Anti-blue-light optical film for display (screen)

Abstract

The invention relates to a display (screen) anti-blue-light optical film, which is characterized in that a plurality of sampling points are selected on a display screen, spectral radiation power corresponding to each sampling point is obtained based on actual measurement data of each sampling point, and the spectral radiation power corresponding to each sampling point is calculated based on the spectral radiation power corresponding to each sampling point. Calculating blue light radiation energy corresponding to each sampling point according to the spectral radiation power and a blue light hazard weighting coefficient, comparing the blue light radiation energy corresponding to each sampling point with a corresponding safety threshold value, assigning a blue light radiation filtering coefficient of each sampling point according to a comparison result, and performing curved surface fitting according to data of each sampling point to obtain a blue light radiation filtering coefficient of each sampling point; the blue light radiation filtering coefficient distribution function of the anti-blue-light optical film is generated and obtained, the anti-blue-light optical film is prepared according to the blue light radiation filtering coefficient distribution function, and the anti-blue-light optical film better conforms to the actual condition and can be used for being attached to an LCD screen or an OLED screen or a Mini LED screen or a Micro LED screen at the outermost end.

Description

Technical Field

[0001] The invention relates to a display (screen) anti-blue light optical film, which is mainly applicable to various medical and civilian displays (screens) and smart phone screens. Background Art

[0002] Blue light refers to visible light with a wavelength in the range of 380nm-700nm on the spectrum. This type of visible light has a short wavelength and high energy. It is the main cause of retinal diseases in the human eye after exposure. The possibility of photochemical retinal damage caused by exposure with wavelengths mainly between 380nm-700nm is usually called Blue Light Hazard (BLH).

[0003] In order to reduce or eliminate the danger of blue light, an optical film that can block / filter blue light can be attached or prepared on the display screen. For example, Chinese patent document CN114806438A discloses an anti-blue light screen film and a preparation method thereof, wherein the anti-blue light screen film comprises the following raw materials: a silicone layer, a first OCA glue, a second OCA glue and a high color point perovskite quantum dot film, wherein the first OCA glue, the high color point perovskite quantum dot film and the second OCA glue are sequentially arranged on the back of the silicone layer from top to bottom; the preparation method thereof comprises the following specific steps: after coating the first OCA glue on the back of the silicone layer, transferring the high color point perovskite quantum dot film, and then encapsulating it with the second OCA glue to obtain the anti-blue light screen film, which is green and is an external film for electronic display screens, and the green quantum dots absorb more blue light and convert it into green light, and then match the red light absorber to reduce the change of CCT, thereby forming an anti-blue light screen film that can meet the high-level RPF standard. Chinese patent document CN216956422U discloses an anti-blue light eye protection film for ultra-large display screens, comprising a protective layer, a first adhesive layer, an anti-blue light layer, a heat dissipation layer, a second adhesive layer and a protective layer; the protective layer is arranged above the first adhesive layer, the first adhesive layer is arranged above the anti-blue light layer, the anti-blue light layer is arranged above the heat dissipation layer, the heat dissipation layer is arranged above the second adhesive layer, and the second adhesive layer is arranged above the protective film; the anti-blue light layer is composed of a nano grating layer and a reinforcing layer, the nano grating layer is arranged above the reinforcing layer, and the nano grating layer has a nano grating microstructure; the anti-blue light layer is bonded to the protective layer through the first adhesive layer, and the heat dissipation layer is bonded to the protective layer through the second adhesive layer, which can not only accurately filter the short-wave blue light of 430nm to 460nm of electronic products, but also suppress environmental glare, without color deviation, low cost, simple and convenient film application, and no bubble residue. When applied to ultra-large display screens, it can greatly reduce the harm of harmful blue light inside the screen to the eyes. Chinese patent document CN112874100A discloses a blue light-proof and ultraviolet-proof polyester film and its preparation method and application, comprising a layer A, a layer B and a layer C of polyester films stacked in sequence; wherein the layer A polyester film and the layer C polyester film both comprise the following raw materials in parts by weight: 30-50 parts of polyester chips and 50-70 parts of an opening agent; the layer B polyester film comprises the following raw materials in parts by weight: 70-80 parts of polyester chips, 10-15 parts of an ultraviolet absorber, 10-15 parts of an anti-blue light additive and 5-10 parts of a blue light absorber. The polyester film of the present invention achieves the effects of anti-ultraviolet and anti-blue light by adding an anti-blue light additive and an anti-ultraviolet additive to the middle layer B, and at the same time has anti-sticking and high light transmittance.

