TWI766688B - Optical multilayer film and use thereof - Google Patents

Abstract

An optical multilayer film includes a substrate, a first coupling layer, a conductive layer and a second coupling layer. The first coupling layer is disposed on the second surface of the substrate. The conductive layer is disposed on the first coupling layer. The second coupling layer is disposed on the conductive layer. The first coupling layer is located between the substrate and the conductive layer.

Description

Optical multilayer film and its use

The present invention relates to an optical multilayer film, and more particularly, to an optical multilayer film capable of anti-reflection, heat defogging, and heat defrosting.

In response to the rise of automatic driving functions of vehicles, the demand for detection lenses and lidar systems around the vehicle body has increased to improve the capabilities of distance detection and object recognition. Therefore, detection lenses require very good high optical characteristics. However, when the vehicle is in extreme weather, such as snow, dense fog, heavy rain, etc., the detection lens may lose its ability to accurately identify objects due to frost or dew condensation.

The invention provides an optical multi-layer film, which has the effects of anti-reflection, heating defogging and heating defrosting at the same time.

The optical multilayer film of the present invention includes a substrate, a first coupling layer, a conductive layer, and a second coupling layer. The first coupling layer is disposed on the substrate. The conductive layer is disposed on the first coupling layer. The second coupling layer is disposed on the conductive layer. The first coupling layer is located between the substrate and the conductive layer.

In an embodiment of the present invention, the above-mentioned substrate has a first surface and a second surface opposite to the first surface. The above-mentioned optical multilayer film further includes an anti-reflection film, which is disposed on the first surface of the substrate. The first coupling layer, the conductive layer and the second coupling layer are disposed on the second surface of the substrate.

In an embodiment of the present invention, the sheet resistance of the conductive layer is 10 Ω/□ to 250 Ω/□.

In an embodiment of the present invention, the sheet resistance of the conductive layer is 10 Ω/□ to 30 Ω/□.

In an embodiment of the present invention, the thickness of the above-mentioned conductive layer is greater than 50 nm and less than or equal to 400 nm.

In an embodiment of the present invention, the above-mentioned optical multilayer film has a reflectivity of 0.1% to 5% when the wavelength is 400 nm to 700 nm.

In an embodiment of the present invention, the above-mentioned optical multilayer film has a reflectance of 0.1% to 1% when the wavelength is 400 nm to 700 nm.

In an embodiment of the present invention, the form of the above-mentioned substrate is non-planar.

In an embodiment of the present invention, the first surface of the substrate is convex, and the second surface is concave.

In an embodiment of the present invention, the material of the above-mentioned conductive layer is a transparent conductive material.

In the use of the optical multilayer film of the present invention, it can be used for anti-reflection, heating defogging and heating defrosting.

Based on the above, in the optical multilayer film of the embodiment of the present invention, by disposing the first coupling layer between the substrate and the conductive layer, and disposing the conductive layer between the first coupling layer and the second coupling layer, The optical specification of the optical multilayer film of this embodiment can be improved, and the optical multilayer film can have an anti-reflection effect.

In order to make the above-mentioned features and advantages of the present invention more obvious and easy to understand, the following embodiments are given and described in detail with the accompanying drawings as follows.

FIG. 1 is a schematic cross-sectional view of an optical multilayer film according to a first embodiment of the present invention. FIG. 2 is a flow chart of the manufacturing method of the optical multilayer film according to the first embodiment of the present invention. FIG. 3 is a schematic top view of the vacuum coating equipment.

Referring to FIG. 1 , the optical multilayer film 100 of this embodiment includes a substrate 110 , an anti-reflection film 120 , a first coupling layer 130 , a conductive layer 140 and a second coupling layer 150 . The substrate 110 has a first surface 111 and a second surface 112 opposite to the first surface 111 . The substrate 110 may include glass or transparent organic material, but is not limited thereto. For example, the glass may include highly transparent glass B270, and the transparent organic material may include polymethyl methacrylate (PMMA) or other suitable transparent organic materials. In addition, in this embodiment, the form of the substrate 110 may be, for example, a plane, but not limited thereto. In some embodiments, the form of the substrate 110 may also be non-planar, as shown in FIG. 4 .

