JP2013513136A - Transparent sheet and transparent touch switch - Google Patents

Abstract

A transparent planar body and a transparent touch switch capable of improving visibility are provided.
A silicon-containing layer, an adhesive layer disposed on at least one surface of the silicon-containing layer, and a patterned transparent conductive layer provided between the silicon-containing layer and the adhesive layer. A transparent planar body 1 having a reflectance for each wavelength of light irradiated to a pattern forming region in which the transparent conductive layer 12 is formed via the silicon-containing layer 11, and via the silicon-containing layer 11. The difference between the maximum absolute value and the minimum absolute value of the difference in reflectance for each wavelength of light irradiated to the non-pattern forming region where the transparent conductive layer 12 is not formed is 0.65 or less at 450 nm to 700 nm. A transparent planar body 1.
[Selection] Figure 1

Description

  The present invention relates to a transparent planar body and a transparent touch switch.

  Various configurations of touch switches for detecting an input position have been conventionally studied. As an example, a capacitive touch switch is known. For example, the touch switch disclosed in Patent Document 1 is configured such that a dielectric layer is interposed between a pair of transparent planar bodies each having a transparent conductor having a predetermined pattern shape. When the operation surface is touched, the touch position can be detected by utilizing the change in capacitance caused by being grounded via the human body.

JP2003-173238A (FIGS. 1 and 5)

  The touch switch described above is used by being mounted on the surface of a liquid crystal display device, a CRT, or the like, but the pattern shape of the transparent conductor formed on the transparent sheet is conspicuous, leading to a decrease in visibility. Such a problem has arisen not only in a capacitive touch switch but also in a touch switch that requires a matrix type pattern.

  Therefore, an object of the present invention is to provide a transparent planar body and a transparent touch switch that can improve visibility.

  The object of the present invention is to provide a silicon-containing layer, an adhesive layer disposed on at least one surface of the silicon-containing layer, and a patterned transparent conductive layer provided between the silicon-containing layer and the adhesive layer. A transparent planar body having a reflectance for each wavelength of light irradiated to a pattern formation region in which the transparent conductive layer is formed via the silicon-containing layer, and the silicon-containing layer The difference between the maximum absolute value and the minimum difference in reflectance for each wavelength of light irradiated to the non-pattern forming region where the transparent conductive layer is not formed is 0.65 or less at 450 nm to 700 nm. This is achieved with a transparent sheet.

  In the transparent planar body, the maximum value is preferably 0.8 or less.

  The silicon-containing layer includes a low refractive index layer and a high refractive index layer having a higher optical refractive index than the low refractive index layer, and the transparent conductive layer is formed on the low refractive index layer side. It is preferable.

  The light refractive index of the low refractive index layer is 1.45 to 1.47, and the light refractive index of the high refractive index layer is preferably larger than 1.47 and not more than 1.53.

Further, the low refractive index layer is formed by SiO _2, the high refractive index layer is preferably formed by a glass material.

  The transparent conductive layer preferably has a thickness of 12 nm or less.

  The transparent conductive layer preferably has a thickness of 12 nm to 14 nm, and the low refractive index layer preferably has a thickness of 10 nm to 45 nm.

Moreover, it is preferable that the thickness of the said low-refractive-index layer is below the value calculated by following Numerical formula 1 which makes the thickness of the said transparent conductive layer X.
[Formula 1] 0.3409X ² -16.705X + 217.73

Moreover, it is preferable that the thickness of the said low-refractive-index layer is below the value calculated by following Numerical formula 2 which makes the thickness of the said transparent conductive layer X.
[Formula 2] −10X + 185

  The object is a transparent touch switch including the transparent sheet, wherein the transparent conductive layer of the transparent sheet and a second transparent conductive layer different from the transparent conductive layer face each other. This is achieved by the transparent touch switch arranged in the direction or in the same direction.

  ADVANTAGE OF THE INVENTION According to this invention, the transparent planar body and transparent touch switch which can improve visibility can be provided.