[0004] Existing anti-blue light optical films basically have a pre-set filtration rate coefficient (such as 40%, 50%, or 60%, etc.). The amount of anti-blue light additive added and the thickness of the film are determined based on the set filtration rate coefficient to make films of equal thickness with consistent filtration rates in various parts. Therefore, they cannot be simultaneously applicable to the actual conditions of different displays, nor can they simultaneously adapt to the actual conditions of different parts of the same display.

[0005] On the other hand, Chinese patent document CN113916505A discloses a method for judging the safety threshold and safety of blue light radiation of a display. On the basis of determining the safety threshold of blue light radiation energy or blue light radiation power, a spectroradiometer is used to detect the spectral radiation power data of each detection point of the display screen at maximum brightness and not less than a certain color temperature value T according to an appropriate method such as a nine-point detection method. The exposure time required for calculation is set according to actual needs or specifications, and a wavelength-related blue light hazard weighting coefficient is introduced to calculate the blue light radiation energy or blue light radiation power. The blue light radiation energy or blue light radiation power is compared with the corresponding safety threshold to determine whether there is a blue light hazard risk. The method is suitable for the use of spectral radiation power more frequently in the test process of production and manufacturing or on-site use, and is conducive to simplifying the blue light radiation safety judgment process of various displays (screens) for medical and civilian use or other on-site use in industrial production and manufacturing, and provides favorable conditions for the refined design of anti-blue light optical films. Summary of the invention

[0006] The purpose of the present invention is to provide a refined and personalized display (screen) anti-blue light optical film that is more in line with actual conditions.

[0007] The technical solution of the present invention is: a display (screen) anti-blue light optical film, selects a number of sampling points on the display screen, obtains the spectral radiation power corresponding to each sampling point based on the measured data (or detection data) of each sampling point, and calculates the blue light radiation energy corresponding to each sampling point based on the spectral radiation power corresponding to each sampling point using the following formula:

[0008]

[0009] The blue light radiation filtering coefficient of each sampling point (each point on the anti-blue light optical film corresponding to each sampling point) is assigned a value according to the following method:

[0010]

[0011] In the display screen coordinate system (including its equivalent coordinate system), the blue light radiation filtering coefficient of each sampling point (each point on the anti-blue light optical film corresponding to each sampling point) is surface fitted to obtain the blue light radiation filtering coefficient distribution function that the anti-blue light optical film should have:

[0012] K=f(x,y)

[0013] The anti-blue light optical film is prepared according to the blue light radiation filtering coefficient distribution function that the anti-blue light optical film should have.

[0014] In the above formula, P B is the blue light radiation power, t is the exposure time, P B t is the blue light radiation energy with blue light radiation hazard, which is the product of blue light radiation power and exposure time, P λ (λ) is the wavelength-related spectral radiation power, B(λ) is the wavelength-related blue light hazard weighting coefficient, λ is the wavelength, E L is the safety threshold of blue light radiation energy, K is the blue light radiation filtering coefficient distribution function of the anti-blue light optical film, i is the number of the sampling point (the sampling point with number i can be recorded as sampling point i), P Bi t is the blue light radiation energy with blue light radiation hazard corresponding to sampling point i, K i Assign a value to the blue light radiation filtering coefficient of sampling point i (the point on the anti-blue light optical film corresponding to sampling point i), where (x, y) is the coordinate in the display screen coordinate system.

