and the update supplied from the update probability calculation unit 112 The position update determination unit 114 that determines whether the position data SDd of the seed point SD is updated or not based on the probability, and one image data Img as output image data ImgOut in response to a notification from the pseudo temperature management unit 110. And an output image data determination unit 116 to determine.

  FIG. 5 is a diagram illustrating an example of a setting screen for image data creation conditions.

  The setting screen 120 includes a left pull-down menu 122, a left display column 124, a right pull-down menu 126, a right display column 128, and seven text boxes 130, 132, 134, 136 in order from the top. , 138, 140, 142 and buttons 144, 146 displayed as [Setting] and [Cancel].

  On the left side of the pull-down menus 122 and 126, a character string “kind” is displayed. By a predetermined operation of the input unit 20 (for example, a mouse), a selection field (not shown) is also displayed in the lower part of the pull-down menus 122 and 126, and items in the selection field can be selected freely.

The display column 124 includes five columns 148a, 148b, 148c, 148d, and 148e. On the left side of these, "light transmittance", "light reflectance", "color value L ^* ", Character strings “color value a ^* ” and “color value b ^* ” are respectively displayed.

Similar to the display column 124, the display column 128 includes five columns 150a, 150b, 150c, 150d, and 150e. In the left part of these, the “light transmittance”, “light reflectance”, Character strings “color value L ^* ”, “color value a ^* ”, and “color value b ^* ” are displayed.

  “Total transmittance” is displayed on the left side of the text box 130, and “%” is displayed on the right side thereof. “Film thickness” is displayed on the left side of the text box 132, and “μm” is displayed on the right side thereof. “Wiring width” is displayed on the left side of the text box 134 and “μm” is displayed on the right side thereof. “Wiring thickness” is displayed on the left side of the text box 136, and “μm” is displayed on the right side thereof. “Pattern size H” is displayed on the left side of the text box 138, and “mm” is displayed on the right side thereof. “Pattern size V” is displayed on the left side of the text box 140, and “mm” is displayed on the right side thereof. "Image resolution" is displayed on the left side of the text box 142, and "dpi" is displayed on the right side thereof.

  In any of the seven text boxes 130, 132, 134, 136, 138, 140, 142, arithmetic numbers can be input by a predetermined operation of the input unit 20 (for example, a keyboard).

  Basically, the operation of the manufacturing apparatus 10 configured as described above will be described with reference to the flowchart of FIG.

  First, various conditions necessary for creating image data Img (including output image data ImgOut) representing a pattern corresponding to the mesh pattern M are input (step S1).

  The operator inputs an appropriate numerical value or the like via the setting screen 120 (see FIG. 5) displayed on the display unit 22. Thereby, the visual information regarding the visibility of the mesh pattern M can be input. Here, the visual information is various information that contributes to the shape and optical density of the mesh pattern M, and includes visual information of the wire (metal thin wire 54) and visual information of the transparent substrate (transparent film substrate 56). It is. The visual information of the wire includes, for example, at least one of the type, color value, light transmittance, or light reflectance of the wire, or the cross-sectional shape or thickness of the thin metal wire 54. The visual information of the transparent substrate includes, for example, at least one of the type, color value, light transmittance, light reflectance, or film thickness of the transparent substrate.

The operator uses the pull-down menu 122 to select one type of wire for the conductive film 14 to be manufactured. In the example of FIG. 5, “silver (Ag)” is selected. When one type of wire is selected, the display column 124 is immediately updated, and a known numerical value corresponding to the physical property of the wire is newly displayed. In columns 148a, 148b, 148c, 148d, and 148e, light transmittance (unit:%), light reflectance (unit:%), color value L ^* , color value a ^* , and color of silver having a thickness of 100 μm are described. Each value b ^* (CIELAB) is displayed.

The operator selects one type of film material (transparent film substrate 56) using the pull-down menu 126 for the conductive film 14 to be manufactured. In the example of FIG. 5, “PET film” is selected. When one type of film material is selected, the display field 128 is immediately updated, and a known numerical value corresponding to the physical property of the film material is newly displayed. In the columns 150a, 150b, 150c, 150d, and 150e, the light transmittance (unit:%), light reflectance (unit:%), color value L ^* , color value a ^* , and PET film having a thickness of 1 mm are included. Each of the color values b ^* (CIELAB) is displayed.

  It should be noted that by selecting the “manual input” item (not shown) of the pull-down menus 122 and 126, the physical property values may be directly input from the display columns 124 and 128.

  Further, the operator inputs various conditions of the mesh pattern M using the text box 130 or the like regarding the conductive film 14 to be manufactured.

  The input values of the text boxes 130, 132, 134, and 136 are the overall light transmittance (unit:%), the film thickness of the transparent film substrate 56 (unit: μm), and the line width of the metal thin wire 54 (unit: μm). , Corresponding to the thickness (unit: μm) of the thin metal wire 54.

  The input values in the text boxes 138, 140, and 142 correspond to the horizontal size of the mesh pattern M, the vertical size of the mesh pattern M, and the image resolution (pixel size) of the output image data ImgOut.

  The image information estimation unit 36 estimates the image information corresponding to the mesh pattern M in response to the click operation of the “set” button 144 by the operator. This image information is referred to when creating image data Img (including output image data ImgOut).

  For example, the number of pixels in the horizontal direction of the output image data is calculated based on the vertical size of the mesh pattern M (input value of the text box 138) and the image resolution of the output image data ImgOut (input value of the text box 142). In addition, the number of pixels corresponding to the line width of the thin metal wire 54 can be calculated based on the width of the wiring (input value of the text box 134) and the image resolution.

  Further, the light transmittance of the single metal wire 54 can be estimated based on the light transmittance of the wire (display value in the column 148a) and the thickness of the wiring (input value in the text box 136). In addition, based on the light transmittance of the film material (display value in the column 150a) and the film thickness (input value in the text box 132), the thin metal wire 54 is laminated on the transparent film substrate 56. Light transmittance can be estimated.

  Furthermore, the light transmittance of the wire (displayed in the column 148a), the light transmittance of the film material (displayed in the column 150a), the overall transmittance (input value of the text box 130), and the width of the wiring (text box 132). The number of openings 52 and the number of seed points SD can be estimated based on the input value). Note that the number of seed points SD may be estimated in accordance with an algorithm for determining the region of the opening 52.

  Next, output image data ImgOut for forming the mesh pattern M is created (step S2).

  Prior to the description of the generation method of the output image data ImgOut, the evaluation method of the image data Img will be described first. In the present embodiment, evaluation is performed based on an evaluation value EVP obtained by quantifying noise characteristics (for example, granular noise).

  As an example of evaluating the noise characteristics, a predetermined region range of the image data Img may be defined, and RMS (Root Mean Square) may be obtained for the pixel values in the region range. In the present embodiment, human visual response characteristics are taken into account for evaluation, and a further improved evaluation value EVP is used.

  FIG. 7A is a schematic explanatory diagram in which image data Img representing the mesh pattern M is visualized. Hereinafter, the image data Img will be described as an example.

  First, FFT is applied to the image data Img shown in FIG. 7A. Thereby, about the shape of the mesh pattern M, it can grasp | ascertain not as a partial shape but as the whole tendency (spatial frequency distribution).

  FIG. 7B is a distribution diagram of a spectrum Spc obtained by performing FFT on the image data Img of FIG. 7A. Here, the horizontal axis of the distribution diagram indicates the spatial frequency in the X-axis direction, and the vertical axis indicates the spatial frequency in the Y-axis direction. Further, the intensity level (spectrum Spc value) decreases as the display density for each spatial frequency band decreases, and the intensity level increases as the display density increases. In the example of this figure, the distribution of this spectrum Spc is isotropic and has two circular peaks.

  FIG. 7C is a cross-sectional view of the distribution of spectrum Spc shown in FIG. 7B along the VIIC-VIIC line. Since the spectrum Spc is isotropic, FIG. 7C corresponds to the radial distribution for all angular directions. As can be understood from this figure, the intensity level in the low spatial frequency band and the high spatial frequency band is reduced, and a so-called bandpass type characteristic is obtained in which the intensity level is increased only in the intermediate spatial frequency band. That is, it can be said that the image data Img shown in FIG. 7A represents a pattern having the characteristics of “green noise” according to technical terms in the field of image engineering.

  FIG. 8 is a graph showing the Dooley-Shaw function (observation distance 300 mm).