The anti-reflection film 120 is disposed on the first surface 111 of the substrate 110 . The anti-reflection film 120 includes at least one first dielectric material layer 121 and at least one second dielectric material layer 122 . The first dielectric material layer 121 and the second dielectric material layer 122 can be stacked on each other to form a multi-layer structure, and the number of layers in the multi-layer structure can be adjusted as required. The material of the first dielectric material layer 121 may be, for example, a high refractive index material, and the material of the second dielectric material layer 122 may be, for example, a low refractive index material, but not limited thereto. Therefore, in this embodiment, the anti-reflection film 120 may be a multilayer structure formed by stacking a high refractive index material and a low refractive index material, thereby reducing the reflectivity of the optical multilayer film 100 . In this embodiment, the high refractive index material may include titanium dioxide (TiO ₂ ), tantalum pentoxide (Ta ₂ O ₅ ), niobium pentoxide (Nb ₂ O ₅ ), aluminum nitride (AlN), or aluminum oxynitride (AlON), the low refractive index material may include magnesium fluoride (MgF ₂ ), silicon dioxide (SiO ₂ ) or aluminum oxide (Al ₂ O ₃ ), but not limited thereto.

The first coupling layer 130 is disposed on the second surface 112 of the substrate 110 . The first coupling layer 130 and the anti-reflection film 120 are respectively located on opposite sides of the substrate 110 . The first coupling layer 130 is located between the substrate 110 and the conductive layer 140 . The first coupling layer 130 includes at least one first dielectric material layer 131 and at least one second dielectric material layer 132 . The first dielectric material layer 131 and the second dielectric material layer 132 can be stacked on each other to form a multi-layer structure, and the number of layers in the multi-layer structure can be adjusted as required. Wherein, the materials of the first dielectric material layer 131 and the second dielectric material layer 132 may be the same or similar to the materials of the first dielectric material layer 121 and the second dielectric material layer 132 in the anti-reflection film 120 , so the This will not be repeated here. Specifically, the first coupling layer 130 may be a multi-layer structure (three layers are schematically shown in FIG. 1 , but not limited thereto), such as a sandwich structure. The uppermost layer and the lowermost layer in the sandwich structure are both the first dielectric material layer 131 , and the middle layer is the second dielectric material layer 132 . Therefore, in this embodiment, the first coupling layer 130 may be a multi-layer structure formed by stacking a high refractive index material and a low refractive index material, thereby reducing the reflectivity of the optical multilayer film 100 .

The conductive layer 140 is disposed on the second surface 112 of the substrate 110 and on the first coupling layer 130 . The conductive layer 140 and the substrate 110 are respectively located on opposite sides of the first coupling layer 130 . The conductive layer 140 is disposed between the first coupling layer 130 and the second coupling layer 150 . In this embodiment, since the sheet resistance value of the conductive layer 140 can be, for example, 10 Ω/□ (ohm/square) to 250 Ω/□, and the thickness T1 of the conductive layer 140 can be, for example, greater than 50 nanometers (nm) and less than or equal to 400 nm (ie, 50 nm<T≦400 nm), so that the conductive layer 140 can pass through the applied low voltage (such as 3V to 10V, but not limited to) and have the functions of conduction and heating, thereby making The optical multilayer film 100 of this embodiment can have the effects of heating defogging and heating defrosting.

In detail, when the sheet resistance value is greater than 250 Ω/□ and/or the thickness T1 of the conductive layer 140 is less than 50 nm, a power source with strong power will be required to provide enough current to generate heat, thus resulting in excessive energy consumption. The problem. When the sheet resistance value is less than 10 Ω/□, the thickness T1 of the conductive layer 140 will be too thick, which will cause the transmittance to decrease significantly, and even affect the anti-reflection effect. When the thickness T1 of the conductive layer 140 is greater than 400 nm, the transmittance will be significantly reduced, and the anti-reflection effect will be affected. In addition, in some embodiments, the sheet resistance value of the conductive layer 140 may also be 10 Ω/□ to 100 Ω/□. In some embodiments, the sheet resistance of the conductive layer 140 can also be 10 Ω/□ to 30 Ω/□, so that the optical multilayer film 100 containing the conductive layer 140 can have better heating defogging and heating defrosting properties. Effect. In some embodiments, the thickness T1 of the conductive layer 140 may also be greater than 100 nm and less than or equal to 300 nm (ie, 100 nm<T≦300 nm). In addition, the disposition of the conductive layer 140 can also enable the optical multilayer film 100 to have an anti-electromagnetic interference effect.

