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CN-122018055-A - Optical film and application thereof

CN122018055ACN 122018055 ACN122018055 ACN 122018055ACN-122018055-A

Abstract

The application provides an optical film and application thereof. The optical film includes an interference layer and a first scratch resistant layer. The interference layer comprises a high refractive index film layer and a low refractive index film layer which are stacked. The first scratch-resistant layer comprises at least three film layers which are arranged in a laminated mode and have different refractive indexes, at least one of the film layers is a diamond-like film layer, at least one of the film layers is a film layer with a refractive index of more than or equal to 1.8, at least one of the film layers is a film layer with a refractive index of less than or equal to 1.5, the average reflectivity of the optical film within the wavelength range of 400-700nm is less than or equal to 2%, the scratch depth of the optical film under the conditions that the Mohs hardness is 7 and the load is applied to be less than or equal to 750g is less than or equal to 10nm, and the nano indentation hardness of the optical film is more than or equal to 14GPa, so that the optical film can maintain higher anti-reflection effect and color development effect under wide angles and meanwhile the hardness and scratch resistance of the optical film are improved.

Inventors

  • ZHANG YANMING
  • LI FENGXIANG
  • HUANG YIHONG
  • XING CHONG

Assignees

  • 华为技术有限公司

Dates

Publication Date
20260512
Application Date
20250430

Claims (20)