  The Dooley-Shaw function is a kind of VTF (Visual Transfer Function) and is a representative function that imitates human visual response characteristics. Specifically, this corresponds to the square value of the contrast ratio characteristic of luminance. The horizontal axis of the graph is the spatial frequency (unit: cycle / mm), and the vertical axis is the VTF value (unit is dimensionless).

  If the observation distance is 300 mm, the VTF value is constant (equal to 1) in the range of 0 to 1.0 cycle / mm, and the VTF value tends to gradually decrease as the spatial frequency increases. That is, this function functions as a low-pass filter that cuts off the medium to high spatial frequency band.

  Note that the actual human visual response characteristic has a value smaller than 1 in the vicinity of 0 cycle / mm, which is a so-called band-pass filter characteristic. However, in this embodiment, as illustrated in FIG. 8, the contribution to the evaluation value EVP is increased by setting the VTF value to 1 even in an extremely low spatial frequency band. Thereby, the effect which suppresses the periodicity resulting from the repeating arrangement | positioning of the mesh pattern M is acquired.

The evaluation value EVP is calculated by the following equation (1) when the value of the spectrum Spc is F (Ux, Uy).

  According to the Wiener-Khintchen's theorem, the value obtained by integrating the spectrum Spc over the entire spatial frequency band matches the square value of RMS. A value obtained by multiplying the spectrum Spc by VTF and integrating the new spectrum Spc in the entire spatial frequency band is an evaluation index that substantially matches human visual characteristics. This evaluation value EVP can be said to be RMS corrected by human visual response characteristics. Similar to normal RMS, the evaluation value EVP always takes a value of 0 or more, and the closer to 0, the better the noise characteristics.

  Further, by performing inverse Fourier transform (for example, IFFT) on the VTF shown in FIG. 8, a mask in the real space corresponding to the VTF is calculated, and the mask is applied to the image data Img to be evaluated. Then, a convolution operation may be performed to obtain RMS for new image data Img. Thereby, the operation result equivalent to the said method using (1) Formula can be obtained.

  Needless to say, the calculation formula of the evaluation value EVP can be variously changed according to the target level (allowable range) for determining the mesh pattern M and the evaluation function.

  Hereinafter, a specific method for determining the output image data ImgOut based on the evaluation value EVP will be described. For example, it is possible to use a method in which the creation of image data Img having a different pattern and the evaluation using the evaluation value EVP are sequentially repeated. In such a case, various search algorithms such as a structural algorithm and a sequential improvement algorithm can be used as an optimization problem for determining the output image data ImgOut.

  In the present embodiment, a mesh pattern M optimization method using a simulated annealing method (hereinafter referred to as SA method) will be described with reference mainly to the flowchart of FIG. 9 and the functional block diagram of FIG. The SA method is a probabilistic search algorithm that imitates the “annealing method” in which robust iron is obtained by hitting iron in a high temperature state.

  First, the initial position selection unit 28 selects the initial position of the seed point SD (step S21).

  Prior to selection of the initial position, the random number generator 26 generates a random value using a pseudo-random number generation algorithm. Here, various algorithms such as Mersenne Twister, SFMT (SIMD-oriented Fast Mersenne Twister), and Xorshift method may be used as a pseudo-random number generation algorithm. Then, the initial position selecting unit 28 randomly determines the initial position of the seed point SD using the random number value supplied from the random number generating unit 26. Here, the initial position selection unit 28 selects the initial position of the seed point SD as the address of the pixel on the image data Img, and sets the seed points SD at positions where they do not overlap each other.

  Note that the initial position selection unit 28 determines the range of the two-dimensional image region in advance based on the number of pixels in the vertical and horizontal directions of the image data Img supplied from the image information estimation unit 36. Further, the initial position selection unit 28 acquires the number of seed points SD from the image information estimation unit 36 in advance, and determines the number.

  FIG. 10 is a graph showing an example of the relationship between the arrangement density of the seed points SD and the overall transmittance of the mesh pattern M. This figure shows that the covering area of the wiring increases as the arrangement density increases, and as a result, the overall transmittance of the mesh pattern M decreases.

  This graph characteristic changes according to the light transmittance of the film material (indicated by the column 150a in FIG. 5), the wiring width (input value in the text box 132 in FIG. 5), and the region determination algorithm (for example, Voronoi diagram). . Therefore, characteristic data corresponding to each parameter such as the width of the wiring may be stored in the storage unit 24 in advance in various data formats such as functions and tables.

  Alternatively, the correspondence between the arrangement density of the seed points SD and the electric resistance value of the mesh pattern M may be acquired in advance, and the number of seed points SD may be determined based on a specified value of the electric resistance value. This is because the electrical resistance value is one parameter representing the conductivity of the conductive portion 50 and is indispensable for the design of the mesh pattern M.

  Note that the initial position selection unit 28 may select the initial position of the seed point SD without using a random number value. For example, the initial position can be determined with reference to data acquired from an external device including a scanner and a storage device (not shown). This data may be, for example, predetermined binary image data, specifically, halftone dot data for printing.

  Next, the image data creation unit 38 creates image data ImgInit as initial data (step S22). The image data creation unit 38 is an image representing a pattern corresponding to the mesh pattern M based on the number and position data SDd of the seed points SD supplied from the storage unit 24 and the image information supplied from the image information estimation unit 36. Data ImgInit (initial data) is created.

  An algorithm for determining a mesh pattern from a plurality of seed points SD may take various methods. Hereinafter, it demonstrates in detail, referring FIG. 11A-FIG. 12B.

As shown in FIG. 11A, for example, it is assumed that _eight points P _{1 to} P ₈ are randomly selected in a square two-dimensional image region 200.

FIG. 11B is an explanatory diagram showing a result of defining _eight regions V _{1 to} V ₈ surrounding the eight points P _{1 to} P ₈ , respectively, using the Voronoi diagram. The Euclidean distance was used as the distance function. As can be understood from the figure, the point P _i is the closest point at any point in the region V _i (i = 1 to 8).

Further, FIG. 12B shows a result of defining eight triangular regions having vertices at points P _{1 to} P ₈ in FIG. 12A (same as FIG. 11A) using Delaunay triangulation.

The Delaunay triangulation method is a method of defining a triangular region by connecting adjacent points among the points P _{1 to} P ₈ . Also by this method, the same number of regions V _{1 to} V ₈ as the number of points P _{1 to} P ₈ can be determined.

  By the way, before creating image data Img (including initial image data ImgInit), pixel address and pixel value definitions are determined in advance.

  FIG. 13A is an explanatory diagram illustrating the definition of a pixel address in the image data Img. For example, the pixel size is 10 μm, and the number of vertical and horizontal pixels of the image data is 8192. For convenience of FFT calculation processing described later, it is set to be a power of 2 (for example, 2 to the 13th power). At this time, the entire image area of the image data Img corresponds to a rectangular area of about 82 mm square.

FIG. 13B is an explanatory diagram illustrating the definition of pixel values in the image data Img. For example, the number of gradations per pixel is 8 bits (256 gradations). The optical density 0 corresponds to the pixel value 0 (minimum value), and the optical density 4.5 corresponds to the pixel value 255 (maximum value). In the intermediate pixel values 1 to 254, values are determined so as to have a linear relationship with the optical density. Here, the optical density is not limited to the transmission density but may be the reflection density, and can be appropriately selected according to the use mode of the conductive film 14 and the like. In addition to the optical density, each pixel value can be defined in the same manner as described above even for tristimulus values XYZ, color values RGB, L ^* a ^* b ^* , and the like.

In this way, the image data creation unit 38 determines the image corresponding to the mesh pattern M based on the data definition of the image data Img and the image information estimated by the image information estimation unit 36 (see the description of step S1). Data ImgInit is created (step S22). The image data creation unit 38 determines the initial state of the mesh pattern M shown in FIG. 14B using a Voronoi diagram based on the initial position of the seed point SD (see FIG. 14A). Appropriate processing is performed on the edge of the image so that it is repeatedly arranged in the vertical and horizontal directions. For example, for the seed point SD near the left end (or right end) of the image, a region V _i is obtained between the seed point SD near the right end (or left end) of the image. Similarly, the upper (or lower) seed point SD near the image, so as to obtain a region V _i between the lower end of the image (upper end) in the vicinity of the seed point SD.

