KR100346422B1 - Anti-reflection anti-static film - Google Patents

Abstract

The present invention is a non-reflective anti-static film for the purpose of reducing the reflectance of light incident from the outside, static electricity, and blocking harmful electromagnetic waves in display devices such as cathode-ray tube (CRT), plasma display panel (PDP), etc. In particular, in the display device, a glass layer through which an image is transmitted and an absorbing layer of a metal material which improves contrast by preventing static electricity and harmful electromagnetic waves caused by light transmitted from the glass layer and absorbing only a certain amount of the light. And an adhesive layer made of a material that is adhered between the glass layer and the absorbent layer to have excellent light transmittance, and which is adhered to the absorbent layer to be in contact with air to prevent physical scratches, and at the same time, has excellent light transmittance. Consists of a protective layer of material;

As it shows a reflectance of less than 1% and transmittance of more than 60 to 80% in all areas of visible light, it provides a clear image and consists of three layers or four layers, resulting in a shorter working time and a reduced thickness compared to four or more layers of film. The present invention relates to an anti-reflection and anti-static film that provides an effect of saving material costs.

Description

Anti-reflection anti-static film {Anti-reflection anti-static film}

The present invention is a non-reflective anti-static film for the purpose of reducing the reflectance of light incident from the outside, static electricity, and blocking harmful electromagnetic waves in display devices such as cathode-ray tube (CRT), plasma display panel (PDP), etc. In particular, the film consists of three to four layers of a silicon dioxide (SiO ₂ ) layer, an absorbing layer, and an adhesive layer, which reduces static electricity, blocks harmful electromagnetic waves, and reflects 1% of all visible light (380 nm to 780 nm). It relates to an antireflective antistatic film which is reduced below.

As shown in FIG. 1, the incident light 2, which is light incident from the outside on the monitor surface 1, is reflected light 3 reflected from the surface 1 and refracted light refracted in the material. (refraction ray) 4, absorbed absorption light (absorption ray) 5, and transmitted ray (transmittance ray) 4a.

In this case, the reflected light 3 reflected from the surface 1 of the monitor overlaps with the image coming from the surface 1 of the monitor as shown in FIG. ) Easily fatigued.

Therefore, manufacturers of display devices can absorb incident light so that a user can see a clear image having a reflectance of 1% or less, and suppress generation of static electricity, which is harmful to humans, and at the same time, Non-reflective antistatic films that are effective in improving and preventing harmful electromagnetic waves continue to be developed.

For reference, the above-mentioned contrast is a term used in television and photography, and refers to a contrast between the brightness of the light side and the dark side of the screen. When too weak, black and white becomes unclear, and when too strong, it is unsightly. A high contrast screen is displayed.

Referring to the prior art of the non-reflective antistatic film as described above with reference to the drawings as follows.

First, FIG. 2 is a partial cross-sectional view of a display device in which a non-reflective anti-static film is coated on the surface of the monitor. If the non-reflective anti-static film is not coated, external light is reflected from the surface 1 of the monitor. This will result in degradation of the image. However, when the non-reflective antistatic film is coated, the reflection of the incident light 2 is reduced, the image is clear, the charge accumulation on the monitor surface 1 is removed, and thus the static electricity is prevented, and the electron gun 7 is used. The human body can be protected from harmful electromagnetic waves generated on the surface 1 of the monitor.

Here, in the case where the non-reflective antistatic film is a single layer film, a typical non-reflective film should satisfy Equations 1 and 2 below as a quarter-wave film.

Here, n ₀ represents the refractive index of air, n ₁ represents the refractive index of the film, n ₂ represents the refractive index of the monitor glass, d represents the thickness of the film, and λ represents the wavelength of light to which reflection is prevented.

When the above equations (1) and (2) are satisfied, the light having the wavelength λ has a reflectance of zero.

