KR102064878B1 - Glass for display touch panel - Google Patents

Abstract

Y_inc : 입사 매질(공기)의 어드미턴스(admittance)
Y_eq : 유리 기판으로부터 제1층까지의 대체 어드미턴스(admittance)
Y₂ : 제2층의 어드미턴스(admittance)
d₂ : 제2층의 두께Disclosed is a glass for a display touch panel using a two-layer thin film.
The glass for display touch panel according to the present invention includes a glass substrate and an antireflection layer disposed on the glass substrate, wherein the antireflection layer is disposed on a glass substrate and a second layer disposed on the first layer. It has a two-layer structure consisting of a layer, the thickness of the first layer is thicker than the thickness of the second layer, the thickness of the first layer and the thickness of the second layer is characterized in that the following [Formula 1] .
[Equation 1]

Y _inc : Admittance of the incident medium (air)
Y _eq : alternative admittance from the glass substrate to the first layer
Y ₂ : admittance of the second layer
d ₂ : thickness of the second layer

Description

Glass for display touch panel {GLASS FOR DISPLAY TOUCH PANEL}

TECHNICAL FIELD The present invention relates to glass for display touch panels, and more particularly, to glass including an antireflection layer.

Recently, touch panels have been used as input interfaces, and in particular, they are mainly applied to displays such as mobile phones and digital cameras.

The glass for the touch panel applied to the display includes a thin film layer made of a transparent conductive oxide material, and the touched portion is sensed by a finger or other conductive object to enable touch control. However, such a touch panel glass is easy to control touch, but when the outdoor light or the indoor illumination light is reflected on the glass, it causes glare.

In order to solve this problem, a diffusion sheet having a function of imparting light uniformity and widening the viewing angle is applied to the touch panel, but there is a limit in displaying an antireflection effect close to 0% reflectance.

Therefore, there is a need for a glass for display touch panel having an antireflection function.

Background art related to the present invention discloses an antireflection film for a display disclosed in the Republic of Korea Patent Publication No. 10-2008-0030259 (published on April 04, 2008) and a manufacturing method thereof.

An object of the present invention is to provide a glass for a display touch panel having an antireflection effect in the configuration of a two-layer thin film.

Glass for a display touch panel according to the present invention for achieving the above object comprises a glass substrate and an antireflection layer disposed on the glass substrate, the first layer and the first layer is disposed on the glass substrate It has a two-layer structure consisting of a second layer disposed on one layer, wherein the thickness of the first layer is thicker than the thickness of the second layer, the thickness of the first layer and the thickness of the second layer is the following [Formula 1] ] To be satisfied.

[Equation 1]

Y _inc : Admittance of the incident medium (air)

Y _eq : alternative admittance from the glass substrate to the first layer

Y ₂ : admittance of the second layer

d ₂ : thickness of the second layer

The first layer may be a transparent conductive oxide (TCO) material, and the second layer may be a ceramic material.

The transparent conductive oxide may include at least one of indium tin oxide (ITO), indium zinc oxide (IZO), antimony tin oxide (ATO), and antimony zinc oxide (AZO).

The first layer may have a thickness of about 80 nm to about 200 nm.

The thickness of the second layer may be 10 ~ 80nm.

Glass for a display touch panel according to the present invention is composed of a two-layer thin film is easy to produce stable. In addition, it is possible to provide a thin film having an appropriate thickness by a reflectance formula, and the thin film may exhibit an anti-reflective effect.

1 is a cross-sectional view showing a glass for a display touch panel according to the present invention.
Figure 2 is a graph showing the reflectance according to the wavelength according to the present invention.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the present embodiments are intended to complete the disclosure of the present invention, and the general knowledge in the art to which the present invention pertains. It is provided to fully convey the scope of the invention to those skilled in the art, and the present invention is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

Hereinafter, a glass for a display touch panel according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In general, the touch panel glass applied to the display includes a thin film layer made of a transparent conductive oxide material, and the touched part is sensed by a finger or other conductive object to enable touch control. The touch panel glass is easy to control the touch, but causes glare when the outdoor light or the indoor illumination light is reflected on the glass. In order to solve this problem, a diffusion sheet having a function of imparting light uniformity and widening the viewing angle is applied to the touch panel, but there is a limit in displaying an antireflection effect close to 0% reflectance.