Hereinafter, it is assumed that the image data Img (including the image data ImgInit) is image data including each data of four channels of the optical density OD, the color value L ^* , the color value a ^* , and the color value b ^* .

  Next, the mesh pattern evaluation unit 40 calculates an evaluation value EVPInit (step S23). In the SA method, the evaluation value EVP plays a role as a cost function.

  Specifically, the FFT operation unit 100 shown in FIG. 4 performs FFT on the image data ImgInit. Then, the evaluation value calculation unit 102 calculates the evaluation value EVP based on the spectrum Spc supplied from the FFT calculation unit 100.

In the image data Img, the evaluation values EVP (L ^* ), EVP (a ^* ), and EVP (b ^* ) described above are applied to the channels of the color value L ^* , the color value a ^* , and the color value b ^* , respectively. Calculate {refer to equation (1)}. Then, an evaluation value EVP is obtained by performing a product-sum operation using a predetermined weight coefficient.

The optical density OD may be used instead of the color value L ^* , the color value a ^* , and the color value b ^* . Regarding the evaluation value EVP, the type of observation mode, specifically, whether the auxiliary light source is dominant in transmitted light, dominant in reflected light, or mixed light of transmitted and reflected light. Accordingly, it is possible to appropriately select a calculation method that is more suitable for human visibility.

  Needless to say, the calculation formula of the evaluation value EVP can be variously changed according to the target level (allowable range) for determining the mesh pattern M and the evaluation function.

  In this way, the mesh pattern evaluation unit 40 calculates the evaluation value EVPInit (step S23).

  Next, the storage unit 24 temporarily stores the image data ImgInit created in step S22 and the evaluation value EVPInit calculated in step S23 (step S24). In addition, an initial value nΔT (n is a natural number and ΔT is a positive real value) is substituted for the pseudo temperature T.

  Next, the counter 108 initializes a variable K (step S25). That is, 0 is substituted for K.

  Next, the image data ImgTemp is generated in a state where a part of the seed point SD (second seed point SDS) is replaced with the candidate point SP, and the evaluation value EVPTtemp is calculated. "Update" is determined (step S26). Step S26 will be described in more detail with reference to the functional block diagrams of FIGS. 1 and 4 and the flowchart of FIG.

First, the update candidate position determination unit 30 extracts candidate points SP from a predetermined two-dimensional image region 200 and determines them (step S261). For example, the update candidate position determination unit 30 determines a position that does not overlap with any position of the seed point SD using the random number value supplied from the random number generation unit 26. Note that the number of candidate points SP may be one or plural. In the example shown in FIG. 16A, there are two candidate points SP (point Q ₁ and point Q ₂ ) with respect to eight current seed points SD (points P _{1 to} P ₈ ).

Next, a part of the seed point SD and the candidate point SP are randomly exchanged (step S262). The update candidate position determination unit 30 associates each seed point SD exchanged (or updated) with each candidate point SP at random. In FIG. 16A, it is assumed that the point P ₁ and the point Q ₁ are associated with each other, and the point P ₃ and the point Q ₂ are associated with each other. As shown in FIG. 16B, the point P ₁ and the point Q ₁ are exchanged, and the point P ₃ and the point Q ₂ are exchanged. Here, the point P ₂ and the points P _{4 to} P ₈ that are not the object of exchange (or update) are referred to as the first seed point SDN, and the points P ₁ and P ₃ that are the object of exchange (or update) are the second seed point SDS. That's it.

  Next, the image data creation unit 38 creates image data ImgTemp using the exchanged new seed point SD (see FIG. 16B) (step S263). At this time, since the same method as in the case of step S22 (see FIG. 9) is used, the description is omitted.

  Next, the mesh pattern evaluation unit 40 calculates an evaluation value EVPTemp based on the image data ImgTemp (step S264). Since the same method as in the case of step S23 (see FIG. 9) is used, the description is omitted.

  Next, the update probability calculation unit 112 calculates the update probability Prob of the position of the seed point SD (step S265). Here, “update of position” means that the seed point SD (that is, the first seed point SDN and the candidate point SP) obtained by provisional exchange in step S262 is determined as a new seed point SD. .

Specifically, the probability of updating or not updating the seed point SD is calculated according to the metropolis standard. The update probability Prob is given by the following equation (2).

  Here, T represents a pseudo temperature, and the update law changes deterministically from probabilistic as it approaches the absolute temperature (T = 0).

  Next, the position update determination unit 114 determines whether or not to update the position of the seed point SD according to the update probability Prob calculated by the update probability calculation unit 112 (step 266). For example, the random number value supplied from the random number generator 26 may be used to make a probabilistic determination.

  When updating the seed point SD, the storage unit 24 is instructed to “update” and when not updating, the storage unit 24 is instructed (steps S267 and S268).

  In this way, step S26 is completed.

  Returning to FIG. 9, it is determined whether or not the seed point SD is to be updated in accordance with either “update” or “non-update” instruction (step S27). If the seed point SD is not updated, the process proceeds to the next step S29 without performing step S28.

  On the other hand, when updating the seed point SD, the storage unit 24 overwrites and updates the image data ImgTemp obtained in step S263 with respect to the currently stored image data Img (step S28). Further, the storage unit 24 overwrites and updates the evaluation value EVPTemp obtained in step S263 with respect to the evaluation value EVP currently stored (step S28). Further, the storage unit 24 overwrites and updates the position data SPd of the candidate point SP obtained in step S261 with respect to the position data SDSd of the second seed point SDS currently stored (step S28). Thereafter, the process proceeds to next Step S29.

  Next, the counter 108 adds 1 to the current value of K (step S29).

  Next, the counter 108 compares the magnitude relationship between the current value of K and a predetermined value of Kmax (step S30). If the value of K is smaller, the process returns to step S26, and thereafter steps S26 to S30 are repeated. In order to ensure sufficient convergence in this optimization calculation, for example, Kmax = 10000 can be set.

  In other cases, the pseudo temperature management unit 110 subtracts the pseudo temperature T by ΔT (step S31), and proceeds to the next step S32. The change amount of the pseudo temperature T may be not only the subtraction of ΔT but also a multiplication of a constant δ (0 <δ <1). In this case, the probability Prob (lower stage) shown in the equation (2) is subtracted by a certain value.

  Next, the pseudo temperature management unit 110 determines whether or not the current pseudo temperature T is equal to 0 (step S32). If T is not equal to 0, the process returns to step S25, and steps S25 to S32 are repeated thereafter.

  On the other hand, when T is equal to 0, the pseudo temperature management unit 110 notifies the output image data determination unit 116 that the evaluation of the mesh pattern by the SA method has ended. Then, the storage unit 24 overwrites and updates the output image data ImgOut with the content of the image data Img last updated in step S28 (step S33).

  In this way, the creation of the output image data ImgOut is finished (step S2). The output image data ImgOut is image data that is then supplied to the exposure data conversion unit 32 and converted into a control signal for the exposure unit 18.

  Note that the output image data ImgOut obtained may be displayed on the display unit 22 and the mesh pattern M may be visualized in a pseudo manner for visual confirmation by the operator.

  FIG. 17 is a cross-sectional view along the X axis of the spectrum Spc obtained by performing FFT on the image data Img representing the patterns of the mesh pattern M according to the present embodiment and the various patterns PT1 to PT3 according to the conventional example. It is.

  The spectrum Spc of the pattern PT1 shown in FIG. 27A has a wide peak (range of 2 to 30 cycles / mm) with the apex of about 10 cycles / mm. In addition, the spectrum Spc of the pattern PT2 shown in FIG. 27B has a wide peak (a range of 3 to 20 cycles / mm) centered at about 3 cycles / mm. Further, the spectrum Spc of the pattern PT3 shown in FIG. 27C has a slightly narrow peak (in the range of 8 to 18 cycles / mm) with a center of about 10 cycles / mm. On the other hand, the spectrum Spc of the mesh pattern M has a narrow peak centered on 8.8 cycles / mm.

By the way, the relationship between the characteristics of the spectrum Spc shown in FIG. 7C and the centroid position of each mesh will be described below. As shown in FIG. 18, it is assumed that polygonal regions V _{1 to} V ₈ are defined using the Voronoi diagram described above with respect to the two-dimensional image region 202 similar to FIG. 11B. Each point C ₁ -C ₈ respectively belonging to each area V ₁ ~V within ₈ represents the position of the center of gravity of each region.