Referring to the case of practical application of the above equation, n ₀ is the case, and so the refractive index of air n ₀ is 1, n is _2, the glass n ₂ is because the 1.52 is the n ₁ is 1.23 by equation (2) . However, the lowest refractive index thin film material currently used is MgF ₂ (magnesium fluoride), MgF ₂ has a refractive index of 1.38, and the refractive index n ₁ of the film satisfying Equations 1 and 2 above is 1.23. Becomes larger.

Therefore, the use of a monolayer film is inappropriate for reducing reflectance and giving satisfaction to users.

Next, look at the non-reflective antistatic film composed of two layers as follows.

In order for the two-layer antireflective antistatic film to perform its role properly, the following Equations 3, 4, and 5 must be satisfied.

Where n ₀ is the refractive index of the air, n ₂ is the refractive index of the monitor glass, n ₃ is the refractive index of the film coated between the air and the glass, n ₄ is the film coated between the glass and the film having a refractive index of n ₃ the refractive index, d ₁ is the thickness of the film, a refractive index of n _3, d ₂ is the thickness of the refractive index n ₄ of the film, λ represents a wavelength of each light reflection is prevented.

G. A practical example of the non-reflection anti-electrostatic film of two-layer structure as described above, n is ₀ and 1, n ₂ is 1.52, so when the glass is the n ₄ / n ₃ = 1.23 by Equation (5). And when the refractive indexes of Al ₂ O ₃ (aluminum oxide) and MgF ₂ (magnesium fluoride) are n ₃ and n ₄ , respectively, n ₃ is 1.3826 and n ₄ is 1.6710.

Solving the above practical example by the equations (3) to (5), λ is 550 nm and n ₄ / n ₃ is 1.21, which satisfies the above conditions similarly, but only at the reference wavelength of 550 nm as shown in FIG. It is impossible to obtain a reflectance of 1% or less in the entire visible light region because the reflectance becomes zero, and a "V" shaped curve in which the reflectance increases rapidly around it is displayed. In addition, since there is no conducting layer, it does not have a function of preventing the electromagnetic wave, which is currently the greatest concern.

As described above, since a reflectance of 1% or less cannot be obtained with a single layer or a two-layer film, a product which further increases the number of layers of the film comes out.

That is, in the case of US Patent No. 4,846,551, which is a three-layer film coating, Al ₂ O ₃ (aluminum oxide) from the glass, cerium stannate or zirconium oxide (ZrO ₂ ) or ITO ( indium-tin-oxide) and MgF ₂ (magnesium fluoride) in this order.

It can be seen that the three-layer film according to the US Patent No. 4,846,551 is better than the two-layer film as shown in Figure 4, but this also shows a high reflectance except for the central region of visible light In addition, there is a problem that the total thickness of the film is too thick to be commercialized at 1570 nm.

On the other hand, US Patent No. 5,407,733 is a four-layer coating of the film, from the glass of TiN (titanium nitride) of 20.9nm thickness, SnO ₂ (tin oxide) of 48.4nm thickness, TiN (titanium nitride) of 12.7nm thickness, Coated in the order of SiO ₂ (silicon dioxide), a portion where the reflectance X is reduced as shown in FIG. 5 is wide in the visible light region.

However, the transmittance (Y) is extremely low as 10% to 20%, and because the overall thickness of the film is also 157.2 thick, there are many problems in terms of material cost and productivity.

In addition, U.S. Patent No. 5.53658 million discloses as a coating a film with five layers, ITO from the glass (indium - tin - oxide), PrTiO 3 ( titanium praseodymium oxide), MgF ₂ (peulreu ohreuhwa magnesium), PrTiO ₃ (titanium oxide, praseodymium ), MgF ₂ (magnesium fluoride) is coated in order of, and as shown in FIG. There is a problem that appears.