It is a schematic sectional drawing of the transparent touch switch which concerns on one Embodiment of this invention. It is a top view which shows a part of transparent touch switch shown in FIG. It is a top view which shows another part of transparent touch switch shown in FIG. It is a top view which shows a part of modification of the transparent touch switch shown in FIG. It is a top view which shows another part of the modification of the transparent touch switch shown in FIG. It is a schematic structure sectional drawing of the transparent planar body which comprises the transparent touch switch shown in FIG. It is a figure which shows the measurement result of the reflectance difference by the presence or absence of the transparent conductive layer in a sample. It is a figure which shows the simulation result of the reflectance difference by the presence or absence of a transparent conductive layer in case the film thickness of a transparent conductive layer is 8 nm. It is a figure which shows the simulation result of the reflectance difference by the presence or absence of a transparent conductive layer when the film thickness of a transparent conductive layer is 10 nm. It is a figure which shows the simulation result of the reflectance difference by the presence or absence of a transparent conductive layer when the film thickness of a transparent conductive layer is 12 nm. It is a figure which shows the simulation result of the reflectance difference by the presence or absence of a transparent conductive layer when the film thickness of a transparent conductive layer is 14 nm. It is a graph which shows the relationship between the thickness of the low-refractive-index layer with which the difference of the maximum value of a reflectance difference and the minimum value satisfy | fills 0.65 or less or 0.5 or less, and the thickness of a transparent conductive layer. It is a graph which shows the relationship between the low-refractive-index layer thickness with which the maximum value of a reflectance difference satisfy | fills 0.8 or less or 0.7 or less, and the thickness of a transparent conductive layer.

  Hereinafter, actual forms of the present invention will be described with reference to the accompanying drawings. Each drawing is partially enlarged or reduced to facilitate understanding of the configuration, not the actual size ratio.

FIG. 1 is a schematic cross-sectional view of a transparent touch switch according to an embodiment of the present invention. The transparent touch switch 101 is a capacitive touch switch,
A transparent silicon-containing layer 11, an adhesive layer 13 disposed on at least one surface of the silicon-containing layer 11, and a patterned transparent conductive layer 12 provided between the silicon-containing layer 11 and the adhesive layer 13. 1 transparent planar body 1 and a second transparent planar body 2 having a patterned transparent conductive layer 22 formed on one surface of a transparent substrate 21. The first transparent planar body 1 and the second transparent planar body 2 are arranged so that the transparent conductive layers 12 and 22 face each other. In addition, you may arrange | position so that each transparent conductive layer 12 and 22 may face the same direction.

The silicon-containing layer 11 includes a low refractive index layer 111 and a high refractive index layer 112 having a higher optical refractive index than the low refractive index layer 111, and the transparent conductive layer 12 is formed on the low refractive index layer 111 side. Has been. An example of the material constituting the low refractive index layer 111 is SiO ₂ . The light refractive index of the low refractive index layer 111 is preferably in the range of 1.45 to 1.47. Examples of the material constituting the high refractive index layer 112 include glass materials such as soda glass, non-alkali glass, and borosilicate glass. The thickness of the high refractive index layer 112 is not particularly specified, but is preferably about 0.3 to 5.0 mm, and the optical refractive index is preferably greater than 1.47 and not greater than 1.53. In addition, when a pen or a finger may come into contact with the surface of the silicon-containing layer 11, a surface treatment process may be performed to improve transparency, scratch resistance, wear resistance, and non-glare properties.
Moreover, you may bond a film as a crack countermeasure.

  The transparent substrate 21 is preferably made of a highly transparent material. Specifically, polyethylene terephthalate (PET), polyimide (PI), polyethylene naphthalate (PEN), polyethersulfone (PES), polyetherether Ketone (PEEK), polycarbonate (PC), polypropylene (PP), polyamide (PA), polyacryl (PAC), acrylic, amorphous polyolefin resin, cyclic polyolefin resin, aliphatic cyclic polyolefin, norbornene thermoplastic Examples thereof include a flexible film such as a transparent resin, a laminate of two or more of these, and glass.

  The materials of the transparent conductive layers 12 and 22 include indium tin oxide (ITO), indium oxide, antimony-added tin oxide, fluorine-added tin oxide, aluminum-added zinc oxide, potassium-added zinc oxide, silicon-added zinc oxide, and zinc oxide. -Transparent conductive materials such as tin oxide, indium oxide-tin oxide, zinc oxide-indium oxide-magnesium oxide, zinc oxide, tin oxide film, or metal materials such as tin, copper, aluminum, nickel, chromium, Metal oxide materials can be exemplified, and two or more of these may be formed in combination. In addition, a simple metal weak against acid or alkali can be used as a conductive material. Examples of methods for forming the transparent conductive layers 12 and 22 include PVD methods such as sputtering, vacuum deposition, and ion plating, CVD, coating, and printing. The thickness of the transparent conductive layers 12 and 22 is preferably 14 nm or less, and more preferably 12 nm or less. Note that when the film thickness is 5 nm or less, it is difficult to form a continuous film, and it is difficult to form a stable conductive layer.