  FIG. 19 is a schematic explanatory diagram showing the relationship between a plurality of meshes and the center of gravity position of each mesh with respect to the mesh pattern M according to the present embodiment.

  FIG. 20A is a schematic visualization of image data (hereinafter referred to as “centroid image data Imgc”) representing the distribution of the center of gravity of each mesh (hereinafter referred to as “centroid distribution C”) included in the mesh pattern M of FIG. It is explanatory drawing. As can be understood from the figure, in the center of gravity distribution C, the positions of the center of gravity are appropriately dispersed without overlapping each other.

  20B is a distribution diagram of a two-dimensional power spectrum (hereinafter referred to as “centroid spectrum Spcc”) obtained by performing FFT on the centroid image data Imgc of FIG. 20A. Here, the horizontal axis of the distribution diagram indicates the spatial frequency in the X-axis direction, and the vertical axis indicates the spatial frequency in the Y-axis direction. Further, the intensity level (spectrum value) decreases as the display density for each spatial frequency band decreases, and the intensity level increases as the display density increases. In the example of this figure, the distribution of the centroid spectrum Spcc is isotropic and has one circular peak.

  FIG. 20C is a cross-sectional view along the line XXC-XXC of the distribution of the centroid spectrum Spcc shown in FIG. 20B. Since the center-of-gravity spectrum Spcc is isotropic, FIG. 20C corresponds to the radial direction distribution for all angular directions. As can be understood from this figure, the intensity level in the low spatial frequency band is small, and the intermediate spatial frequency band has a wide peak. Furthermore, it has a so-called high-pass characteristic in which the intensity level in the high spatial frequency band is higher than the low space fractional band. That is, it can be said that the center-of-gravity image data Imgc shown in FIG. 20A represents a pattern having the characteristics of “blue noise” according to technical terms in the field of image engineering.

FIG. 21 is a comparative diagram of the graphs of FIGS. 7C and 20C. Specifically, the spectrum Spc of the mesh pattern M and the centroid spectrum Spcc of the centroid distribution C are compared. For convenience, the intensities of the spectra Spc and Spcc are normalized so that the maximum peak values P _K coincide.

According to the figure, the spatial frequency F _P peak Pk is coincident, this value corresponds to 8.8cycle / mm. The high spatial frequency band exceeding the spatial frequency F _P, while reducing the spectral intensity of Spc gradually, the strength of the center of gravity spectrum Spcc maintains a still higher value. The reason for this is presumed that the constituent elements of the center of gravity distribution C are dots while the constituent elements of the mesh pattern M are line segments having a predetermined width intersecting each other.

  FIG. 22 is a schematic explanatory diagram illustrating the features of the center-of-gravity spectrum Spcc of FIG. 20C. The value of the center-of-gravity spectrum Spcc gradually increases in the range of 0 to 5 cycles / mm, increases rapidly around 6 cycles / mm, and has a wide peak at about 10 cycles / mm. Then, it gradually decreases in the range of 10 to 15 cycles / mm and maintains a high value in a high spatial frequency band exceeding 15 cycles / mm.

Here, the reference spatial frequency Fb (predetermined spatial frequency) is set to 6 cycles / mm. Let P _{L be} the average value of the centroid spectrum Spcc in the spatial frequency band side lower than Fb, that is, in the range of 0 to Fb [cycle / mm]. On the other hand, a high spatial frequency band side than Fb, i.e., the mean value of centroid spectrum Spcc in Fb [cycle / mm] ~ Nyquist frequency and P _H. In this way, P _H is larger than P _L. Since the center-of-gravity spectrum Spcc has such a feature, the noise feeling visually felt by the observer is reduced. The basis for this is as follows.

  For example, the value of Fb is set so that the human visual response characteristic is a spatial frequency corresponding to 5% of the maximum response. This is because at this strength level, it is difficult to view. Moreover, as shown in FIG. 8, the visual response characteristic obtained based on the Dooley-Shaw function with a clear visual distance of 300 mm is used. This is because this function fits well with human visual response characteristics.

  That is, as the value of Fb, a spatial frequency of 6 cycles / mm corresponding to 5% of the maximum response can be used in the Dooley-Shaw function with a clear visual distance of 300 mm. Note that 6 cycles / mm corresponds to an interval of 167 μm.

  By the way, the power spectrum of the centroid position distribution of the mesh pattern M included in the conductive film 14 corresponds to a spectrum obtained by the following process. That is, the image data ImgOut representing the pattern of the mesh pattern M is acquired, each mesh (closed space) is identified, the center of gravity position (for example, one pixel dot) is calculated, and the center of gravity image data Imgc is obtained. By obtaining the dimensional power spectrum (spectrum Spcc), the power spectrum of the gravity center position distribution of the mesh pattern M is obtained.

  The image data ImgOut may be acquired as grayscale image data of the conductive film 14 using an input device such as a scanner, or the image data ImgOut actually used for forming the mesh pattern M (see FIG. 1).

  Returning to FIG. 6, the exposure unit 18 performs an exposure process for the mesh pattern M (step S3), and then performs a development process (step S4).

  Here, several methods (first method to fourth method) for forming the mesh pattern M by the fine metal wires 54 on the transparent film substrate 56 will be described with reference to FIGS. 23A to 26.

  The first manufacturing method is a method in which a mesh pattern M is formed by a metallic silver portion formed by exposing, developing and fixing a silver salt photosensitive layer provided on a transparent film substrate 56.

  Specifically, as shown in FIG. 23A, a silver salt photosensitive layer 66 obtained by mixing silver halide 62 (for example, silver bromide grains, silver chlorobromide grains or silver iodobromide grains) with gelatin 64 is formed as a transparent film. It is applied on the substrate 56. In FIG. 23A to FIG. 23C, although the silver halide 62 is described as “grains”, it is exaggerated to help understanding of the present invention, and the size, concentration, etc. are shown. It is not a thing.

  Thereafter, as shown in FIG. 23B, the silver salt photosensitive layer 66 is subjected to exposure necessary for forming the conductive portion 50. That is, the light 16 is irradiated to the silver salt photosensitive layer 66 through the mask pattern corresponding to the exposure pattern obtained through the pattern generation process shown in FIG. Alternatively, the exposure pattern generated by the pattern generation process is exposed to the silver salt photosensitive layer 66 by digital writing exposure on the silver salt photosensitive layer 66. When silver halide 62 receives light energy, it is exposed to light and generates fine silver nuclei called “latent images” that cannot be observed with the naked eye.

  Thereafter, development processing is performed as shown in FIG. 23C in order to amplify the latent image into a visualized image that can be observed with the naked eye. Specifically, the silver salt photosensitive layer 66 on which the latent image is formed is developed with a developer (both alkaline solutions and acidic solutions, but usually alkaline solutions are large). In this development process, silver ions supplied from silver halide grains or a developer are reduced to metallic silver by using a latent image silver nucleus as a catalyst nucleus by a reducing agent called a developing agent in the developer, and as a result The image silver nuclei are amplified to form a visualized silver image (developed silver 68).

  After the development processing is completed, silver halide 62 which can be exposed to light remains in the silver salt photosensitive layer 66. To remove this, a fixing processing solution (either an acidic solution or an alkaline solution is used as shown in FIG. 23D). However, fixing is usually performed by using an acidic solution.

  By performing this fixing process, the metallic silver portion 70 is formed in the exposed portion, and only the gelatin 64 remains in the unexposed portion to become the light transmitting portion 72. That is, a mesh pattern M is formed on the transparent film substrate 56 by a combination of the metallic silver portion 70 and the light transmitting portion 72.

The reaction formula of the fixing process in the case where silver bromide is used as the silver halide 62 and the fixing process is performed with thiosulfate is shown below.
AgBr (solid) + 2 S ₂ O ₃ ions → Ag (S ₂ O ₃ ) ₂
(Easily water-soluble complex)

That is, two thiosulfate ions S ₂ O ₃ and silver ions in gelatin 64 (silver ions from AgBr) form a silver thiosulfate complex. Since the silver thiosulfate complex has high water solubility, it is eluted from the gelatin 64. As a result, the developed silver 68 is fixed and remains as the metallic silver portion 70. The mesh pattern M is constituted by the metal silver portion 70.