In addition, in this embodiment, the material of the conductive layer 140 may include transparent conducting oxide (TCO), but not limited thereto. For example, the transparent conductive material can be, for example, indium tin oxide (ITO) or other suitable transparent conductive materials. In this way, the conductive layer 140 can have better optical properties, such as anti-reflection and light-transmitting properties, in addition to the electrical conductivity.

The second coupling layer 150 is disposed on the second surface 112 of the substrate 110 and on the conductive layer 140 . The second coupling layer 150 and the first coupling layer 130 are respectively located on opposite sides of the conductive layer 140 . The second coupling layer 150 includes at least one first dielectric material layer 151 and at least one second dielectric material layer 152 . The first dielectric material layer 151 and the second dielectric material layer 152 can be stacked on each other to form a multi-layer structure, and the number of layers in the multi-layer structure can be adjusted as required. The materials of the first dielectric material layer 151 and the second dielectric material layer 152 may be the same or similar to the materials of the first dielectric material layer 121 and the second dielectric material layer 132 in the anti-reflection film 120, so the This will not be repeated here. Therefore, in this embodiment, the second coupling layer 150 may be a multi-layer structure formed by stacking a high refractive index material and a low refractive index material, thereby reducing the reflectivity of the optical multilayer film 100 .

In this embodiment, by disposing the first coupling layer 130 between the substrate 110 and the conductive layer 140, and disposing the conductive layer 140 between the first coupling layer 130 and the second coupling layer 150, the conduction can be achieved The layer 140 does not directly contact the substrate 110, and can improve the optical specification of the optical multilayer film 100, for example, the reflectivity of the optical multilayer film 100 of this embodiment can be, for example, 0.1 when the wavelength is 400 nm to 700 nm % to 5%, and has an anti-reflection effect. In some embodiments, the reflectivity of the optical multilayer film 100 at a wavelength of 400 nm to 700 nm can also be 0.1% to 1%, so that the optical multilayer film 100 can have a better anti-reflection effect.

Although the wavelength range of the reflectance (eg, 0.1% to 5%, or 0.1% to 1%) of the optical multilayer film 100 of the present embodiment is 400 nm to 700 nm, the present invention does not affect the wavelength range of the reflectivity. be restricted. That is, in some embodiments, the wavelength range can also be adjusted as needed. For example, the wavelength range may also be 380 nm to 680 nm, 420 nm to 780 nm, or 800 nm to 1100 nm, but not limited thereto.

Although the optical multilayer film 100 of the present embodiment may include the anti-reflection film 120 , the first coupling layer 130 , the conductive layer 140 and the second coupling layer 150 , the anti-reflection film 120 can be selected as needed. That is, in some embodiments, the optical multilayer film may not need to be provided with an anti-reflection film, as shown in FIG. 5A .

2 and 3 at the same time, the manufacturing method of the optical multilayer film 100 of the present embodiment and the vacuum coating equipment 200 used in the manufacturing process will be illustrated below, but not limited thereto.

First, referring to FIG. 3 , the vacuum coating apparatus 200 of this embodiment may include a vacuum reaction chamber 210 , a sputtering target base 220 , a thin film reaction source 230 , a vacuum system 240 , a plasma power supply (not shown), and an equipment control parts (not shown). The vacuum reaction chamber 210 is where the optical multilayer film is prepared. The sputtering target 220 is the source of the thin film material, and the metal film 221 can be formed. The thin film reaction source 230 is a source for the formation of the dielectric film 231 . The vacuum system 240 is composed of various types of vacuum pumps, which can be used to create a vacuum. The form of plasma power supply can be DC, intermediate frequency, radio frequency, high-power magnetron pulse, etc., which can be used as the power to generate plasma. Equipment control materials can be industrial computers, programmable controllers, fuseless switches, electromagnetic switches and other components.

