Coating structure and method for producing a coating structure

Abstract

According to an embodiment, a coating structure is disclosed, the coating structure comprising: a substrate; a first thin film disposed on the substrate; a second film disposed on the first film; and a metal pattern protruding from the substrate. The metal pattern penetrates through the first thin film and a portion of the second thin film.

Description

Technical Field

[0001] The embodiments relate to coating structures. More specifically, the embodiments relate to low-reflectivity coating structures with high transmittance and low reflectance in the wide-angle visible wavelength band. Background Technology

[0002] When external image information is transmitted to the image sensor through a lens, reflection may occur due to the difference in refractive index between the external environment and the lens. When light enters the lens at a high angle of incidence, it will undergo multiple reflections inside the lens, resulting in a ghosted image. Such ghosted images degrade the performance of the image sensor.

[0003] When light is partially reflected between two materials with different refractive indices, it results in a loss due to Fresnel reflection. This loss reduces the intensity of light reaching the sensor and affects image quality. When the reflectivity between the lens and the external environment (air) is high, light that has already reached the sensor after reflection within the lens may produce a ghosting image. In particular, the reflectivity between the two materials tends to increase for light entering at a wide angle, making it necessary to prevent ghosting images caused by wide-angle incidence. Summary of the Invention

[0004] [Technical Issues]

[0005] The embodiments provide a coating structure with high transmittance and low reflectance in a wide-angle visible wavelength band, and a method for manufacturing the coating structure.

[0006] The embodiments also provide a coating structure capable of preventing ghosting images and a method for manufacturing the coating structure.

[0007] The problems to be solved by the implementation methods are not limited to those described herein, but also include purposes or effects that can be understood from the way the problems are solved or from the implementation methods described below.

[0008] [Technical Solutions]

[0009] The coating structure according to the embodiment includes: a substrate; a first thin film disposed on the substrate; a second thin film disposed on the first thin film; and a metal pattern protruding from the substrate, wherein the metal pattern passes through the first thin film and partially passes through the second thin film.

[0010] The first thin film and the second thin film can overlap in a first direction, and the first direction can be the incident direction of light and can be perpendicular to the first thin film and the second thin film.

[0011] The first thin film can have a refractive index of 1.3 to 3.0.

[0012] The first thin film may include a metal oxide.

[0013] The first thin film may include TiO2, ZnO or Al2O3.

[0014] The thickness of the first thin film in the first direction can be 0.1 to 0.7 times the height of the metal pattern in the first direction.

[0015] The second thin film can have a refractive index of 1.2 to 1.4.

[0016] The second film may include a hydrophobic material.

[0017] The second film may include polytetrafluoroethylene (PTFE) or fluorinated ethylene propylene (FEP).

[0018] The thickness of the second film in the first direction can be from 50 nm to 200 nm.

[0019] Metallic patterns can have a refractive index of 1.3 to 3.0.

[0020] Metal patterns can include metal oxides.

[0021] Metal patterns can include TiO2, ZnO, or Al2O3.

[0022] The height of the metal pattern in the second direction can be from 50 nm to 300 nm.

[0023] The refractive index of the first thin film and the refractive index of the metal pattern can be greater than the refractive index of the second thin film.

[0024] A method for manufacturing a coating structure according to an embodiment may include: dispersing PS microspheres on a substrate; depositing a metal thin film on the substrate; removing the PS microspheres; forming a random pattern using the metal thin film; forming an oxide thin film on the substrate; and forming a hydrophobic thin film on the oxide thin film.

[0025] [Beneficial Effects]

[0026] According to the implementation method, a coating structure with high transmittance and low reflectance in a wide-angle visible wavelength band can be realized.

[0027] In addition, it is possible to achieve a coating structure that can prevent ghosting images.

[0028] The various and beneficial advantages and effects of the present invention are not limited to those described above, and will be more readily understood in the process of describing specific embodiments of the invention. Attached Figure Description

[0029] Figure 1 and Figure 2 This is a conceptual diagram of the coating structure according to the implementation method.

[0030] Figure 3 This is a flowchart illustrating a method for manufacturing a coating structure according to an embodiment.

[0031] Figures 4 to 9 This is a diagram illustrating a method for manufacturing a coating structure according to an embodiment.

[0032] Figure 10 This is a graph showing the transmittance of incident light with wavelength according to the coating structure of the embodiment.

[0033] Figures 11 to 13 This is a graph showing the transmittance of incident light as a function of the incident angle for the coating structure according to the embodiment. Detailed Implementation

[0034] In the following, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0035] However, the spirit of the present invention is not limited to the described embodiments, and can be implemented in various different forms. Within the scope of the spirit of the present invention, one or more of the components of the embodiments can be selectively combined or substituted.