  Therefore, the development step is a step of causing the reducing agent to react with the latent image to precipitate the developed silver 68, and the fixing step is a step of eluting the silver halide 62 that has not become the developed silver 68 into water. For details, see T.W. H. James, The Theory of the Photographic Process, 4th ed. , Macmillan Publishing Co. , Inc, NY, Chapter 15, pp. 438-442. See 1977.

  In many cases, the development process is performed with an alkaline solution. Therefore, when entering the fixing process from the development process, the alkaline solution adhered in the development process is a fixing process solution (in many cases, an acidic solution). Therefore, there is a problem that the activity of the fixing processing solution changes. Further, there is a concern that an unintended development reaction may further progress due to the developer remaining in the film after leaving the development processing tank. Therefore, it is preferable to neutralize or acidify the silver salt photosensitive layer 66 with a stop solution such as an acetic acid (vinegar) solution after the development processing and before entering the fixing processing step.

  Then, as shown in FIG. 23E, for example, by performing a plating process (single or combination of electroless plating and electroplating) and supporting the conductive metal 74 only on the metal silver part 70, the metal silver part 70 and the metal silver part 70 The mesh pattern M may be formed by the conductive metal 74 carried on the metal silver part 70.

  Here, the difference between the above-described method using the silver salt photosensitive layer 66 (silver salt photographic technology) and the method using photoresist (resist technology) will be described.

  In resist technology, the photopolymerization initiator absorbs light by the exposure process and the reaction starts, and the photoresist film (resin) itself undergoes a polymerization reaction to increase or decrease the solubility in the developer. The exposed resin is removed. Note that a solution called a developing solution in the resist technique is an alkaline solution that does not contain a reducing agent and dissolves an unreacted resin component, for example. On the other hand, in the exposure processing of the silver salt photographic technique of the present invention, as described above, fine silver nuclei called so-called “latent image” are formed from photoelectrons and silver ions generated in the silver halide 62 at the site receiving light. The latent image silver nuclei are amplified by a development process (in this case, the developer always contains a reducing agent called a developing agent) to become a visualized silver image. Thus, the resist technology and the silver salt photographic technology have completely different reactions from exposure processing to development processing.

  In the development process of the resist technique, a resin part that has not undergone a polymerization reaction in an exposed part or an unexposed part is removed. On the other hand, in the development processing of the silver salt photographic technology, the developed silver 68 grows to a visible size by causing a reduction reaction with a reducing agent called a developing agent contained in the developer using the latent image as a catalyst nucleus. The gelatin 64 in the unexposed part is not removed. In this way, the resist technology and the silver salt photographic technology have completely different reactions in development processing.

  Note that the silver halide 62 contained in the unexposed portion of the gelatin 64 is eluted by the subsequent fixing process, and the gelatin 64 itself is not removed.

  Thus, in silver salt photographic technology, the main reaction (photosensitive) is silver halide, whereas in resist technology, it is a photopolymerization initiator. In the development processing, the binder (gelatin 64) remains in the silver salt photographic technique, but the binder disappears in the resist technique. In this respect, the silver salt photographic technique and the photoresist technique are greatly different.

  As another manufacturing method (second manufacturing method), as shown in FIG. 24A, for example, a photoresist film 76 on a copper foil 75 formed on a transparent film substrate 56 is formed to obtain a photosensitive material. Thereafter, the photosensitive material is exposed. That is, the photoresist film 76 is irradiated with light through a mask pattern corresponding to the exposure pattern obtained through the pattern generation process shown in FIG. Alternatively, the exposure pattern generated by the pattern generator is exposed to the photoresist film 76 by digital writing exposure on the photoresist film 76. Thereafter, by developing, a resist pattern 78 corresponding to the conductive portion 50 is formed on the transparent film substrate 56, and the copper foil 75 exposed from the resist pattern 78 is etched as shown in FIG. 24B. At this stage, the conductive portion 50 (mesh pattern M) made of the copper foil 75 is formed on the transparent film substrate 56.

  As a third manufacturing method, as shown in FIG. 25A, a paste 80 containing fine metal particles is printed on a transparent film substrate 56, and as shown in FIG. 25B, a metal plating is applied to the printed paste 80. By performing step 82, the conductive portion 50 (mesh pattern M) may be formed.

  Alternatively, as a fourth manufacturing method, as shown in FIG. 26, the metal thin film 84 may be printed on the transparent film substrate 56 by a screen printing plate or a gravure printing plate to form the mesh pattern M.

  Next, in the conductive film 14 according to the present embodiment, a method for producing a conductive metal thin film using a silver halide photographic light-sensitive material which is a particularly preferable embodiment will be mainly described.

  As described above, the conductive film 14 according to the present embodiment is exposed by exposing a photosensitive material having an emulsion layer containing a photosensitive silver halide salt on the transparent film substrate 56 and developing the photosensitive material. The metallic silver portion 70 and the transparent portion 72 are respectively formed in the exposed portion and the unexposed portion, and the metallic silver portion 70 is further subjected to physical development and / or plating treatment, thereby supporting the conductive metal 74 on the metallic silver portion 70. Can be manufactured.

  The method for forming the conductive film 14 according to the present embodiment includes the following three forms depending on the photosensitive material and the form of development processing.

(1) An embodiment in which a photosensitive silver halide black-and-white photosensitive material that does not contain physical development nuclei is chemically or physically developed to form a metallic silver portion 70 on the photosensitive material.

(2) An embodiment in which a photosensitive silver halide black-and-white photosensitive material containing physical development nuclei in a silver halide emulsion layer is physically developed to form a metallic silver portion 70 on the photosensitive material.

(3) A photosensitive silver halide black-and-white photosensitive material that does not contain physical development nuclei and an image-receiving sheet having a non-photosensitive layer that contains physical development nuclei are overlaid and diffused and transferred to develop a non-photosensitive image of the metallic silver portion 70. Form formed on a sheet.

  The aspect (1) is an integrated black-and-white development type, and a light-transmitting conductive film such as a light-transmitting electromagnetic wave shielding film or a light-transmitting conductive film is formed on the photosensitive material. The resulting developed silver is chemically developed silver or physical developed silver, and is highly active in the subsequent plating or physical development process in that it is a filament with a high specific surface.

  In the above aspect (2), the light-transmitting conductive film is formed on the photosensitive material by dissolving the silver halide near the physical development nucleus and depositing it on the development nucleus in the exposed portion. This is also an integrated black-and-white development type. Although the development action is precipitation on the physical development nuclei, it is highly active, but the specific surface of developed silver is a small sphere.

  In the aspect (3), the light-transmitting conductive film is formed on the image receiving sheet by dissolving and diffusing the silver halide in the unexposed area and depositing on the development nuclei on the image receiving sheet. This is a so-called separate type in which the image receiving sheet is peeled off from the photosensitive material.

  In either embodiment, either negative development processing or reversal development processing can be selected (in the case of the diffusion transfer method, negative development processing is possible by using an auto-positive type photosensitive material as the photosensitive material). .

  The chemical development, thermal development, dissolution physical development, and diffusion transfer development mentioned here have the same meanings as are commonly used in the industry, and are general textbooks of photographic chemistry such as Shinichi Kikuchi, “Photochemistry” (Kyoritsu Publishing) (Published in 1955), C.I. E. K. It is described in “The Theory of Photographic Process, 4th ed.” Edited by Mees (Macmillan, 1977). Although this case is an invention related to liquid processing, a technique of applying a thermal development system as another development system can also be referred to. For example, the techniques described in Japanese Patent Application Laid-Open Nos. 2004-184893, 2004-334077, and 2005-010752, and Japanese Patent Application Nos. 2004-244080 and 2004-085655 can be applied. it can.

(Photosensitive material)
The photosensitive material (photosensitive web) as the material to be plated is, for example, a long flexible base material in which a silver salt-containing layer containing a silver salt (for example, silver halide) is provided on the transparent film base material 56. Further, a protective layer may be provided on the silver salt-containing layer, and this protective layer means a layer made of a binder such as gelatin or a high molecular polymer, and exhibits effects of preventing scratches and improving mechanical properties. To be formed on the silver salt-containing layer. The thickness of the protective layer is preferably 0.02 to 20 μm.

  The composition of these silver salt-containing layers and protective layers, such as silver halide photographic film, photographic paper, film for printing plate making, emulsion mask for photomask, silver halide emulsion layer (silver salt-containing layer) and protection Layers can be applied as appropriate.