[0015] Preferably, the sampling points are selected according to the nine-point detection method or the 25-point detection method.

[0016] Preferably, the spectral radiation brightness is used to detect the sampling point data, and the spectral radiation power corresponding to the sampling point is calculated according to the following formula:

[0017] P λ (λ) = L λ (λ)*A*Ω

[0018] In the above formula, P λ (λ) is the spectral radiation power corresponding to the sampling point, L λ (λ) is the spectral radiance of the light source related to the wavelength λ, A is the effective radiation source area obtained based on the maximum opposite angle; Ω is the solid angle of the pupil to the light source.

[0019] Preferably, set E L =0.220J.

[0020] Preferably, the anti-blue light optical film is attached to the outermost LCD screen, or OLED screen, or MiniLED screen, or Micro LED screen.

[0021] The beneficial effect of the present invention is: since the blue light filtration rate coefficient that each sampling point should have is determined based on multi-point measured data, surface fitting is performed according to the blue light filtration rate coefficient of each sampling point, and the blue light filtration coefficient distribution function of the entire anti-blue light optical film is obtained, thereby making the anti-blue light capability of each part of the anti-blue light optical film adapt to the blue light radiation conditions of each part on the display, effectively avoiding insufficient and / or excessive local blue light filtration, and being able to obtain a more refined and personalized display (screen) anti-blue light optical film that is more in line with actual conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a distribution diagram of nine points involved in the nine-point detection method of the present invention on the display screen;

[0023] Figure 2 is a B(λ) curve diagram (λ-B(λ) curve) involved in the present invention;

[0024] Figure 3 It is a schematic diagram (cross section) of the blue light protection optical film of unequal thickness according to the present invention;

[0025] Figure 4 It is a schematic diagram of equal thickness lines of the blue light filtering layer of the anti-blue light optical film of unequal thickness involved in the present invention. DETAILED DESCRIPTION

[0026] See also Figure 1-Figure 4 For any specific display, or displays of the same batch with good consistency produced by the factory, a spectroradiometer is used to perform multi-point detection of the spectral radiation power of the display. The detection can be carried out when the display is at maximum brightness (design maximum brightness) or normal usage brightness, and is not lower than the set color temperature value T (such as T = 6000K or other color temperature values). The exposure time can be based on actual usage requirements or specifications (including technical standards), for example, medical displays can usually be 28800s.

[0027] The wavelength-dependent spectral radiation power P can be calculated based on the measured data λ (λ), according to P λ (λ) and the known blue light hazard weighting coefficient B(λ) (recognized or standard B(λ) function), the blue light radiation energy (blue light radiation power) is calculated according to the following formula:

[0028]

[0029] in,

[0030] P B is the blue light radiation power, commonly used unit: J·s -1 ;

[0031] t is the exposure time, commonly used unit: s;

[0032] p B ·t is the product of blue light radiation power and exposure time, which can be regarded as the blue light radiation energy with blue light radiation hazards, and the commonly used unit is J;

[0033] P λ (λ) is the wavelength-dependent spectral radiation power, commonly used unit: J·s -1 ·nm -1

[0034] B(λ) is the wavelength-dependent blue light hazard weighting factor (see Figure 2 ), dimensionless;

[0035] λ is the wavelength, commonly used unit: nm (nanometer).

[0036] The spectral radiation power P can be calculated according to the following formula: λ (λ):

[0037] P λ (λ) = L λ (λ)*A*Ω

[0038] Where A is the effective radiation source area (commonly used unit: m) obtained based on the maximum opposite angle (0.1 rad) 2 );Ω is the solid angle of the pupil to the light source (common unit: sr), its size is related to the pupil diameter and the observation distance. According to the set scene, L λ (λ) is the spectral radiance of the light source related to wavelength λ (common unit: W·m -2 sr -1 nm -1 ).