  Moreover, a composite material in which ultrafine conductive carbon fibers such as carbon nanotubes, carbon nanohorns, carbon nanowires, carbon nanofibers, and graphite fibrils are dispersed in a nonconductive polymer material can also be used as a material for the transparent conductive layer.

  As shown in FIGS. 2 and 3, the transparent conductive layers 12 and 22 are each formed as an aggregate of a plurality of strip-like conductive portions 12 a and 22 a extending in parallel, and the strip-like conductive portions of the transparent conductive layers 12 and 22. 12a and 22a are arrange | positioned so that it may mutually orthogonally cross. The transparent conductive layers 12 and 22 are connected to an external drive circuit (not shown) through a routing circuit (not shown) made of conductive ink or the like. The pattern shape of the transparent conductive layers 12 and 22 is not limited to that of the present embodiment, and may be any shape as long as a contact point such as a finger can be detected. For example, as shown in FIGS. 4 and 5, the transparent conductive layers 12 and 22 have a configuration in which a plurality of rhombus-shaped conductive portions 12 b and 22 b are linearly connected, and the rhombus-shaped conductivity in each of the transparent conductive layers 12 and 22. The connecting directions of the portions 12b and 22b may be orthogonal to each other, and the upper and lower rhombus-shaped conductive portions 12b and 22b may not be overlapped in plan view. Note that the operation performance such as the resolution of the transparent touch switch 101 is configured such that when the first transparent planar body 1 and the second transparent planar body 2 are overlapped, a region where no conductive portion exists is reduced. It is better to adopt From this point of view, the pattern shape of the transparent conductive layers 12 and 22 is preferably a configuration in which a plurality of rhombus-shaped conductive portions 12b and 22b are connected in a straight line rather than a rectangular configuration.

  The patterning of the transparent conductive layers 12 and 22 is performed by forming a mask portion having a desired pattern shape on the surface of the transparent conductive layers 12 and 22 formed on the silicon-containing layer or the transparent substrate, respectively, and removing the exposed portion with an acid solution. Etching and removal can be performed by dissolving the mask portion with an alkaline solution or the like.

  The adhesive layer 13 may be made of a general transparent adhesive such as epoxy or acrylic, and may include a core made of a norbornene resin transparent film. Moreover, an adhesive layer may be formed by overlapping a plurality of sheet-like adhesive materials, and further, a plurality of types of sheet-like adhesive materials may be overlapped. The thickness of the pressure-sensitive adhesive layer 13 is not particularly specified, but is practically preferably 100 μm or less, and particularly preferably 25 μm to 75 μm. Further, the optical refractive index of the adhesive layer is preferably 1.40 to 1.70, and more preferably 1.46 to 1.57. If the refractive index of the adhesive layer is made closer to (higher) the refractive index of the transparent conductive layer, the difference in refractive index at the interface will be reduced and the effect of making the pattern shape inconspicuous will increase. The addition of fine particles of high refractive material is necessary, and there is a problem that the transmittance as a transparent planar body is lowered. In addition, the adhesive layer is in contact with the transparent conductive layer, and it is not preferable to include a material that damages the transparent conductive layer such as an acid.

  In the transparent touch switch 101 having the above configuration, the touch position detection method is the same as that of the conventional electrostatic capacitance type touch switch, and an arbitrary position on the surface side of the first transparent planar body 1 is set to a finger or the like. The transparent conductive layers 12 and 22 are grounded through the capacitance of the human body at the contact position, and the coordinates of the contact position are calculated by detecting the current value flowing through the transparent conductive layers 12 and 22.