  In particular, as the light-sensitive material, a silver salt photographic film (silver salt light-sensitive material) is preferable, and a black-and-white silver salt photographic film (black-and-white silver salt light-sensitive material) is the best. The silver salt applied to the silver salt-containing layer is most preferably silver halide. The width of the photosensitive material is, for example, 20 cm or more, and the thickness is preferably 50 to 200 μm.

[Transparent film substrate 56]
As the transparent film base material 56 used in the manufacturing method of the present embodiment, a flexible plastic film can be used.

  Examples of the raw material for the plastic film include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyvinyl chloride, polyvinylidene chloride, polyvinyl butyral, polyamide, polyether, polysulfone, polyethersulfone, polycarbonate, and polyarylate. , Polyetherimide, polyetherketone, polyetheretherketone, polyolefins such as EVA, polycarbonate, triacetylcellulose (TAC), acrylic resin, polyimide, or aramid can be used.

  In the present embodiment, the plastic film is preferably a polyethylene terephthalate (PET) film or a triacetyl cellulose (TAC) film from the viewpoint of translucency, heat resistance, ease of handling, and price.

  Since the transparent heating element for window glass requires translucency, it is desirable that the translucency of the transparent film substrate 56 is high. In this case, the total visible light transmittance of the plastic film is preferably 70 to 100%, more preferably 85 to 100%, and particularly preferably 90 to 100%. Moreover, in this invention, what was colored to such an extent that the objective of this invention is not prevented as said plastic film can also be used.

  The plastic film in this embodiment can be used as a single layer, but can also be used as a multilayer film in which two or more layers are combined.

[Protective layer]
The photosensitive material used may be provided with a protective layer on the emulsion layer described later. In the present embodiment, the “protective layer” means a layer made of a binder such as gelatin or a high molecular polymer, and is formed on a photosensitive emulsion layer in order to exhibit an effect of preventing scratches or improving mechanical properties. . The protective layer is preferably not provided for the plating treatment, and even if provided, the protective layer is preferably thin. The thickness is preferably 0.2 μm or less. The formation method of the coating method of the said protective layer is not specifically limited, A well-known coating method can be selected suitably.

[Emulsion layer]
The photosensitive material used in the manufacturing method of the present embodiment preferably has an emulsion layer (silver salt photosensitive layer 66) containing a silver salt as a photosensor on the transparent film substrate 56. In addition to the silver salt, the emulsion layer in the present embodiment can contain a dye, a binder, a solvent, and the like as required.

<Silver salt>
The silver salt used in the present embodiment is preferably an inorganic silver salt such as silver halide. In particular, the silver salt is preferably used in the form of silver halide grains for a silver halide photographic light-sensitive material. Silver halide is excellent in characteristics as an optical sensor.

  The silver halide preferably used in the form of a photographic emulsion of the silver halide photographic light-sensitive material will be described.

  In the present embodiment, it is preferable to use silver halide in order to function as an optical sensor, and a technique used for silver halide photographic film, photographic paper, printing plate making film, emulsion mask for photomask, etc. relating to silver halide. Can also be used in this embodiment.

  The halogen element contained in the silver halide may be any of chlorine, bromine, iodine and fluorine, or a combination thereof. For example, silver halide mainly composed of AgCl, AgBr, and AgI is preferably used, and silver halide mainly composed of AgBr or AgCl is preferably used. Silver chlorobromide, silver iodochlorobromide and silver iodobromide are also preferably used. More preferred are silver chlorobromide, silver bromide, silver iodochlorobromide and silver iodobromide, and most preferred are silver chlorobromide and silver iodochlorobromide containing 50 mol% or more of silver chloride. Used.

  Here, “silver halide mainly composed of AgBr (silver bromide)” refers to silver halide in which the molar fraction of bromide ions in the silver halide composition is 50% or more. The silver halide grains mainly composed of AgBr may contain iodide ions and chloride ions in addition to bromide ions.

  The silver halide emulsion used in this embodiment may contain a metal belonging to Group VIII or Group VIIB. In particular, it is preferable to contain a rhodium compound, an iridium compound, a ruthenium compound, an iron compound, an osmium compound or the like in order to obtain a gradation of 4 or more or to achieve low fog.

For high sensitivity, doping with a metal hexacyanide complex such as K ₄ [Fe (CN) ₆ ], K ₄ [Ru (CN) ₆ ] or K ₃ [Cr (CN) ₆ ] is advantageous. Done.

The amount of these compounds added is preferably 10 ⁻¹⁰ to 10 ⁻² mol / mol Ag per mol of silver halide, more preferably 10 ⁻⁹ to 10 ⁻³ mol / mol Ag.

  In addition, in the present embodiment, silver halide containing Pd (II) ions and / or Pd metal can be preferably used. Pd may be uniformly distributed in the silver halide grains, but is preferably contained in the vicinity of the surface layer of the silver halide grains. Here, Pd “contains in the vicinity of the surface layer of the silver halide grains” means that the Pd content is higher than the other layers within 50 nm in the depth direction from the surface of the silver halide grains. means.

  Such silver halide grains can be prepared by adding Pd in the course of forming silver halide grains. After adding silver ions and halogen ions to 50% or more of the total addition amount, Pd Is preferably added. It is also preferred that Pd (II) ions be present in the surface layer of the silver halide by a method such as addition at the time of post-ripening.

  The Pd-containing silver halide grains increase the speed of physical development and electroless plating, increase the production efficiency of a desired heating element, and contribute to the reduction of production costs. Pd is well known and used as an electroless plating catalyst. However, in the present invention, Pd can be unevenly distributed on the surface layer of silver halide grains, so that extremely expensive Pd can be saved. is there.

In the present embodiment, the content of Pd ions and / or Pd metal contained in the silver halide is 10 ^{−4 to} 0.5 mol / mol Ag with respect to the number of moles of silver in the silver halide. It is more preferable that it is 0.01-0.3 mol / mol Ag.

Examples of the Pd compound to be used include PdCl ₄ and Na ₂ PdCl ₄ .

  In this embodiment, in order to further improve the sensitivity as an optical sensor, chemical sensitization performed with a photographic emulsion can be performed. As the chemical sensitization method, sulfur sensitization, selenium sensitization, chalcogen sensitization such as tellurium sensitization, noble metal sensitization such as gold sensitization, reduction sensitization and the like can be used. These are used alone or in combination. When the above chemical sensitization methods are used in combination, for example, sulfur sensitization method and gold sensitization method, sulfur sensitization method and selenium sensitization method and gold sensitization method, sulfur sensitization method and tellurium sensitization. A combination of a method and a gold sensitization method is preferable.

<Binder>
In the emulsion layer, a binder can be used for the purpose of uniformly dispersing silver salt grains and assisting the adhesion between the emulsion layer and the support. In the present invention, as the binder, both a water-insoluble polymer and a water-soluble polymer can be used as a binder, but a water-soluble polymer is preferably used.

  Examples of the binder include polysaccharides such as gelatin, polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), starch, cellulose and derivatives thereof, polyethylene oxide, polysaccharides, polyvinylamine, chitosan, polylysine, polyacrylic acid, poly Examples include alginic acid, polyhyaluronic acid, and carboxycellulose. These have neutral, anionic, and cationic properties depending on the ionicity of the functional group.

  The content of the binder contained in the emulsion layer is not particularly limited, and can be appropriately determined as long as dispersibility and adhesion can be exhibited. For example, the binder content in the emulsion layer is preferably adjusted so that the Ag / binder volume ratio in the silver salt photosensitive layer 66 is ¼ or more, and is ½ or more. It is further preferable to adjust.

<Solvent>
The solvent used for the formation of the emulsion layer is not particularly limited. For example, water, organic solvents (for example, alcohols such as methanol, ketones such as acetone, amides such as formamide, dimethyl sulfoxide, etc. Sulphoxides, esters such as ethyl acetate, ethers, etc.), ionic liquids, and mixed solvents thereof.

  The content of the solvent used in the emulsion layer of the present invention is in the range of 30 to 90% by mass and in the range of 50 to 80% by mass with respect to the total mass of silver salt, binder and the like contained in the emulsion layer. Preferably there is.

  Next, each process for forming the electroconductive part 50 (mesh pattern M) is demonstrated.

[exposure]
In the present embodiment, the exposure unit 18 exposes the photosensitive material having the silver salt photosensitive layer 66 provided on the transparent film substrate 56. The exposure can be performed using electromagnetic waves. Examples of the electromagnetic wave include light such as visible light and ultraviolet light, and radiation such as X-rays. Furthermore, a light source having a wavelength distribution may be used for exposure, or a light source having a specific wavelength may be used.