  1. 1. An optical film applied to a transparent substrate is characterized by comprising an interference layer and a first scratch-resistant layer arranged on one side surface of the interference layer; The interference layer comprises a high refractive index film layer and a low refractive index film layer which are stacked, wherein the high refractive index film layer is a film layer with refractive index larger than that of the transparent substrate, and the low refractive index film layer is a film layer with refractive index smaller than that of the transparent substrate; The first scratch-resistant layer comprises at least three film layers which are arranged in a stacked mode and have different refractive indexes, at least one of the at least three film layers having different refractive indexes is a diamond-like film layer, at least one of the at least three film layers has a refractive index of 1.8 or more, and at least one of the at least three film layers has a refractive index of 1.5 or less; The average reflectivity of the optical film in the wavelength of 400-700nm is less than or equal to 2%, the scratch depth of the optical film under the conditions of Mohs hardness of 7 and load of less than or equal to 750g is less than or equal to 10nm, and the nano indentation hardness of the optical film is more than or equal to 14GPa.
  2. 2. The optical film of claim 1, wherein the diamond-like film layer is an N-doped diamond-like film layer.
  3. 3. An optical film according to claim 2, wherein the mass fraction of N in the diamond-like film layer is 1-20%.
  4. 4. An optical film according to any one of claims 1 to 3, wherein the diamond-like film layer has a thickness of 5nm or less.
  5. 5. An optical film according to any one of claims 1 to 4, wherein the diamond-like film layer has a thickness of 2 to 4nm.
  6. 6. An optical film according to any one of claims 1 to 5, wherein the nanoindentation hardness of the diamond-like film layer is 30-45GPa and the refractive index is 2.1-2.3.
  7. 7. An optical film according to any one of claims 1 to 6, wherein the total thickness of the first scratch resistant layer is 130nm or less.
  8. 8. An optical film according to claim 7, wherein the first scratch resistant layer has a total thickness of 60-120nm.
  9. 9. An optical film according to any one of claims 1 to 8, wherein at least one of the first scratch-resistant layer having a refractive index of 1.8 or more and the refractive index of 1.5 or less has a thickness of 10nm or less and at least one of the first scratch-resistant layers has a thickness of 30nm or more.
  10. 10. The optical film according to any one of claims 1 to 9, wherein the remaining film layers of the first scratch-resistant layer other than the diamond-like film layer are each independently selected from one of a high-refractive-index high-hardness material, a high-refractive-index low-hardness material, or a low-refractive-index low-hardness material, the high-refractive-index high-hardness material being a material having a refractive index of 1.8 or more and a nanoindentation hardness of 14GPa or more, the high-refractive-index low-hardness material being a material having a refractive index of 1.8 or more and a nanoindentation hardness of less than 10GPa, and the low-refractive-index low-hardness material being a material having a refractive index of 1.5 or less and a nanoindentation hardness of less than 10 GPa; The high-refraction and high-hardness material comprises at least one of silicon nitride, silicon oxynitride, aluminum-containing nitride, aluminum-containing silicon oxynitride, silicon carbide, titanium nitride and titanium-containing nitride; The high-folding low-hardness material comprises at least one of titanium oxide, niobium oxide, zirconium oxide and tantalum oxide; The low-profile low hardness material includes at least one of silicon oxide, aluminum-containing oxide, boron-containing oxide, magnesium fluoride, and aluminum-containing silicon oxynitride.
  11. 11. An optical film according to any one of claims 1 to 10, wherein in the first scratch-resistant layer, the diamond-like film layer is provided in a first layer or a second layer of the first scratch-resistant layer, in a direction in which the first scratch-resistant layer points toward the interference layer.
  12. 12. The optical film according to claim 11, wherein the first scratch-resistant layer is a layer having a refractive index of 1.5 or less along a direction in which the first scratch-resistant layer is directed toward the interference layer, and the diamond-like film is a layer having a thickness of 2 to 5nm in the second layer of the first scratch-resistant layer.
  13. 13. The optical film of claim 12, wherein the film layer of the first scratch resistant layer is a silicon dioxide film layer.
  14. 14. The optical film of claim 13, wherein the total number of layers of the first scratch resistant layer is four, wherein: The first layer is a silicon dioxide film layer, the refractive index of the first layer is 1.4-1.5, and the thickness of the first layer is 2-4nm; The second layer is a diamond-like film layer, the refractive index of the second layer is 2.1-2.3, and the thickness of the second layer is 2-4nm; the third film layer is a silicon nitride film layer, the refractive index of the third layer is 1.93-2.0, and the thickness of the third layer is 1-3nm; The fourth layer is a silicon dioxide film layer, the refractive index of the fourth layer is 1.4-1.5, and the thickness of the fourth layer is 80-100nm.
  15. 15. The optical film of claim 13 wherein the total number of scratch resistant layers is seven, wherein, The first layer is a silicon dioxide film layer, the refractive index of the first layer is 1.4-1.5, and the thickness of the first layer is 2-4nm; The second layer is a diamond-like film layer, the refractive index of the second layer is 2.1-2.3, and the thickness of the second layer is 2-4nm; the third layer is a silicon dioxide film layer, the refractive index of the third layer is 1.4-1.5, and the thickness of the third layer is 25-35nm; The fourth layer is a silicon oxynitride film layer containing aluminum, the refractive index of the fourth layer is 1.55-1.65, and the thickness of the fourth layer is 15-25nm; the fifth layer is a silicon oxynitride film layer containing aluminum, the refractive index of the fifth layer is 1.66-1.75, and the thickness of the fifth layer is 15-25nm; The sixth layer is a silicon oxynitride film layer containing aluminum, the refractive index of the sixth layer is 1.76-1.85, and the thickness of the sixth layer is 15-25nm; The seventh layer is a silicon nitride film layer, the refractive index of the seventh layer is 1.93-2.0, and the thickness of the seventh layer is 65-75nm.
  16. 16. An optical film as recited in claim 13, wherein the total number of scratch resistant layers of the first scratch resistant layer is seven, wherein, The first layer is a silicon dioxide film layer, the refractive index of the first layer is 1.4-1.5, and the thickness of the first layer is 2-4nm; The second layer is a diamond-like film layer, the refractive index of the second layer is 2.1-2.3, and the thickness of the second layer is 2-4nm; the third layer is a silicon nitride film layer, the refractive index of the third layer is 1.93-2.0, and the thickness of the third layer is 3-7nm; The fourth layer is a silicon dioxide film layer, the refractive index of the fourth layer is 1.4-1.5, and the thickness of the fourth layer is 40-50nm; the fifth layer is a silicon oxynitride film layer containing aluminum, the refractive index of the fifth layer is 1.56-1.65, and the thickness of the fifth layer is 12-18nm; the sixth layer is a silicon oxynitride film layer containing aluminum, the refractive index of the sixth layer is 1.66-1.75, and the thickness of the sixth layer is 12-18nm; The seventh layer is a silicon oxynitride film layer containing aluminum, the refractive index of the seventh layer is 1.76-1.85, and the thickness of the seventh layer is 12-18nm.
  17. 17. An optical film as recited in any one of claims 1-16, wherein said first scratch resistant layer further comprises a film layer having a refractive index greater than 1.5 and less than 1.8, each film layer having a refractive index greater than 1.5 and less than 1.8 having a thickness of from 10nm to 50nm.
  18. 18. An optical film as recited in claim 17, wherein the number of film layers having a refractive index greater than 1.5 and less than 1.8 is 1-3.
  19. 19. The optical film according to any one of claims 1 to 18, wherein in the first scratch-resistant layer, the diamond-like film layer is one layer, the number of film layers having a refractive index of 1.8 or more is 1 to 4, and the number of film layers having a refractive index of 1.5 or less is 1 to 4.
  20. 20. The optical film of any of claims 1-19, further comprising a second scratch resistant layer comprising at least one film layer having a refractive index of 1.8 or greater, the second scratch resistant layer being disposed between the interference layer and the first scratch resistant layer, or between the interference layer, or on a surface of the interference layer facing away from the first scratch resistant layer, the second scratch resistant layer having a thickness of 300nm or greater and 3000nm or less.