[0039] The coordinates of the display screen coordinate system are (x i ,y o ) at any sampling point i, the blue light radiation energy obtained by calculating the detection data at that point and the safety threshold (set value) E of the blue light radiation energy L Compare and determine the blue light radiation filtering coefficient K of sampling point i according to the comparison result. i :

[0040] When the blue light radiation energy calculated based on the detection data of this point is not greater than the safety threshold of blue light radiation energy, K i =0;

[0041] When the blue light radiation energy calculated based on the detection data of this point is greater than the safety threshold of blue light radiation energy,

[0042] E LIt can be determined based on relevant technical specifications, standards and other documents and / or through experiments or theoretical analysis. For example, according to the currently recognized or appropriate standard, E L =0.220J.

[0043] Based on the blue light radiation filtering coefficient K of each sampling point i , the blue light radiation filter coefficient distribution function (data) matching the display (screen) size is obtained by surface fitting:

[0044] K=f(x,y)

[0045] The corresponding blue light protection optical film is prepared according to the above-mentioned filter coefficient distribution data (function).

[0046] For example, see Figure 3 and Figure 4 , under the condition that the anti-blue light material remains unchanged, the required blue light radiation filtering coefficient can be obtained by controlling the thickness of the anti-blue light material layer 2. The anti-blue light material layer can be set between the base layer 1 and the surface layer 3 according to the existing technology, or other single-layer or multi-layer structures of adaptive forms can be used. The preparation method of the anti-blue light material layer and the anti-blue light optical film can adopt any suitable existing technology. For example, for hard anti-blue light materials, grinding can be used to make the thickness change of the anti-blue light material layer meet the requirements of K=f(x,y); for the anti-blue light material layer formed by spraying, digital control technology can be used to realize spraying control so that the change of spraying thickness meets the requirements of K=f(x,y). Applying this anti-blue light optical film to the front end of the display can achieve better anti-blue light radiation safety effect.

[0047] Further explanation on sampling points (detection points):

[0048] Figure 1 An example of sampling points of the nine-point test method is shown, and nine points (i.e., P0-P8) are located on the display to be tested. In the figure, h is the height of the display screen, and w is the width of the display screen. The nine points are aligned in three rows and three columns, and the vertical and horizontal lines are in a rectangular grid. They are evenly spaced in the horizontal direction (width direction) and the vertical direction (height direction). One of the points is located in the center of the display screen, and the distance between the outermost point in the horizontal direction and the corresponding side of the display screen is w / 9-w / 10, and the distance between the outermost point in the vertical direction and the corresponding side of the display screen is h / 9-h / 10 (depending on the actual situation, other distances can also be used, such as: the distance between the outermost point in the horizontal direction and the corresponding side of the display screen is w / 3-w / 4, and the distance between the outermost point in the vertical direction and the corresponding side of the display screen is h / 3-h / 4, etc.), wherein w is the width of the display screen (display area), and h is the height of the display screen (display area).

[0049] As needed, the 25-point detection method or other number of detection points can be used. The positions of the detection points can usually be determined by arranging them in a rectangular grid in a vertical and horizontal manner. Other adaptive point selection methods can also be used so that the conditions of each detection point can basically reflect the conditions of the display screen. For example, the points are aligned and distributed in rows and columns (for example, the 25 points of the 25-point detection method are divided into 5 rows and 5 columns). There is usually one point located in the center of the display screen (the number of rows and columns are both odd), the spacing between adjacent points in the horizontal direction is equal, the spacing between adjacent points in the vertical direction is equal, and there is usually a spacing between the outermost points in the horizontal and vertical directions and the corresponding sides of the display screen. The size of the spacing can adopt the corresponding spacing of the aforementioned nine-point detection method, or it can be set according to actual needs or specifications.

[0050] The above-mentioned regular and evenly distributed sampling points are conducive to obtaining higher accuracy with less data processing. However, since the present invention adopts a fitting method to obtain the blue light radiation filter coefficient distribution function, other sampling point selection methods are also allowed or effective. The sampling points should be distributed throughout the display screen, and denser sampling points can be set in areas with greater changes.