  As an exposure method for forming a pattern image, a surface exposure method for irradiating a photosensitive surface with uniform light through a mask pattern to form a mask pattern imagewise, and a pattern irradiation unit by scanning a beam such as a laser beam There is a scanning exposure method in which is formed on the photosensitive surface.

  The exposure can be performed using various laser beams. For example, the exposure in this embodiment is performed by using a monochromatic light source such as a gas laser, a light emitting diode, a semiconductor laser, a semiconductor laser, or a second harmonic light source (SHG) that combines a solid state laser using a semiconductor laser as a pumping light source and a nonlinear optical crystal. A scanning exposure method using high-density light can be preferably used, and a KrF excimer laser, ArF excimer laser, F2 laser, or the like can also be used. In order to make the system compact and inexpensive, exposure is more preferably performed using a semiconductor laser, a semiconductor laser, or a second harmonic generation light source (SHG) that combines a solid-state laser and a nonlinear optical crystal. In particular, in order to design a compact, inexpensive, long-life and high-stability device, it is most preferable to perform exposure using a semiconductor laser.

  The method of exposing the silver salt photosensitive layer 66 in a pattern is preferably scanning exposure using a laser beam. In particular, a capstan type laser scanning exposure apparatus described in Japanese Patent Application Laid-Open No. 2000-39677 is preferable. Further, in this capstan method, a DMD described in Japanese Patent Application Laid-Open No. 2004-1224 is optically used instead of beam scanning by rotation of a polygon mirror. It is also preferable to use it for a beam scanning system. In particular, when a long flexible film heater having a length of 3 m or more is produced, it is preferable to perform exposure with a laser beam while conveying the photosensitive material on a curved exposure stage.

  As will be described later, the mesh pattern M includes lattice patterns such as triangles, quadrilaterals (diamonds, squares, etc.) and hexagons formed by intersecting substantially parallel straight thin lines, parallel straight lines, zigzag lines, wavy lines, etc. The structure is not particularly limited as long as a current can flow between electrodes to which a voltage is applied.

[Development processing]
In this embodiment, after the emulsion layer is exposed, development processing is further performed. The development processing can be performed by a normal development processing technique used for silver salt photographic film, photographic paper, printing plate-making film, photomask emulsion mask, and the like. The developer is not particularly limited, but a PQ developer, MQ developer, MAA developer and the like can also be used. Commercially available products include, for example, CN-16, CR-56, CP45X, and FD prescribed by FUJIFILM Corporation. -3, Papitol, a developer such as C-41, E-6, RA-4, D-19, D-72, etc. formulated by KODAK, or a developer included in the kit can be used.

  Lith developer can also be used. As the lith developer, D85 or the like prescribed by KODAK can be used. In the present invention, by performing the above exposure and development processing, a metal silver portion 70, preferably a patterned metal silver portion 70 is formed in the exposed portion, and a light transmitting portion 72 described later is formed in the unexposed portion. The

  The developer used in the development process can contain an image quality improver for the purpose of improving the image quality. Examples of the image quality improver include nitrogen-containing heterocyclic compounds such as benzotriazole. Further, when a lith developer is used, it is particularly preferable to use polyethylene glycol.

  The mass of the metallic silver contained in the exposed portion after the development treatment is preferably a content of 50% by mass or more, and 80% by mass or more with respect to the mass of silver contained in the exposed portion before exposure. More preferably. If the mass of silver contained in the exposed portion is 50% by mass or more based on the mass of silver contained in the exposed portion before exposure, it is preferable because high conductivity can be obtained.

  The gradation after the development processing in the present embodiment is not particularly limited, but is preferably more than 4.0. When the gradation after the development processing exceeds 4.0, the conductivity of the conductive metal portion can be increased while keeping the translucency of the translucent portion high. Examples of means for setting the gradation to 4.0 or higher include the aforementioned doping of rhodium ions and iridium ions.

[Physical development and plating]
In the present embodiment, for the purpose of improving the conductivity of the metal silver portion 70 formed by the exposure and development processes described above, physical development and / or plating treatment for supporting the conductive metal particles on the metal silver portion 70. May be performed. In the present embodiment, it is possible to carry the conductive metal particles on the metal silver portion 70 by only one of the physical development and the plating treatment, but the conductive metal particles are further combined by combining physical development and the plating treatment. It can also be carried on the metallic silver part 70.

  “Physical development” in the present embodiment means that metal particles such as silver ions are reduced by a reducing agent on metal or metal compound nuclei to deposit metal particles. This physical phenomenon is used for instant B & W film, instant slide film, printing plate manufacturing, and the like, and the technology can be used in the present invention.

[Calendar processing]
The developed metal silver portion 70 (entire metal silver portion, metal mesh pattern portion, or metal wiring pattern portion) may be smoothed by performing a calendar process. As a result, the conductivity of the metallic silver part 70 is significantly increased. The calendar process can be performed by a calendar roll. The calendar roll usually consists of a pair of rolls.

As a roll used for the calendar process, a plastic roll or a metal roll such as epoxy, polyimide, polyamide, polyimide amide or the like is used. In particular, when emulsion layers are provided on both sides, it is preferable to treat with metal rolls. When an emulsion layer is provided on one side, a combination of a metal roll and a plastic roll can be used from the viewpoint of preventing wrinkles. The upper limit of the linear pressure is 1960 N / cm (200 kgf / cm, converted to a surface pressure of 699.4 kgf / cm ² ) or more, more preferably 2940 N / cm (300 kgf / cm, converted to a surface pressure of 935.8 kgf / cm ^2). ) That's it. The upper limit of the linear pressure is 6880 N / cm (700 kgf / cm) or less.

  The application temperature of the smoothing treatment represented by the calender roll is preferably 10 ° C. (no temperature control) to 100 ° C., and the more preferable temperature varies depending on the line density and shape of the metal mesh pattern and metal wiring pattern, and the binder type. , Approximately 10 ° C. (no temperature control) to 50 ° C.

[Vapor contact treatment]
The effect of the calendar process can be further brought out by bringing it into contact with steam immediately before or after the calendar process. That is, the conductivity can be significantly improved. The temperature of the steam used is preferably 80 ° C. or higher, more preferably 100 ° C. or higher and 140 ° C. or lower. The contact time with steam is preferably about 10 seconds to 5 minutes, more preferably 1 minute to 5 minutes.

  In addition, this invention can be used in combination with the technique of the publication | presentation gazette and international publication pamphlet which are described in following Table 1 and Table 2 suitably. Notations such as “JP,” “Gazette” and “No. Pamphlet” are omitted.

  Hereinafter, the present invention will be described more specifically with reference to examples of the present invention. In addition, the material, usage-amount, ratio, processing content, processing procedure, etc. which are shown in the following Examples can be changed suitably unless it deviates from the meaning of this invention. Accordingly, the scope of the present invention should not be construed as being limited by the specific examples shown below.

[Silver halide photosensitive material]
An emulsion containing 10.0 g of gelatin per 60 g of Ag in an aqueous medium and containing silver iodobromochloride grains having an average equivalent spherical diameter of 0.1 μm (I = 0.2 mol%, Br = 40 mol%) was prepared. .

In this emulsion, K ₃ Rh ₂ Br ₉ and K ₂ IrCl ₆ were added so as to have a concentration of 10 ⁻⁷ (mol / mol silver), and silver bromide grains were doped with Rh ions and Ir ions. . After adding Na ₂ PdCl ₄ to this emulsion and further performing gold-sulfur sensitization with chloroauric acid and sodium thiosulfate, together with the gelatin hardener, the coating amount of silver is 1 g / m ^2. It was coated on polyethylene terephthalate (PET). At this time, the volume ratio of Ag / gelatin was ½.

  Coating was performed for 20 m with a width of 25 cm on a PET support having a width of 30 cm, and both ends were cut off by 3 cm so as to leave a central portion of the coating, thereby obtaining a roll-shaped silver halide photosensitive material.

[Create exposure pattern]
Using the SA method (see FIG. 9 and the like) described in the present embodiment, output image data ImgOut representing a mesh pattern M (see FIG. 2A) composed of wirings arranged irregularly is created.