  Here, as shown in the schematic cross-sectional view of the transparent planar body 1 in FIG. 6, in the reflected light L <b> 1 of the light irradiated to the pattern formation region where the transparent conductive layer 12 is formed via the silicon-containing layer 11. The maximum absolute value of the difference in reflectance for each wavelength and the reflectance difference for each wavelength in the reflected light L2 of the light irradiated to the non-pattern forming region where the transparent conductive layer 12 is not formed via the silicon-containing layer 11 The difference between the value and the minimum value is preferably 0.65 or less, more preferably 0.5 or less, and more preferably 0.4 or less in the visible wavelength range of 450 nm to 700 nm. Further preferred. When the difference between the maximum value and the minimum value is 0.65 or less, the pattern shape of the transparent conductive layer 12 can be made inconspicuous, and visibility can be improved.

  The inventors create a sample of the transparent planar body having the above-described configuration, and in the reflected light L1 of the light irradiated to the pattern formation region where the transparent conductive layer 12 is formed via the silicon-containing layer 11 The maximum absolute value of the difference in reflectance for each wavelength and the reflectance difference for each wavelength in the reflected light L2 of the light irradiated to the non-pattern forming region where the transparent conductive layer 12 is not formed via the silicon-containing layer 11 A sensory test was performed to determine whether the pattern shape of the transparent conductive layer 12 was not noticeable while measuring the difference between the value and the minimum value and the maximum value of the difference in reflectance. The sample has the structure shown in FIG. 6, and the high refractive index layer 112 and the low refractive index layer 111 constituting the silicon-containing layer 11 are each formed of a soda glass plate and a SiO 2 thin film. Moreover, the ITO film | membrane was employ | adopted as the transparent conductive layer 12, and the film | membrane formed with the acrylic adhesive (refractive index 1.52) was employ | adopted as the adhesion layer 13, and the sample was comprised. The prepared samples are five types in which the thickness of the transparent conductive layer 12 (ITO film) is changed to 8 nm, 10 nm, 12 nm, 14 nm, and 16 nm. In all samples, the thickness of the high refractive index layer 112 (glass plate) was 1.1 mm, the thickness of the low refractive index layer 111 (SiO 2 thin film) was 12.5 nm, and the thickness of the adhesive layer 13 was 25 μm. The low refractive index layer 111 (SiO2 thin film) and the transparent conductive layer 12 (ITO film) are formed on the glass plate by sputtering.

For these five types of samples, the spectral reflectance (first spectral reflectance) for each wavelength in the reflected light of the light irradiated to the pattern formation region where the transparent conductive layer 12 is formed via the silicon-containing layer 11, and The spectral reflectance (second spectral reflectance) for each wavelength in the reflected light of the light irradiated to the non-pattern forming region where the transparent conductive layer 12 was not formed via the silicon-containing layer 11 was measured. FIG. 7 shows the relationship between the absolute value of the difference between the measured first spectral reflectance and the second spectral reflectance and the wavelength. In addition, in FIG. 7, the measurement result in 450 nm-700 nm which is the visible range wavelength of light is shown. Here, a device (V670 + integral sphere unit) manufactured by JASCO Corporation was used for measuring the spectral reflectance. Measurement conditions are photometry mode:% R, measurement range: 800-300 nm, data capture interval: 5 nm, UV / Vis bandwidth: 5.0
nm, NIR Bandwidth: 2.0 nm, Response: Medium, Scanning speed: 400 nm / min, Light source switching: 340 nm, Grating switching: 850 nm, Light source: D2 / WI, Filter switching: Step, Correction: Baseline did.

○：三波長蛍光灯下でもパターン形状確認が困難。
△：通常の蛍光灯下ではパターン形状確認が困難だが、三波長蛍光灯下ではパターン形状確認が可能。
×：通常の蛍光灯下でもパターン形状確認が可能。 The maximum and minimum absolute values of the difference between the measured first spectral reflectance and the second spectral reflectance, and the difference between these maximum and minimum values were calculated. Table 1 shows the difference between the calculated maximum value and the minimum value (reflectance difference Δ) and the maximum value of the difference in reflectance. Table 1 also shows the surface resistance value (Rs) of each sample. Here, the surface resistance value (Rs) was measured by a resistivity meter Lorestar EP MCP-T360 type manufactured by Mitsubishi Chemical Analytech Co., Ltd. Table 1 also shows the results of sensory tests for the visibility of the pattern shape performed on each sample under a normal indoor fluorescent lamp and a three-wavelength fluorescent lamp in a booth with a black sheet. It is described.