In addition, U.S. Patent No. 5,091,244 is a coating of six layers of films, from 7.9 nm TiN (titanium nitride), 38.2 nm SnO ₂ (tin oxide), 23.6 nm TiN (titanium nitride), 49.2 nm SnO ₂ (tin oxide), TiN (titanium nitride) at 14.5 nm, and SiO ₂ (silicon oxide) at 75.1 nm, and the reflectance (X ′) is reduced in the visible light region as shown in FIG. Although the part is widely shown in the visible light region, the reflectance (X ') is high in the low wavelength region of visible light, and the transmittance (Y') is also extremely low, which is 20% or less. In addition, there is a problem that the overall thickness of the film also appears thick at 208.5nm.

The present invention has been made to solve the above-mentioned problems of the prior art, it is a minimum layer capable of performing the role of a non-reflective anti-static film to show a reflectance within 1% and transmittance of 60 to 80% or more at the same time It is an object of the present invention to provide a non-reflective anti-static film that can be.

1 is a state diagram when general incident light is incident on a material;

2 is a partial cross-sectional view of a display device coated with a non-reflective antistatic film on the surface of a monitor;

3 is a graph of reflectance when a non-reflective antistatic film having a two-layer structure according to the prior art is used,

4 is a graph of reflectance when a non-reflective antistatic film having a three-layer structure according to the prior art is used,

5 is a graph of reflectance and transmittance when a non-reflective antistatic film having a four-layer structure according to the prior art is used,

6 is a graph of reflectance when a non-reflective antistatic film having a 5-layer structure according to the prior art is used,

7 is a graph of reflectance and transmittance when a non-reflective antistatic film having a six-layer structure according to the prior art is used,

8 is a cross-sectional view of an antireflective antistatic film according to a first embodiment of the present invention;

9 is a graph of reflectance according to the first embodiment of the present invention;

10 is a graph of transmittance according to the first embodiment of the present invention;

11 is a cross-sectional view of an antireflective antistatic film according to a second embodiment of the present invention;

12 is a graph of reflectance according to a second embodiment of the present invention;

13 is a graph of transmittance according to a second embodiment of the present invention;

14 is a cross-sectional view of an antireflective antistatic film according to a third embodiment of the present invention;

15 is a graph of reflectance according to a third embodiment of the present invention;

16 is a graph of transmittance according to a third embodiment of the present invention;

17 is a cross-sectional view of an antireflective antistatic film according to a fourth embodiment of the present invention;

18 is a graph of reflectance of each of the antireflective antistatic film according to the change in the thickness of the film in the fourth embodiment of the present invention;

19 is a graph of transmittance of each of the antireflective antistatic film according to the change of the thickness of the film in the fourth embodiment of the present invention;

20 is a graph showing changes in refractive index and absorption coefficient according to the wavelength of Cr ₂ O ₃ , which is a part of the fourth embodiment of the present invention;

FIG. 21 is a graph showing changes in refractive index and absorption coefficient according to the wavelength of SiO ₂ , which is a part of the fourth embodiment of the present invention.

<Explanation of symbols on main parts of the drawings>

51, 61, 71, 81: glass 52: Al ₂ O ₃ 53, 63, 73, 83: Cu

54, 64, 72. 74, 85: SiO ₂ 62: TiO ₂ , X, X ': reflectance

Y, Y ': transmittance

The present invention provides a glass layer through which an image is transmitted in a display device, an absorption layer of a metal material which improves contrast by preventing static electricity and harmful electromagnetic waves caused by light transmitted from the glass layer and absorbing only a predetermined amount of the light; An adhesive layer made of a material bonded between the glass layer and the absorbent layer and having excellent light transmittance, and a material adhered to the absorbent layer and in contact with air to prevent physical scratches, and at the same time have a high transmittance to light. Characterized in that consisting of a protective layer.

In addition, the absorption layer is characterized in that consisting of one of Cu, Au, Ag.

In addition, the adhesive layer is characterized in that made of one of SiO ₂ , TiO ₂ , Al ₂ O ₃ , CrO ₂ , Cr ₂ O ₃ .