The setting conditions of the mesh pattern M were 93% overall transmittance, the thickness of the transparent film substrate 56 was 20 μm, the width of the fine metal wire 54 was 20 μm, and the thickness of the fine metal wire 54 was 10 μm. The pattern size was 5 mm both vertically and horizontally, and the image resolution was 3500 dpi (dot per inch). The initial position of the seed point SD was randomly determined using a Mersenne twister, and each polygonal mesh region was defined using a Voronoi diagram. The evaluation value EVP was calculated based on the color value L ^* , the color value a ^* , and the color value b ^* of the image data Img. A periodic exposure pattern was formed by arranging the same output image data ImgOut in the vertical direction and the horizontal direction.

  On the other hand, output image data ImgOut representing patterns PT1 to PT3 (see FIGS. 27A to 27C) according to the conventional example was also created.

[exposure]
Exposure of the exposure pattern to the silver halide photosensitive material is performed by arranging exposure heads using DMD (digital mirror device) described in the embodiment of Japanese Patent Application Laid-Open No. 2004-1224 so as to have a width of 25 cm. The exposure head and exposure stage are curved and arranged so that the laser beam forms an image on the photosensitive layer of the material, and the photosensitive material feeding mechanism and winding mechanism are attached, and the tension control and winding and feeding mechanism of the exposure surface are attached. The continuous exposure apparatus was provided with a bend having a buffering action so that the speed fluctuation of the above does not affect the speed of the exposed portion. The wavelength of exposure was 400 nm, the beam shape was approximately 12 μm, and the output of the laser light source was 100 μJ.

[Developer composition]
The following compounds are contained in 1 liter of developer.
Hydroquinone 20 g
Sodium sulfite 50 g
Potassium carbonate 40 g
Ethylenediamine tetraacetic acid 2 g
Potassium bromide 3 g
Polyethylene glycol 2000 1 g
Potassium hydroxide 4 g
Adjust to pH 10.3

[Fixing solution composition]
The following compounds are contained in 1 liter of the fixing solution.
Ammonium thiosulfate solution (75%) 300 ml
Ammonium sulfite monohydrate 25 g
1,3-diaminopropane tetraacetic acid 8 g
Acetic acid 5 g
Ammonia water (27%) 1 g
Adjust to pH 6.2

[Development processing]
The photosensitive material exposed using the above-mentioned processing agent is processed using an automatic developing machine FG-710PTS manufactured by FUJIFILM Corporation. Development conditions: development at 35 ° C. for 30 seconds, fixing at 34 ° C. for 23 seconds, washing water (5 L / min) for 20 seconds Made in the process.

As running conditions, the processing amount of the photosensitive material was 100 m ² / day, the developer was replenished at 500 ml / m ² , and the fixing solution was 640 ml / m ² for 3 days. At this time, it was confirmed that the copper pattern after the plating treatment had a 12 μm line width and a 300 micron pitch.

  Further, plating solution (copper sulfate 0.06 mol / L, formalin 0.22 mol / L, triethanolamine 0.12 mol / L, polyethylene glycol 100 ppm, yellow blood salt 50 ppm, α, α′-bipyridine 20 ppm is contained. Electroless copper plating treatment at 45 ° C. using an electroless Cu plating solution having a pH of 12.5), followed by an oxidation treatment with an aqueous solution containing 10 ppm of Fe (III) ions. Each sample of film was obtained.

  Hereinafter, the conductive film 14 having the patterns PT1 to PT3 is referred to as first to third samples, and the conductive film 14 having the mesh pattern M is referred to as fourth sample.

[Evaluation]
(Surface resistance measurement)
In order to evaluate the uniformity of the surface resistivity, the surface resistivity of the conductive film 14 was measured at 10 arbitrary points with a Lillestar GP (model number MCP-T610) series 4-probe probe (ASP) manufactured by Dia Instruments. Is the average value.

(Evaluation of noise)
A commercially available color liquid crystal display (screen size 4.7 type, 640 × 480 dots) is used. A touch panel to which the first to fourth samples were attached was incorporated in the liquid crystal display, an LED lamp as auxiliary light was turned on from the back surface of the liquid crystal panel, the display screen was observed, and a visual evaluation of the noise feeling was performed. The visibility of the noise feeling was performed at an observation distance of 300 mm from the front side of the liquid crystal panel.

[result]
In all of the ten first to fourth samples, the surface resistivity was a level that could be sufficiently put into practical use as a transparent electrode, and the translucency was also good. In particular, the fourth sample (conductive film 14 according to the present invention) had the smallest variation in surface resistivity.

  Regarding the visibility of the noise feeling, high evaluation results were obtained in the order of the fourth sample, the third sample, the first sample, and the second sample. This order matches the order in which the areas formed by the peaks of the power spectrum shown in FIG. 17 are small. In particular, it was confirmed that the noise sensation in the fourth sample (conductive film 14 according to the present invention) was less noticeable.

Thus, with respect to the center-of-gravity spectrum Spcc of each mesh, the average intensity P _H on the spatial frequency band side higher than the predetermined spatial frequency BF is higher than the average intensity P _L on the spatial frequency band side lower than the predetermined spatial frequency. Since the mesh pattern M is formed so as to increase, the amount of noise on the high spatial frequency band side is relatively larger than that on the low spatial frequency band side. Human vision has a high response characteristic in the low spatial frequency band, but has a property that the response characteristic sharply decreases in the medium to high spatial frequency band, so that a sense of noise visually felt by humans is reduced. Thereby, the noise graininess resulting from the pattern which the electroconductive film 14 has can be reduced, and the visibility of an observation target object can be improved significantly. In addition, since a plurality of polygonal meshes are provided, the cross-sectional shape of each wiring (the metal thin wire 54) after cutting is substantially constant, and has stable energization performance.

  In addition, this invention is not limited to embodiment mentioned above, Of course, it can change freely in the range which does not deviate from the main point of this invention.

DESCRIPTION OF SYMBOLS 10 ... Manufacturing apparatus 12 ... Image processing apparatus 14 ... Conductive film 16 ... Light 18 ... Exposure part 20 ... Input part 24 ... Memory | storage part 28 ... Initial position selection part 30 ... Update candidate position determination part 32 ... Exposure data conversion part 36 ... Image information estimation unit 38 ... Image data creation unit 40 ... Mesh pattern evaluation unit 42 ... Data update instruction unit 50 ... Conductive unit 52 ... Opening 54 ... Metal thin wire 56 ... Transparent film substrate 57 ... Filter member 59 ... Black matrix 60 ... the unit pixel 62 ... silver halide 64 ... gelatin 66 ... photosensitive silver salt layer 68 ... ... developed silver 70 ... metallic silver portion 72 ... light transmission portion 74 ... conductive metal 75 ... copper foil 76 the photoresist film 78 ... resist pattern 80 ... Paste 82 ... Metal plating 84 ... Metal thin film 100 ... FFT operation unit 102 ... Evaluation value calculation unit 108 ... Counter 110 ... Pseudo temperature management unit 112 ... More New probability calculation unit 114 ... position update determination unit 116 ... output image data determination unit 120 ... setting screen 122, 126 ... pull-down menu 124, 128 ... display fields 130, 132, 134, 136, 138, 140, 142 ... text boxes 144, 146 ... button 200, 202 ... two-dimensional image region Img, ImgInit ... image data Imgc ... centroid image data ImgOut ... output image data M ... mesh pattern PT1-PT3 ... pattern SD ... seed point SDd, SDNd, SDSd, SPd ... position data SDN ... first seed point SDS ... second seed point SP ... candidate point Spc ... spectrum Spcc ... centroid spectrum

Claims (3)

A transparent conductive film having a mesh pattern comprising a plurality of polygonal meshes,
Regarding the power spectrum of the centroid position distribution of each mesh, the average intensity on the spatial frequency band side higher than the predetermined spatial frequency is larger than the average intensity on the spatial frequency band side lower than the predetermined spatial frequency. The transparent conductive film, wherein the mesh pattern is formed. The transparent conductive film according to claim 1,
The transparent conductive film, wherein the predetermined spatial frequency is a spatial frequency corresponding to 5% of a maximum response of human visual response characteristics. The transparent conductive film according to claim 2,
The human visual response characteristic is a visual response characteristic obtained based on a Dooley-Shaw function with a clear visual distance of 300 mm,
The said predetermined spatial frequency is 6 cycle / mm. The transparent conductive film characterized by the above-mentioned.

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