Next, please refer to FIG. 1 , FIG. 2 and FIG. 3 at the same time, in the manufacturing method of the optical multilayer film 100 of the present embodiment, the vacuum reaction chamber 210 is evacuated by the vacuum system 240 in the vacuum coating apparatus 200 first. Next, an anti-reflection film 120 is formed on the first surface 111 of the substrate 110 . Next, a first coupling layer 130 is formed on the second surface 112 of the substrate 110 . Next, a conductive layer 140 is formed on the first coupling layer 130 , so that the first coupling layer 130 is located between the substrate 110 and the conductive layer 140 . Then, a second coupling layer 150 is formed on the conductive layer 140 . So far, the optical multilayer film 100 of this embodiment has been fabricated.

In this embodiment, the principle of forming the anti-reflection film 120 , the first coupling layer 130 , the conductive layer 140 and the second coupling layer 150 is physical vapor deposition (PVD), and the method used is sputtering, for example. High-refractive index materials and low-refractive index materials of optical design are generated by sputtering and reactively depositing metals by inductively-coupled plasma (ICP).

Other examples are listed below for illustration. It must be noted here that the following embodiments use the element numbers and part of the contents of the previous embodiments, wherein the same numbers are used to represent the same or similar elements, and the description of the same technical contents is omitted. For the description of the omitted part, reference may be made to the foregoing embodiments, and repeated descriptions in the following embodiments will not be repeated.

4 is a schematic cross-sectional view of an optical multilayer film according to a second embodiment of the present invention. Please refer to FIG. 1 and FIG. 4 at the same time. The optical multilayer film 100a of this embodiment is similar to the optical multilayer film 100 in FIG. 1, but the main difference between the two lies in the form of the substrate 110a.

Specifically, referring to FIG. 4 , in the optical multilayer film 100a of the present embodiment, the form of the substrate 110a is non-planar, such as a curved surface, but not limited thereto. Wherein, the first surface 111a of the substrate 110a may be a convex surface, and the second surface 112a may be a concave surface, but not limited thereto. In some embodiments, the first surface 111a of the substrate 110a may also be concave, and the second surface 112a may also be convex (not shown). In other words, the optical multilayer film 100a of the present embodiment can be applied to a lens of a convex lens or a concave lens, or to a mirror surface of a convex mirror or a concave mirror.

5A is a schematic cross-sectional view of an optical multilayer film according to a third embodiment of the present invention. FIG. 5B shows the reflectance and transmittance of the optical multilayer film of the third embodiment of FIG. 5A at different wavelengths. 1 and 5A at the same time, the optical multilayer film 100b of this embodiment is similar to the optical multilayer film 100 in FIG. 1, but the main difference between the two is that the optical multilayer film 100b of this embodiment does not have an anti-reflection film, In addition, the number of layers of the first coupling layer 130b and the number of layers of the second coupling layer 150b of the optical multilayer film 100b of the present embodiment are different from those of the optical multilayer film 100 .

Specifically, please refer to FIG. 5A first, the optical multilayer film 100b of this embodiment includes the substrate 110, the first coupling layer 130b, the conductive layer 140 and the second coupling layer 150b, and does not include the anti-reflection film. The first coupling layer 130 b , the conductive layer 140 and the second coupling layer 150 b are sequentially disposed on the second surface 112 of the substrate 110 . The first coupling layer 130b is located between the substrate 110 and the conductive layer 140 . In this embodiment, the first coupling layer 130b includes, for example, four layers of the first dielectric material layer 131 and four layers of the second dielectric material layer 132, and the second dielectric material layer 132 and the first dielectric material layer The layers 131 are sequentially stacked on the substrate 110 . The second coupling layer 150b, for example, includes a first dielectric material layer 151 and a second dielectric material layer 152, and the first dielectric material layer 151 and the second dielectric material layer 152 are sequentially stacked on on the conductive layer 140 .

In this embodiment, the material of the substrate 110 is, for example, glass, the material of the first dielectric material layer 131 and the first dielectric material layer 151 is, for example, aluminum nitride, and the material of the second dielectric material layer 132 and the second dielectric material The material of the material layer 152 is, for example, silicon dioxide, and the material of the conductive layer 140 is, for example, indium tin oxide, but not limited thereto. In addition, in this embodiment, the thickness T2 of the first coupling layer 130b is, for example, about 580 nm to 590 nm, the thickness T1 of the conductive layer 140 is, for example, about 250 nm, and the thickness T3 of the second coupling layer 150b is, for example, about 250 nm. is about 170 nm to 175 nm, but not limited thereto. In this embodiment, the sheet resistance of the conductive layer 140 is, for example, about 25 Ω/□, but not limited thereto.