[0051] Since there is no substantial difference between displays and screens in practice when only display screen display or blue light radiation is involved, the display (screen), monitor and display screen referred to in this specification may refer to various commonly referred to displays and screens that display in related display modes, including independent displays, screens, and displays and screens integrated or installed on other devices.

[0052] For any determined exposure time, the blue light radiation energy (the product of the blue light radiation power and the exposure time) can also be compared with the safety threshold of the blue light radiation energy. When the blue light radiation energy is not greater than the safety threshold of the blue light radiation energy, there is no blue light hazard risk. When the blue light radiation energy is greater than the safety threshold of the blue light radiation energy, there is a blue light hazard risk. This comparison or operation method is consistent with the conclusion of comparing the blue light radiation power with the safety threshold of the blue light radiation power. Therefore, in the present invention, according to the relevant formula, the relevant comparison or operation method based on the blue light radiation power or its threshold is equivalent to the relevant comparison and operation method based on the blue light radiation energy or its threshold.

[0053] The safe area with no blue light hazard risk or other similar expressions referred to in the present invention is limited to the safety relative to the blue light hazard of the blue light radiation of the display to the human eye during viewing, and does not involve the safety relative to other hazard modes or other hazard factors. At the same time, the safety evaluation is based on the existing research results or cognition of related hazards to the general population, and does not involve the possible hazards to specific individuals due to individual differences and other factors.

[0054] Unless otherwise specified or when one preferred or optional technical means is a further limitation of another technical means, the preferred and optional technical means disclosed in the present invention can be arbitrarily combined to form several different specific implementation methods.

Claims

1. A display (screen) anti-blue light optical film, characterized in that Select several sampling points on the display screen, obtain the spectral radiation power corresponding to each sampling point based on the measured data of each sampling point, and calculate the blue light radiation energy corresponding to each sampling point based on the spectral radiation power corresponding to each sampling point using the following formula: The blue light radiation filter coefficient of each sampling point is assigned according to the following method: In the display screen coordinate system, the blue light radiation filter coefficient of each sampling point is surface fitted to obtain the blue light radiation filter coefficient distribution function of the anti-blue light optical film: K=f(x,y) The anti-blue light optical film is prepared according to the blue light radiation filtering coefficient distribution function that the anti-blue light optical film should have. In the above formula, P B is the blue light radiation power, t is the exposure time, P B t is the blue light radiation energy with blue light radiation hazard, which is the product of blue light radiation power and exposure time, P λ (λ) is the wavelength-related spectral radiation power, B(λ) is the wavelength-related blue light hazard weighting coefficient, λ is the wavelength, E L is the safety threshold of blue light radiation energy, K is the blue light radiation filtering coefficient distribution function of the anti-blue light optical film, i is the number of the sampling point, P Bi t is the blue light radiation energy with blue light radiation hazard corresponding to sampling point i, K i Assign a value to the blue light radiation filtering coefficient of sampling point i, where (x, y) is the coordinate in the display screen coordinate system.

2. The display (screen) anti-blue light optical film according to claim 1, characterized in that Sampling points are selected based on the nine-point detection method or the 25-point detection method.

3. The display (screen) anti-blue light optical film according to claim 1, characterized in that The spectral radiation brightness is used to detect the sampling point data, and the spectral radiation power corresponding to the sampling point is calculated according to the following formula: P λ (λ)=L λ (l)*A*Ω In the above formula, P λ (λ) is the spectral radiation power corresponding to the sampling point, L λ (λ) is the spectral radiance of the light source related to the wavelength λ, A is the effective radiation source area obtained based on the maximum opposite angle; Ω is the solid angle of the pupil to the light source.

4. The display (screen) anti-blue light optical film according to claim 1, characterized in that Setting E L =0.220J.

5. The display (screen) anti-blue light optical film according to claim 1, characterized in that The anti-blue light optical film is attached to the outermost LCD screen, OLED screen, MiniLED screen, or Micro LED screen.

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