[0036] Furthermore, unless otherwise clearly and specifically defined, the terms (including technical and scientific terms) used in embodiments of this invention may be interpreted as having the meaning commonly understood by one of ordinary skill in the art to which this invention pertains. Commonly used terms, such as those defined in dictionaries, may be interpreted based on their contextual meaning in the relevant art.

[0037] Furthermore, the terminology used in the embodiments of this invention is intended to describe the embodiments and not to limit the invention.

[0038] In this specification, unless otherwise expressly stated, the singular form may include the plural form. Additionally, when expressions such as "at least one (or one or more) of A, B, and C" are used, they may include any one and all combinations of A, B, and C.

[0039] When describing components of embodiments of the present invention, terms such as first, second, A, B, (a), and (b) may be used.

[0040] These terms are used only to distinguish components from other components and do not restrict the nature, order, sequence, etc. of the corresponding components.

[0041] Furthermore, when a component is described as “connected,” “coupled,” or “linked” to another component, this includes not only cases where the component is directly connected, coupled, or linked to other components, but also cases where the component is connected, coupled, or linked to other components via one or more other components inserted therein.

[0042] Additionally, when a component is described as being formed or disposed "above" or "below" another component, "above" or "below" includes not only the case where the two components are in direct contact with each other, but also the case where one or more other components are formed or disposed between the two components. Furthermore, when expressed as "above" or "below," this can include meanings based on a component that refer not only to the upward direction but also to the downward direction.

[0043] Figure 1 and Figure 2 This is a conceptual diagram of the coating structure according to the implementation method.

[0044] Reference Figure 1 and Figure 2 The coating structure 1000 according to the embodiment may include a substrate 1100, a first thin film 1200 disposed on the substrate 1100, a second thin film 1300 disposed on the first thin film 1200, and a metal pattern 1400 protruding from the substrate 1100. The metal pattern 1400 may pass through the first thin film 1200 and may partially pass through the second thin film 1300.

[0045] The coating structure 1000 can refer to a structure in which multiple thin films are coated on the surface of an optical element (e.g., a lens). The coating structure 1000 can be disposed on the incident surface of the optical element, onto which an optical signal is incident when the optical signal passes through the optical element.

[0046] The coating structure 1000 may include a substrate 1100. The substrate 1100 may be the surface of an optical element, on which multiple thin films are disposed. The substrate 1100 may refer to the surface of a lens. The substrate 1100 may include glass or plastic material. The substrate 1100 may have a refractive index of 1.3 to 2.0. Optical signals can be incident on the optical element through the substrate 1100. A first thin film 1200 may be disposed on the substrate 1100. Additionally, a metallic pattern 1400 may be formed on the substrate 1100. The substrate 1100 may include an incident surface P onto which the optical signals are incident. The incident surface P of the substrate 1100 may be in contact with a first surface P1 of the first thin film 1200.

[0047] The coating structure 1000 may include a first thin film 1200. The first thin film 1200 may be disposed on a substrate 1100. The first thin film 1200 may include a metal oxide. The first thin film 1200 may include TiO2, ZnO, or Al2O3. The first thin film 1200 may include an oxide. For example, the first thin film 1200 may include SiO2 or HfO2. The first thin film 1200 may include an oxide thin film. The first thin film 1200 may have a refractive index of 1.3 to 3.0. The first thin film 1200 may be disposed between a second thin film 1300 and the substrate 1100. The first thin film 1200 may overlap with the second thin film 1300 in a first direction, along which an optical signal is incident. The first thin film 1200 may partially overlap with a metal pattern 1400. The first thin film 1200 may overlap with the metal pattern 1400 in a second direction perpendicular to the first direction. The thickness 'a' of the first thin film 1200 in the first direction may be 0.1 to 0.7 times the height 'c' of the metal pattern 1400. The metal pattern 1400 can be disposed within the first thin film 1200. The first thin film 1200 may include a first surface P1 and a second surface P2 disposed opposite to the first surface P1. The first surface P1 of the first thin film 1200 may contact the incident surface P of the substrate 1100. The second surface P2 may contact the second thin film 1300. By including the first thin film 1200, the coating structure 1000 can improve the adhesion of the metal pattern 1400 to the substrate 1100.