Next, according to the results of measuring the reflectance and transmittance of the optical multilayer film 100b at different wavelengths in FIG. 5B, it can be seen that when the wavelength is from 420 nm to 700 nm, the reflectivity of the optical multilayer film 100b does not change much and Roughly 0.1% to 0.5%. When the wavelength is 500 nm to 700 nm, the transmittance of the optical multilayer film 100b does not change much and is approximately 97.5% to 98.5%.

FIG. 6A is a schematic cross-sectional view of an optical multilayer film of a comparative example. FIG. 6B shows the reflectance and transmittance of the optical multilayer film of the comparative example of FIG. 6A at different wavelengths. 5A and FIG. 6A at the same time, the optical multilayer film 100c of this comparative embodiment is similar to the optical multilayer film 100b of FIG. 5A, but the main difference between the two is that the optical multilayer film 100c of this comparative embodiment does not have the first The number of layers of the second coupling layer 150c of the optical multilayer film 100c of the present comparative example is different from that of the optical multilayer film 100b.

Specifically, referring to FIG. 6A , the optical multilayer film 100 c of the present comparative embodiment includes the substrate 110 , the conductive layer 140 and the second coupling layer 150 c , and does not include the first coupling layer. The conductive layer 140 and the second coupling layer 150c are sequentially disposed on the second surface 112 of the substrate 110 . The conductive layer 140 can directly contact the substrate 110 , and there is no other film layer between the conductive layer 140 and the substrate 110 . In the present comparative embodiment, the second coupling layer 150c includes, for example, three layers of the first dielectric material layer 151 and four layers of the second dielectric material layer 152, and the second dielectric material layer 152 is connected to the first dielectric material layer 152. The material layers 151 are sequentially stacked on the conductive layer 140 .

In this comparative embodiment, the material of the substrate 110 is glass, for example, the material of the first dielectric material layer 151 is, for example, aluminum nitride, the material of the second dielectric material layer 152 is, for example, silicon dioxide, and the material of the conductive layer 140 is The material is for example, but not limited to, indium tin oxide. In addition, in the present comparative embodiment, the thickness T1 of the conductive layer 140 is, for example, about 250 nm, and the thickness T3 of the second coupling layer 150 c is, for example, about 360 nm to 370 nm, but not limited thereto.

Next, according to the results of measuring the reflectivity and transmittance of the optical multilayer film 100c at different wavelengths in FIG. 6B, it can be seen that when the wavelength is from 420 nm to 700 nm, the change of the reflectivity of the optical multilayer film 100b is large and approximately 0.1% to 2% above. When the wavelength is 500 nm to 700 nm, the transmittance of the optical multilayer film 100c varies greatly and is approximately 95.5% to 99%.

Therefore, according to the structures of FIGS. 5A and 6A and the measurement results of FIGS. 5B and 6B , compared with the optical multilayer film 100c without the first coupling layer, the optical multilayer film 100b has a structure disposed between the conductive layer 140 and the substrate 110 . Therefore, the reflectivity of the optical multilayer film 100b is smaller and more stable, and the transmittance of the optical multilayer film 100b is more stable. In addition, when light propagates from a medium with a specific refractive index into another medium with a different refractive index, reflection will occur at the interface between the two different media. As shown in FIG. 6A , in the substrate 110 of the optical multilayer film 100c Reflection occurs at the interface with the conductive layer 140 . However, different from the structural design of the optical multilayer film 100c in FIG. 6A , the optical multilayer film 100b in FIG. 5A can reduce the reflection phenomenon at the interface between different media through the arrangement of the first coupling layer 130b, thereby achieving the anti-reflection effect.

To sum up, in the optical multilayer film of the embodiment of the present invention, the first coupling layer 130 is disposed between the substrate 110 and the conductive layer 140, and the conductive layer 140 is disposed between the first coupling layer 130 and the conductive layer 140. Between the second coupling layers 150 , the optical specification of the optical multilayer film 100 of this embodiment can be improved, and the optical multilayer film 100 can have an anti-reflection effect. In addition, by setting the sheet resistance of the conductive layer 140 to be 10 Ω/□ to 250 Ω/□, and the thickness T1 of the conductive layer 140 is greater than 50 nm and less than or equal to 400 nm, the conductive layer 140 can be electrically conductive and heated. function, and make the optical multilayer film 100 of this embodiment have the effects of heating defogging and heating defrosting. In this way, the application of the optical multi-layer film of this embodiment can have the effects of anti-reflection, heating defogging and heating defrosting at the same time.