○: It is difficult to confirm the pattern shape even under a three-wavelength fluorescent lamp.
Δ: Although it is difficult to confirm the pattern shape under normal fluorescent lamps, it is possible to confirm the pattern shape under three-wavelength fluorescent lamps.
×: Pattern shape can be confirmed even under normal fluorescent lamps.

  From Table 1, when the thickness of the transparent conductive layer 12 (ITO film) is 8 nm, 10 nm, and 12 nm, the pattern shape of the transparent conductive layer 12 (ITO film) can be made almost unnoticeable, which is very excellent. The result of having visibility was obtained. Further, from FIG. 7, in these cases, the difference between the maximum value and the minimum value of the difference between the first spectral reflectance and the second spectral reflectance (reflectance difference Δ) is the visible range wavelength of light. It is also found that the difference between the first spectral reflectance and the second spectral reflectance is 0.7 or less at 450 nm to 700 nm. Even when the thickness of the transparent conductive layer 12 (ITO film) is 14 nm, the pattern shape is confirmed under a three-wavelength fluorescent lamp, which is a strict evaluation condition, but is hardly visible under a normal fluorescent lamp, and the reflectance difference Δ is 0. When the absolute value of the difference between the first spectral reflectance and the second spectral reflectance is 0.8 or less, it can be seen that there is practical visibility. On the other hand, the visibility is not so good when the reflectivity difference Δ is larger than 0.65 and the ITO film thickness is 16 nm where the absolute value of the difference between the first spectral reflectance and the second spectral reflectance is larger than 0.8. The result was obtained. From Table 1, the surface resistance value (Rs) shows a higher value as the thickness of the transparent conductive layer 12 (ITO film) becomes thinner. However, when the thickness becomes thinner than 8 nm, the surface resistance value becomes 500 Ω / The value may exceed □ and the touch switch sensing accuracy may be reduced. Therefore, the thickness of the transparent conductive layer 12 (ITO film) is particularly preferably 8 nm or more.

Moreover, the present inventors performed simulation about the transparent planar body of the said structure. The model used for this simulation has the structure shown in FIG. 6, and various setting conditions in the simulation are that the silicon-containing layer 11 is made of a low refractive index layer 111 made of SiO ₂ (light refractive index: 1.46). And a high refractive index layer 112 formed of soda glass (light refractive index: 1.52). The transparent conductive layer 12 was an ITO film (light refractive index: 2.0). The pressure-sensitive adhesive layer 13 was an acrylic pressure-sensitive adhesive (light refractive index: 1.52).

  In the transparent planar body 11 thus set, the transparent conductive layer 12 is formed by changing the thickness of the transparent conductive layer 12 (ITO film) and the thickness of the low refractive index layer 111 of the silicon-containing layer 11. The difference in light reflectance (%) between the portion (pattern forming region) and the portion where the transparent conductive layer 12 is not formed (non-pattern forming region) was obtained by simulation. The reflectance was calculated using a thin film design software (OPTAS-FILM) manufactured by Cybernet System. In this simulation, the high refractive index layer 112 of the silicon-containing layer 11, which is a member having an extremely large thickness compared to the low refractive index layer 111 and the transparent conductive layer 12 of the silicon-containing layer 11 having a nano-order thickness, About the adhesion layer 13, the thickness was set to infinity (infinity) and the reflectance was calculated.

  The inconspicuousness of the pattern shape of the transparent conductive layer 12 has a correlation with the difference in reflectance between the portion where the transparent conductive layer 12 is formed and the portion where the transparent conductive layer 12 is not formed, and the entire visible region (wavelength: 450). The smaller the absolute value of the difference in reflectance at ˜700 nm), the less noticeable the pattern shape, and the better the visibility. When the maximum value of the reflectance difference is 0.8 or less, preferable visibility can be obtained, when 0.7 or less is more preferable, and when it is 0.5 or less, more preferable visibility is obtained. be able to. Further, when the difference between the absolute maximum value and the minimum absolute value of the difference in reflectance in the wavelength range of 450 nm to 700 nm, which is the visible wavelength range of light, is 0.65 or less, the transparent conductive layer further increases. The pattern shape can be made inconspicuous and visibility can be improved.