Description

Optical film and application thereof Technical Field The application relates to the field of optical devices, in particular to an optical film and application thereof. Background With the rapid development of electronic devices, consumers have increasingly higher requirements on electronic products, for example, the electronic products are required to improve the damage resistance of display screens under the condition of higher display effects. In order to achieve a better display effect, a layer of anti-reflection and anti-reflection film is usually additionally arranged on the surface of the glass substrate, so that the reflection on the surface of the display screen is reduced. The antireflection film can reduce the reflectivity of the surface of a lens substrate such as glass, sapphire and the like, and increase the transmittance, and is widely applied to the fields of display equipment, optical devices, solar cells and the like. The antireflection film is mainly formed by utilizing the interference effect of light, which is also called an interference layer, namely, the antireflection film is realized by utilizing light waves to generate destructive interference on the reflected light on the upper surface and the lower surface of the antireflection film. The interference layer is typically realized by a multilayer film structure with materials of different refractive index. In the interference layer, at least one of the film layers has a refractive index higher than that of the substrate, and at least one of the film layers has a refractive index lower than that of the substrate. However, the interference layer has low hardness, is not scratch-resistant, and is liable to cause screen damage. In order to solve the problem that the interference layer is easy to scratch, various high-hardness film layers such as a silicon nitride film layer or a diamond-like film layer can be arranged on the surface of the interference layer in the prior art to serve as scratch-resistant layers. However, after the scratch-resistant layer of the existing structure is added to the interference layer, the interference layer has the problem of abnormal color development caused by poor antireflection effect and large reflectivity fluctuation under a wide angle. Disclosure of Invention The application provides an optical film and application thereof, which can keep high anti-reflection effect and color development effect of the optical film at a wide angle and improve the hardness and scratch resistance of the optical film. In a first aspect, the present application provides an optical film applied to a transparent substrate, the optical film including an interference layer and a first scratch-resistant layer provided on a side surface of the interference layer. The interference layer comprises a high refractive index film layer and a low refractive index film layer which are arranged in a laminated mode, wherein the high refractive index film layer is a film layer with refractive index larger than that of the transparent substrate, and the low refractive index film layer is a film layer with refractive index smaller than that of the transparent substrate. The first scratch-resistant layer comprises at least three film layers which are arranged in a laminated mode and have different refractive indexes, at least one of the at least three film layers having different refractive indexes is a diamond-like film layer, at least one of the at least one film layer having a refractive index of 1.8 or more, at least one film layer having a refractive index of 1.5 or less, the average reflectivity of the optical film within the wavelength range of 400-700nm is less than or equal to 2%, the scratch depth of the optical film under the conditions of Mohs hardness of 7 and 750g load is less than or equal to 10nm, and the nano indentation hardness of the optical film is more than or equal to 14GPa. The nano indentation hardness of the optical film in the application is a hardness value corresponding to the indentation depth of the optical film surface reaching 200nm when pressure is applied to the optical film along the direction vertical to the optical film surface. The nano indentation hardness can be obtained by testing by a nano indentation tester. In the optical film, the interference layer is used for eliminating reflected light and has the functions of extinction and antireflection. By providing the first scratch-resistant layer having the diamond-like film layer on one side surface of the interference layer, the hardness of the first scratch-resistant layer can be improved by using the diamond-like film layer, and the scratch-resistant property of the optical film can be improved. Meanwhile, the rest film layer in the first scratch-resistant layer also comprises at least two other film layers with different refractive indexes with the diamond-like film layer, and the rest film layer is combined with the diamond-like film layer to assi