In addition, the protective layer is characterized in that consisting of SiO ₂ .

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

In the embodiment of the present invention by applying an absorbing layer made of copper, gold, silver, etc. to prevent static electricity and to prevent harmful electromagnetic waves at the same time to improve the contrast by absorbing light within 10 to 40%, It is generally known that the adhesion of glass is not good. Therefore, in the present invention, the adhesive layer is used to improve the adhesion between the absorbing layer and the glass, but the consideration here is the light transmittance.

Therefore, in the present invention, SiO ₂ , TiO ₂ , Al ₂ O ₃ , CrO _2, etc., which have excellent adhesion and transmittance, are used.

First, referring drawings, Figure 8 is a cross-sectional view according to a first embodiment of the present invention.

As shown in FIG. 8, the non-reflective antistatic film according to the present invention includes Al ₂ O ₃ (aluminum oxide) 52, Cu (copper) 53, and SiO ₂ on the glass 51 of the monitor. (Silicon oxide) 54 is coated in sequence.

The refractive index (n), absorption coefficient (k), and thickness (nm) at the reference wavelength (550 nm) of the components of the non-reflective antistatic film are as follows.

matter Refractive index (n) Absorption coefficient (k) Thickness (nm) SiO ₂ 1.4618 0.0000 64.83 Cu 0.8380 2.6725 4.59 Al ₂ O ₃ 1.6726 0.0000 21.1

As shown in FIG. 9 and FIG. 10, the non-reflective antistatic film configured as described above may obtain a reflectance of 1% or less in all regions of visible light and a transmittance of 80% or more.

In addition, since the total thickness of the antireflective antistatic film is also 90.5 nm, the material cost is reduced and the working time is shortened.

On the other hand, the non-reflective anti-static film of the second embodiment according to the present invention is TiO ₂ (titanium oxide) 62, Cu (copper) 63, SiO _{2 in} the glass 61 of the monitor as shown in FIG. (Silicone Oxide) 64 is coated in sequence.

The refractive index (n), absorption coefficient (k), and thickness (nm) at the reference wavelength (550 nm) of the components of the non-reflective antistatic film are as follows.

matter Refractive index (n) Absorption coefficient (k) Thickness (nm) SiO ₂ 1.4618 0.0000 65.75 Cu 0.8380 2.6725 4.66 TiO ₂ 2.3487 0.0004 3.23

As shown in FIG. 12 and FIG. 13, the non-reflective antistatic film configured as described above can obtain a reflectance of 1% or less in all regions of visible light and a transmittance of 80% or more. In addition, the total thickness of the non-reflective antistatic film is also 73.6nm, saving material cost and shortening working time.

On the other hand, the non-reflective anti-static film of the third embodiment according to the present invention is SiO ₂ (silicon oxide) 72, Cu (copper) 73, SiO _{2 in} the glass 71 of the monitor as shown in FIG. (Silicone Oxide) 74 is coated in sequence.

The refractive index (n), absorption coefficient (k), and thickness (nm) at the reference wavelength (550 nm) of the components of the non-reflective antistatic film are as follows.

matter Refractive index (n) Absorption coefficient (k) Thickness (nm) SiO ₂ 1.4618 0.0000 55.32 Cu 0.8380 2.6725 3.75 SiO ₂ 1.4618 0.0000 108.43

As shown in FIG. 15 and FIG. 16, the non-reflective antistatic film configured as described above can obtain a reflectance of 1% or less in all regions of visible light and a transmittance of 80% or more. In addition, the total thickness of the non-reflective anti-static film is also slightly thicker to 167.5nm, but compared to the six-layer film of the prior art, the material cost is reduced and the working time is shortened.