Hereinafter, the simulation result will be described. FIG. 8 shows simulation results when the thickness of the transparent conductive layer 12 (ITO film) is 8 nm and the thickness of the low refractive index layer 111 (SiO ₂ film) of the silicon-containing layer 11 is changed to 0 nm, 10 nm, 20 nm, and 30 nm. Further, the simulation results when the thickness of the transparent conductive layer 12 (ITO film) is 10 nm and the thickness of the low refractive index layer 111 (SiO ₂ film) of the silicon-containing layer 11 is changed to 0 nm, 10 nm, 20 nm, and 30 nm are shown. As shown in FIG. The simulation results when the thickness of the transparent conductive layer 12 (ITO film) is 12 nm and the thickness of the low refractive index layer 111 (SiO ₂ film) of the silicon-containing layer 11 is changed to 0 nm, 10 nm, 20 nm, and 30 nm are shown. FIG. 10 shows a simulation when the thickness of the transparent conductive layer 12 (ITO film) is 14 nm and the thickness of the low refractive index layer 111 (SiO ₂ film) of the silicon-containing layer 11 is changed to 0 nm, 10 nm, 20 nm, and 30 nm. The results are shown in FIG.

Table 2 shows the difference between the maximum value and the minimum value of the reflectance difference at 450 nm to 700 nm, which is the visible wavelength range of light, from the simulation results shown in FIGS. In addition, in each simulation result shown in FIGS. 8-11, the maximum value of a reflectance difference is a value of the reflectance difference in wavelength 450nm, and the minimum value of a reflectance difference is the value of reflectance difference in wavelength 700nm. It is.

Table 3 shows the extracted maximum value of the difference in reflectance at 450 nm to 700 nm, which is the visible wavelength range of light.

  8 to 11 and Table 2, when the thickness of the transparent conductive layer 12 (ITO film) is 12 nm or less, the difference between the maximum value and the minimum value of the reflectance difference is 0.65 or less. 8 to 11 and Table 3, when the thickness of the transparent conductive layer 12 (ITO film) was 12 nm or less, the maximum value of the difference in reflectance was 0.8 or less. In addition, it is recognized that these simulation results are consistent with the measurement values in the above-described sample.

Further, from FIGS. 8 to 11 and Tables 2 and 3, when the transparent conductive layer 12 (ITO film) has a thickness of 14 nm, the low refractive index layer 111 (SiO ₂ film) has a thickness range of 0 to 30 nm. The difference between the maximum value and the minimum value of the difference in reflectivity was 0.65 or less. Further, when the thickness of the low refractive index layer 111 (SiO ₂ film) is 10 nm, 20 nm, and 30 nm, the maximum value of the difference in reflectance is 0.8 or less, but the low refractive index layer 111 (SiO ₂ film). When the thickness of the film was 0 nm, the maximum reflectance difference exceeded 0.8.

Then, by further changing the thickness of the low refractive index layer 111 (SiO ₂ film), the difference between the maximum value and the minimum value of the reflectance difference is 0.65 or less low refractive index layer 111 (SiO ₂ The maximum thickness of the film was calculated by the above simulation, and the results are shown in Table 4. Table 4 shows the difference between the maximum value and the minimum value of the difference in reflectance at 450 nm to 700 nm, which is the visible wavelength range of light. Further, the difference between the maximum value and the minimum value of the reflectance difference changes from a decreasing tendency to an increasing tendency as the thickness of the low refractive index layer 111 (SiO ₂ film) is increased. The calculation of the difference between the value and the minimum value is partially omitted.

From Table 4, the maximum thickness of the low refractive index layer 111 (SiO ₂ film) where the difference between the maximum value and the minimum value of the reflectance difference satisfies 0.65 or less is the thickness of the transparent conductive layer 12 (ITO film). When the thickness is 10 nm, it is about 85 nm, and when the thickness of the transparent conductive layer 12 (ITO film) is 12 nm, it is found that the thickness is about 65 nm. Further, it can be seen that when the thickness of the transparent conductive layer 12 (ITO film) is 13 nm, it is 60 nm, and when the thickness of the transparent conductive layer 12 (ITO film) is 14 nm, it is 50 nm.