[0048] The coating structure 1000 may include a second film 1300. The second film 1300 may be disposed on the first film 1200. The second film 1300 may be disposed on a second surface P2 of the first film 1200. The second film 1300 may have a refractive index of 1.2 to 1.4. The second film 1300 may include a hydrophobic material. The second film 1300 may include polytetrafluoroethylene (PTFE) or fluorinated ethylene propylene (FEP). The thickness b of the second film 1300 in a first direction may be 50 nm to 200 nm. The second film 1300 may overlap with the first film 1200 in the first direction. The second film 1300 may partially overlap with the metal pattern 1400. The second film 1300 may partially overlap with the metal pattern 1400 in a second direction. By including the second film 1300, the coating structure 1000 allows for easy removal of foreign matter from the coating structure 1000. Additionally, by including the second film 1300, the coating structure 1000 can protect the metal pattern 1400.

[0049] The coating structure 1000 may include a metal pattern 1400. The metal pattern 1400 may protrude from the substrate 1100. The metal pattern 1400 may be disposed on an incident surface P of the metal pattern 1400. The metal pattern 1400 may pass through a first thin film 1200 and may partially pass through a second thin film 1300. The metal pattern 1400 may pass through a second surface P2 of the first thin film 1200 and protrude in a first direction. The metal pattern 1400 may be disposed to pass through the entire thickness a of the first thin film 1200 in the first direction. The metal pattern 1400 may be disposed to pass through a portion of the thickness b of the second thin film 1300 in the first direction. The height c of the metal pattern 1400 may be greater than the thickness a of the first thin film 1200 in the first direction. The height c of the metal pattern 1400 may be less than the sum of the thickness a of the first thin film 1200 in the first direction and the thickness b of the second thin film 1300 in the first direction. The metal pattern 1400 may have a refractive index of 1.3 to 3.0. The metal pattern 1400 may include a metal oxide. The metal pattern 1400 may include TiO2, ZnO, or Al2O3. The height c of the metal pattern 1400 in the first direction may be from 50 nm to 300 nm. The refractive index of the first thin film 1200 and the refractive index of the metal pattern 1400 may be greater than the refractive index of the second thin film 1300. By including the metal pattern 1400 and the second thin film 1300 having a refractive index of 1.2 to 1.4, the coating structure 1000 can have a gradual change in refractive index, thereby improving the low reflectivity of the optical element.

[0050] Figure 3 This is a flowchart illustrating a method for manufacturing a coating structure according to an embodiment. Figures 4 to 9 This is a diagram illustrating a method for manufacturing a coating structure according to an embodiment.

[0051] Reference Figure 4 The method for manufacturing the coating structure according to the embodiment may include the step of cleaning the substrate 1100.

[0052] Reference Figure 5The method for manufacturing the coating structure according to the embodiment may include the step of dispersing polystyrene microspheres (PS microspheres) 10. The PS microspheres 10 may be disposed on a substrate 1100 and dispersed on the substrate 1100 by spin coating. In this case, the PS microspheres 10 may have a diameter of 50 nm to 1000 nm. Specifically, the PS microspheres 10 may be dispersed at 0 wt% to 20 wt% in a mixed solution of an organic solvent (e.g., divinylbenzene) and deionized (DI) water. In this case, the organic solvent and DI water may have a 1:1 ratio. The mixed solution may be coated onto the substrate, and as a coating method, blade coating or spin coating at a rotation speed of 1000 RPM to 3000 RPM may be used. By using PS microspheres to control the density of the metal pattern, the refractive index difference between the lens or substrate and the thin film can be reduced.

[0053] Reference Figure 6 The method for fabricating the coating structure according to the embodiments may include the step of depositing metal. Metals (e.g., titanium, zinc, and aluminum) can be deposited on the substrate 1100 using a physical vapor deposition (PVD) method. The metal can be deposited in the form of a metal thin film 20, and the metal thin film 20 can have a deposition thickness of 10 nm to 500 nm. Two or more metals can be deposited. The metal thin film 20 can be deposited on portions other than the PS microspheres 10.

[0054] Reference Figure 7 The method for manufacturing the coating structure according to the embodiments may include the step of removing PS microspheres. PS microspheres can be removed by immersion in an organic solvent (e.g., chloroform).

[0055] Reference Figure 8 A method for manufacturing a coating structure according to an embodiment may include the step of forming a random pattern 30. The random pattern 30 can be formed by a boiling process in DI water. During boiling, oxygen in the water can react with metal oxides to form oxidized metal. The oxidized metal can form the random pattern 30 in DI water through processes such as release, migration, and redeposition. The pattern can be formed at a water temperature of 50°C to 95°C for 0 to 15 hours. Using a boiling process can improve productivity.