Meanwhile, according to the fourth embodiment of the present invention, the Cr ₂ O ₃ layer 82, the Cu layer 83, the Cr ₂ O ₃ layer 84, SiO, and the glass 81 of the monitor as shown in FIG. _{The two} layers 85 are coated sequentially. That is, the Cr ₂ O ₃ layers 82 and 84 are coated to bond the glass 81 and the Cu layer 83, and again the Cu layer 83 and the SiO ₂ layer 85 as adhesive layers.

17 is a cross-sectional view of a non-reflective antistatic film according to a fourth embodiment of the present invention, and FIG. 18 is a reflectance of each of the non-reflective antistatic films according to a thickness change of a film in a fourth embodiment of the present invention. 19 is a graph of transmittance of each of the antireflective antistatic films according to the change of the thickness of the film in the fourth embodiment of the present invention, and FIG. 20 is a Cr ₂ O component of the fourth embodiment of the present invention. FIG. 21 is a graph showing the change in refractive index and absorption coefficient according to the wavelength of ₃ , and FIG. 21 is a graph showing the change in refractive index and absorption coefficient according to the wavelength of SiO ₂ , which is a component of the fourth embodiment of the present invention. .

In the above, the most important factor in the electromagnetic wave coating is to use a material having a low resistance, that is, a high electrical conductivity. In the fourth embodiment, a four-layer coating film is made of copper (Cu), which is cheaper than other semiconductors or alloys and has a high electrical conductivity, and the electrical conductivity of Cu is a semiconductor material of carbon ( The electrical conductivity is 2.8 × 10 ⁴ (Ωm) ^-1 ) or silicon (Si) (the electrical conductivity is 1.6 × 10 ⁴ (Ωm) ^-1 ), and the manganese alloy (the conductivity is 2.27 × 10 ⁶ (Ωm) ^{- 1} ), nichrome (electric conductivity is 1.0 × 10 ⁶ (m ⁻¹ )), and aluminum, which is the same metal (electric conductivity is 3.54 × 10 ⁶ (m ⁻¹ ) ^-1 ), and is much more conductive. In addition, since the absorbency is inferior to a metal such as Cr (chromium) or Nb (niobium), the permeability is good. However, since the adhesive strength with glass has a disadvantage, in order to overcome the disadvantage, the Cr film is used by adhering the Cr film to both sides of the copper film. In the present invention, if Cr is used as it is, the permeability decreases a lot, but the coating method using Cr oxide film, that is, Cr ₂ O ₃ , is used as a method that does not degrade the permeability while using the adhesion of Cr. That is, Cr ₂ O ₃ having good permeability is used as an oxide film for improving adhesion between Cu and glass.

In addition, a SiO ₂ film, which is hard as the last layer and has a similar refractive index with air, is used. SiO ₂ is a glass-like material, which also does not adhere well to Cu. Thus, a Cr ₂ O ₃ film is inserted between the Cu and SiO ₂ films to compensate for this.

The refractive index (n) and absorption coefficient (k) at the reference wavelength (550 nm) of the material used in the fourth embodiment are shown in the table below.

matter Reference wavelength Refractive index (n) Absorption coefficient (k) SiO ₂ 550 nm 1.46 0.00 Cu 550 nm 1.04 2.16 Cr ₂ O ₃ 550 nm 2.32 0.26

Here, the Cu layer 83 uses 6 to 10 nm, the Cr ₂ O ₃ layers 82 and 84 use 4 to 6 nm, and the SiO ₂ layer 85 uses a thickness of 60 to 80 nm.

The table below shows the case where the thicknesses of the respective layers are combined and varied.

division matter Film thickness A B C D Board Glass First floor Cr ₂ O ₃ 4 nm 4 nm 5 nm 6 nm Second floor Cu 6 nm 8 nm 8 nm 7 nm 3rd Floor Cr ₂ O ₃ 4 nm 4 nm 6 nm 6 nm 4th floor SiO ₂ 74 nm 73 nm 70 nm 73 nm

By changing the thickness of the film as shown in the above table, a graph of reflectance as shown in FIG. 18 can be obtained. In the case of A, B, C, and D, all have a reflectance of 1% or less in the wavelength band of 450 nm to 650 nm. Particularly in the case of B, the graph has a low reflectance above 500 nm. The transmittance graph according to the change in the thickness of the film is shown in FIG. 19, where the transmittance is between 60 and 80%, and the reflectance is less than 1%.