Further, the maximum thickness of the low refractive index layer 111 (SiO ₂ film) satisfying the difference between the maximum value and the minimum value of the above-described reflectance difference of 0.65 or less, the thickness of the transparent conductive layer 12 (ITO film), This relationship is shown in FIG. 12, in which the maximum thickness is on the vertical axis and the thickness of the transparent conductive layer 12 (ITO film) is on the horizontal axis. FIG. 12 also shows a recent curve calculated from the relationship between each maximum thickness and the thickness of the transparent conductive layer 12 (ITO film). This recent curve is expressed by the following formula, where X is the thickness of the transparent conductive layer 12 (ITO film) and Y1 is the maximum thickness of the low refractive index layer 111 (SiO ₂ film).
[Formula 1] Y1 = 0.3409X ² -16.705X + 217.73
In FIG. 12, each maximum thickness of the low refractive index layer 111 (SiO ₂ film) satisfying a difference between the maximum value and the minimum value of the above-described reflectance difference of 0.5 or less, and the transparent conductive layer 12 ( The relationship with the thickness of the ITO film is also shown, and an approximate curve calculated from these relationships is also shown.

  From the above, if the thickness of the low refractive index layer 111 is equal to or less than the value calculated by Equation 1, the portion where the transparent conductive layer 12 is formed (pattern formation region) and the transparent conductive layer 12 are not formed. The difference between the maximum value and the minimum value in the reflectance difference for each wavelength with respect to the portion (non-pattern forming region) can be 0.65 or less. Therefore, in the transparent touch switch 101 having the configuration shown in FIG. 1, the thickness of the low refractive index layer 111 is set to be equal to or less than the value calculated by Equation 1 above in relation to the thickness of the transparent conductive layer 12. It is possible to obtain the transparent touch switch 101 having a good visibility, in which the pattern shape is not conspicuous.

In addition, the maximum thickness of the low refractive index layer 111 (SiO ₂ film) in which the maximum value of the reflectance difference in the visible wavelength range of 450 nm to 700 nm is 0.8 or less was also calculated by the above simulation. Table 5 shows. Since the maximum value of the reflectance difference changes from a decreasing tendency to an increasing tendency as the thickness of the low refractive index layer 111 (SiO ₂ film) is increased, the calculation of the maximum value of the reflectance difference is partially performed. I'm omitted.

From Table 5, the maximum thickness of the low refractive index layer 111 (SiO ₂ film) satisfying the maximum reflectance difference of 0.8 or less is when the thickness of the transparent conductive layer 12 (ITO film) is 10 nm. When it is 85 nm and the thickness of the transparent conductive layer 12 (ITO film) is 12 nm, it can be seen that it is 65 nm. Moreover, when the thickness of the transparent conductive layer 12 (ITO film | membrane) is 8 nm, even if it is 100 nm, it turns out that the maximum value of a reflectance difference is 0.8 or less. Further, when the thickness of the transparent conductive layer 12 (ITO film) is 14 nm, the maximum thickness of the low refractive index layer 111 (SiO ₂ film) that satisfies the maximum reflectance difference of 0.8 or less is 45 nm. I understand that there is.

The relationship between the maximum thickness of the low refractive index layer 111 (SiO ₂ film) satisfying the maximum reflectance difference of 0.8 or less and the thickness of the transparent conductive layer 12 (ITO film) 13 is shown in FIG. 13 with the vertical axis representing the thickness and the horizontal axis representing the thickness of the transparent conductive layer 12 (ITO film). FIG. 13 also shows a recent straight line calculated from the relationship between each maximum thickness and the thickness of the transparent conductive layer 12 (ITO film). This recent straight line is expressed by the following formula, where X is the thickness of the transparent conductive layer 12 (ITO film) and Y2 is the maximum thickness of the low refractive index layer 111 (SiO ₂ film).
[Formula 2] Y2 = −10X + 185
If the thickness of the low refractive index layer 111 (SiO ₂ film) is not more than the value calculated by the above formula, the maximum value of the reflectance difference satisfies 0.8 or less (however, the transparent conductive layer 12 ( When the thickness of the ITO film) is 12 nm to 14 nm, the thickness of the low refractive index layer 111 (SiO ₂ film) is less than 10 nm). In FIG. 13, each maximum thickness of the low refractive index layer 111 (SiO ₂ film) satisfying the maximum reflectance difference of 0.7 or less, and the thickness of the transparent conductive layer 12 (ITO film) The approximate line calculated from these relationships is also shown.