In addition, in the related art, since it was difficult to form an antireflection layer having excellent transmissive characteristics in a wide area by only one layer, the two materials were mixed to form a thin film layer having a multilayer structure having different refractive indices. However, these antireflective layers require precise thickness.

The glass for display touch panel of the present invention is composed of a two-layer thin film may exhibit an anti-reflective effect close to 0%. The reflectance formula is also used to provide the proper thickness of the thin film.

1 is a cross-sectional view showing a glass for a display touch panel according to the present invention.

Referring to FIG. 1, the glass for display touch panel according to the present invention includes a glass substrate and an antireflection layer disposed on the glass substrate.

In order to satisfy the light transmittance of the glass substrate, a material having a high transmittance of 80% or more and a low absorption coefficient may be used, and a glass substrate having a refractive index of about 1.3 to 1.5 may be used. Examples thereof include borosilicate glass containing B ₂ O ₃ , soda lime glass of Na ₂ O—CaO—SiO ₂ system, and the like.

The anti-reflection layer has a two-layer structure consisting of a first layer disposed on a glass substrate and a second layer disposed over the first layer.

The first layer may be a transparent conductive oxide (TCO) material. The first layer formed of the TCO (Transparent Conductive Oxide) material is a thin film having high light transmittance and electrical conductivity, and exhibits a transmittance of about 80% or more. The thin film layer formed of a TCO material may be applied to a transparent electrode of a liquid crystal display device, glass having a low reflection function, and a touch panel of a display.

The transparent conductive oxide may include at least one of indium tin oxide (ITO), indium zinc oxide (IZO), antimony tin oxide (ATO), and antimony zinc oxide (AZO).

The second layer is made of a ceramic material such as SiO ₂ , Al ₂ O ₃ , Y ₂ O ₃ , and generally used SiO ₂ may be applied to the second layer.

According to the reflectance formula, when the optical admittance of the incident medium and the replacement admittance of the optical element coincide, the reflectance becomes 0%.

Applying the two-layer thin film as shown in Figure 1 to the following equation 1, it can be concluded that the reflectance is 0%.

In order to exhibit the antireflection effect of the thin film, it is preferable that the thickness of the first layer is thicker than the thickness of the second layer. More specifically, the first layer is a conductive oxide material, the thickness is 80 ~ 200nm, the thickness of the second layer may be 10 ~ 80nm.

When the thickness of the first layer is 80 nm or less or thinner than the thickness of the second layer, when a finger or a conductive object is detected on the outer surface of the glass for the touch panel, the touch control function of the touch panel may be degraded.

When the thickness of the second layer is less than 10 nm, the thickness may be so thin that the reflectance may increase due to a decrease in transmittance. On the contrary, when the thickness exceeds 80 nm, the transparency and the touch function of the touch panel may decrease while the layer thickness becomes thick.

The thickness d ₁ of the first layer and the thickness d ₂ of the second layer of the present invention satisfy the following formula (1).

[Equation 1]

Y _inc : Admittance of the incident medium (air)

Y _eq : alternative admittance from the glass substrate to the first layer

Y ₂ : admittance of the second layer

d ₂ : thickness of the second layer

Since the left side and the right side of Equation 1 are always present in the form of a complex number (i), the real side / imaginary side of the right side = real side / imaginary side of the left side should be satisfied. That is, the ratio of real and imaginary numbers on the left and right sides must be the same.

Y _eq is a variable that depends on d ₁ and is the refractive index from the glass substrate to the first layer, Y ₂ is the refractive index of the second layer. K ₀ is a phase constant (wavelength constant), K ₀ = 2π / wavelength length in the visible region (nm), and the actual variables in Equation 1 are d ₁ and d ₂ .

TABLE 1

For example, the value of Table 1 may be applied to Equation 1 to obtain the value of d ₁ from which Y _eq may be derived, and then the right side d ₂ may be obtained from the left side of the completed value.