Another important point in such coatings is that the materials used do not significantly change the properties of the material depending on the coating conditions. It should also not be very sensitive to changes in thickness. Materials such as Cr ₂ O ₃ and SiO ₂ do not significantly change the refractive index, a property of the material depending on the coating conditions. 20 shows an example of coating while changing the flow rate of Ar and the flow rate of O ₂ when coating Cr ₂ O ₃ . As shown, it can be seen that the refractive index does not change significantly, and as shown in FIG. 21, the refractive index does not change significantly even in the case of SiO ₂ .

As described above, the non-reflective antistatic film according to the fourth embodiment of the present invention can obtain a reflectance of 1% or less and a transmittance of 60 to 80% or more in all regions of visible light. In addition, since the thickness of the entire film is 100 nm or less, the process may be shortened and material costs may be reduced.

Of course, when each coating film in the first to third embodiments do not adhere well to each other, as shown in the fourth embodiment, by coating the Cr ₂ O ₃ between the respective components as an adhesive layer can improve the adhesive force. .

As described above, the anti-reflective anti-static film according to the present invention exhibits a reflectance of 1% or less and a transmittance of 60 to 80% or more in all areas of visible light, thereby providing a clear image and consisting of three or four layers. Compared to the made film, the working time is shortened and the thickness is reduced, thus providing the effect of saving material costs.

Claims (9)

In the display device, a glass layer through which an image is transmitted, an absorption layer of a metal material which improves contrast by preventing static electricity and harmful electromagnetic waves caused by light transmitted from the glass layer and absorbing only a certain amount of the light, and the glass layer And a first adhesive layer made of one of SiO ₂ , TiO ₂ , Al ₂ O ₃ , CrO ₂ , Cr ₂ O ₃ , which is adhered therebetween to adhere the absorbent layer and has excellent light transmittance, to be in contact with the air by adhering to the absorbent layer. And a protective layer made of SiO ₂ having excellent light transmittance while preventing physical scratches and the like, wherein the protective layer and the absorbing layer are adhered therebetween and are excellent in light transmittance, such as SiO ₂ , TiO ₂ , Al ₂ O Non-reflective antistatic film, characterized in that consisting of a second adhesive layer consisting of one of ₃ , CrO ₂ , Cr ₂ O ₃ delete delete The method of claim 1, The absorption layer is a non-reflective anti-static film, characterized in that consisting of one of Cu, Au, Ag. delete The method of claim 1, The absorption layer is Cu of 3 ~ 6.59nm thickness, the adhesive layer is Al ₂ O ₃ of 10 ~ 30nm thickness, the protective layer is a non-reflective anti-static film, characterized in that the SiO. ₂ 59.83 ~ 69.83nm thickness. The method of claim 1, Non-reflective anti-static film, characterized in that the absorption layer is 3.5-6 nm thick Cu, the adhesive layer is TiO ₂ 2 ~ 4nm thickness and the protective layer is SiO ₂ having a thickness of 60 ~ 70nm. The method of claim 1, The absorption layer is 3.5 ~ 5nm thick Cu, the adhesive layer is 10 ~ 120nm thickness SiO ₂ , The protective layer is a non-reflective anti-static film, characterized in that 50 ~ 60nm thickness SiO ₂ . The method of claim 1, The absorption layer is Cu 6 ~ 10nm thick, the adhesive layer is 4 ~ 6nm thick Cr ₂ O ₃ , The protective layer is anti-reflective anti-static film, characterized in that 60 ~ 80nm thick SiO ₂ .