[0056] Reference Figure 9The method for manufacturing the coating structure according to the embodiment may include a nanofilm deposition step and a hydrophobication step. An oxide film 40 (e.g., SiO2, HfO, and TiO2) can be deposited using a PVD method. After forming the oxide film, a fluorine-based material can be coated to form a hydrophobic film 50. Spin coating or blade coating can be used as the coating method. By depositing the oxide film 40, the adhesion of the random pattern 30 to the substrate 1100 can be improved. By depositing the hydrophobic film 50, foreign matter on the coating structure can be easily removed. Additionally, by depositing the hydrophobic film 50, the random pattern 30 can be protected. Furthermore, by depositing the oxide film 40 and the hydrophobic film 50 together, a gradually varying refractive index can be achieved between the hydrophobic film 50, having a refractive index of 1.2 to 1.4, and the random pattern 30, thereby improving low reflectivity.

[0057] Figure 10 This is a graph showing the transmittance of incident light with wavelength according to the coating structure of the embodiment.

[0058] Reference Figure 10 When the coating structure according to the embodiment is used, the transmittance of incident light can be improved.

[0059] When using a lens with a metallic pattern formed thereon (Case 1), the transmittance of incident light is higher than that of a conventional lens alone (Case 0). When using a lens with both a metallic pattern formed thereon and a hydrophobic film (Case 2), the transmittance of incident light is higher than that of a conventional lens alone (Case 0). When the wavelength of the incident light is approximately 480 nm or more, the transmittance of the incident light in Case 2 may be higher than that in Case 1. Conversely, when the wavelength of the incident light is approximately 480 nm or less, the transmittance of the incident light in Case 2 may be lower than that in Case 1.

[0060] Figures 11 to 13 This is a graph showing the transmittance of incident light as a function of the incident angle for the coating structure according to the embodiment.

[0061] Figure 11 This is a graph showing the transmittance as a function of the incident angle when the incident light has a wavelength of 650 nm and is visible light in the red wavelength region. Figure 12 This is a graph showing the transmittance as a function of the incident angle when the incident light has a wavelength of 430 nm and is visible light in the blue wavelength region. Figure 13 It is a graph showing the change in transmittance as a function of the incident angle when the incident light has a wavelength of 540 nm and is visible light in the green wavelength region.

[0062] Reference Figures 11 to 13 When using the coating structure according to the embodiment, the decrease in transmittance caused by the increase in the incident angle of light can be reduced.

[0063] Reference Figures 11 to 13 When using a lens with both a metallic pattern formed thereon and a hydrophobic film (Case 2), the transmittance difference d2, depending on the incident angle range (0° to 60°), may be smaller than the transmittance differences d0 and d1, respectively, under the case of a conventional lens alone (Case 0) and under the case of a lens with only a metallic pattern formed thereon (Case 1), depending on the same incident angle range (0° to 60°).

[0064] Although embodiments have been described above with reference to specific examples, these embodiments are merely illustrative and not intended to limit the invention. Those skilled in the art will understand that various modifications and applications not illustrated above can be made without departing from the essential characteristics of the embodiments. For example, each component specifically shown in the embodiments can be implemented in a modified form. Differences associated with such modifications and applications should be interpreted as being included within the scope of the invention as defined by the appended claims.

Claims

1. A coating structure, comprising: substrate; A first thin film disposed on the substrate; A second film disposed on the first film; as well as Metal patterns protruding from the substrate The metal pattern passes through the first film and partially passes through the second film.

2. The coating structure according to claim 1, wherein, The first film and the second film overlap in a first direction, and The first direction is the incident direction of the optical signal and is perpendicular to the first film and the second film.

3. The coating structure according to claim 2, wherein, The first film includes a first surface and a second surface disposed opposite to the first surface. The substrate includes an incident surface, onto which the optical signal is incident, and The first surface is in contact with the incident surface.

4. The coating structure according to claim 3, wherein, The metallic pattern is disposed on the incident surface, passes through the second surface of the first film, and protrudes in the first direction.

5. The coating structure according to claim 1, wherein, The first thin film has a refractive index of 1.3 to 3.

0.

6. The coating structure according to claim 5, wherein, The first thin film comprises a metal oxide.

7. The coating structure according to claim 6, wherein, The first thin film includes TiO2, ZnO or Al2O3.

8. The coating structure according to claim 2, wherein, The thickness of the first film in the first direction is 0.1 to 0.7 times the height of the metal pattern in the first direction.

9. The coating structure according to claim 8, wherein, The height of the metal pattern in the first direction is less than the sum of the thicknesses of the first film and the second film in the first direction.

10. The coating structure according to claim 1, wherein, The second film has a refractive index of 1.2 to 1.4.

Images