  From the above, if the thickness of the low refractive index layer 111 is equal to or less than the value calculated by Equation 2, the portion where the transparent conductive layer 12 is formed (pattern formation region) and the transparent conductive layer 12 are not formed. The maximum value of the difference in reflectance for each wavelength with respect to the portion (non-pattern forming region) can be set to 0.8 or less. Therefore, in the transparent touch switch 101 having the configuration shown in FIG. 1, the thickness of the low refractive index layer 111 is set to be equal to or less than the value calculated by Equation 2 above in relation to the thickness of the transparent conductive layer 12. It is possible to obtain the transparent touch switch 101 having a good visibility, in which the pattern shape is not conspicuous.

  The embodiment of the transparent planar body 1 and the transparent touch switch 101 using the same has been described above, but the specific configuration is not limited to the above embodiment. For example, in the above embodiment, the second transparent planar body 2 is configured by forming the patterned transparent conductive layer 22 on one surface of the transparent substrate 21, but instead of the transparent substrate 21. The silicon-containing layer 11 can be used to have the same configuration as the first transparent planar body 1.

In the above embodiment, the silicon-containing layer 11 is configured to include the low-refractive index layer 111 and the high-refractive index layer 112. However, the silicon-containing layer 11 is configured only by the high-refractive index layer 112. May be. Referring to the simulation results of FIGS. 8 to 11, even when the silicon-containing layer 11 is composed of only the high refractive index layer 112 (when the thickness of the low refractive index layer 111 made of SiO ₂ is 0 nm). Even in the visible wavelength range of 450 nm to 700 nm, the portion where the transparent conductive layer 12 is formed (pattern formation region) and the portion where the transparent conductive layer 12 is not formed (non-pattern formation region) The transparent planar body 1 and the transparent touch switch that can make the difference between the maximum value and the minimum value of the difference in reflectance for each wavelength 0.65 or less and the pattern shape of the transparent conductive layer 12 is inconspicuous and has good visibility 101 can be obtained.

DESCRIPTION OF SYMBOLS 101 Transparent touch switch 1 1st transparent planar body 2 2nd transparent planar body 11 Silicon-containing layer 111 Low refractive index layer 112 High refractive index 12 Transparent conductive layer 13 Adhesive layer 21 Transparent substrate 22 Transparent conductive layer

Claims (10)

A transparent planar body having a silicon-containing layer, an adhesive layer disposed on at least one surface of the silicon-containing layer, and a patterned transparent conductive layer provided between the silicon-containing layer and the adhesive layer. And
The reflectance for each wavelength of light irradiated to the pattern formation region where the transparent conductive layer is formed via the silicon-containing layer, and the non-transparent conductive layer is not formed via the silicon-containing layer A transparent planar body in which the difference between the maximum absolute value and the minimum absolute value of the difference in reflectance for each wavelength of light applied to the pattern forming region is 0.65 or less at 450 nm to 700 nm.   The transparent planar body according to claim 1, wherein the maximum value is 0.8 or less. The silicon-containing layer includes a low refractive index layer and a high refractive index layer having a higher optical refractive index than the low refractive index layer,
The transparent planar body according to claim 1, wherein the transparent conductive layer is formed on the low refractive index layer side. The light refractive index of the low refractive index layer is 1.45 to 1.47,
The transparent planar body according to claim 3, wherein the high refractive index layer has a light refractive index of greater than 1.47 and not greater than 1.53. The low refractive index layer is made of SiO ₂ ,
The transparent planar body according to claim 3 or 4, wherein the high refractive index layer is formed of a glass material.   The transparent planar body according to claim 1, wherein the transparent conductive layer has a thickness of 12 nm or less.   The transparent planar body according to any one of claims 1 to 5, wherein the transparent conductive layer has a thickness of 12 nm to 14 nm, and the low refractive index layer has a thickness of 10 nm to 45 nm. The transparent planar body according to any one of claims 3 to 7, wherein the thickness of the low refractive index layer is equal to or less than a value calculated by the following mathematical formula 1 where X is the thickness of the transparent conductive layer.
[Formula 1] 0.3409X ² -16.705X + 217.73 9. The transparent planar body according to claim 8, wherein the thickness of the low refractive index layer is equal to or less than a value calculated by the following formula 2 where X is the thickness of the transparent conductive layer.
[Formula 2] −10X + 185   A transparent touch switch comprising at least one transparent planar body according to claim 1, wherein the transparent conductive layer of the transparent planar body is different from the transparent conductive layer. A transparent touch switch in which layers are arranged in a direction facing each other or in the same direction.

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