Although the present invention has been disclosed above by the embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, The protection scope of the present invention shall be determined by the scope of the appended patent application.

100, 100a, 100b, 100c: Optical multilayer films

110, 110a: Substrate

111, 111a: first surface

112, 112a: second surface

120: Anti-reflection film

121, 131, 151: the first dielectric material layer

122, 132, 152: the second dielectric material layer

130, 130b: the first coupling layer

140: Conductive layer

150, 150b, 150c: second coupling layer

200: Vacuum coating equipment

210: Vacuum reaction chamber

220: Sputtering target base

221: Metal Film

230: Thin Film Reactor

231: Dielectric film

240: Vacuum System

T1, T2, T3: Thickness

FIG. 1 is a schematic cross-sectional view of an optical multilayer film according to a first embodiment of the present invention. FIG. 2 is a flow chart of the manufacturing method of the optical multilayer film according to the first embodiment of the present invention. FIG. 3 is a schematic top view of the vacuum coating equipment. 4 is a schematic cross-sectional view of an optical multilayer film according to a second embodiment of the present invention. 5A is a schematic cross-sectional view of an optical multilayer film according to a third embodiment of the present invention. FIG. 5B shows the reflectance and transmittance of the optical multilayer film of the third embodiment of FIG. 5A at different wavelengths. FIG. 6A is a schematic cross-sectional view of an optical multilayer film of a comparative example. FIG. 6B shows the reflectance and transmittance of the optical multilayer film of the comparative example of FIG. 6A at different wavelengths.

100: Optical multilayer film

110: Substrate

111: First surface

112: Second Surface

120: Anti-reflection film

121, 131, 151: the first dielectric material layer

122, 132, 152: the second dielectric material layer

130: first coupling layer

140: Conductive layer

150: Second coupling layer

T1: Thickness

Claims (11)

An optical multilayer film, comprising: a substrate; a first coupling layer disposed on the substrate, comprising: at least one first dielectric material layer and at least one second dielectric material layer, the first dielectric material The layer and the second dielectric material layer are stacked on each other to form a multi-layer structure, wherein the material of the first dielectric material layer includes titanium dioxide, tantalum pentoxide, niobium pentoxide, aluminum nitride or aluminum oxynitride, and the The material of the second dielectric material layer includes magnesium fluoride, silicon dioxide or aluminum oxide; a conductive layer disposed on the first coupling layer; and a second coupling layer disposed on the conductive layer, wherein The first coupling layer is located between the substrate and the conductive layer. The optical multilayer film of claim 1, wherein the substrate has a first surface and a second surface opposite to the first surface, and the optical multilayer film further comprises: an anti-reflection film disposed on the base on the first surface of the substrate, wherein the first coupling layer, the conductive layer and the second coupling layer are disposed on the second surface of the substrate. The optical multilayer film of claim 1, wherein the conductive layer has a sheet resistance value of 10Ω/□ to 250Ω/□. The optical multilayer film of claim 1, wherein the sheet resistance value of the conductive layer is 10Ω/□ to 30Ω/□. The optical multilayer film of claim 1, wherein the thickness of the conductive layer is greater than 50 nanometers and less than or equal to 400 nanometers. The optical multilayer film of claim 1, wherein the optical multilayer film has a reflectance of 0.1% to 5% at a wavelength of 400 nm to 700 nm. The optical multilayer film of claim 1, wherein the optical multilayer film has a reflectance of 0.1% to 1% at a wavelength of 400 nm to 700 nm. The optical multilayer film of claim 1, wherein the form of the substrate is non-planar. The optical multilayer film of claim 8, wherein the substrate has a first surface and a second surface opposite to the first surface, the first surface of the substrate is convex, and the second surface is Concave. The optical multilayer film according to claim 1, wherein the material of the conductive layer is a transparent conductive material. A use of the optical multilayer film according to claim 1, which is used for anti-reflection, heating defogging and heating defrosting.

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