As shown in Table 1, the d ₂ value may be obtained using a glass substrate made of soda lime, an ITO material, a first layer having a thickness of 97.3 nm, and a second layer made of SiO ₂ .

First, tan ^-1 {1- (1.87-2.05i) / i (1.46- (1.87-2.05i) /1.46)} = 0.01232Х1.46Хd _{2 where} tan ^-1 {1.586-2.711i} = 0.01799Хd ₂ Derived. Calculation from the 1.209 value on the left side yields a result with d ₂ = 67.2 nm.

Therefore, it is possible to calculate the thickness d ₁ of the first layer and the thickness d ₂ of the second layer having the antireflection effect of which the reflectance is close to 0%.

Figure 2 is a graph showing the reflectance according to the wavelength according to the present invention.

Conventionally, in the case of glass for touch panels having a diffusion sheet or a multilayer antireflection layer, the longer the wavelength, the thinner the diffusion sheet or the antireflection layer is, so that the reflectance is increased. For this reason, there is a problem in that the reflectance is almost 0% in some wavelength regions and the reflectance is high at 10% or more in some wavelength regions.

Referring to FIG. 2, the average reflectance in the visible wavelength range from 700 nm (red) to 400 nm (purple) is approximately 0-1%. In particular, the average reflectance of the thin film in the wavelength range of approximately 500nm to 520nm is closest to 0%. These results indicate that the reference wavelength applied to the K ₀ wave number of Equation 1 is 510 nm.

In the same way, when the reference wavelength is set to 400 nm and the calculation result is derived from Equation 1, the reflectance of the thin film in the 400 nm region approaches 0%. When the reference wavelength is set to 600 nm and the calculation result is derived from Equation 1, the reflectance of the thin film is close to 0% in the 600 nm region.

As such, in the present invention, the reflection color of the thin film may be adjusted by adjusting the reference wavelength closest to the reflectance of 0%. The reflection color refers to a wavelength in which reflection occurs a lot.

The thickness of the first layer and the second layer may be uniformly formed by uniformly dispersing the particles on the glass substrate. For example, sputter, sol-gel, spray, chemical vapor deposition (CVD), organometallic chemical vapor deposition (MOCVD), electron beam (E-beam), laser deposition (LDP) By using various methods such as the above, the first layer may be formed from the transparent conductive oxide material.

In addition, a layer capable of imparting high hardness performance may be further formed on the second layer, but is not limited thereto.

As described above, the glass for display touch panel according to the present invention forms an antireflection layer having a two-layer structure on a glass substrate, and thus, relatively stable production is easy as compared with glass having a thin film of a conventional multilayer structure. In addition, by the formula 1 derived from the reflectance formula, the thicknesses of the first layer and the second layer thin film exhibiting the anti-reflective effect can be set.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to the above embodiments, but may be manufactured in various forms, and having ordinary skill in the art to which the present invention pertains. It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without changing the technical spirit or essential features of the present invention. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

d ₁ : thickness of the first layer
d ₂ : thickness of the second layer

Claims (5)

A glass substrate and an antireflection layer disposed on the glass substrate,
The anti-reflection layer has a two-layer thin film structure consisting of a first layer disposed on a glass substrate and a second layer disposed on the first layer, wherein the thickness of the first layer is thicker than the thickness of the second layer,
The thickness of the first layer and the thickness of the second layer satisfies the following [Formula 1],
The anti-reflection layer is glass for display touch panel, characterized in that the anti-reflection.
[Equation 1]

Y _inc : Admittance of the incident medium (air)
Y _eq : alternative admittance from the glass substrate to the first layer
Y ₂ : admittance of the second layer
d ₂ : thickness of the second layer
The method of claim 1,
The first layer is a transparent conductive oxide (TCO) material, the second layer is a glass for a display touch panel, characterized in that the ceramic material.
The method of claim 2,
The transparent conductive oxide may include at least one of indium tin oxide (ITO), indium zinc oxide (IZO), antimony tin oxide (ATO), and antimony zinc oxide (AZO).
The method of claim 1,
The thickness of the first layer is a glass for a display touch panel, characterized in that 80 ~ 200nm.
The method of claim 1,
The thickness of the second layer is 10 ~ 80nm glass for a display touch panel.

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